Academic literature on the topic 'ABM Pathogens'
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Journal articles on the topic "ABM Pathogens"
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Bannister, Stephanie, Stephen Kidd, Elizabeth Kirby, et al. "Development and Assessment of a Diagnostic DNA Oligonucleotide Microarray for Detection and Typing of Meningitis-Associated Bacterial Species." High-Throughput 7, no. 4 (2018): 32. http://dx.doi.org/10.3390/ht7040032.
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Meningitis is commonly caused by infection with a variety of bacterial or viral pathogens. Acute bacterial meningitis (ABM) can cause severe disease, which can progress rapidly to a critical life-threatening condition. Rapid diagnosis of ABM is critical, as this is most commonly associated with severe sequelae with associated high mortality and morbidity rates compared to viral meningitis, which is less severe and self-limiting. We have designed a microarray for detection and diagnosis of ABM. This has been validated using randomly amplified DNA targets (RADT), comparing buffers with or without formamide, in glass slide format or on the Alere ArrayTubeTM (Alere Technologies GmbH) microarray platform. Pathogen-specific signals were observed using purified bacterial nucleic acids and to a lesser extent using patient cerebral spinal fluid (CSF) samples, with some technical issues observed using RADT and glass slides. Repurposing the array onto the Alere ArrayTubeTM platform and using a targeted amplification system increased specific and reduced nonspecific hybridization signals using both pathogen nucleic and patient CSF DNA targets, better revealing pathogen-specific signals although sensitivity was still reduced in the latter. This diagnostic microarray is useful as a laboratory diagnostic tool for species and strain designation for ABM, rather than for primary diagnosis.
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Khaled, Alhomsi. "Study of Acute Bacterial Meningitis: Demographics, Symptoms and Signs." Chemistry Research Journal 5, no. 6 (2020): 21–24. https://doi.org/10.5281/zenodo.13147151.
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<strong>Abstract </strong><em>Objective: </em>This study aimed to determine the most common age, presentation (symptoms and signs) of acute bacterial meningitis (ABM) for each age group and the most common pathogens responsible for it. <em>Methods:</em> This is a retrospective study composed of all children (newborns until 12 years old) who reviewed clinics between 30/5/2018 and 21/3/2020 and were diagnosed with ABM. <em>Results: </em>This study included 50 patients. Most of the participants were boys between (1 month -6 months) old. The most common results of CSF culture in our study were sterile (25 cases of all patients). In addition, the most common pathogen was Streptococcus pneumoniae (13 cases of all patients). The most common symptom-sign for each age group (<month, 1 month-6 months, 6 months- 1 year, 1 year- 6 years and 6 years- 12 years) was poor breastfeeding-hyperreflexia, poor breastfeeding and convulsion equally-bulging fontanelle, fever- bulging fontanelle, fever- positive Neck Stiffness, upper Brudzinski, lower Brudzinski, Kernig equally and fever-neck stiffness, upper Brudzinski equally), respectively. <em>Conclusion: </em>We found that acute bacterial meningitis (ABM) is most common in boys between (1 month- 6 months) old. The most common pathogen causing ABM is streptococcus pneumoniae while the most common culture result was sterile.The mortality rate in our study was 21.8% (12 patients)
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Jamali, Yousef. "Modeling the Immune System Through Agent-based Modeling: A Mini-review." Immunoregulation 6, no. 1 (2024): 3–12. http://dx.doi.org/10.32598/immunoregulation.6.1.7.
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The immune system plays a critical role in protecting the human body against various pathogens and diseases. Understanding the complexity and dynamics of the immune system is essential for developing effective therapies and interventions. Agent-based modeling (ABM) has emerged as a powerful tool for simulating and studying the behavior of complex systems, including the immune system. This review examines the advantages, challenges, and applications of ABM in immune system modeling. ABM captures the complexity of immune cell behavior, spatial effects and stochasticity. It has been applied to study immune cell dynamics, immune responses to pathogens, immune cell migration, immunotherapies and immune system disorders. Challenges include parameterization, validation, and computational resource requirements. Future directions involve integrating multi-omics and single-cell data, incorporating machine learning, exploring multi-scale modeling, and developing user-friendly interfaces. ABM holds promise for enhancing our understanding of immune system dynamics and advancing diagnostics and treatments in immunology.
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Nwala, Chuks G., Oluchi M. Izuka, Ifeyinwa Roseann Chidomere, Ikechukwu Frank Ogbonna, Ichie Eziyi Kalu, and Ihuoma Kathleen Ukpabi. "Drug resistance profiling, antimicrobial susceptibility and demographic characteristics of children with acute bacterial meningitis in a Southeastern tertiary health facility." International Journal of Scientific Reports 10, no. 11 (2024): 392–98. http://dx.doi.org/10.18203/issn.2454-2156.intjscirep20243051.
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Background: Over the years, varying patterns of bacterial susceptibility and multidrug resistance (MDR) rates have been reported in different settings. Detailed evaluation of the drug profile of the bacterial pathogens implicated in children with invasive bacterial infection helps to reduce the heightened risk of adverse events that could follow poorly managed or complicated cases in resource limited environment like ours. This study therefore, aimed to highlight the antibiotic susceptibility and MDR rate, and establish the relationship if any, between demographic characteristics and positive CSF- bacterial isolates of post neonatal children with suspected acute bacterial meningitis (ABM). The findings would guide practitioners on the empirical antimicrobials to consider in the event of clinical suspicion of ABM pending the availability of CSF isolates' antibiogram. Methods: A prospective review of 100 children with clinical suspicion of ABM from January 2016- December 2020. Descriptive statistics, chi square and regression analysis were used to establish MDR rates, Isolates' susceptibility pattern and the relationship between demographic variables and positive isolates respectively. P<0.05 was accepted as significant. Results: Fluroquinolones, cephalosporins, imipenem and aminoglycosides were susceptible anti-microgram in children with ABM. Sixty-four (85.5%) of the isolates showed MDR pattern, and young children (infants and toddlers) were significantly associated with positive CSF bacterial isolates. Conclusions: ABM should be treated with combination of CNS penetrating empirical antibiotics due to rising rate of MDR pathogens. Young children with febrile illnesses should be thoroughly evaluated for possibility of CNS infection.
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Suryaminarsih, Penta, Tri Mujoko, K. Gusriyan, Fitri Wijayanti, and Salmah Mohammad. "Study of antibiosis of Streptomyces sp. from the land of shallot plants as biological agents of Fusariumsp. cause of Twisted diseases (Moler)." IOP Conference Series: Earth and Environmental Science 1131, no. 1 (2023): 012017. http://dx.doi.org/10.1088/1755-1315/1131/1/012017.
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Abstract The use of bio pesticides and organic pesticides from secondary metabolic filtrate of APH microorganisms is one of the food and horticulture cultivation technology packages which are the basis for this research objective. The research objective was to explore, isolate and identify of Streptomyces sp. in the land of shallot plants (Abm) and the antibiosis against the pathogens Fusariumsp cause of Moler shallot plant in vitro. Observer of Quality and quantity characteristics of secondary metabolites as antibiosis, The results showed that Streptomyces sp from land of shallot plant (Abm) isolates producing little antibiosis less able to inhibit the development of the pathogens Fusariumsp cause of Moler shallot plant in vitro. The identification of Actinomycetes spp. based on the morphology characteristic showed that Actinomycetes isolates are closely related with Streptomyces sp.
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Sarvepalli, Ajay Kumar, and Prakash Kalakappa Dharana. "Clinical profile, bacterial profile and outcomes of acute bacterial meningitis in a tertiary care hospital– one year study." International Journal of Advances in Medicine 4, no. 2 (2017): 502. http://dx.doi.org/10.18203/2349-3933.ijam20171050.
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Background: Bacterial meningitis is still one of the major causes of mortality and morbidity among all groups in developing countries. The mortality and prevalence of common pathogens has reduced in developing countries with implementation of successful vaccination against the pathogens. Laboratory surveillance of pathogens is crucial in formulating the empirical treatment guidelines and to identify the targets of immunization. The present study was undertaken to evaluate the clinical profile, bacterial pathogens and their antibiotic sensitivity pattern of the pathogens. The outcome of the cases was recorded and followed for six months to detect any neurological sequelae.Methods: A one year prospective cross sectional study was done and all suspected cases of acute bacterial meningitis (ABM) were screened and confirmed by diagnostic criteria. Clinical features were recorded and entered into the case sheet. CSF culture was done and biochemical analysis and cell counts were performed. All the data was entered in Microsoft excel and analysed.Results: A total of 547 cases were screened and 282 confirmed with 164 males and 116 females. 282 pathogens were isolated with 266 bacterial and 12 fungal isolates. Gram negative bacterial pathogens were predominant than gram positive. Streptococcus pneumoniae was the common isolate in the study followed by others like S. aureus, Coagulase negative staphylococci and Acinetobacter sp., Escherichia coli, Klebsiella pneumoniae and meningococci. Candida albicans and Cryptococcus sp. were fungal pathogens. Community acquired meningitis was commonest cause and seen in 51-60 years of age. Gram positive pathogens exhibited maximum sensitivity to vancomycin and linezolid whereas Gram negative pathogens to carbapenems.Conclusions: There is an overwhelming need to formulate policies in the management of cases of ABM. The rationale use of antibiotics is necessary to prevent the development of antibiotic resistance. Hence minimizing the emergence of antibiotic resistance and its spread is necessary, which can be achieved by regular prevalence and antibiotic susceptibility studies.
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Heinzen, Robert A., Scott S. Grieshaber, Levi S. Van Kirk, and Clinton J. Devin. "Dynamics of Actin-Based Movement byRickettsia rickettsii in Vero Cells." Infection and Immunity 67, no. 8 (1999): 4201–7. http://dx.doi.org/10.1128/iai.67.8.4201-4207.1999.
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ABSTRACT Actin-based motility (ABM) is a virulence mechanism exploited by invasive bacterial pathogens in the genera Listeria,Shigella, and Rickettsia. Due to experimental constraints imposed by the lack of genetic tools and their obligate intracellular nature, little is known about rickettsial ABM relative toListeria and Shigella ABM systems. In this study, we directly compared the dynamics and behavior of ABM ofRickettsia rickettsii and Listeria monocytogenes. A time-lapse video of moving intracellular bacteria was obtained by laser-scanning confocal microscopy of infected Vero cells synthesizing β-actin coupled to green fluorescent protein (GFP). Analysis of time-lapse images demonstrated that R. rickettsii organisms move through the cell cytoplasm at an average rate of 4.8 ± 0.6 μm/min (mean ± standard deviation). This speed was 2.5 times slower than that of L. monocytogenes, which moved at an average rate of 12.0 ± 3.1 μm/min. Although rickettsiae moved more slowly, the actin filaments comprising the actin comet tail were significantly more stable, with an average half-life approximately three times that of L. monocytogenes (100.6 ± 19.2 s versus 33.0 ± 7.6 s, respectively). The actin tail associated with intracytoplasmic rickettsiae remained stationary in the cytoplasm as the organism moved forward. In contrast, actin tails of rickettsiae trapped within the nucleus displayed dramatic movements. The observed phenotypic differences between the ABM of Listeria andRickettsia may indicate fundamental differences in the mechanisms of actin recruitment and polymerization.
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Rastogi, M., M. Kumar, A. Trivedi, and D. Rastogi. "CLINICAL PRESENTATION OF ACUTE BACTERIAL MENINGITIS ANDC.S.F. ANALYSIS OF ATTENDING OPDPATIENTS IN A TERTIARY CARE HOSPITAL KANPUR, INDIA." International Journal of Advanced Research 12, no. 05 (2024): 612–17. http://dx.doi.org/10.21474/ijar01/18760.
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Background:Meningitis is an infection of the Meninges. Generally caused by Viral, Bacterial and Fungal Pathogens. Viral Meningitis is less severe and heals without specific treatment whereas Acute Bacterial Meningitis (ABM) can be relatively severe and affect in internal illness. Acute Bacterial Meningitis (ABM) is a prime reason for loss of life and incapacity worldwide. Aim of this study is play important role in the diagnosis and more accurate treatment of patient. Method:In this study, all age groups were enrolled at one tertiary care hospital between November 2022 and April 2024. A total of 147 CSF clinically suspected Meningitis samples were submitted for analysis. Result:During the study, A total of 147 CSF samples were studied. Of these, 18 were identified as bacterial meningitis on the basis of Grams staining and cultures, with an Incidence of (12.24%). Acute bacterial meningitis was more frequent in paediatric patients than in adults. Gram-positive bacteria were the most common Organism, accounting for (77.77%) of the total.The male and female ratio among all Culture Positive cases was (1.57:1).
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Krisanapan, Pajaree, and Romanee Chaiwarith. "Time to blood cultures positivity of microorganisms using a continuous-monitoring automated blood cultures system." Asian Biomedicine 13, no. 2 (2019): 61–69. http://dx.doi.org/10.1515/abm-2019-0041.
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Abstract Background Previous studies showed that clinically significant pathogens were detected within 3 days of incubation using a continuous monitoring automated blood culture instrument. Objectives To determine time to blood culture positivity (TTP) of microorganisms using a BD BACTEC™ FX. Methods A cross-sectional study was conducted at Maharaj Nakorn Chiang Mai Hospital, Thailand from October to November 2014. Results One-hundred and eighty-one patients with 195 episodes of infection and 436 cultures were included in the analysis. Among 181 patients, 55.2% were male and the median age was 61 years (interquartile range (IQR) 50, 76). Of the 195 episodes of infections, the most common source was genitourinary tract (15.4%). Overall, the median TTP was 17 hours (IQR 11.5, 24.5), the shortest TTP was observed in Streptococcus agalactiae. Four-hundred and seventy-eight cultures (97.6%) and all (100%) were detected at 3 days and 5 days of incubation. Factors associated with TTP ≤24 hour were blood drawn from patients who had hematologic malignancy (odds ratio (OR) 9.6, 95% confidence interval (CI) 1.2, 74.3, P = 0.030), endocarditis and vascular infection (OR 8.7, 95% CI 1.1, 67.2, P = 0.038), thrombocytopenia (OR 2.4, 95% CI 1.3, 4.4, P = 0.004), clinical of systemic inflammatory response syndrome (SIRS) (OR 2.3, 95% CI 1.2, 4.5, P = 0.014), and not receiving antimicrobials within 72 hours before cultures taken (OR 2.2, 95% CI 1.4, 3.6, P < 0.001). Conclusions TTP varied depends upon the pathogens and clinical settings. However, bacteria were isolated from almost, but not all of the blood cultures within 3 days of incubation.
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Bagudo, Ahmad Ibrahim, Godwin Attah Obande, Azian Harun, and Kirnpal Kaur Banga Singh. "Advances in automated techniques to identify Acinetobacter calcoaceticus–Acinetobacter baumannii complex." Asian Biomedicine 14, no. 5 (2020): 177–86. http://dx.doi.org/10.1515/abm-2020-0026.
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AbstractAcinetobacter species, particularly those within Acinetobacter calcoaceticus–A. baumannii complex (ACB complex), have emerged as clinically relevant pathogens in hospital environments worldwide. Early and quick detection and identification of Acinetobacter infections is challenging, and traditional culture and biochemical methods may not achieve adequate levels of speciation. Moreover, currently available techniques to identify and differentiate closely related Acinetobacter species are insufficient. The objective of this review is to recapitulate the current evolution in phenotypic and automated techniques used to identify the ACB complex. Compared with other automated or semiautomated systems of bacterial identification, matrix-assisted laser desorption–ionization time-of-flight mass spectrometry (MALDI-TOF MS) demonstrates a high level of Acinetobacter species identification and discrimination, including newly discovered species A. seifertii and A. dijkshoorniae.
Dissertations / Theses on the topic "ABM Pathogens"
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Ha, Tracy. "The role of pathogen defense signaling components in ABA signal transduction and isolation of an ABA/C23 signaling mutant." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p1469579.
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Thesis (M.S.)--University of California, San Diego, 2009.<br>Title from first page of PDF file (viewed Oct. 15, 2009). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 67-76).
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Lebrette, Hugo. "Etude structurale de l'import de nickel par les protéines extracytoplasmiques de systèmes ABC chez les bactéries : le nickel voyage-t-il seul ou accompagné ?" Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENV086.
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Chez les procaryotes, les systèmes ABC (ATP-binding cassette) canoniques permettent un import efficace et de haute affinité du nickel, en grande partie via l'action de la Ni-BP (nickel-binding protein) qui va jouer le rôle de récepteur extracytoplasmique du nickel avant son passage à travers la membrane interne. Dans ces travaux, nous avons cherché à mieux caractériser les stratégies d'import de nickel par les bactéries, notamment par l'étude cristallographique des Ni-BP. La résolution des structures de cinq de ces protéines, en interaction avec du nickel, nous a permis d'identifier les sites de fixation et ainsi de mettre en évidence les différents modes d'interaction de ce métal avec les Ni-BP. Nos résultats montrent notamment que la coordination du nickel requiert toujours la présence d'un métallophore exogène, appelé nickelophore. En parallèle, des études in vivo ont été conduites sur Escherichia coli, montrant que cette bactérie semble être capable de synthétiser son propre nickelophore. D'autre part, ces travaux ont permis la résolution de la structure de HypB de Helicobacter pylori en interaction avec du nickel. Celle-ci permet de mieux appréhender le rôle central de cette protéine au sein des voies de maturation des enzymes à nickel<br>In prokaryotes, canonical ABC (ATP-binding cassette) importers allow an efficient uptake of nickel with high affinity through the inner membrane, largely via the action of the extracytoplasmic nickel-binding protein (Ni-BP). In this work, we intended to better understand the strategies developed by bacteria to scavenge nickel in the environment, especially through the structural studies of several Ni-BP. The resolution of the crystal structures of five Ni-BPs from diverse bacteria, in interaction with nickel, led us to identify their nickel-binding sites and shed light on the different binding modes. Our results show that the presence of an exogenous metallophore, called nickelophore, is always required. In vivo studies in Escherichia coli were also conducted, showing that this bacteria seems to be able to synthesize its own nickelophore. In addition, we have solved the crystal structure of Helicobacter pylori HypB in complex with nickel. This result provides insight into its cellular function in nickel enzyme maturation pathways
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Lin, Ann En-Ju. "Atypical roles for campylobacter jejuni AA-ABC transporter components PAQP and PAQQ in bacterial stress tolerance and pathogen-host cell dynamics." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/4181.
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Campylobacter jejuni is a human pathogen that causes severe diarrhea! disease. However,
our understanding of C. jejuni virulence mechanisms and survival during disease and
transmission remains limited. Amino acid ATP Binding Cassette (AA-ABC) transporters in C.
jejuni have been proposed as being important for bacterial physiology and pathogenesis. We
have investigated a novel AA-ABC transporter system, encoded by cj0467-9, by generating
targeted deletions of cj0467 (membrane transport component) and cj0469 (ATPase component)
in C. jejuni 81-176. Analyses described herein have led us to designate these genes paqP and
paqQ, respectively [pathogenesis-ssociated glutamine (q) ABC transporter permease () and
ATPase (Q)]. We found that loss of either component resulted in amino acid uptake defects,
most notably diminished glutamine uptake. Both ΔpaqP and ΔpaqQ mutants also exhibited a
surprising but significant increase in short-term intracellular survival in macrophages and
epithelial cells. Levels of resistance to a series of environmental and in vivo stresses were
examined. Both mutants were hyper-resistant to aerobic and oxidative stress, and while ΔpaqP
was also hyper-resistant to heat and osmotic shock, ΔpaqQ was more susceptible than wild-type
to the latter two stresses. Annexin-V staining coupled with fluorescence microscopy revealed
that macrophages infected with the ΔpaqP and ΔpaqQ mutants underwent a lower level of
apoptosis than cells infected with wild-type bacteria. Macrophages infected with the mutant
strains exhibited a transient decrease in ERK activation compared to wild type-infected
macrophages, potentially explaining the reduced apoptosis phenotype. The ΔpaqP mutant did not
exhibit a defect for short or longer term mouse colonization, consistent with its increased stress
survival and diminished host cell damage phenotypes. Collectively, these results demonstrate a
unique correlation between an AA-ABC transporter with bacterial stress tolerance, intracellular
survival, host cell damage, and host signal transduction in response to pathogen infection.
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Konieczny, Andreas. "Bedeutung der Rezeptor-Tyrosinkinase c-Kit in der Pathogenese der, Philadelphiatranslokation Bcr-Abl positiven, chronischen myeloischen Leukämie." Diss., lmu, 2003. http://nbn-resolving.de/urn:nbn:de:bvb:19-15621.
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Salvador, Ellaine Riciel P. [Verfasser], and Ulrich [Akademischer Betreuer] Dobrindt. "Characterization of Asymptomatic Bacteriuria (ABU) Escherichia coli Isolates: virulence traits and host-pathogen interactions / Ellaine Riciel P. Salvador. Betreuer: Ulrich Dobrindt." Würzburg : Universitätsbibliothek der Universität Würzburg, 2012. http://d-nb.info/1023205858/34.
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Giordano, Laïla. "Le récepteur IOS1 d’Arabidopsis thalisana - modulateur de l’homéostasie protéique du réticulum endoplasmique en réponse au stress biotique." Electronic Thesis or Diss., Université Côte d'Azur (ComUE), 2019. http://theses.univ-cotedazur.fr/2019AZUR6023.
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Les cellules végétales possèdent un nombre éminent de récepteurs localisés à la membrane plasmique. Ils sont spécialisés dans la détection des changements environnementaux et permettent à la plante de s'adapter en conséquence. Environ 200 de ces récepteurs sont composés d'un domaine extracellulaire avec des répétitions riches en leucine (LRR) et d’un domaine kinase intracellulaire. Nous avons préalablement identifié un membre de cette famille de récepteurs chez Arabidopsis, qui contribue au succès d’infection par des agents pathogènes filamenteux biotrophes, comme l'oomycète Hyaloperonospora arabidopsidis (Hpa). Une plante mutante pour le gène du récepteur perd sa sensibilité à l'infection et d'après ce phénotype le récepteur a été nommé "Impaired Oomycete Susceptibility 1" (IOS1). IOS1 régule négativement la voie de signalisation à l'hormone acide abscissique (ABA) au cours de l’infection. De plus, il a été démontré que le récepteur fait partie d'un complexe de récepteurs du plasmalemme qui détecte les infections bactériennes et déclenche les réactions de l’immunité innée. La région extracellulaire de l'IOS1 contient un domaine supplémentaire appelé « Malectin-Like Domain » (MLD). Le MLD présente de fortes similitudes structurelles avec la malectine animale qui réside dans le réticulum endoplasmique (RE), où elle interagit avec les ribophorines du complexe oligosaccharyltransférase (OST). Les protéines de ce complexe assurent la maturation post-traductionnelle des protéines en ajoutant des N-glycosylations. Les ribophorines surveillent le repliement correct des glycoprotéines néo-synthétisées. Les changements environnementaux modifient fréquemment le taux de protéines produites qui nécessitent une maturation. Si le système de surveillance n'est pas efficace, des protéines néo-synthétisées s'accumulent dans le RE et génèrent l’« Unfolded Protein Response » (UPR). Le mécanisme de contrôle de la maturation des glycoprotéines et les mécanismes de l'UPR existent également chez les cellules végétales. Afin de caractériser les fonctions du domaine extracellulaire (ED) de l'IOS1, nous montrons par microscopie confocale à balayage laser que le MLD est le médiateur de la rétention du récepteur dans la RE. Ici, le MLD du récepteur atténue l'UPR déclenché par l'infection avec l'oomycète. Nous avons identifié la ribophorine végétale HAP6 et l'atténuateur de mort cellulaire Bax-Inhibitor-1 (BI-1) comme protéine résidant dans la RE qui interagissent avec l’ED de l'IOS1. Dans des expériences de complémentation fonctionnelle impliquant le mutant ios1-1 transformé avec des domaines IOS1 individuels, nous avons évalué le rôle de IOS1 et du MLD dans les réponses d’Arabidopsis à la signalisation de stress. Nous montrons que le MLD atténue l'UPR pendant l'interaction plante-oomycète, favorisant ainsi une infection réussie. Nous montrons également que la signalisation ABA est en corrélation positive avec l'UPR, indiquant que l’interférence de IOS1 avec la signalisation hormonale est une conséquence de l’interférence avec l'UPR. Ensemble, nos données suggèrent que les différents domaines du récepteur IOS1 ciblent des fonctions distinctes dans différents compartiments subcellulaires<br>Plant cells have a diversifying number of plasma membrane-localized receptors, which are specialized in detecting environmental changes and allow the plant to adapt accordingly. About 200 of these receptors are composed of an extracellular domain with leucine-rich repeats (LRR) and an intracellular kinase domain. We have previously identified a member of this receptor family in Arabidopsis, which contributes to the infection success by biotrophic filamentous pathogens, such as the oomycete Hyaloperonospora arabidopsidis (Hpa). The plant mutant for the receptor gene loses its susceptibility to infection, and according to this phenotype the receptor has been named "Impaired Oomycete Susceptibility 1" (IOS1). IOS1 negatively regulates the abscisic acid (ABA) hormone signaling pathway upon infection. In addition, the receptor has been shown to be part of a plasma membrane receptor complex that detects bacterial infections and triggers innate immunity. The extracellular region of IOS1 harbors an additional so-called Malectin-Like Domain (MLD), which has strong structural similarities to animal malectin. Animal malectin resides in the endoplasmic reticulum (ER), where it interacts with ribophorins from the oligosaccharyltransferase (OST) complex. Proteins from this complex ensure post-translational protein maturation by adding N-glycosylations. Ribophorins monitor the correct folding of neo-synthetized glycoproteins. Environmental changes frequently alter the rate of proteins that are produced and require maturation. If monitoring system is not efficient, neo-synthetized proteins accumulate in the ER and generate the "Unfolded Protein Response" (UPR). The mechanism for controlling glycoprotein maturation and the UPR also exist in plant cells. In order to characterize the functions of the extracellular domain (ED) of IOS1, we show by confocal laser-scanning microscopy that the MLD mediates a retention of the receptor in the ER. Here, the MLD of the receptor attenuates the UPR, which is triggered by the oomycete infection. We identified the plant ribophorin HAP6 and the cell death attenuator Bax-Inhibitor-1 (BI-1) as ER-residing proteins that interact with the ED of IOS1. In functional complementation experiments involving the ios1-1 mutant transformed with individual IOS1 domains, we further evaluated the role of IOS1 and the MLD in the plant responses to ER and ABA stress signaling. We show that the MLD attenuates the UPR during the plant-oomycete interaction, thus promoting successful infection. We also show that ABA signaling correlates positively with the UPR, indicating that the observed IOS1-mediated regulation of hormone signaling is a consequence of interference with the UPR. Taken together, our data suggest that individual domains of the IOS1 receptor target distinct functions in different subcellular compartments
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Abd, el-Whab El-Sayed Mohammed [Verfasser]. "Highly pathogenic H5N1 avian influenza virus epidemic in Egypt : detection and protection studies / El-Sayed Mohammed Abd El-Whab." Berlin : Freie Universität Berlin, 2012. http://d-nb.info/1026991919/34.
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Zukauskas, Andrew. "The Role of Eukaryotic ABC-Transporters in Eliciting Neutrophil infiltration during Streptococcus pneumoniae infection." eScholarship@UMMS, 2018. https://escholarship.umassmed.edu/gsbs_diss/982.
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Streptococcus pneumoniae (S. pneumoniae) is a Gram-positive, encapsulated bacterium capable of causing significant morbidity and mortality throughout the world. A hallmark of S. pneumoniae infection is infiltration of neutrophils (PMNs) that assist in controlling the spread infection but may also contribute to pathology. Paradoxically, studies have shown that limiting PMN infiltration into the lumen of the lung during infection actually betters clinical outcome in experimental S. pneumoniae infection. The final step in PMN luminal trafficking is a Hepoxilin A3 (HXA3)-dependent migration across the pulmonary epithelium. HXA3 is a PMN chemoattractant that forms gradients along the polarized epithelial face, drawing PMNs from the basolateral to the apical surface during proinflammatory responses. HXA3 requires assistance of an integral- membrane protein transporter to escape the cell and form the gradient. The pulmonary HXA3 transporter is currently unidentified.
In this work, we identify the pulmonary HXA3 transporter as the ATP-Binding Cassette Transporter (ABC transporter) Multi-drug Resistance Associated Protein 2 (ABCC2, MRP2). We demonstrate that MRP1 and MRP2 are divergent ABC- transporters that control transepithelial PMN migration through efflux of a distinct anti-inflammatory substance and the pro-inflammatory HXA3 in the context of Streptococcus pneumoniae infection. Enrichment of MRP2 on the plasma membrane requires detection of the bacterial virulence factors pneumolysin (PLY) and hydrogen peroxide. PLY and hydrogen peroxide not only coordinate MRP2 apical membrane enrichment but also influence HXA3-dependent PMN transepithelial migration. They influence migration through stimulation of epithelial intracellular calcium increases that are crucial for HXA3 production as well as MRP2 translocation to the plasma membrane. PLY and hydrogen peroxide are not sufficient in their signaling alone, however, and require at least one additional bacterial signal to induce HXA3/MRP2 proinflammatory activities.
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Loisel, Elise. "Étude des transporteurs ABC chez le champignon pathogène des plantes Botrytis Cinerea au cours de l'infection et en réponse à certains fongicides." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10103.
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Lors de l'interaction entre un champignon phytopathogène et une plante hôte, des molécules toxiques peuvent être générées par l'agresseur mais aussi par les réactions de défense de la plante. Par ailleurs, les champignons phytopathogènes sont exposés aux traitements chimiques utilisés au champ à des fins antifongiques. Mieux comprendre les mécanismes impliqués dans la tolérance de ces microorganismes à ces molécules toxiques constitue ainsi un point important tant au point de vue des interactions plante-pathogène que de la tolérance aux produits fongicides. Les transporteurs à efflux sont décrits comme participant activement au phénomène de tolérance en exportant les molécules toxiques hors de la cellule. Chez l'agent de la pourriture grise B. cinerea, différentes approches génétiques et bio-informatiques ont conduit à l'existence de 53 transporteurs ABC, dont quatre seulement ont été caractérisés et dont le rôle dans le processus infectieux du champignon est limité. Au cours de ce travail de thèse, la mesure de la réponse transcriptionnelle de l'ensemble des gènes ABC a montré une forte mobilisation des transporteurs à efflux au cours du processus infectieux de B. cinerea, et suggère un rôle global de cette super-famille de gènes dans l'interaction. Jusqu'à aujourd'hui, les études de tolérance des champignons phytopathogènes aux fongicides rapportées dans la littérature ont été conduites in vitro. Ici, l'étude a été conduite in planta et a révélé cinq gènes codant pour des transporteurs ABC sur-exprimés en réponse au traitement fongicide. Leur implication dans la détoxication a été étudiée par une approche de mutagenèse dirigée. Cette méthode n'a cependant pas permis de conclure quant au rôle des transporteurs délétés dans la tolérance au fongicide et/ou dans la pathogénie. Enfin, des résultats contradictoires co-existent actuellement sur le lien qu'il pourrait exister entre les tolérances des champignons aux antifongiques et l'activation de la transcription des gènes codant pour les transporteurs ABC impliqués dans l'efflux de ces derniers. Dans ce travail, ce point a été exploré à l'échelle de tous les gènes ABC de B. cinerea. Leur comportement transcriptionnel a été étudié en réponse à deux fongicides de mode d'action différents, dans des conditions de culture in vitro, mais également à différents stades d'une infection. L'analyse des séquences promotrices des gènes co-régulés par ces deux produits in vitro a permis l'identification de deux motifs putatifs de régulation et suggère l'implication potentielle de plusieurs facteurs de transcription dans la réponse aux fongicides
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Salvador, Ellaine Riciel P. "Characterization of Asymptomatic Bacteriuria (ABU) Escherichia coli Isolates: virulence traits and host-pathogen interactions." Doctoral thesis, 2011. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-71283.
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Urinary tract infection (UTI) is one of the most serious health problems worldwide. It accounts for a million hospital visits annually in the United States. Among the many uropathogenic bacteria, uropathogenic Escherichia coli (UPEC) is the most common causative agent of UTI. However, not all E. coli that inhabit the urinary tract can cause UTI. Some of them thrive for long periods of time in the urinary bladder without causing overt symptoms of infection. This carrier state is called asymptomatic bacteriuria (ABU). E. coli ABU isolates can live in the host without inducing host response due to deletions, insertions and point mutations in the genome leading to the attenuation of virulence genes. They therefore behave in the same way as commensals. Since bacteria that inhabit the urinary tract are said to originate from the lower intestinal tract and ABU behave in a similar way as commensals, this study compared various phenotypic and genotypic characteristics of ABU and commensal E. coli fecal isolates. The two groups did not show a strict clustering with regards to phylogenetic lineage since there appears to be overlaps in their distribution in some clonal complexes. In addition, it was observed that the UPEC virulence genes were more frequently inactivated in ABU than in fecal isolates. Hence, ABU tend to have less functional virulence traits compared to the fecal isolates. The ABU model organism E. coli 83972 which is known not only for its commensal behavior in the urinary bladder but its ability to outcompete other bacteria in the urinary tract is currently being used as prophylactic treatment in patients who have recurrent episodes of UTI at the University Hospital in Lund, Sweden. The pilot studies showed that upon deliberate long-term colonization of the patients with E. coli 83972, they become protected from symptomatic UTI. In this study, the phenotypic and genotypic characteristics of eight re-isolates taken from initially asymptomatically colonized patients enrolled in the deliberate colonization study who reported an episode of symptoms during the colonization period were investigated. Two out of the eight re-isolates were proven to be a result of super infection by another uropathogen. Six re-isolates, on the other hand, were E. coli 83972. The urine re-isolates confirmed to be E. coli 83972 were phenotypically heterogeneous in that they varied in colony size as well as in swarming motility. Four of these re-isolates were morphologically homogenous and similar to the parent isolate E. coli 83972 whereas one of them appeared phenotypically heterogenous as a mixture of smaller and normal-sized colonies. Still another re-isolate phenotypically resembled small colony variants. Meanwhile, three of the six re-isolates did not differ from the parent isolate with regards to motility. On the other hand, three exhibited a markedly increased motility compared to the parent isolate. Transcriptome analysis demonstrated the upregulation of a cascade of genes involved in flagellar expression and biosynthesis in one of the three motile re-isolates. However, upon further investigation, it was found out that the expression of flagella had no effect on bacterial adhesion to host cells in vitro as well as to the induction of host inflammatory markers. Thus, this implies that the increased motility in the re-isolates is used by the bacteria as a fitness factor for its benefit and not as a virulence factor. In addition, among the various deregulated genes, it was observed that gene regulation tends to be host-specific in that there is no common pattern as to which genes are deregulated in the re-isolates. Taken together, results of this study therefore suggest that the use of E. coli 83972 for prophylactic treatment of symptomatic UTI remains to be very promising<br>Harnwegsinfektionen (HWI) sind weltweit ein ernstes Gesundheitsproblem, auf welches allein in den USA jährlich ca. eine Million Krankenhausbesuche entfallen. Innerhalb der Gruppe uropathogener Bakterien stellen die uropathogenen Escherichia coli (UPEC) die wichtigsten Verursacher akuter Harnwegserkrankungen dar. Interessanterweise führen nicht alle E. coli Varianten, die den Harnweg besiedeln, zwangsläufig zu HWI. Einige von ihnen sind in der Lage, die Harnblase über einen langen Zeitraum zu kolonisieren ohne Symptome einer HWI auszulösen. Dieses Phänomen wird als asymptomatische Bakteriurie (ABU) bezeichnet. Die Eigenschaft von E. coli ABU-Isolaten innerhalb des Wirtsorganismus leben zu können, ohne eine deutliche Wirtsabwehrreaktion hervorzurufen, ist unter anderem bedingt durch Deletionen, Insertionen und Punktmutationen im bakteriellen Genom und der daraus resultierenden Inaktivierung einiger Virulenzgene. Ihre Lebensweise ist daher mit der kommensaler Organismen vergleichbar. Da die den Harnweg besiedelnden Bakterien mit hoher Wahrscheinlichkeit ihren Ursprung im unteren Darmtrakt haben und sich die ABU-Isolate ähnlich der Kommensalen verhalten, wurden in dieser Arbeit zahlreiche phäno- und genotypische Charakteristika von ABU-Isolaten mit denen kommensaler E. coli-Fäkalisolate verglichen. Für diese beiden Gruppen konnte hinsichtlich ihrer phylogenetischen Abstammung keine strikte Clusterbildung festgestellt werden, da ihre Verteilung in einigen klonalen Komplexen Überlappungen aufwies. Es zeigte sich jedoch, dass die UPEC-Virulenzgene in den ABU-Isolaten häufiger inaktiviert vorlagen als in den Fäkalisolaten. Demzufolge scheinen die ABU-Isolate weniger funktionale Virulenzeigenschaften zu besitzen als die Fäkalisolate. Der Modell-ABU Stamm E. coli 83972 ist sowohl für sein kommensales Verhalten in der menschlichen Blase bekannt, als auch für seine Fähigkeit, andere Bakterien aus dem Harntrakt zu verdrängen. Er wird gegenwärtig am Universitätsklinikum in Lund (Schweden) als prophylaktisches Therapeutikum bei der Behandlung von Patienten mit rezidivierenden HWI eingesetzt. In Pilotstudien konnte gezeigt werden, dass eine vorsätzliche Langzeit-Kolonisierung von Patienten mit E. coli 83972 zum Schutz vor symptomatischen HWI führt. In der vorliegenden Arbeit wurden die phäno- und genotypischen Charakteristika von acht Patienten-Reisolaten dieser Langzeitstudie untersucht. Die Reisolate wurden aus zunächst asymptomatisch kolonisierten Patienten isoliert, die allerdings im Verlauf der Langzeit-Kolonisierung über eine Reihe von Symptomen klagten. Zwei dieser acht Reisolate waren nachweislich das Resultat einer Superinfektion mit einem anderen uropathogenen Bakterium. Die restlichen sechs Reisolate konnten jedoch als E. coli 83972 identifiziert werden. Für diese sechs Reisolate war eine phänotypische Heterogenität zu beobachten, die sich zum einen in variierender Koloniegröße, zum anderen in unterschiedlichem Schwärmverhalten zeigte: Vier der Reisolate entsprachen morphologisch dem Ausgangsstamm E. coli 83972, wohingegen ein Reisolat phänotypisch abweichend als Mischung von kleineren und normal-großen Kolonien in Erscheinung trat. Ein weiteres Reisolat ähnelte phänotypisch sogenannten „Small Colony Variants“. Das Schwärmverhalten betreffend unterschieden sich indessen drei der sechs Reisolate vom Ausgangsstamm. Sie zeigten im Vergleich eine erhöhte Motilität. In einem dieser drei motilen Reisolate konnte mittels Transkriptomanalyse die hochregulierte Expression einer Reihe von Genen, welche für die Flagellenexpression und -biosynthese verantwortlich sind, aufgezeigt werden. Weiterführende in vitro-Untersuchungen ergaben jedoch, dass diese erhöhte Flagellenexpression weder einen verstärkenden Effekt auf die bakterielle Adhäsion an die Wirtszellen hat, noch in der Wirtszelle die Bildung von Entzündungsmarkern induziert. Dieses Ergebnis impliziert, dass die erhöhte Motilität der Reisolate als Fitnessfaktor und nicht als Virulenzfaktor zu betrachten ist. Ferner führte die genauere Analyse der deregulierten Gene zu der Annahme, dass die Genregulation in den Reisolaten wirtsspezifisch ist, da sich kein übereinstimmendes Muster bezüglich der Deregulation abzeichnete. Unter Berücksichtigung aller Ergebnisse dieser Studie lässt sich abschließend sagen, dass die Verwendung des E. coli Stammes 83972 als prophylaktisches Therapeutikum bei der Behandlung von symptomatischen HWI weiterhin als sehr vielversprechend angesehen werden kann
Books on the topic "ABM Pathogens"
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Gozlan, Rodolphe E., and Marine Combe. Environmental change and pathogen transmission. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198789833.003.0005.
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The majority of emerging pathogens has an environmental origin. These pathogens are increasing in incidence and geographic distribution. Because of the continuous worldwide population growth, and global changes, the emergence of pathogens will continue to intensify, particularly in tropical areas where demographic growth is uncontrolled and socioeconomic and environmental changes rapid. Using a set of case studies, we look at the role of biodiversity alteration on zoonoses emergence and transmission routes, as well as the existing links between climate variability and pathogen emergence. Pathogen emergence and transmission are closely associated with habitat alterations and vector or host-species changes. Because of environmental changes, pathogens that were previously in a dynamic equilibrium, with local host communities in a pristine habitat, without human contact, are now redistributed locally, and over long distances, owing to increasing global pathways. Thus, we aim to characterize the environmental determinants of pathogen transmission in the tropics.
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Rohani, Pejman, and Samuel Scarpino, eds. Pertussis. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198811879.001.0001.
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Pertussis, or whooping cough, is a respiratory disease caused primarily by infection with the bacterium Bordetella pertussis. It remains one of the leading causes of death among vaccine-preventable diseases worldwide and recent years have seen its alarming re-emergence in many regions (including the United States and much of Europe), despite sustained high levels of vaccine coverage. The causes of the resurgence remain contentious, in part due to inherent complexities of the pathogen’s biology, in part due to pronounced variation in the treatment and prevention strategies between different countries and regions, and in part due to long-standing disagreement among scientific researchers studying pertussis. This edited volume brings together expert knowledge from disparate fields with the overall aim of synthesizing the current understanding of this critically important, global pathogen. Pertussis: Epidemiology, Immunology, and Evolution is an advanced text suitable for graduate-level students taking courses in evolutionary epidemiology, disease ecology, and evolutionary biology, as well as academics, public health officials, and researchers in these fields. It also offers a very useful introduction to a wider audience of public health practitioners, microbiologists, epidemiologists, medical professionals, and vaccine biologists
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Ladds, Philip. Pathology of Australian Native Wildlife. CSIRO Publishing, 2009. http://dx.doi.org/10.1071/9780643097933.
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Pathology of Australian Native Wildlife brings together in one volume available information on the pathology of Australian native vertebrate wildlife, excluding fish. It provides rapid access to documented information on diseases in Australian wildlife, domiciled either in Australia or overseas. 
 
 The book comprises 45 chapters, each detailing pathological changes caused by specific pathogens including viruses, bacteria, fungi, protozoa, helminths and ectoparasites, and other injurious agents and conditions such as toxins and neoplasia affecting terrestrial and marine mammals, birds, reptiles and amphibians. Although the aim is to describe morphological (gross and microscopic) changes, the author also indicates history and clinical signs, thus providing guidance as to which lesions should be specifically searched for, and what ancillary testing might be needed to confirm a diagnosis.
 Illustrated throughout with colour photographs, this will be the essential reference for veterinary pathologists and clinicians, as well as wildlife researchers, zoos, wildlife parks, environmentalists, conservationists and students.
 Awarded a 2010 Whitley Certificate of Commendation for Zoological Resource.
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Guidelines for Diagnosing and Managing Disseminated Histoplasmosis among People Living with HIV. Organización Panamericana de la Salud, 2020. http://dx.doi.org/10.37774/9789275122488.
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Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum. This disease is highly endemic in some regions of North America, Central America, and South America and is also reported in certain countries of Asia and Africa. It often affects people with impaired immunity, including people living with HIV, among whom the most frequent clinical presentation is disseminated histoplasmosis. The symptoms of disseminated histoplasmosis are non-specific and may be indistinguishable from those of other infectious diseases, especially disseminated tuberculosis (TB), thus complicating diagnosis and treatment. Histoplasmosis is one of the most frequent opportunistic infections caused by fungal pathogens among people living with HIV in the Americas and may be responsible for 5–15% of AIDS-related deaths every year in this Region. These guidelines aim to provide recommendations for the diagnosis, treatment, and management of disseminated histoplasmosis in persons living with HIV. Although the burden of disease is concentrated in the Americas, the recommendations presented within these guidelines are applicable globally. These guidelines were produced in accordance with the World Health Organization (WHO) handbook for guideline development. The Guideline Development Group elaborated the final recommendations based on a systematic review of scientific literature and critical evaluation of the evidence available using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. These guidelines are intended for health-care providers, HIV program managers, policy-makers, national treatment advisory boards, researchers, and other professionals involved in caring for people who either have or may be at risk of developing disseminated histoplasmosis.
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El Kenz, Hanane, and Philippe Van der Linden. The physiology of blood in anaesthetic practice. Edited by Jonathan G. Hardman. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199642045.003.0011.
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Following the discovery of the ABO blood groups by Landsteiner in 1901, Albert Hustin described the first transfusion of a whole blood unit in 1914. The modern transfusion era really begins in 1916 with the discovery of sodium citrate as an anticoagulant by the same physician, allowing blood conservation in dedicated packs. Since that time, many advances have been made especially over the past two decades in the storage, the conservation, and the laboratory testing of blood components and in transfusion medicine practice. Transfusion of whole blood has been replaced by blood component therapy, which consists of the administration of packed red blood cells, fresh frozen plasma, or platelets. Although blood transfusion is safer than ever, the risk of complications will never reach zero. The risk of infectious transfusion-transmitted diseases has been markedly reduced by the implementation of extensive infectious disease testing, donor selection, and pathogen-inactivation procedures. In countries with a high human development index, the leading causes of allogeneic blood transfusion-related deaths actually resulted from immunological and septic complications. The first section of this chapter describes the structure, function, and immunological aspects of the different blood components that are routinely transfused today. The second section details the composition of the different blood components, their indications, the pre-transfusion compatibility tests, and the main adverse effects associated with their transfusion.
Book chapters on the topic "ABM Pathogens"
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Kovalchuk, Andriy, Stefan S. Weber, Jeroen G. Nijland, Roel A. L. Bovenberg, and Arnold J. M. Driessen. "Fungal ABC Transporter Deletion and Localization Analysis." In Plant Fungal Pathogens. Humana Press, 2011. http://dx.doi.org/10.1007/978-1-61779-501-5_1.
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Falke, Dietrich. "Pathogenese der Viruskrankheiten." In Virologie am Krankenbett. Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-642-72181-6_3.
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Koneman, Elmer W. "3. Sitzung Mikrobielle Pathogenese und menschliche Infektionskrankheiten." In Am anderen Ende des Mikroskops. Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-8274-2672-7_4.
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Kunz, Meik. "Einleitung." In Modellierung und Simulation von Protein-Interaktionen am Beispiel von Wirts-Pathogen-Interaktionen. Springer Fachmedien Wiesbaden, 2017. http://dx.doi.org/10.1007/978-3-658-16778-3_1.
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Kunz, Meik. "Material und Methoden." In Modellierung und Simulation von Protein-Interaktionen am Beispiel von Wirts-Pathogen-Interaktionen. Springer Fachmedien Wiesbaden, 2017. http://dx.doi.org/10.1007/978-3-658-16778-3_2.
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Kunz, Meik. "Ergebnisse." In Modellierung und Simulation von Protein-Interaktionen am Beispiel von Wirts-Pathogen-Interaktionen. Springer Fachmedien Wiesbaden, 2017. http://dx.doi.org/10.1007/978-3-658-16778-3_3.
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Kunz, Meik. "Diskussion." In Modellierung und Simulation von Protein-Interaktionen am Beispiel von Wirts-Pathogen-Interaktionen. Springer Fachmedien Wiesbaden, 2017. http://dx.doi.org/10.1007/978-3-658-16778-3_4.
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Mark, Eccleston-Turner, and Rourke Michelle. "Pathogen Sharing." In Global Health Law & Policy. Oxford University Press, 2023. http://dx.doi.org/10.1093/law/9780197687710.003.0017.
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This chapter, “Pathogen Sharing,” introduces the role of “access and benefit sharing” (ABS)—a transactional mechanism designed to allow countries to trade access to their sovereign genetic resources for monetary and non-monetary benefits—in global health law. Combating emerging and re-emerging infectious diseases requires a coordinated international scientific response that includes testing, surveillance, risk assessments, and the development of vaccines and other medical countermeasures. Each of these vital activities relies upon prompt access to pathogen samples. The international scientific community had long treated these pathogen samples as common resources, belonging to everyone, sharing samples freely and informally with scientists around the world to monitor the changing genetic sequences of pathogens and seeking to detect pathogens with pandemic potential before they take hold in the human population. However, international environmental law has come to impact the management of pathogen samples, recognizing genetic resources as the sovereign resources of the country of origin and allowing that country to negotiate the terms of access to these samples though an ABS transaction. Where countries seek to negotiate access to pathogen samples in exchange for sharing associated medicines and vaccines, the ABS transaction may not be the most efficient way to realize global health goals.
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Singh, Joginder, Joydeep Dutta, and Ravi Kant Pathak. "Antibacterial Peptides: Potential Therapeutic Agent." In Recent Trends and The Future of Antimicrobial Agents - Part I. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815079609123010006.
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With the changing environment, microbial pathogens continuously develop antibiotic resistance (AR). As a response to this host-pathogen interaction, host organisms sometimes develop a strategy to stay ahead of the AR developed by pathogens. These molecules are small peptides known as antimicrobial peptides (AMPs). These peptides are short in length, specific in structure and thus have a unique mechanism of action. The uniqueness and specificity in the mechanism come due to the positively charged amino acids which are responsible for initial interaction among AMPs and the negatively charged membrane of the pathogenic cell. Microbes do not develop much ABR against AMPs because of the absence of epitopic regions on AMPs. This property makes AMPs the new therapeutic strategy against microbes. Here, we present a review of the AMPs, their sequence, structure, classification, mechanism of action and the computational strategy developed so far to identify new and improved AMPs that can be used as therapeutic agents.
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Bozbuga, Refik, Bekir Bulent Arpaci, Selman Uluisik, Pakize Gok Guler, Hatice Nilufer Yildiz, and Songul Yalcin Ates. "Genetic Modification of Plant Hormones Induced by Parasitic Nematodes, Virus, Viroid, Bacteria, and Phytoplasma in Plant Growing." In Plant Hormones - Recent Advances, New Perspectives and Applications [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102721.
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Plant hormones, such as auxin, play crucial roles in many plant developmental processes, which is crosstalk with gibberellin and strigolactone. The roles of hormones may vary in the biosynthesis of metabolisms. During the pathogen attack, including plant-parasitic nematodes, viroid, phytoplasma, virus, and bacteria, plant hormones are involved in several plant processes. Ethylene (ET), salicylate (SA), jasmonate (JA), and abscisic acid (ABA) primarily regulate synergistically or antagonistically against pathogens. Those pathogens—nematodes, bacteria, viroid, phytoplasma, and viruses regulate several plant hormones for successful parasitism, influencing the phytohormone structure and modifying plant development. Several genes are related to plant hormones that are involved in pathogens parasitism. In this chapter, how pathogens affect plant hormones in plants growing are discussed.
Conference papers on the topic "ABM Pathogens"
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Onyango Awuor, Silas Onyango Awuor. "Long-term Home Enteral Nutrition: Feeding Tube-related Complications and Problems in old age Patients." In 4th International Nutrition and Dietetics Scientific Conference. KENYA NUTRITIONISTS AND DIETICIANS INSTITUTE, 2024. http://dx.doi.org/10.57039/jnd-conf-abt-2024-gioh-06.
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The highest infusion therapy at home nowadays is tube feeding or Home enteral Nutrition (HEN) normally used in patient who have a functional gastrointestinal tract but are unable to meet their nutrient requirement through oral intake. This study aim was to evaluate the long-term complications, pathogens and problems related to gastrostomy and jejunostomy feeding tubes used for home enteral nutrition support and the effect these have on health care use. This was retrospectively study among 50 patients (28 having gastrostomy and 22 with jejunostomy) who have been discharged on long-term (>2 months) enteral nutrition and followed up at regular intervals by a nurse. Data were collected and analyzed on complication associated with tube feeding as well as the intervention for a period of six months. From this study it was found that 28 (55.1%) of the participant frequently removes the tube, 23 (46.6%) tube leakage, and 18 (36.4%) had dermatitis of the stoma. Some of the patient 8 (16.4%) developed diarrhea which was seen due to pathogens causing diarrhoea in which Escherichia coli emerged the highest at 5 (30%) even though it is classified as non-pathogenic organism but can enhance other pathogen infection, followed by Salmonella spp. and Shigella spp. at 4 (25%) and lastly Campylobacter spp. at 2 (12%). From this study it was found that most of our patients receiving long-term home enteral nutrition feeding tube-related complications are frequently expose themselves to common pathogens which may lead to other complication to them. Therefore, further studies are needed to address their optimal prevention modalities and management. Key words: Complications, Gastrostomy, Jejunostomy, pathogens, Home enteral nutrition
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Belyakova, N. V., E. A. Vorobyova, and V. A. Sivolapov. "MOLECULAR-GENETIC ANALYSIS OF PHYTOPATHOGENS IN STANDS OF THE VORONEZH REGION." In Modern machines, equipment and IT solutions for industrial complex: theory and practice. Voronezh State University of Forestry and Technologies named after G.F. Morozov, Voronezh, Russia, 2021. http://dx.doi.org/10.34220/mmeitsic2021_29-33.
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This paper presents the results of DNA diagnostics of phytopathogens in the Voronezh region. DNA diagnostics was carried out step by step: isolation of total DNA from the sample by CTAB method, amplification of marker regions of phytopathogenic organisms using primers ITS1 and ITS4, electrophoretic separation of the obtained amplicons in 2% agarose gel followed by staining with ethidium bromide, determination of the nucleotide sequence of the amplified loci ABI Prism 310. The study identified the following plant diseases: Sphaeropsis sapinea, Rhizoctonia solani, Cladosporium herbarum. Along with this, we identified the Neocatenulostroma pathogen, which had not previously been found in the territories under its jurisdiction. This disease cannot be determined by phenological signs. The degree of infection by pathogens ranged from 15 to 40%. At present, the problem of protecting plants from diseases is especially urgent. It has been established that the greatest damage to forestry activities is caused by fungal and infectious diseases. At the same time, among phytopathogens, about 97% are fungal infections, 2% are bacterial and 1% are viral.
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Roberts, Anthony, Richard McClatchey, Saad Liaquat, Nigel Edwards, and Mike Wray. "POSTER: Introducing pathogen." In the 2013 ACM SIGSAC conference. ACM Press, 2013. http://dx.doi.org/10.1145/2508859.2512518.
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Garneau, P., O. Labrecque, C. Maynard, S. Messier, M. Archambault, and J. Harel. "Diagnostic microarrays for antimicrobial resistance bacterial gene (ABG) identification." In Eighth International Symposium on the Epidemiology and Control of Foodborne Pathogens in Pork. Iowa State University, Digital Press, 2009. http://dx.doi.org/10.31274/safepork-180809-826.
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Makled, Elhassan, Amal Yassien, Passant Elagroudy, Mohamed Magdy, Slim Abdennadher, and Nabila Hamdi. "PathoGenius VR." In PerDis '19: The 8th ACM International Symposium on Pervasive Displays. ACM, 2019. http://dx.doi.org/10.1145/3321335.3329694.
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Herrmann, Julien, Zachary L. Witter, Nakul Patel, Jonathan Kho, Daniel A. Janies, and Ümit V. Çatalyürek. "Visual analytics on the spread of pathogens." In BCB '16: ACM International Conference on Bioinformatics, Computational Biology, and Health Informatics. ACM, 2016. http://dx.doi.org/10.1145/2975167.2985666.
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Hannigan, Joseph, Suzanne J. Matthews, John K. Wickiser, and Paulo Shakarian. "A Network-Based Approach for Identifying Cancer Causing Pathogens." In the 2014 ACM Southeast Regional Conference. ACM Press, 2014. http://dx.doi.org/10.1145/2638404.2735459.
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Gebreyes, Wondwossen A., Siddhartha Thakur, and W. E. Morgan Morrow. "Prevalence and antimicrobial resistance of Salmonella isolated from conventional and antimicrobial-free (ABF) swine herds in North Carolina." In Sixth International Symposium on the Epidemiology and Control of Foodborne Pathogens in Pork. Iowa State University, Digital Press, 2005. http://dx.doi.org/10.31274/safepork-180809-757.
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Chen, Yahui, Yankun Peng, and Qinghui Guo. "Surface-enhanced Raman spectroscopic technique for identification and classification of foodborne pathogens." In 2022 Houston, Texas July 17-20, 2022. American Society of Agricultural and Biological Engineers, 2022. http://dx.doi.org/10.13031/aim.202200186.
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Khalil Bhuiyan, Md Ebrahim, Dustin Smith, Eric J. Voss, Chin-Chuan Wei, and Mohammad Shavezipur. "Surface Functionalization of Silicon MEMS Biochemical Sensors for the Detection of Foodborne Pathogens." In ASME 2021 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/detc2021-69708.
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Abstract This work presents the surface modification of silicon chips as a platform for silicon-based biosensors with applications aiming for the detection of foodborne bacteria in aqueous solution. The detection requires high selectivity as the solution may contain a variety of biological species, which affect the outcome of the sensing process. The silicon surface is functionalized by a self-assembled monolayer (SAM) with thiol groups followed by immobilizing a thiol-linked DNA aptamer. The DNA aptamer used in this work has reported to recognize a biological species, E. coli ATCC 25922. The presence of DNA aptamer on the sensor surface allows the capture of the specific E. coli cells on the surface, while other potential biological (and chemical) species would not attach to the sensor surface, thus improving the selectivity of the sensor. The uniform formation of the SAM on the surface is an important step toward uniformly coating the sensor surface with the desired DNA aptamer. The SAM is created on the silicon surface by surface modification with the MPTS (3-mercaptopropyl trimethoxy silane) solution. Then the aptamer DNA solution is applied as droplets on the chip followed by a cure process. The attachment of the SAM and DNA aptamers are verified by atomic force microscopy (AFM). The surface functionalization presented in this work can be used for sensors made of silicon coated with a thin layer of native oxide, and can be adopted for detection of other cells and biological agents using the proper SAM and DNA aptamer.
Reports on the topic "ABM Pathogens"
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Chejanovsky, Nor, and Bruce A. Webb. Potentiation of Pest Control by Insect Immunosuppression. United States Department of Agriculture, 2010. http://dx.doi.org/10.32747/2010.7592113.bard.
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The restricted host range of many baculoviruses, highly pathogenic to Lepidoptera and non-pathogenic to mammals, limits their use to single or few closely related Lepidopteran species and is an obstacle to extending their implementation for pest control. The insect immune response is a major determinant of the ability of an insect pathogen to efficiently multiply and propagate. We have developed an original model system to study the Lepidopteran antiviral immune response based on Spodoptera littoralis resistance to AcMNPV (Autographa californica multiple nucleopolyhedrovirus) infection and the fascinating immunosuppressive activity of polydnaviruses .Our aim is to elucidate the mechanisms through which the immunosuppressive insect polydnaviruses promote replication of pathogenic baculoviruses in lepidopteran hosts that are mildly or non-permissive to virus- replication. In this study we : 1- Assessed the extent to which and the mechanisms whereby the immunosuppressive Campoletis sonorensis polydnavirus (CsV) or its genes enhanced replication of a well-characterized pathogenic baculovirus AcMNPV, in polydnavirus-immunosuppressedH. zea and S. littoralis insects and S. littoralis cells, hosts that are mildly or non-permissive to AcMNPV. 2- Identified CsV genes involved in the above immunosuppression (e.g. inhibiting cellular encapsulation and disrupting humoral immunity). We showed that: 1. S. littoralis larvae mount an immune response against a baculovirus infection. 2. Immunosuppression of an insect pest improves the ability of a viral pathogen, the baculovirus AcMNPV, to infect the pest. 3. For the first time two PDV-specific genes of the vankyrin and cystein rich-motif families involved in immunosuppression of the host, namely Pvank1 and Hv1.1 respectively, enhanced the efficacy of an insect pathogen toward a semipermissive pest. 4. Pvank1 inhibits apoptosis of Spodopteran cells elucidating one functional aspect of PDVvankyrins. 5. That Pvank-1 and Hv1.1 do not show cooperative effect in S. littoralis when co-expressed during AcMNPV infection. Our results pave the way to developing novel means for pest control, including baculoviruses, that rely upon suppressing host immune systems by strategically weakening insect defenses to improve pathogen (i.e. biocontrol agent) infection and virulence. Also, we expect that the above result will help to develop systems for enhanced insect control that may ultimately help to reduce transmission of insect vectored diseases of humans, animals and plants as well as provide mechanisms for suppression of insect populations that damage crop plants by direct feeding.
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Evans, Donald L., Avigdor Eldar, Liliana Jaso-Friedmann, and Herve Bercovier. Streptococcus Iniae Infection in Trout and Tilapia: Host-Pathogen Interactions, the Immune Response Towards the Pathogen and Vaccine Formulation. United States Department of Agriculture, 2005. http://dx.doi.org/10.32747/2005.7586538.bard.
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The objectives of the BARD proposal were to determine the mechanisms of nonspecific cytotoxic cells (NCC) that are necessary to provide heightened innate resistance to infection and to identify the antigenic determinants in Streptococcus iniae that are best suited for vaccine development. Our central hypothesis was that anti-bacterial immunity in trout and tilapia can only be acquired by combining "innate" NCC responses with antibody responses to polysaccharide antigens. These Objectives were accomplished by experiments delineated by the following Specific Aims: Specific aim (SA) #1 (USA) "Clone and Identify the Apoptosis Regulatory Genes in NCC"; Specific aim #2 (USA)"Identify Regulatory Factors that Control NCC Responses to S. iniae"; Specific aim #3 (Israel) "Characterize the Biological Properties of the S. iniae Capsular Polysaccharide"; and Specific aim #4 (Israel) "Development of an Acellular Vaccine". Our model of S. iniae pathogenesis encompassed two approaches, identify apoptosis regulatory genes and proteins in tilapia that affected NCC activities (USA group) and determine the participation of S.iniae capsular polysaccharides as potential immunogens for the development of an acellular vaccine (Israel group). We previously established that it was possible to immunize tilapia and trout against experimental S. difficile/iniaeinfections. However these studies indicated that antibody responses in protected fish were short lived (3-4 months). Thus available vaccines were useful for short-term protection only. To address the issues of regulation of pathogenesis and immunogens of S. iniae, we have emphasized the role of the innate immune response regarding activation of NCC and mechanisms of invasiveness. Considerable progress was made toward accomplishing SA #1. We have cloned the cDNA of the following tilapia genes: cellular apoptosis susceptibility (CAS/AF547173»; tumor necrosis factor alpha (TNF / A Y 428948); and nascent polypeptide-associated complex alpha polypeptide (NACA/ A Y168640). Similar attempts were made to sequence the tilapia FasLgene/cDNA, however these experiments were not successful. Aim #2 was to "Identify Regulatory Factors that Control NCC Responses to S. iniae." To accomplish this, a new membrane receptor has been identified that may control innate responses (including apoptosis) of NCC to S. iniae. The receptor is a membrane protein on teleost NCC. This protein (NCC cationic antimicrobial protein-1/ncamp-1/AAQ99138) has been sequenced and the cDNA cloned (A Y324398). In recombinant form, ncamp-l kills S. iniae in vitro. Specific aim 3 ("Characterize the Biological Properties of the S.iniae Capsular Polysaccharide") utilized an in- vitro model using rainbow trout primary skin epithelial cell mono layers. These experiments demonstrated colonization into epithelial cells followed by a rapid decline of viable intracellular bacteria and translocation out of the cell. This pathogenesis model suggested that the bacterium escapes the endosome and translocates through the rainbow trout skin barrier to further invade and infect the host. Specific aim #4 ("Development of an Acellular Vaccine") was not specifically addressed. These studies demonstrated that several different apoptotic regulatory genes/proteins are expressed by tilapia NCC. These are the first studies demonstrating that such factors exist in tilapia. Because tilapia NCC bind to and are activated by S. iniae bacterial DNA, we predict that the apoptotic regulatory activity of S. iniae previously demonstrated by our group may be associated with innate antibacterial responses in tilapia.
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Horwitz, Benjamin, and Barbara Gillian Turgeon. Secondary Metabolites, Stress, and Signaling: Roles and Regulation of Peptides Produced by Non-ribosomal Peptide Synthetases. United States Department of Agriculture, 2005. http://dx.doi.org/10.32747/2005.7696522.bard.
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Fungal pathogens of plants produce a diverse array of small molecules. Often referred to as secondary metabolites because they were thought to be dispensable for basic functions, they may indeed have central roles as signals for the fungal cell, and in interactions with the host. We have identified more than a dozen genes encoding nonribosomal peptide synthetases (NPS) in Cochliobolusheterostrophus, the agent of southern corn leaf blight. The aim of this project was to identify roles of these genes in stress responses and signaling. The first objective was to test a complete collection of C. heterostrophus nonribosomal peptide synthetase (NRPS)-encoding gene deletion mutant and wildtype (WT) strains for sensitivity to various agents of oxidative (ROS) and nitrosative (RNOS) stress, in vitro. The second objective and next step in this part of the project was to study the relevance of sensitivity to ROS and RNOS in the host pathogen interaction, by measuring the production of ROS and RNOS in planta, when plants are inoculated with wild type and mutant strains. A third objective was to study expression of any genes shown to be involved in sensitivity to ROS or RNOS, in vitro and in planta. Another objective was to determine if any of the genes involved in oxidative or nitrosative stress responses are regulated by components of signal transduction pathways (STP) that we have identified and to determine where mechanisms overlap. Study of the collection of nps mutants identified phenotypes relevant for virulence, development and oxidative stress resistance for two of the genes, NPS2 and NPS6. Mutants in genes related to RNOS stress have no virulence phenotypes, while some of those related to ROS stress have reduced virulence as well as developmental phenotypes, so we focused primarily on ROS stress pathways. Furthermore, the identification of NPS2 and NPS6 as encoding for NRPS responsible for siderophore biosynthesis lent a new focus to the project, regulation by Fe. We have not yet developed good methods to image ROS in planta and work in this direction is continuing. We found that NPS6 expression is repressed by Fe, responding over the physiological Fe concentration range. Studying our collection of mutants, we found that conserved MAPK and G protein signal transduction pathways are dispensable for Fe regulation of NPS6, and initiated work to identify other pathways. The transcription factor SreA is one candidate, and is responsible for part, but not all, of the control of NPS6 expression. The results of this project show that the pathogen contends with oxidative stress through several signaling pathways. Loss of the siderophore produced by Nps6 makes the fungus sensitive to oxidative stress, and decreases virulence, suggesting a central role of the ability to sequester and take up extracellular iron in the host-pathogen interaction. Siderophores, and manipulation of Fe levels, could be targets for new strategies to deal with fungal pathogens of maize and other plants.
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Levisohn, Sharon, Maricarmen Garcia, David Yogev, and Stanley Kleven. Targeted Molecular Typing of Pathogenic Avian Mycoplasmas. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7695853.bard.
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Intraspecies identification (DNA "fingerprinting") of pathogenic avian mycoplasmas is a powerful tool for epidemiological studies and monitoring strain identity. However the only widely method available for Mycoplasma gallisepticum (MG) and M. synoviae (MS)wasrandom amplified polymorphic DNA (RAPD). This project aimed to develop alternative and supplementary typing methods that will overcome the major constraints of RAPD, such as the need for isolation of the organism in pure culture and the lack of reproducibility intrinsic in the method. Our strategy focussed on recognition of molecular markers enabling identification of MG and MS vaccine strains and, by extension, pathogenic potential of field isolates. Our first aim was to develop PCR-based systems which will allow amplification of specific targeted genes directly from clinical material. For this purpose we evaluated the degree of intraspecies heterogeneity in genes encoding variable surface antigens uniquely found in MG all of which are putative pathogenicity factors. Phylogenic analysis of targeted sequences of selected genes (pvpA, gapA, mgc2, and lp) was employed to determine the relationship among MG strains.. This method, designated gene targeted sequencing (GTS), was successfully employed to identify strains and to establish epidemiologically-linked strain clusters. Diagnostic PCR tests were designed and validated for each of the target genes, allowing amplification of specific nucleotide sequences from clinical samples. An mgc2-PCR-RFLP test was designed for rapid differential diagnosis of MG vaccine strains in Israel. Addressing other project goals, we used transposon mutagenesis and in vivo and in vitro models for pathogenicity to correlated specific changes in target genes with biological properties that may impact the course of infection. An innovative method for specific detection and typing of MS strains was based on the hemagglutinin-encoding gene vlhA, uniquely found in this species. In parallel, we evaluated the application of amplified fragment length polymorphism (AFLP) in avian mycoplasmas. AFLP is a highly discriminatory method that scans the entire genome using infrequent restriction site PCR. As a first step the method was found to be highly correlated with other DNA typing methods for MG species and strain differentiation. The method is highly reproducible and relatively rapid, although it is necessary to isolate the strain to be tested. Both AFLP and GTS are readily to amenable to computer-assisted analysis of similarity and construction of a data-base resource. The availability of improved and diverse tools will help realize the full potential of molecular typing of avian mycoplasmas as an integral and essential part of mycoplasma control programs.
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Perk, Simon, Egbert Mundt, Alexander Panshin, et al. Characterization and Control Strategies of Low Pathogenic Avian Influenza Virus H9N2. United States Department of Agriculture, 2012. http://dx.doi.org/10.32747/2012.7697117.bard.
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The avian influenza virus, subtype H9N2 subtype, defined as having a low pathogenicity, causes extensive economical losses in commercial flocks, probably due to management and synergism with other pathogens. AIV H9N2 was first identified in Israel in the year 2000, and since then it became endemic and widespread in Israel. Control by vaccination of commercial flocks with an inactivated vaccine has been introduced since 2007. In face of the continuous H9N2 outbreaks, and the application of the vaccination policy, we aimed in the present study to provide a method of differentiating naturally infected from vaccinated animals (DIVA). The aim of the assay would be detect only antibodies created by a de-novo infection, since the inactivated vaccine virus is not reproducing, and might provide a simple tool for mass detection of novel infections of commercial flocks. To fulfill the overall aim, the project was designed to include four operational objectives: 1. Evaluation of the genetic evolution of AIV in Israel; 2. Assessment of the diagnostic value of an NS1 ELISA; 3. NS1 ELISA as evaluation criteria for measuring the efficacy of vaccination against H9N2 AIV; 4. Development of an AIV H9 subtype specific ELISA systems. Major conclusion and implications drawn from the project were: 1. A continuous genetic change occurred in the collection of H9N2 isolates, and new introductions were identified. It was shown thatthe differences between the HA proteins of viruses used for vaccine productionand local fieldisolatesincreasedin parallelwith the durationand intensity ofvaccine use, therefore, developing a differential assay for the vaccine and the wild type viruses was the project main aim. 2. To assess the diagnostic value of an NS1 ELISA we first performed experimental infection trials using representative viruses of all introductions, and used the sera and recombinant NS1 antigens of the same viruses in homologous and heterologous NS1 ELISA combination. The NS1 ELISA was evidently reactive in all combinations, and did not discriminate significantly between different groups. 3. However, several major drawbacks of the NS1 ELISA were recognized: a) The evaluation of the vaccination effect in challenged birds, showed that the level of the NS1 antibodies dropped due to the vaccination-dependent virus level drop; b) the applicability of the NS1-ELISA was verified on sera of commercial flocks and found to be unusable due to physico-chemical composition of the sera and the recombinant antigen, c) commercial sera showed non-reactivity that might be caused by many factors, including vaccination, uncertainty regarding the infection time, and possibly low antigen avidity, d) NS1 elevated antibody levels for less than 2 months in SPF chicks. Due to the above mentioned reasons we do not recommend the application of the DIVA NS1 ELISA assay for monitoring and differentiation AIV H9N2 naturally-infected from vaccinated commercial birds.
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Minz-Dub, A., G. J. Muehlbauer, E. Millet, and A. Sharon. ing and characterization of a novel leaf rust and stripe rust resistance gene from Sharon goatgrass. United States-Israel Binational Agricultural Research and Development Fund, 2021. http://dx.doi.org/10.32747/2021.8134171.bard.
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Each year, significant global wheat yield loss occurs due to diseases that affect yield quantity or quality. Breeding for resistance has been the best economic and environmentally safe approach to control wheat diseases, however many disease resistance (R) genes succumbed to the pathogens and are no longer effective. Hence, new sources of resistance are necessary to boost the wheat gene pool. The main source for such genes are species of wheat wild relatives in the secondary gene pool that contain an unexploited reservoir of novel R genes. Sharon goatgrass (Aegilops sharonensis Eig) is a wild diploid relative of wheat (genome SshS sh). It is native to the coastal plain of Israel, growing mostly on stabilized dunes, and is highly resistant to rust pathogens. Previously, we introgressed a leaf and stripe rust resistance locus from Ae. sharonensis into bread wheat using chromosome engineering (Millet et al., 2014). We mapped the alien region to the short arm of chromosome six using genotyping by sequencing, identified SNPs, and used them to generate diagnostic markers (Khazan et al., 2020).
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Splitter, Gary A., Menachem Banai, and Jerome S. Harms. Brucella second messenger coordinates stages of infection. United States Department of Agriculture, 2011. http://dx.doi.org/10.32747/2011.7699864.bard.
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Aim 1: To determine levels of this second messenger in: a) B. melitensiscyclic-dimericguanosinemonophosphate-regulating mutants (BMEI1448, BMEI1453, and BMEI1520), and b) B. melitensis16M (wild type) and mutant infections of macrophages and immune competent mice. (US lab primary) Aim 2: To determine proteomic differences between Brucelladeletion mutants BMEI1453 (high cyclic-dimericguanosinemonophosphate, chronic persistent state) and BMEI1520 (low cyclicdimericguanosinemonophosphate, acute virulent state) compared to wild type B. melitensisto identify the role of this second messenger in establishing the two polar states of brucellosis. (US lab primary with synergistic assistance from the Israel lab Aim 3: Determine the level of Brucellacyclic-dimericguanosinemonophosphate and transcriptional expression from naturally infected placenta. (Israel lab primary with synergistic assistance from the US lab). B. Background Brucellaspecies are Gram-negative, facultative intracellular bacterial pathogens that cause brucellosis, the most prevalent zoonosis worldwide. Brucellosis is characterized by increased abortion, weak offspring, and decreased milk production in animals. Humans are infected with Brucellaby consuming contaminated milk products or via inhalation of aerosolized bacteria from occupational hazards. Chronic human infections can result in complications such as liver damage, orchitis, endocarditis, and arthritis. Brucellaspp. have the ability to infect both professional and non-professional phagocytes. Because of this, Brucellaencounter varied environments both throughout the body and within a cell and must adapt accordingly. To date, few virulence factors have been identified in B. melitensisand even less is known about how these virulence factors are regulated. Subsequently, little is known about how Brucellaadapt to its rapidly changing environments, and how it alternates between acute and chronic virulence. Our studies suggest that decreased concentrations of cyclic dimericguanosinemonophosphate (c-di-GMP) lead to an acute virulent state and increased concentrations of c-di-GMP lead to persistent, chronic state of B. melitensisin a mouse model of infection. We hypothesize that B. melitensisuses c-di-GMP to transition from the chronic state of an infected host to the acute, virulent stage of infection in the placenta where the bacteria prepare to infect a new host. Studies on environmental pathogens such as Vibrio choleraeand Pseudomonas aeruginosasupport a mechanism where changes in c-di-GMP levels cause the bacterium to alternate between virulent and chronic states. Little work exists on understanding the role of c-di-GMP in dangerous intracellular pathogens, like Brucellathat is a frequent pathogen in Israeli domestic animals and U.S. elk and bison. Brucellamust carefully regulate virulence factors during infection of a host to ensure proper expression at appropriate times in response to host cues. Recently, the novel secondary signaling molecule c-di-GMP has been identified as a major component of bacterial regulation and we have identified c-di-GMP as an important signaling factor in B. melitensishost adaptation. C. Major conclusions, solutions, achievements 1. The B. melitensis1453 deletion mutant has increased c-di-GMP, while the 1520 deletion mutant has decreased c-di-GMP. 2. Both mutants grow similarly in in vitro cultures; however, the 1453 mutant has a microcolony phenotype both in vitro and in vivo 3. The 1453 mutant has increased crystal violet staining suggesting biofilm formation. 4. Scanning electron microscopy revealed an abnormal coccus appearance with in increased cell area. 5. Proteomic analysis revealed the 1453 mutant possessed increased production of proteins involved in cell wall processes, cell division, and the Type IV secretion system, and a decrease in proteins involved in amino acid transport/metabolism, carbohydrate metabolism, fatty acid production, and iron acquisition suggesting less preparedness for intracellular survival. 6. RNAseq analysis of bone marrow derived macrophages infected with the mutants revealed the host immune response is greatly reduced with the 1453 mutant infection. These findings support that microlocalization of proteins involved in c-di-GMP homeostasis serve a second messenger to B. melitensisregulating functions of the bacteria during infection of the host.
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Cahaner, Avigdor, Susan J. Lamont, E. Dan Heller, and Jossi Hillel. Molecular Genetic Dissection of Complex Immunocompetence Traits in Broilers. United States Department of Agriculture, 2003. http://dx.doi.org/10.32747/2003.7586461.bard.
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Objectives: (1) Evaluate Immunocompetence-OTL-containing Chromosomal Regions (ICRs), marked by microsatellites or candidate genes, for magnitude of direct effect and for contribution to relationships among multiple immunocompetence, disease-resistance, and growth traits, in order to estimate epistatic and pleiotropic effects and to predict the potential breeding applications of such markers. (2) Evaluate the interaction of the ICRs with genetic backgrounds from multiple sources and of multiple levels of genetic variation, in order to predict the general applicability of molecular genetic markers across widely varied populations. Background: Diseases cause substantial economic losses to animal producers. Emerging pathogens, vaccine failures and intense management systems increase the impact of diseases on animal production. Moreover, zoonotic pathogens are a threat to human food safety when microbiological contamination of animal products occurs. Consumers are increasingly concerned about drug residues and antibiotic- resistant pathogens derived from animal products. The project used contemporary scientific technologies to investigate the genetics of chicken resistance to infectious disease. Genetic enhancement of the innate resistance of chicken populations provides a sustainable and ecologically sound approach to reduce microbial loads in agricultural populations. In turn, animals will be produced more efficiently with less need for drug treatment and will pose less of a potential food-safety hazard. Major achievements, conclusions and implications:. The PI and co-PIs had developed a refined research plan, aiming at the original but more focused objectives, that could be well-accomplished with the reduced awarded support. The successful conduct of that research over the past four years has yielded substantial new information about the genes and genetic markers that are associated with response to two important poultry pathogens, Salmonella enteritidis (SE) and Escherichia coli (EC), about variation of immunocompetence genes in poultry, about relationships of traits of immune response and production, and about interaction of genes with environment and with other genes and genetic background. The current BARD work has generated a base of knowledge and expertise regarding the genetic variation underlying the traits of immunocompetence and disease resistance. In addition, unique genetic resource populations of chickens have been established in the course of the current project, and they are essential for continued projects. The US laboratory has made considerable progress in studies of the genetics of resistance to SE. Microsatellite-marked chromosomal regions and several specific genes were linked to SE vaccine response or bacterial burden and the important phenomenon of gene interaction was identified in this system. In total, these studies demonstrate the role of genetics in SE response, the utility of the existing resource population, and the expertise of the research group in conducting such experiments. The Israeli laboratories had showed that the lines developed by selection for high or low level of antibody (Ab) response to EC differ similarly in Ab response to several other viral and bacterial pathogens, indicating the existence of a genetic control of general capacity of Ab response in young broilers. It was also found that the 10w-Ab line has developed, possibly via compensatory "natural" selection, higher cellular immune response. At the DNA levels, markers supposedly linked to immune response were identified, as well as SNP in the MHC, a candidate gene responsible for genetic differences in immunocompetence of chickens.
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Asdal, Åsmund. Seed Longevity and Survival of Seed Borne Diseases After 35 Years Conservation in Permafrost – Report From the 100 Year Storage Experiment. Nordic Genetic Resource Center (NordGen), 2024. http://dx.doi.org/10.53780/hkqq8789.
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The Nordic Gene Bank (predecessor to today's plant section of The Nordic Genetic Resource Center, NordGen) established the 100 year seed storage experiment in Coal mine no. 3 outside Longyearbyen in 1986. The experiment was established with the aim to monitor the longevity of seeds in this Nordic back-up seed collection that were deposited in the coal mine from 1984 and to gain general knowledge about the longevity of seed stored under permafrost conditions, as well as studying the survival of seed borne plant pathogens. Seed samples have regularly been withdrawn for analysis according to a fixed withdrawal and analyze plan, that will continue until the last samples are analyzed in 2086.
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Sharon, Amir, and Maor Bar-Peled. Identification of new glycan metabolic pathways in the fungal pathogen Botrytis cinerea and their role in fungus-plant interactions. United States Department of Agriculture, 2012. http://dx.doi.org/10.32747/2012.7597916.bard.
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The involvement of glycans in microbial adherence, recognition and signaling is often a critical determinant of pathogenesis. Although the major glycan components of fungal cell walls have been identified there is limited information available on its ‘minor sugar components’ and how these change during different stages of fungal development. Our aim was to define the role of Rhacontaining-glycans in the gray mold disease caused by the necrotrophic fungus B. cinerea. The research was built on the discovery of two genes, Bcdhand bcer, that are involved in formation of UDP-KDG and UDP-Rha, two UDP- sugars that may serve as donors for the synthesis of cell surface glycans. Objectives of the proposed research included: 1) To determine the function of B. cinereaBcDh and BcEr in glycan biosynthesis and in pathogenesis, 2) To determine the expression pattern of BcDH and BcERand cellular localization of their encoded proteins, 3) Characterize the structure and distribution of Rha- containing glycans, 4) Characterization of the UDP-sugar enzymes and potential of GTs involved in glycanrhamnosylation. To address these objectives we generated a series of B. cinereamutants with modifications in the bchdhand bcergenes and the phenotype and sugar metabolism in the resulting strains were characterized. Analysis of sugar metabolites showed that changes in the genes caused changes in primary and secondary sugars, including abolishment of rhamnose, however abolishment of rhamnose synthesis did not cause changes in the fungal phenotype. In contrast, we found that deletion of the second gene, bcer, leads to accumulation of the intermediate sugar – UDP- KDG, and that such mutants suffer from a range of defects including reduced virulence. Further analyses confirmed that UDP-KDG is toxic to the fungus. Studies on mode of action suggested that UDP-KDG might affect integrity of the fungal cell wall, possibly by inhibiting UDP-sugars metabolic enzymes. Our results confirm that bcdhand bcerrepresent a single pathway of rhamnose synthesis in B. cinerea, that rhamnose does not affect in vitro development or virulence of the fungus. We also concluded that UDP-KDG is toxic to B. cinereaand hence UDP-KDG or compounds that inhibit Er enzymes and lead to accumulation of UDP-KDG might have antifungal activity. This toxicity is likely the case with other fungi, this became apparent in a collaborative work with Prof. Bart Thomma of Wageningen University, NETHERLANDS . We have shown the deletion of ER mutant in Verticillium dahlia gave plants resistance to the fungal infection.