Academic literature on the topic 'Bacterial diseases – Diagnosis'
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Journal articles on the topic "Bacterial diseases – Diagnosis"
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KNOWLES, D. P. jr, and J. R. GORHAM. "Diagnosis of viral and bacterial diseases." Revue Scientifique et Technique de l'OIE 9, no. 3 (September 1, 1990): 733–57. http://dx.doi.org/10.20506/rst.9.3.515.
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Ozaslan, Mehmet, and Idress Hamad Attitalla. "DNA Based Diagnosis of Canine Bacterial Diseases." Journal of Animal and Veterinary Advances 11, no. 11 (November 1, 2012): 1954–64. http://dx.doi.org/10.3923/javaa.2012.1954.1964.
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Raoult, Didier, Cyrille Bonhomme, and Patricia Renesto. "Bacterial Protein Microarrays for Diagnosis of Infectious Diseases." Current Immunology Reviews 4, no. 1 (February 1, 2008): 28–36. http://dx.doi.org/10.2174/157339508783597316.
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Austin, Brian. "Methods for the diagnosis of bacterial fish diseases." Marine Life Science & Technology 1, no. 1 (August 27, 2019): 41–49. http://dx.doi.org/10.1007/s42995-019-00002-5.
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ABIDOV, A. "Laboratory diagnosis of bacterial vaginosis." Journal of the European Academy of Dermatology and Venereology 11 (September 1998): S299. http://dx.doi.org/10.1016/s0926-9959(98)95725-7.
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Obaro, Stephen. "Updating the diagnosis of bacterial meningitis." Lancet Infectious Diseases 19, no. 11 (November 2019): 1160–61. http://dx.doi.org/10.1016/s1473-3099(19)30549-3.
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Hung, Yuan-Pin, Yu-Fon Chen, Pei-Jane Tsai, I.-Hsiu Huang, Wen-Chien Ko, and Jeng-Shiung Jan. "Advances in the Application of Nanomaterials as Treatments for Bacterial Infectious Diseases." Pharmaceutics 13, no. 11 (November 12, 2021): 1913. http://dx.doi.org/10.3390/pharmaceutics13111913.
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Bacteria-targeting nanomaterials have been widely used in the diagnosis and treatment of bacterial infectious diseases. These nanomaterials show great potential as antimicrobial agents due to their broad-spectrum antibacterial capacity and relatively low toxicity. Recently, nanomaterials have improved the accurate detection of pathogens, provided therapeutic strategies against nosocomial infections and facilitated the delivery of antigenic protein vaccines that induce humoral and cellular immunity. Biomaterial implants, which have traditionally been hindered by bacterial colonization, benefit from their ability to prevent bacteria from forming biofilms and spreading into adjacent tissues. Wound repair is improving in terms of both the function and prevention of bacterial infection, as we tailor nanomaterials to their needs, select encapsulation methods and materials, incorporate activation systems and add immune-activating adjuvants. Recent years have produced numerous advances in their antibacterial applications, but even further expansion in the diagnosis and treatment of infectious diseases is expected in the future.
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Alvarez, Anne M. "INTEGRATED APPROACHES FOR DETECTION OF PLANT PATHOGENIC BACTERIA AND DIAGNOSIS OF BACTERIAL DISEASES." Annual Review of Phytopathology 42, no. 1 (September 2004): 339–66. http://dx.doi.org/10.1146/annurev.phyto.42.040803.140329.
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Patel, Robin. "MALDI-TOF MS for the Diagnosis of Infectious Diseases." Clinical Chemistry 61, no. 1 (January 1, 2015): 100–111. http://dx.doi.org/10.1373/clinchem.2014.221770.
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Abstract BACKGROUND First introduced into clinical microbiology laboratories in Europe, MALDI-TOF MS is being rapidly embraced by laboratories around the globe. Although it has multiple applications, its widespread adoption in clinical microbiology relates to its use as an inexpensive, easy, fast, and accurate method for identification of grown bacteria and fungi based on automated analysis of the mass distribution of bacterial proteins. CONTENT This review provides a historical perspective on this new technology. Modern applications in the clinical microbiology laboratory are reviewed with a focus on the most recent publications in the field. Identification of aerobic and anaerobic bacteria, mycobacteria, and fungi are discussed, as are applications for testing urine and positive blood culture bottles. The strengths and limitations of MALDI-TOF MS applications in clinical microbiology are also addressed. SUMMARY MALDI-TOF MS is a tool for rapid, accurate, and cost-effective identification of cultured bacteria and fungi in clinical microbiology. The technology is automated, high throughput, and applicable to a broad range of common as well as esoteric bacteria and fungi. MALDI-TOF MS is an incontrovertibly beneficial technology for the clinical microbiology laboratory.
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Nakamura, Shota, Norihiro Maeda, Ionut Mihai Miron, Myonsun Yoh, Kaori Izutsu, Chidoh Kataoka, Takeshi Honda, et al. "Metagenomic Diagnosis of Bacterial Infections." Emerging Infectious Diseases 14, no. 11 (November 2008): 1784–86. http://dx.doi.org/10.3201/eid1411.080589.
Full textDissertations / Theses on the topic "Bacterial diseases – Diagnosis"
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Young, Hugh. "Laboratory diagnosis and epidemiology of bacterial sexually transmitted diseases." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/27730.
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This thesis brings together 118 published studies on the microbiology of sexually transmitted diseases resulting from work performed in the University of Edinburgh Department of Medical Microbiology between 1973 and 1995. The main aim of these studies was to improve microbiological aspects of the diagnosis and management of syphilis and gonorrhoea. The earliest publication on syphilis serology was the first to recommend the use of a specific treponemal antigen test, the Treponema pallidum haemagglutination assay (TPHA) for routine screening. As a result of this study a screening schedule comprising the Venereal Diseases Research Laboratory (VDRL) and TPHA tests was introduced into routine practice in late 1973. Soon the same screening schedule was widely adopted in the United Kingdom and Europe. Appreciating the importance of computerised and automation I validated and standardised a prototype commercial enzyme immunoassay (EIA) as a single serological screening test and demonstrated that this gave a performance comparable to screening with the VDRL and TPHA tests while being suitable for automation and electronic report generation. Screening for syphilis by EIA is now becoming widespread throughout Europe. Because false positive EIA reactions may also show reactivity in the FTA-abs test, immunoblotting was evaluated as a confirmatory test. The possibility of syphilis reactivation and loss of treponemal markers in patients co-infected with HIV were also studied.
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Collins, Ann. "A review and retrospective study of some major bacterial orofacial infections." Thesis, The University of Sydney, 1990. http://hdl.handle.net/2123/4209.
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History has recorded the antiquity of serious infections in the region of the head and neck. Today, our community still experiences major life-threatening infections in these anatomical locations, which pose significant management difficulties to the oral and maxillofacial surgeon. The aim of this thesis is to review the aetiology, diagnosis and treatment of some bacterial infections involving structures of the head and neck. Such infections may spread, causing serious complications with severe morbidity and occasionally death. This theses deals only with infections of bacterial origin and does not attempt to cover viral, or fungal agents or the chronic specific diseases of tuberculosis and syphilis, and makes no attempt to address the old question of focal infection. The literature review relates especially to Ludwig’s Angina which was first described so dramatically in 1836. To this day it remains as a clinically potentially lethal disease despite the progress of modern medicine. Numerous descriptions in the literature warn of the rapid appearance of symptoms and the danger of respiratory obstruction when management of the airway is not satisfactorily undertaken. Both odontogenic and non-odontogenic causes of orofacial and neck infections are reviewed. Odontogenic problems are given special emphasis as they are now of major concern. The significance of the potential fascial spaces in the face and neck which allow the spread of dental infections is also highlighter. A thorough knowledge of these anatomical relationships is still of the utmost importance to the surgeon if he is to be successful in treatment. The principle of surgical drainage of pus is as important in 1990 as it was 150 years ago. The biological basis for the onset and progress of such fulminating infections in the head and neck region is still poorly understood. One constant need is that the bacteria, both aerobic and anaerobic, be correctly identified. Microbiological techniques are constantly improving and provide an important adjuvant investigation, which then allows the surgeon to provide the most appropriate antimicrobial therapy. Principal to the many aspects of treatment is the ability to maintain the airway of the patient and to provide the depth of anaesthesia necessary to undertake the required surgery. Major bacterial orofacial infections may have severe local and far-reaching systemic effects. Such complications are discussed in all their ramifications. It should be realised that the presentation of these patients at a late stage, when complications have already supervened, may make diagnosis difficult. There is always a necessity to ensure that the underlying cause of the disease is accurately defined and that complication are not allowed to progress further. Finally, a retrospective study of the management of 90 patients with major bacterial orofacial infections who have been treated at Westmead Hospital is presented. The outcome of this study of some major bacterial orofacial infections of the head and neck is the need to stress the importance of urgent surgical management and maintenance of the airway, together with the microbiological determination of the causative organisms and their sensitivities, so that other than empirical antibiotics can be instituted early. This must be combined with an upgrading of the patients’ medical and dental status. It was demonstrated that, in the majority of these patients, ignorance and fear combined with a lack of routine dental care resulted in major infections arising from relatively simple odontogenic causes such as dental caries, periodontal disease and pericoronal infection related to impacted teeth. Without doubt, the immediate care of these patients demanded intensive management. However, it is important to recognise that dental education forms an integral part not only of the recovery programme for the afflicted patient, but also as a community health preventive measure of profound significance.
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Collins, Ann. "A review and retrospective study of some major bacterial orofacial infections." University of Sydney, 1990. http://hdl.handle.net/2123/4209.
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Master of Dental SurgeryHistory has recorded the antiquity of serious infections in the region of the head and neck. Today, our community still experiences major life-threatening infections in these anatomical locations, which pose significant management difficulties to the oral and maxillofacial surgeon. The aim of this thesis is to review the aetiology, diagnosis and treatment of some bacterial infections involving structures of the head and neck. Such infections may spread, causing serious complications with severe morbidity and occasionally death. This theses deals only with infections of bacterial origin and does not attempt to cover viral, or fungal agents or the chronic specific diseases of tuberculosis and syphilis, and makes no attempt to address the old question of focal infection. The literature review relates especially to Ludwig’s Angina which was first described so dramatically in 1836. To this day it remains as a clinically potentially lethal disease despite the progress of modern medicine. Numerous descriptions in the literature warn of the rapid appearance of symptoms and the danger of respiratory obstruction when management of the airway is not satisfactorily undertaken. Both odontogenic and non-odontogenic causes of orofacial and neck infections are reviewed. Odontogenic problems are given special emphasis as they are now of major concern. The significance of the potential fascial spaces in the face and neck which allow the spread of dental infections is also highlighter. A thorough knowledge of these anatomical relationships is still of the utmost importance to the surgeon if he is to be successful in treatment. The principle of surgical drainage of pus is as important in 1990 as it was 150 years ago. The biological basis for the onset and progress of such fulminating infections in the head and neck region is still poorly understood. One constant need is that the bacteria, both aerobic and anaerobic, be correctly identified. Microbiological techniques are constantly improving and provide an important adjuvant investigation, which then allows the surgeon to provide the most appropriate antimicrobial therapy. Principal to the many aspects of treatment is the ability to maintain the airway of the patient and to provide the depth of anaesthesia necessary to undertake the required surgery. Major bacterial orofacial infections may have severe local and far-reaching systemic effects. Such complications are discussed in all their ramifications. It should be realised that the presentation of these patients at a late stage, when complications have already supervened, may make diagnosis difficult. There is always a necessity to ensure that the underlying cause of the disease is accurately defined and that complication are not allowed to progress further. Finally, a retrospective study of the management of 90 patients with major bacterial orofacial infections who have been treated at Westmead Hospital is presented. The outcome of this study of some major bacterial orofacial infections of the head and neck is the need to stress the importance of urgent surgical management and maintenance of the airway, together with the microbiological determination of the causative organisms and their sensitivities, so that other than empirical antibiotics can be instituted early. This must be combined with an upgrading of the patients’ medical and dental status. It was demonstrated that, in the majority of these patients, ignorance and fear combined with a lack of routine dental care resulted in major infections arising from relatively simple odontogenic causes such as dental caries, periodontal disease and pericoronal infection related to impacted teeth. Without doubt, the immediate care of these patients demanded intensive management. However, it is important to recognise that dental education forms an integral part not only of the recovery programme for the afflicted patient, but also as a community health preventive measure of profound significance.
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Paradela, Gomes Cláudia Sofia. "Antimicrobial resistance and new insights in the diagnosis of Carrión's Disease." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/401758.
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Carrión's disease is an overlooked disease restricted to the poorest areas of the Andes, with only a few research groups working in this field around the world. Until recently, it was thought that Carrion's disease met the most relevant criteria for being eradicated, but before that happens a number of issues need to be addressed. One of the problems is the lack of well-defined effective treatment program. Both in vitro antimicrobial resistance studies and clinical trials are needed to determine the best treatment approaches. On the other hand, and perhaps the most urgent need, it is necessity to have an easy way to make the correct diagnosis. New immunological studies will help to identify new molecules with diagnostic potential.
The results of this thesis have been separated into 2 different aspects of Carrión's disease; On one hand, antimicrobial resistance (Chapter I) and, on the other hand, the diagnosis and characterization of clinical samples (Chapter II). Chapter I describes a study on resistance mechanisms developed in the presence of the 4 most common antibiotics used in the treatment of Carrion's disease. The ability of Bartonella bacilliformis to become resistant to the main antibiotics used to treat Carrión's disease is evidenced both by the development of antibiotic target alterations and by the overexpression of expulsion pumps. However, total or partial reversion of acquired resistance suggests the existence of a high biological cost derived from the selection of antimicrobial resistance. These instability of the acquired antibiotic resistance may underlie the lack of antibiotic-resistant clinical isolates and the high frequency of microbiological failures during antibiotic treatments. Although studies of mutants obtained in vitro can not be transferred directly to the community, chloramphenicol appears to be the best treatment option in vitro.
Chapter 2 analyzes several aspects of the diagnosis of Carrion's disease that are addressed in 3 studies. In the first study, samples obtained from patients of an suspected Oroya fever outbreak were molecularly characterized. However, we propose that this outbreak was erroneously attributed to B. bacilliformis and our results suggest that the causative agent was Sphingomonas faeni. As far as we know, this was the first reported outbreak caused by Sphingomonas spp. acquired in the community, making clear the need to develop diagnostic techniques that can be implemented in endemic areas. In a second study we evaluated the limit of detection of several PCR approaches to detect B. bacilliformis from blood. It seems that the sensitivity of these techniques could allow the diagnosis of acute cases of Carrion's disease, but its
applicability to detect healthy carriers or acute cases with low bacteraemia remains unclear. In this article we propose the concomitant use of the 3 PCR approaches in combination with the clinical information. Finally, in the third study of this chapter the objective was the identification and characterization of immunogenic candidates of B. bacilliformis that may in the future be used in a rapid diagnostic tool. Four immunogenic B. bacilliformis candidates were selected: 2 proteins were identified with an anti-human IgM secondary antibody (Pap31 and SCS-α) and another 2 with anti- human IgG secondary antibody (GroEL and SCS-β).
The design of treatment schemes that minimize resistance selection along with the development of diagnostic techniques that can be implemented in rural and isolated areas is essential for the control, elimination and eradication of Carrion's disease.La enfermedad de Carrión es una enfermedad desatendida restringida a las zonas más pobres de la región Andina. Uno de los problemas es la falta de programas de tratamiento eficaces bien definidos. Por otro lado, y quizás sea la necesidad más imperiosa, es preciso tener una manera fácil de realizar el diagnóstico. Nuevos estudios inmunológicos ayudarán a identificar nuevas moléculas con potencial diagnóstico. Los resultados de esta tesis han sido separados en 2 aspectos diferentes de la enfermedad de Carrión; la resistencia a los antimicrobianos (Capítulo I) y el diagnóstico y caracterización de muestras clínicas (Capítulo II). El capítulo I describe un estudio sobre los mecanismos de resistencia desarrollados en presencia de los 4 antibióticos más comunmente utilizados en el tratamiento de la enfermedad de Carrión, evidenciándose la capacidad de Bartonella bacilliformis de volverse resistente a estos antibióticos, tanto por el desarrollo de alteraciones en sus dianas, como por la sobreexpresión de bombas de expulsión. El capítulo 2 analiza aspectos del diagnostico de la enfermedad de Carrión que se abordan en 3 estudios. En el primero se caracterizan molecularmente muestras obtenidas de pacientes de un supuesto brote de fiebre de Oroya. Sin embargo, proponemos que este brote se atribuyó erróneamente a B. bacilliformis sugieriéndose que el agente causante fue Sphingomonas faeni. En el segundo hemos evaluado el límite de detección de varios esquemas de PCR para detectar B. bacilliformis. Parece que la sensibilidad de estas técnicas podría permitir el diagnóstico de casos agudos de la enfermedad de Carrión, pero su aplicabilidad para detectar a los portadores sanos o con una baja bacteriemia sigue sin estar clara. Por fin, en el tercer estudio de este capítulo el objetivo fue la identificación y caracterización de candidatos inmunogénicos de B. bacilliformis que puedan en un futuro ser utilizados en una herramienta de diagnostico rápida. Se identificaron 4 proteínas inmunogénicas: Pap31, GroEL, SCS-α y SCS-β. El diseño de esquemas de tratamiento que minimicen la selección de resistencia junto con el desarrollo de técnicas de diagnóstico que puedan ser implementadas en zonas rurales es esencial para el control y eliminación de la enfermedad de Carrión.
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Lewis, Sally. "Development of a Real-time Pcr Assay for the Detection of Campylobacter Jejuni and Campylobacter Coli." Thesis, University of North Texas, 2009. https://digital.library.unt.edu/ark:/67531/metadc9840/.
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Campylobacter organisms are the most commonly reported bacterial causes of foodborne infection in the world, with Campylobacter jejuni and Campylobacter coli responsible for over 99% of reported infections. Traditionally, Campylobacter species detection is an arduous process, requiring a special incubation environment as well as specific growth media for an extended growth period. The development of a rapid and reliable diagnostic tool for the detection of Campylobacter species would be a valuable aid to the medical diagnostic decision process, especially to rule out Campylobacter infection during the enteric pre-surgical time period. Improved patient outcomes would result if this rapid assay could reduce the number of enteric surgeries. Assays performed during this dissertation project have demonstrated that both SYBR® green and hydrolysis probe assays targeting an 84 nucleotide portion of cadF, a fibronectin-binding gene of Campylobacter jejuni and Campylobacter coli, were able to detect from 101 to 108 copies of organism from stool specimens, did not detect nonspecific targets, and exhibited a coefficient of variation (CV) of 1.1% or less. Analytical validation of sensitivity, specificity and precision, successfully performed in these studies, warrants additional clinical validation of these assays.
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SILVA, Karla Patrícia Chaves da. "Produção e avaliação da proteína derivada (PPD) de Burkholderia mallei para o diagnóstico imuno-alérgico do mormo em equídeos." Universidade Federal Rural de Pernambuco, 2010. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5700.
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The objective this study produce and evaluate PPD-mallein with potential for application in the diagnosis of glanders from of the the production and purification of immunogenic proteins of B. mallei isolates from equines with glanders in Brazil. Were isolated and characterized phenotypically and by detecting the activity of proteases, polyphenol oxidases, esterases and determination of the resistance profile in vitro. Samples of B. mallei studied were susceptible to antimicrobial gentamicin, ciprofloxacin, norfloxacin, doxycycline and enrofloxacin and resistant to trimethoprim / sulfamethoxazole, amoxicillin and ampicillin. Was observed the activity of proteases, absence esterases polyphenyloxidase and bacterial growth resulted in toxic metabolites. For the production and purification of the protein partially mallein were used two strains of B. mallei Brazilian already characterized phenotypically and genotypically. Was inoculated broth samples Dorset-Henley to metabolize and get the bacterial proteins. Proteins were separated and precipitated with trichloroacetic acid and ammonium sulphate. The PPD-mallein were concentrated at 1.0 mg / mL and evaluation in guinea pigs previously sensitized with bacter were effective for identifying infection in animals truly positive and exclude the animals truly negative. Histological analysis of the application site of mallein revealed the development of Type IV hypersensitivity. Was evaluated the PPD-mallein about their power in five asinines with clinical signs, with bacteriological diagnosis and positive serology for glanders and five asinines negative in serology and bacteriology. The animals were tested according to the criteria established by paragraph IN nº24 regarding the diagnosis of glanders. After 48 hours of inoculation, there was swelling in the area of injection, presence of ocular discharge and tearing confirming the diagnosis of glanders. The other seronegative animals showed no inflammatory reaction at the site of inoculation of PPD-mallein. This immunogen produced and being tested in Brazil was effective being a new possibility for diagnosis and control of glanders in this country.
Objetivou-se nesse estudo produzir e avaliar PPD-maleína com potencial para aplicação no diagnóstico do mormo a partir da purificação de proteínas imunogênicas de Burkholderia. mallei isoladas de equídeos com mormo no Brasil. As bactérias foram isoladas e caracterizadas fenotipicamente por meio da detecção da atividade de proteases, polifenoloxidases e esterases, além da determinação do perfil de resistência à antimicrobianos in vitro. Para produção e purificação parcial da maleína foram utilizadas duas estirpes de B. mallei brasileiras fenotípica e genotipicamente caracterizadas. Inoculou-se as amostras em caldo Dorset-Henley para metabolizar e obter as proteínas bacterianas. As proteínas foram separadas e precipitadas com ácido tricloroacético e sulfato de amônia. As PPDs maleína foram concentradas em 1,0mg/mL e na avaliação realizada em cobaios previamente sensibilizados com a bactéria foram eficazes na identificação dos animais verdadeiros positivos e na exclusão dos verdadeiros negativos. Avaliou-se a PPD-maleína quanto a sua potência em cinco asininos com sinais clínicos e diagnóstico bacteriológico e sorológico positivo para o mormo e em cinco asininos negativos na sorologia e bacteriologia. As amostras de B. mallei estudadas foram sensíveis à gentamicina, ciprofloxacina, norfloxacina, doxiciclina e enrofloxacina, e resistentes a trimetoprim/sulfametoxazol, amoxacilina e ampicilina. Observou-se a atividade de proteases, ausência de esterases e polifenoloxidades e o crescimento bacteriano em meio de cultura resultou em metabólitos tóxicos. A análise histológica do local de aplicação da maleína, em cobaias, revelou o desenvolvimento de hipersensibilidade do tipo IV. Os asininos foram testados de acordo com os critérios estabelecidos pela IN nº24 do Ministério de Agricultura Pecuária e Abastecimento referente ao diagnóstico do mormo. Após 48 horas da inoculação, observou-se edema na área da injeção, presença de secreção ocular e lacrimejamento, confirmando-se o diagnóstico do mormo. Os outros animais sorologicamente negativos não apresentaram reação inflamatória no local de inoculação da PPD-maleína. Esse imunógeno produzido e em fase de teste no Brasil é uma nova alternativa para o diagnóstico e controle do mormo no país.
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Prudent, Elsa. "Applications de l'hybridation in situ en fluorescence et stratégies moléculaires pour le diagnostic des infections bactériennes." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0253/document.
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Une partie de ce travail de thèse a consisté à appliquer les méthodes de FISH pour l’étude de trois bactéries pathogènes intracellulaires. La viabilité de Bartonella henselae a été évaluée à partir de ganglions de patients atteints de la maladie des griffes du chat (CSD). Le faible taux d’ARN détecté par biologie moléculaire, la stérilité des cultures, l'absence de détection par analyses histologiques et FISH confirment que B. henselae n'est pas ou rarement viable dans les ganglions de patients atteints de CSD. Tropheryma whipplei, l’agent de la maladie de Whipple, a été identifié et localisé par FISH, dans les macrophages d’un ganglion et d’une biopsie pulmonaire, confirmant le diagnostic infectieux. Deux méthodes de FISH ont été testées pour détecter Coxiella burnetii dans des cas d’endocardites et d’infections vasculaires en utilisant des sondes oligonucléotidiques et des sondes PNA. Les résultats ont confirmé une meilleure efficacité des sondes PNA et démontré que les techniques de FISH sont plus sensibles que l’immunohistochimie pour le diagnostic des endocardites et des infections vasculaires à C. burnetii. Nous avons également évalué les stratégies moléculaires mises en place pour le diagnostic syndromique. Bien que la PCR conventionnelle à large spectre permette l'identification de micro-organismes fastidieux et anaérobies, la PCR spécifique en temps réel révèle une supériorité significative dans le diagnostic syndromique. En conclusion, ce travail a permis de démontrer l’efficacité et l’applicabilité de la FISH pour la détection bactérienne. Cette méthode peut être utilisée comme un outil complémentaire afin d'améliorer le diagnostic de microbiologie cliniqueWe applied FISH methods to the study of three intracellular pathogenic bacteria. The viability of Bartonella henselae was evaluated in a large series of lymph nodes from patients with cat scratch disease (CSD). The results obtained, associated with sterile cultures and negative histological analyzes and FISH, as well as the low level of RNA detected by molecular biology, provide evidence that B. henselae are not or are rarely viable in the lymph nodes of patients with CSD. Tropheryma whipplei has been identified by FISH in macrophages from one lymph node and for the first time in a pulmonary biopsy, confirming the diagnosis of infection. Two methods of FISH have been tested to detect Coxiella burnetii in cases of endocarditis and vascular infections using oligonucleotide and PNA probes. The results attested to the greater efficiency of PNA probes, and demonstrated that FISH were applicable for the diagnosis of C. burnetii endocarditis. We also evaluated the molecular strategies used for syndrome-driven diagnosis of infectious diseases. Although conventional broad-spectrum PCR allows for the identification of fastidious and anaerobic microorganisms, real-time specific PCR reveals a significant superiority in syndrome-driven diagnosis. The addition of specific PCRs in real time PCR would improve our molecular strategies, for example, in the case of the detection of Staphylococcus aureus for the diagnosis of lymphadenopathy. In conclusion, this work demonstrates the effectiveness and applicability of FISH for the identification of intracellular bacteria. This method can be used as an important complementary tool to the improvement of clinical microbiological diagnosis
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Surujon, Defne. "Computational approaches in infectious disease research: Towards improved diagnostic methods." Thesis, Boston College, 2020. http://hdl.handle.net/2345/bc-ir:109089.
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Thesis advisor: Kenneth WilliamsDue to overuse and misuse of antibiotics, the global threat of antibiotic resistance is a growing crisis. Three critical issues surrounding antibiotic resistance are the lack of rapid testing, treatment failure, and evolution of resistance. However, with new technology facilitating data collection and powerful statistical learning advances, our understanding of the bacterial stress response to antibiotics is rapidly expanding. With a recent influx of omics data, it has become possible to develop powerful computational methods that make the best use of growing systems-level datasets. In this work, I present several such approaches that address the three challenges around resistance. While this body of work was motivated by the antibiotic resistance crisis, the approaches presented here favor generalization, that is, applicability beyond just one context. First, I present ShinyOmics, a web-based application that allow visualization, sharing, exploration and comparison of systems-level data. An overview of transcriptomics data in the bacterial pathogen Streptococcus pneumoniae led to the hypothesis that stress-susceptible strains have more chaotic gene expression patterns than stress-resistant ones. This hypothesis was supported by data from multiple strains, species, antibiotics and non-antibiotic stress factors, leading to the development of a transcriptomic entropy based, general predictor for bacterial fitness. I show the potential utility of this predictor in predicting antibiotic susceptibility phenotype, and drug minimum inhibitory concentrations, which can be applied to bacterial isolates from patients in the near future. Predictors for antibiotic susceptibility are of great value when there is large phenotypic variability across isolates from the same species. Phenotypic variability is accompanied by genomic diversity harbored within a species. I address the genomic diversity by developing BFClust, a software package that for the first time enables pan-genome analysis with confidence scores. Using pan-genome level information, I then develop predictors of essential genes unique to certain strains and predictors for genes that acquire adaptive mutations under prolonged stress exposure. Genes that are essential offer attractive drug targets, and those that are essential only in certain strains would make great targets for very narrow-spectrum antibiotics, potentially leading the way to personalized therapies in infectious disease. Finally, the prediction of adaptive outcome can lead to predictions of future cross-resistance or collateral sensitivities. Overall, this body of work exemplifies how computational methods can complement the increasingly rapid data generation in the lab, and pave the way to the development of more effective antibiotic stewardship practices
Thesis (PhD) — Boston College, 2020
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Biology
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Strålin, Kristoffer. "Diagnostic methods for bacterial etiology in adult community-acquired pneumonia /." Linköping : Linköpings universitet, 2005. http://www.bibl.liu.se/liupubl/disp/disp2005/med918s.pdf.
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PINHEIRO, JUNIOR José Wilton. "Epidemiologia das infecções por Brucella abortus,Brucella ovis, Chlamydophila abortus e Toxoplasma gondii em rebanhos ovinos no estado de Alagoas." Universidade Federal Rural de Pernambuco, 2008. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5696.
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The objective of this study was to study the production, hygienicalsanitary and reproduction aspects, and the epidemiology bacterial infectious (brucellosis and clamidofilosis) and parasitic (toxoplasmosis) diseases involved in reproduction disturbs in sheep in the state of Alagoas. Twenty seven properties distributed in twenty three municipalities in the state of Alagoas were studied. To the study of the the production, hygienical-sanitary and reproduction aspects, investigative questionnaires involving questions related to the properties were applied and analyzed. To the anti-Brucella abortus antibodies search the Tamponated Acidified Antigen, Modified Tamponated Acidified Antigen and Complement Fixation Reaction techniques were used. The agreement among the tests used in the Brucella abortus infection diagnosis was verified using the Kappa coefficient. For the study of Brucella ovis infection, the immunodiffusion technique in gelatinous agar was employed. To the anti-Chlamydophila abortus antibodies search the Complement Fixation Reaction technique with a 1:32 cutoff point was used. TheToxoplasma gondii infection diagnosis was done based on the indirect immunoflorescency technique considering the cutoff point of 1:64. To the study of risk factors associated with the Clamydophila abortus and Toxosplama gondii infection were selected variables related to properties characteristics, hygienical-sanitary management and reproduction disturbs. The analysis of the sanitary and socio-economic profile allowed to observe that the sheep creator from Alagoas is an individual with reasonable degree of education, that need information about the nutritional, reproductive and sanitary management and they still suffer the effects of the infectious and parasitic diseases occurrence, highlighting the miscarriage and reproduction disturbs. The utilization of biological techniques of reproduction is still ignorant, mainly assembles a natural in most herds studied. It was not observed positive animals to B. abortus and the agreement among the RB, RBm tests comparing to the FCR test was weak (K = 0.00; 0.00). From an amount of two hundred and seventy nine analyzed samples to B. ovis, it was observed that nine (3.2%) were positive and two hundred and seventy (96.8%) negative, distributed in six herds (37.5%) and in sixmunicipalities (46.2%). It was not possible to observe any significant statistics differences among sex, age, region, property size, creation management, significant association was observed for a historical of the reproduction disturbs (p<0,001). The results referents to the C. abortus shown that 59/274 (21.5%) were positive and 187 (68.3%) negative, noting77.7% of focus infection. The only variable that presented a significant association within the multivariate analysis statistics was the region (p<0.001; OR=3.48; I.C. 1.79 – 6.76). To the T. gondii infection, it was possible to see a significant association among the variables: age (OR=4.01; I.C. 2.03 – 7.94), property size (OR=0.48; I.C. 0.26 – 0.90), semi-intensive creation system (OR=3.17; I.C. 1.24 – 8.13), current water fount (OR=3.13; I.C. – 1.66 – 5.87), and the presence of cats (OR=1.72; I.C. 1.08 – 2.75). Based on the obtained results of the sero-epidemiologic inquiry, the conclusion is that the animals are exposed to the B. ovis, C. abortus e T. gondii infection with different epidemiological meanings in the studied population. Sanitary measures and works in health promotion should be encouraged aiming the prevention and control of the dissemination of these important agents in animal and public health.
Objetivou-se com este trabalho estudar aspectos de produção, higiênicosanitário e reprodutivo, além da epidemiologia de algumas doenças infecciosas bacterianas (brucelose e clamidofilose) e parasitária (toxoplasmose) envolvidas em distúrbios reprodutivos em ovinos no Estado de Alagoas. Foram estudadas 27 propriedades distribuídas em 23 municípios nas três mesorregiões do Estado de Alagoas. Para o estudo dos aspectos produtivos, higiênico-sanitário e reprodutivo, foram aplicados e analisados questionários investigativos, abordando perguntas objetivas relacionadas às propriedades. Para a pesquisa de anticorpos anti-Brucella abortus foram utilizadas as técnicas Antígeno Acidificado Tamponado, Antígeno Acidificado Tamponado Modificado e Reação da Fixação do Complemento. A concordância entre os testes utilizados no diagnóstico da infecção por Brucella abortus foi verificada utilizando-se o coeficiente Kappa. Para o estudo da infecção por Brucella ovis empregou-se a técnica de Imunodifusão em Gel de Agar. Para pesquisa de anticorpos anti-Chlamydophila abortus utilizou-se a técnica deReação da Fixação do Complemento com ponto de corte 1:32. O diagnóstico da infecção por Toxoplasma gondii foi realizado com base na técnica de Imunofluorescência Indireta considerado ponto de corte 1:64. Para o estudo dos fatores de risco associados às infecções por Clamydophila abortus e Toxoplasma gondii foram selecionadas variáveis relacionadas às características das propriedades, manejo higiênico-sanitário e distúrbios reprodutivos. A análise do perfil sócio-econômico e sanitário permitiu observar que o ovinocultor alagoano é um indivíduo com razoável grau de escolaridade, necessita de informações sobre práticas de manejo nutricional, reprodutivo e sanitário e ainda sofrem os efeitos da ocorrência de enfermidades infecto-contagiosas e parasitárias, destacando-se o aborto e outros distúrbios reprodutivos. A utilização das biotécnicas da reprodução ainda é insipiente, predominando a monta natural na maioria dos rebanhos estudados. Não foram observados animais positivos para B. abortus e a concordância entre os testes AAT, AATm frente a RFC foifraca (K = 0,00; 0,00). Das 279 amostras analisadas para B. ovis, observou-se que nove (3,2%) foram positivas e 270 (96,8%) negativas, distribuídas em seis rebanhos (37,5%) e em seis municípios (46,2%). Não foram observadas diferenças estatísticas significativas entre sexo, idade, região, tamanho da propriedade, sistema de criação, observou-se associação significativa para histórico de distúrbios reprodutivo(p<0,001). Os resultados referentes à infecção por C. abortus demonstraram que 59/274 (21,5%) animais forampositivos e 187 (68,3%) negativos, constatando-se 77,7% de focos da infecção. A única variável que apresentou associação significativa na análise multivariada foi a região (p<0,001; OR=3,48; I.C. 1,79 – 6,76). Para a infecção por T. gondii, observou-se prevalência geral de 32,9% e o número de focos de 100%. Na análise estatística multivariada, observou-se associação significativa para as variáveis: idade (OR=4,01; I.C. 2,03 – 7,94), tamanho da propriedade (OR=0,48; I.C. 0,26 – 0,90), sistema de criação semiintensivo (OR=3,17; I.C. 1,24 – 8,13), fonte de água corrente (OR=3,13; I.C. – 1,66 – 5,87) e presença de gatos (OR=1,72; I.C. 1,08 – 2,75). Com base nos resultados obtidos nos inquéritos soro-epidemiológicos, conclui-se que os animais estão expostos a infecção por B. ovis, C. abortus e T. gondii com significados epidemiológicos distintos na população estudada. Medidas sanitárias e trabalhos de promoção em saúde devem ser incentivados com objetivo de prevenir e controlar a disseminação destes agentes importantes na saúde animal e coletiva.
Books on the topic "Bacterial diseases – Diagnosis"
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Anaerobic infections: Diagnosis and management. New York: Informa Healthcare, 2008.
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Lelliott, R. A. Methods for the diagnosis of bacterial diseases of plants. Oxford [Oxfordshire]: Published on behalf of the British Society for Plant Pathology by Blackwell Scientific Publications, 1987.
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1957-, Cimolai Nevio, ed. Laboratory diagnosis of bacterial infections. New York: Marcel Dekker, 2001.
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B, Wentworth Berttina, ed. Diagnostic procedures for bacterial infections. 7th ed. Washington, DC: American Public Health Association, 1987.
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Molecular detection of human bacterial pathogens. Boca Raton, FL: Taylor & Francis/CRC Press, 2011.
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File, Thomas. Contemporary diagnosis and management of skin and soft-tissue infections. 3rd ed. Newtown, Pa: Handbooks in Health Care Co., 2009.
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M, Opal Steven, and Powderly William G, eds. Infectious diseases. 3rd ed. [Edinburgh]: Mosby/Elsevier, 2010.
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Narayanasamy, P. Microbial Plant Pathogens-Detection and Disease Diagnosis: Bacterial and Phytoplasmal Pathogens, Vol.2. Dordrecht: Springer Science+Business Media B.V., 2011.
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Zwet, Tom Van Der. Fire blight--its nature, prevention, and control: A practice guide to integrated disease management. [Washington, D.C.?]: U.S. Dept. of Agriculture, 1992.
Find full textBook chapters on the topic "Bacterial diseases – Diagnosis"
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Piot, Peter. "Bacterial Vaginosis." In Laboratory Diagnosis of Infectious Diseases, 94–99. New York, NY: Springer New York, 1988. http://dx.doi.org/10.1007/978-1-4612-3898-0_9.
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Mohapatra, Sarita, Arti Kapil, and Nancy Khardori. "Microbiological Diagnosis of Bacterial Diseases." In Bench to Bedside, 42–58. Boca Raton, FL : CRC Press/Taylor & Francis Group, 2017. |: CRC Press, 2018. http://dx.doi.org/10.1201/9781315156460-3.
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Finegold, Sydney M. "Anaerobic Bacterial Infections (Non-Spore-Forming)." In Laboratory Diagnosis of Infectious Diseases, 39–56. New York, NY: Springer New York, 1988. http://dx.doi.org/10.1007/978-1-4612-3898-0_5.
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Thind, B. S. "Diagnosis of Bacterial Diseases of Plants." In Phytopathogenic Bacteria and Plant Diseases, 23–35. Boca Raton : Taylor & Francis, 2020.: CRC Press, 2019. http://dx.doi.org/10.1201/9780429242786-3.
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Narayanasamy, P. "Diagnosis of Bacterial Diseases of Plants." In Microbial Plant Pathogens-Detection and Disease Diagnosis:, 233–46. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-9769-9_5.
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Sunnapu, Prasad, Shilpa Valiyaparambil, Muddukrishnaiah Kotakonda, Dhanapal Yogananthan, and Natarajan Ashokkumar. "Bacterial Disease of Rice." In Cereal Diseases: Nanobiotechnological Approaches for Diagnosis and Management, 17–29. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-3120-8_2.
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Sletten, A. "Diagnosis of Bacterial Infections by Immunological Methods." In Vascular Wilt Diseases of Plants, 107–11. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-73166-2_6.
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Thind, B. S. "Diagnosis and Management of Bacterial Plant Diseases." In Recent Advances in the Diagnosis and Management of Plant Diseases, 101–17. New Delhi: Springer India, 2015. http://dx.doi.org/10.1007/978-81-322-2571-3_10.
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Gül, Şule, Mehmet Atilla Uysal, and Derya Kocakaya. "Bacterial Pneumonia During Pregnancy." In ENT Diseases: Diagnosis and Treatment during Pregnancy and Lactation, 797–812. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-05303-0_61.
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Sambri, Vittorio. "The Laboratory Diagnosis of Bacterial Sexually Transmitted Diseases." In Sexually Transmitted Infections, 149–70. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-02200-6_7.
Full textConference papers on the topic "Bacterial diseases – Diagnosis"
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de Freitas, Laura M., Ana L. Blanco, and Carla R. Fontana. "Antimicrobial photodynamic therapy proved not to induce bacterial resistance (Conference Presentation)." In Photonic Diagnosis and Treatment of Infections and Inflammatory Diseases, edited by Tianhong Dai. SPIE, 2018. http://dx.doi.org/10.1117/12.2287268.
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Blaskovich, Mark A., Wanida Phetsang, M. Rhia Stone, Urszula Lapinska, Stefano Pagliara, Rajiv Bhalla, and Matthew A. Cooper. "Antibiotic-derived molecular probes for bacterial imaging." In Photonic Diagnosis, Monitoring, Prevention, and Treatment of Infections and Inflammatory Diseases 2019, edited by Tianhong Dai, Mei X. Wu, and Jürgen Popp. SPIE, 2019. http://dx.doi.org/10.1117/12.2507329.
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Leonard, Heidi, Liran Holtzman, Yuri Haimov, Sarel Halachmi, Ofer Nativ, Ester Segal, Yechezkel Kashi, and Daniel Weizman. "Unraveling bacterial networks and their antimicrobial susceptibility on silicon microarchitectures using intrinsic phase-shift spectroscopy." In Photonic Diagnosis and Treatment of Infections and Inflammatory Diseases, edited by Tianhong Dai. SPIE, 2018. http://dx.doi.org/10.1117/12.2287655.
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Ho, Chi-Sing, Neal Jean, Amr Saleh, Stefano Ermon, Niaz Banaei, and Jennifer A. Dionne. "Rapid bacterial identification based on surface-enhanced Raman scattering and machine learning (Conference Presentation) (Withdrawal Notice)." In Photonic Diagnosis and Treatment of Infections and Inflammatory Diseases, edited by Tianhong Dai. SPIE, 2018. http://dx.doi.org/10.1117/12.2291601.
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Bumah, Violet, Daniella Mason-Meyers, Dawn Castel, Chris Castel, and Chukuka Enwemeka. "Development of pulsed blue light technologies for bacterial biofilm disruption." In Photonic Diagnosis, Monitoring, Prevention, and Treatment of Infections and Inflammatory Diseases 2019, edited by Tianhong Dai, Mei X. Wu, and Jürgen Popp. SPIE, 2019. http://dx.doi.org/10.1117/12.2510699.
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Feng, Yanfang, Shoaib Ashraf, and Tayyaba Hasan. "Guide the control and treatment of carbapenem-resistant bacterial infections with FIBA." In Photonic Diagnosis, Monitoring, Prevention, and Treatment of Infections and Inflammatory Diseases 2022, edited by Tianhong Dai, Mei X. Wu, and Jürgen Popp. SPIE, 2022. http://dx.doi.org/10.1117/12.2607887.
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Meeker, Daniel G., Jingyi Chen, Tengjiao Wang, Samir V. Jenkins, Peter R. Panizzi, Ginell R. Post, Robert J. Griffin, and Mark S. Smeltzer. "Biodistribution and toxicity assessment of photoactivatable antibody-conjugated, antibiotic loaded gold nanocages for the treatment of bacterial infections (Conference Presentation)." In Photonic Diagnosis and Treatment of Infections and Inflammatory Diseases, edited by Tianhong Dai. SPIE, 2018. http://dx.doi.org/10.1117/12.2288471.
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Schafer, Mark, and Tessie McNeely. "Coincident light and non-focused ultrasound treatment significantly reduces bacterial biofilms (Conference Presentation)." In Photonic Diagnosis, Monitoring, Prevention, and Treatment of Infections and Inflammatory Diseases 2019, edited by Tianhong Dai, Mei X. Wu, and Jürgen Popp. SPIE, 2019. http://dx.doi.org/10.1117/12.2508738.
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Saiga, Marin, and Kazuhiko Misawa. "Linear and nonlinear effects on enhanced bacterial inactivation using a femtosecond pulsed laser." In Photonic Diagnosis, Monitoring, Prevention, and Treatment of Infections and Inflammatory Diseases 2022, edited by Tianhong Dai, Mei X. Wu, and Jürgen Popp. SPIE, 2022. http://dx.doi.org/10.1117/12.2609487.
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Cao, Tianyuan, Nydia Morales-Soto, Jin Jia, Nameera Baig, Sage Dunham, Joseph Ellis, Jonathan Sweedler, Joshua Shrout, and Paul W. Bohn. "Spatiotemporal dynamics of molecular messaging in bacterial co-cultures studied by multimodal chemical imaging." In Photonic Diagnosis, Monitoring, Prevention, and Treatment of Infections and Inflammatory Diseases 2019, edited by Tianhong Dai, Mei X. Wu, and Jürgen Popp. SPIE, 2019. http://dx.doi.org/10.1117/12.2501349.
Full textReports on the topic "Bacterial diseases – Diagnosis"
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Candrilli, Sean D., and Samantha Kurosky. The Response to and Cost of Meningococcal Disease Outbreaks in University Campus Settings: A Case Study in Oregon, United States. RTI Press, October 2019. http://dx.doi.org/10.3768/rtipress.2019.rr.0034.1910.
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Invasive meningococcal disease (IMD) is a contagious bacterial infection that can occur sporadically in healthy individuals. Symptoms are typically similar to other common diseases, which can result in delayed diagnosis and treatment until patients are critically ill. In the United States, IMD outbreaks are rare and unpredictable. During an outbreak, rapidly marshalling the personnel and monetary resources to respond is paramount to controlling disease spread. If a community lacks necessary resources for a quick and efficient outbreak response, the resulting economic cost can be overwhelming. We developed a conceptual framework of activities implemented by universities, health departments, and community partners when responding to university-based IMD outbreaks. Next, cost data collected from public sources and interviews were applied to the conceptual framework to estimate the economic cost, both direct and indirect, of a university-based IMD outbreak. We used data from two recent university outbreaks in Oregon as case studies. Findings indicate a university-based IMD outbreak response relies on coordination between health care providers/insurers, university staff, media, government, and volunteers, along with many other community members. The estimated economic cost was $12.3 million, inclusive of the cost of vaccines ($7.35 million). Much of the total cost was attributable to wrongful death and indirect costs (e.g., productivity loss resulting from death). Understanding the breadth of activities and the economic cost of such a response may inform budgeting for future outbreak preparedness and development of alternative strategies to prevent and/or control IMD.
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Splitter, Gary, and Menachem Banai. Microarray Analysis of Brucella melitensis Pathogenesis. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7709884.bard.
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Original Objectives 1. To determine the Brucella genes that lead to chronic macrophage infection. 2. To identify Brucella genes that contribute to infection. 3. To confirm the importance of Brucella genes in macrophages and placental cells by mutational analysis. Background Brucella spp. is a Gram-negative facultative intracellular bacterium that infects ruminants causing abortion or birth of severely debilitated animals. Brucellosis continues in Israel, caused by B. melitensis despite an intensive eradication campaign. Problems with the Rev1 vaccine emphasize the need for a greater understanding of Brucella pathogenesis that could improve vaccine designs. Virulent Brucella has developed a successful strategy for survival in its host and transmission to other hosts. To invade the host, virulent Brucella establishes an intracellular niche within macrophages avoiding macrophage killing, ensuring its long-term survival. Then, to exit the host, Brucella uses placenta where it replicates to high numbers resulting in abortion. Also, Brucella traffics to the mammary gland where it is secreted in milk. Missing from our understanding of brucellosis is the surprisingly lillie basic information detailing the mechanisms that permit bacterial persistence in infected macrophages (chronic infection) and dissemination to other animals from infected placental cells and milk (acute infection). Microarray analysis is a powerful approach to determine global gene expression in bacteria. The close genomic similarities of Brucella species and our recent comparative genomic studies of Brucella species using our B. melitensis microarray, suqqests that the data obtained from studying B. melitensis 16M would enable understanding the pathogenicity of other Brucella organisms, particularly the diverse B. melitensis variants that confound Brucella eradication in Israel. Conclusions Results from our BARD studies have identified previously unknown mechanisms of Brucella melitensis pathogenesis- i.e., response to blue light, quorum sensing, second messenger signaling by cyclic di-GMP, the importance of genomic island 2 for lipopolysaccharide in the outer bacterial membrane, and the role of a TIR domain containing protein that mimics a host intracellular signaling molecule. Each one of these pathogenic mechanisms offers major steps in our understanding of Brucella pathogenesis. Strikingly, our molecular results have correlated well to the pathognomonic profile of the disease. We have shown that infected cattle do not elicit antibodies to the organisms at the onset of infection, in correlation to the stealth pathogenesis shown by a molecular approach. Moreover, our field studies have shown that Brucella exploit this time frame to transmit in nature by synchronizing their life cycle to the gestation cycle of their host succumbing to abortion in the last trimester of pregnancy that spreads massive numbers of organisms in the environment. Knowing the bacterial mechanisms that contribute to the virulence of Brucella in its host has initiated the agricultural opportunities for developing new vaccines and diagnostic assays as well as improving control and eradication campaigns based on herd management and linking diagnosis to the pregnancy status of the animals. Scientific and Agricultural Implications Our BARD funded studies have revealed important Brucella virulence mechanisms of pathogenesis. Our publication in Science has identified a highly novel concept where Brucella utilizes blue light to increase its virulence similar to some plant bacterial pathogens. Further, our studies have revealed bacterial second messengers that regulate virulence, quorum sensing mechanisms permitting bacteria to evaluate their environment, and a genomic island that controls synthesis of its lipopolysaccharide surface. Discussions are ongoing with a vaccine company for application of this genomic island knowledge in a Brucella vaccine by the U.S. lab. Also, our new technology of bioengineering bioluminescent Brucella has resulted in a spin-off application for diagnosis of Brucella infected animals by the Israeli lab by prioritizing bacterial diagnosis over serological diagnosis.
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Ficht, Thomas, Gary Splitter, Menachem Banai, and Menachem Davidson. Characterization of B. Melinensis REV 1 Attenuated Mutants. United States Department of Agriculture, December 2000. http://dx.doi.org/10.32747/2000.7580667.bard.
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Brucella Mutagenesis (TAMU) The working hypothesis for this study was that survival of Brucella vaccines was directly related to their persistence in the host. This premise is based on previously published work detailing the survival of the currently employed vaccine strains S19 and Rev 1. The approach employed signature-tagged mutagenesis to construct mutants interrupted in individual genes, and the mouse model to identify mutants with attenuated virulence/survival. Intracellular survival in macrophages is the key to both reproductive disease in ruminants and reticuloendothelial disease observed in most other species. Therefore, the mouse model permitted selection of mutants of reduced intracellular survival that would limit their ability to cause reproductive disease in ruminants. Several classes of mutants were expected. Colonization/invasion requires gene products that enhance host-agent interaction or increase resistance to antibacterial activity in macrophages. The establishment of chronic infection requires gene products necessary for intracellular bacterial growth. Maintenance of chronic infection requires gene products that sustain a low-level metabolism during periods characterized little or no growth (1, 2). Of these mutants, the latter group was of greatest interest with regard to our originally stated premise. However, the results obtained do not necessarily support a simplistic model of vaccine efficacy, i.e., long-survival of vaccine strains provides better immunity. Our conclusion can only be that optimal vaccines will only be developed with a thorough understanding of host agent interaction, and will be preferable to the use of fortuitous isolates of unknown genetic background. Each mutant could be distinguished from among a group of mutants by PCR amplification of the signature tag (5). This approach permitted infection of mice with pools of different mutants (including the parental wild-type as a control) and identified 40 mutants with apparently defective survival characteristics that were tentatively assigned to three distinct classes or groups. Group I (n=13) contained organisms that exhibited reduced survival at two weeks post-infection. Organisms in this group were recovered at normal levels by eight weeks and were not studied further, since they may persist in the host. Group II (n=11) contained organisms that were reduced by 2 weeks post infection and remained at reduced levels at eight weeks post-infection. Group III (n=16) contained mutants that were normal at two weeks, but recovered at reduced levels at eight weeks. A subset of these mutants (n= 15) was confirmed to be attenuated in mixed infections (1:1) with the parental wild-type. One of these mutants was eliminated from consideration due to a reduced growth rate in vitro that may account for its apparent growth defect in the mouse model. Although the original plan involved construction of the mutant bank in B. melitensis Rev 1 the low transformability of this strain, prevented accumulation of the necessary number of mutants. In addition, the probability that Rev 1 already carries one genetic defect increases the likelihood that a second defect will severely compromise the survival of this organism. Once key genes have been identified, it is relatively easy to prepare the appropriate genetic constructs (knockouts) lacking these genes in B. melitensis Rev 1 or any other genetic background. The construction of "designer" vaccines is expected to improve immune protection resulting from minor sequence variation corresponding to geographically distinct isolates or to design vaccines for use in specific hosts. A.2 Mouse Model of Brucella Infection (UWISC) Interferon regulatory factor-1-deficient (IRF-1-/- mice have diverse immunodeficient phenotypes that are necessary for conferring proper immune protection to intracellular bacterial infection, such as a 90% reduction of CD8+ T cells, functionally impaired NK cells, as well as a deficiency in iNOS and IL-12p40 induction. Interestingly, IRF-1-/- mice infected with diverse Brucella abortus strains reacted differently in a death and survival manner depending on the dose of injection and the level of virulence. Notably, 50% of IRF-1-/- mice intraperitoneally infected with a sublethal dose in C57BL/6 mice, i.e., 5 x 105 CFU of virulent S2308 or the attenuated vaccine S19, died at 10 and 20 days post-infection, respectively. Interestingly, the same dose of RB51, an attenuated new vaccine strain, did not induce the death of IRF-1-/- mice for the 4 weeks of infection. IRF-1-/- mice infected with four more other genetically manipulated S2308 mutants at 5 x 105 CFU also reacted in a death or survival manner depending on the level of virulence. Splenic CFU from C57BL/6 mice infected with 5 x 105 CFU of S2308, S19, or RB51, as well as four different S2308 mutants supports the finding that reduced virulence correlates with survival Of IRF-1-/- mice. Therefore, these results suggest that IRF-1 regulation of multi-gene transcription plays a crucial role in controlling B. abortus infection, and IRF-1 mice could be used as an animal model to determine the degree of B. abortus virulence by examining death or survival. A3 Diagnostic Tests for Detection of B. melitensis Rev 1 (Kimron) In this project we developed an effective PCR tool that can distinguish between Rev1 field isolates and B. melitensis virulent field strains. This has allowed, for the first time, to monitor epidemiological outbreaks of Rev1 infection in vaccinated flocks and to clearly demonstrate horizontal transfer of the strain from vaccinated ewes to unvaccinated ones. Moreover, two human isolates were characterized as Rev1 isolates implying the risk of use of improperly controlled lots of the vaccine in the national campaign. Since atypical B. melitensis biotype 1 strains have been characterized in Israel, the PCR technique has unequivocally demonstrated that strain Rev1 has not diverted into a virulent mutant. In addition, we could demonstrate that very likely a new prototype biotype 1 strain has evolved in the Middle East compared to the classical strain 16M. All the Israeli field strains have been shown to differ from strain 16M in the PstI digestion profile of the omp2a gene sequence suggesting that the local strains were possibly developed as a separate branch of B. melitensis. Should this be confirmed these data suggest that the Rev1 vaccine may not be an optimal vaccine strain for the Israeli flocks as it shares the same omp2 PstI digestion profile as strain 16M.