Relevant bibliographies by topics / Pathogenic Organisms

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Pathogenic Organisms'

Author: Grafiati
Published: 4 June 2021
Last updated: 6 September 2023

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Journal articles on the topic "Pathogenic Organisms"

1

Pougnet, L., I. Allio, and R. Pougnet. "Pathogenic organisms in seawater." Archives des Maladies Professionnelles et de l'Environnement 74, no. 5 (November 2013): 566. http://dx.doi.org/10.1016/j.admp.2013.07.143.

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Navrátilová, P. "Pathogenic micro-organisms in waste waters from daiies." Czech Journal of Food Sciences 18, No. 5 (January 1, 2000): 170–74. http://dx.doi.org/10.17221/8338-cjfs.

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Waste waters from dairies were tested for the presence of bacterial pathogens – Listeria monocytogenes, Staphylococcus aureus and Salmonella spp. The prevalence of bacteria was investigated in each stage of the cleaning process (activated sludges systems) too. Two hunder samples of raw waste water, activated sludge, returned activated sludge, excess sludge and treated water from 14 dairies were tested. The samples were all negative for Salmonella spp. From a total of 102 (51%) strains Listeria spp., Listeria inoccua 95 (47.5%) and Listeria monocytogenes 7 (3.5%) were identified. 47 samples were positive for S. aureus. L. monocytogenes were detected in raw waste water 1 (1.6%), in activated sludge 3 (5.5%), in excess sludge 1 and in treated water 2 (3.1%). S. aureus were detected in raw waste water 14 (22.6%), in activated sludge 23 (41.8%), in excess sludge 1 and in treated water 8 (12.3%). These results demonstrate a prevalence of L. monocytogenes and S. aureus in waste waters from dairies. During the cleaning process pathogenic bacteria were not devitalized. The excess sludge and treated water including pathogenic micro-organisms represent a potential health hazard.
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Schuster, George S. "ORAL FLORA AND PATHOGENIC ORGANISMS." Infectious Disease Clinics of North America 13, no. 4 (December 1999): 757–74. http://dx.doi.org/10.1016/s0891-5520(05)70107-0.

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4

Tian, Deqiao. "Bibliometric analysis of pathogenic organisms." Biosafety and Health 2, no. 2 (June 2020): 95–103. http://dx.doi.org/10.1016/j.bsheal.2020.05.004.

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Dalas, Israa Salman, and Muqdad Altae. "Pathogenic organisms in sewage: a review." Science Archives 02, no. 03 (2021): 258–66. http://dx.doi.org/10.47587/sa.2021.2318.

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Northcutt, Alan D., and Jaime A. Tschen. "New ways to demonstrate pathogenic organisms." Clinics in Dermatology 9, no. 2 (April 1991): 205–15. http://dx.doi.org/10.1016/0738-081x(91)90010-i.

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7

Chambers, James P., and James J. Valdes. "Biosensors for detection of pathogenic organisms." Journal of Biotechnology 136 (October 2008): S760. http://dx.doi.org/10.1016/j.jbiotec.2008.07.1645.

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8

Fishelson, Zvi. "Complement-related proteins in pathogenic organisms." Springer Seminars in Immunopathology 15, no. 4 (December 1994): 345–68. http://dx.doi.org/10.1007/bf01837365.

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9

Mistry, Richa, and Gaurav Shah. "Study of Inhibitory Effect of Honey on Various Pathogenic and Non-Pathogenic Microorganisms." International Journal of Applied Sciences and Biotechnology 1, no. 4 (December 21, 2013): 279–81. http://dx.doi.org/10.3126/ijasbt.v1i4.9179.

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Honey is a sweet food made by bees using nectar from flowers. The variety produced by honey bees (the genus Apis). The purpose of the present study was to determine in vitro antibacterial activities of different honey against various pathogenic and non-pathogenic organisms. Antibacterial activity of honey was determine by using well diffusion method in which different concentrations (20, 40, 60, 80, & 100 % v/v) of honey were used against various test pathogen. These organisms also tested against artificial honey for study of effect of sugar on its antibacterial activity. The results of these study was shown that wide range of variation in Zone of Inhibition (mm) of each type of honey and only very few organism inhibited due to effect of sugar. That shows there are also other components other than the sugar present in honey which ultimately responsible for antimicrobial activity. Due to obtaining maximum level of antibacterial activity of each honey it allow further investigation for treatment various infection and in curing of disease.DOI: http://dx.doi.org/10.3126/ijasbt.v1i4.9179 Int J Appl Sci Biotechnol, Vol. 1(4): 279-281
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MORVAN, G. "PATHOGENIC ORGANISMS AS CAUSES OF APRICOT DECLINE." Acta Horticulturae, no. 384 (December 1995): 521–32. http://dx.doi.org/10.17660/actahortic.1995.384.82.

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Dissertations / Theses on the topic "Pathogenic Organisms"

1

Lamb, Kelsey Ellen. "THE SURVIVAL OF VARIOUS PATHOGENIC ORGANISMS IN FATS AND OILS." UKnowledge, 2017. http://uknowledge.uky.edu/animalsci_etds/72.

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The research within this thesis sought to determine the ability of various animal derived fats and plant derived oils to support the survival of several pathogenic cocktails over a multitude of storage times. The Salmonella study explored the survival rate of a four strain Salmonella cocktail in beef tallow, pig lard, duck fat, coconut oil, and extra virgin olive oil over seven days at 26˚C and 37˚C storage. The animal fats and the coconut oil supported the survival of the bacteria until the conclusion of the study. The Shiga-toxin producing Escherichia coli study explored the survival rate of a five strain STECs cocktail in extra virgin olive oil over seven days at 26˚C and 37˚C storage. The two Listeria studies explored the survival rate of a four strain Listeria monocytogenes cocktail in extra virgin olive oil over several time periods with different frequencies of sample mixing. In vitro, all genuses showed a 2.5-log cfu/mL to ≥ 7-log cfu/mL reduction in the extra virgin olive oil by the conclusion of the experiments. Extra virgin olive oil was then applied to cooked pork tenderloin, cheddar cheese snack squares, and turkey lunchmeat in hopes of inhibiting the L. monocytogenes cocktail. No reduction was observed.
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Assenberg, Rene. "Studies on three-way DNA junctions related to the development of a novel method for the detection of genetic polymorphisms." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342647.

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Smit, Nellie Jacoba. "A qualitative study of selected micro-organisms in geophagic soil from Qwa-Qwa." Thesis, Bloemfontein : Central University of Technology, Free State, 2011. http://hdl.handle.net/11462/165.

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Thesis (M. Tech.(Biomedical Technology)) - Central University of technology, Free State, 2011
The existence of geophagia from as early as 460 BC up to now, makes it relevant to investigate all aspects related to geophagia. Geophagia is a direct route for potential transmission of pathogens to the human host, through the ingestion of soil. Soil-borne diseases in humans are causing growing concern as sewage disposal, which involve sewage sludge and waste water drainage from these plants, is on the increase. It is estimated that approximately seven million tons of sewage sludge is produced annually and that 54% of this sewage sludge is introduced into soil. Data on enteric infection in humans caused by contamination from soil is limited and need further investigation. The aim of the study was, therefore, to collect information on the microbiological presence in geophagic soil in the Qwa-Qwa district. Objectives included the collecting of information regarding various sampling sites in the Qwa-Qwa district and also soil samples sold by vendors, investigation of the prevalence of known human pathogenic bacteria and fungi in geophagic soil, investigating the culturability of Salmonella enteritidis in geophagic soil in comparison with the viability of these organisms in soil for long periods of time, investigating potential antimicrobial activity of geophagic soil, as some of the geophagists are convinced that the geophagic soils have medicinal properties, and to determine the microbial diversity of geophagic soils, which can not be accomplished by conventional microbial culturing methods.
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Bonilla, Tonya Davidian. "Fecal Indicator Organisms and Pathogenic Protozoa in South Florida Beach Sand: Implications for Public Health." NSUWorks, 2004. http://nsuworks.nova.edu/occ_stuetd/287.

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Traditionally, the hygienic quality of beaches has been determined by monitoring the water for microbial indicators of fecal pollution. Beach sand, which may also be an important medium for the transmission of fecal borne pathogens, has rarely been examined. The aims of this study where to examine the prevalence of fecal indicator organisms in tidally affected beach sand and in dryer upper beach sand, relative to water; identify the potential sources of indicator organisms in beach sand; examine the prevalence of selected eukaryotic microbes at sandy beaches; and investigate the potential health risks related to beach use. Three south Florida Beaches (Ft. Lauderdale Beach, Hollywood Beach, Hobe Beach) were sampled bimonthly for a I year period. Significantly, enterococci, fecal coliform, and E. coli levels were consistently present at higher concentrations in beach sand compared to the seawater at all 3 study beaches. Levels of somatic and F-specific coliphages were also present at higher concentrations in beach sand. Microbial- source tracking analysis by carbon utilization profiling suggested that the predominate sources of enterococci in beach sand were seagulls, and transiently replicating indigenous populations. Acanthamoeba spp. was the most commonly isolated free-living naked amoeba in this study and molecular analysis revealed that 19 of the 20 beach sand clones were genotype T4, the Acanthamoeba keratitis-associated genotype. With respect to salinity, the growth characteristics of beach sand Acanthamoeba isolates were similar to Acanthamoeba isolated from corneal scrapings. Results from the beach survey indicated that beach goers may have an increased risk for acquiring contact related ailments at Hobe Beach. Accordingly, bacterial and viral fecal indicator microbes were detected at the highest frequency and greatest average concentrations from Robe Beach. Reports of enteric and respiratory related symptoms were not higher in beach goers compared to the control cohort.
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Keesenberg, Willeke. "Food safety and quality throughout the apple export chain." Diss., University of Pretoria, 2006. http://hdl.handle.net/2263/26307.

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One of the factors that maintains fruit quality is its microbial flora. Fruit holds a natural non-pathogenic epiphytic microflora but can become contaminated with pathogenic microorganisms during export, causing either postharvest decay or possibly resulting in a food safety risk. In order to study microbial dynamics on fruit surfaces and the environment fruit moves through in the export chain, fruit washings were made, surfaces were sampled and total populations and diversities determined per cm2. Hygiene and safety levels for fruit export environments were hereby determined by sampling various points along the apple export chain, which included two farms and a harbour in South Africa and two harbours, two repacking facilities and two retail centres in Europe. In this first study of its kind, all the surfaces that were sampled exceeded the international standard for cleaning efficacy of food-processing equipment that is <5 cfu/cm2, while several areas exceeded the maximum acceptable index level of microbial air contamination of 22 cfu/h in food industries. Washing of containers on a harbour in South Africa did not have a significant impact on microbial populations. Regarding fruit quality, it was determined that apple microflora fluctuate throughout the export process and that postharvest pathogens that are known to cause great economic losses in the apple industry, proved to be of little significance in this investigation. The presence of six foodborne pathogens i.e. Shigella sonnei, Salmonella muenchen, Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Staphylococcus epidermidi/s was monitored throughout the chain. Of these, only S. aureus and E. coli were recorded, although pathogenicity was not confirmed for the latter. Staphylococcus aureus was found in containers and at a retail centre in Europe, and S. aureus and S. epidermidis were recorded on apple surfaces for the first time. Escherichia coli was present in great numbers in fruit washing water on a farm in South Africa. Since the standard for food premises is very stringent and perhaps inapplicable for fresh fruit handling and holding facilities, future research should include development of a more realistic hygiene standard for fresh fruit environments.
Dissertation (MSc(Agric) : Plant Pathology)--University of Pretoria, 2006.
Microbiology and Plant Pathology
unrestricted
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6

Shaib, Houssam. "Impact of avian influenza-H9N2 passaging in avian and mammalian organisms on its pathogenic adaptability and genetic mutations." Compiègne, 2011. http://www.theses.fr/2011COMP1979.

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Trois études ont été réalisées sur l’adaptation d'une souche aviaire H9N2 de faible pouvoir pathogène sur trois modèles différents : embryons de poulet, poulet de chair puis hamster. La première visait à évaluer l'influence du passage embryonnaire du virus H9N2 sur la stabilité de la séquence d'acides aminés de l'Hémagglutinine 1 (HA1) et sa relation avec la pathogénicité. Elle a montré une augmentation significative de la pathogénicité du virus suite au passage embryonnaire, malgré la présence du même motif au site de clivage. La deuxième partie du travail a consisté à évaluer l'effet de trois passages consécutifs du virus H9N2 chez les poulets de chair sur sa pathogénicité et les variations moléculaires qui en sont responsables. Nous avons montré qu'un passage d'H9N2 faiblement pathogène dans les poulets de chair provoque une augmentation de la pathogénicité, associée à une stabilité de la séquence d'acides aminés de l'Hémagglutinine au site de clivage, et une variabilité dans la séquence de la tige de la neuraminidase. Le risque d'évolution d'une souche peu pathogène vers une souche hautement pathogène a été démontré. La troisième étude, menée sur des hamsters, a mis en évidence l'adaptation de la pathogénicité lors du franchissement de la barrière inter-espèces et a signalé le risque potentiel de maladies zoonotiques dans certains élevages
Three studies were carried out for studying the adaptation of avian H9N2 virus after embryonic, broilers or hamster passaging. The first study have shown that the pathogenicity increased significantly upon passaging in chicken embryos in spite of the presence of the same motif at the HA1 cleavage site. The second study assessed the impact of H9N2 viral passaging in broilers on amino acid sequences of the hemagglutin cleavage site and neuraminidase stalk, and their relatedness to pathogenicity. In that case, we observed that passaging leads to a trand of increase in pathogenic adaptability, associated with a conserved a. A. Sequence of the hemagglutinin cleavage site, and a variability in the sequence of the neuraminidase stalk. The third study demonstrates the impact of avian-H9N2 viral passaging in hamsters on its cross species-pathogenic adaptability, and variability of amino acid sequences of the hemagglutinin and neuraminidase stalk of the original and the differently passaged H9N2 viruses. The adaptation of avian virus to mammalian cells raise a concern of a possible public health threat since the mixing of avian with mammalian animal species is a common practise on farms and petshops of most developing countries
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Kepekci, Aysun Remziye. "Antifungal Spectrum Determination Of The K5 Type Yeast Killer Protein On Fungi Causing Spoilage In Citrus Fruits." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/12607858/index.pdf.

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Some yeast strains under certain conditions secrete polypeptide toxins which are inhibitory to sensitive fungal cells into the medium. These yeast strains are termed as killer yeasts and their toxins are designated as killer proteins or killer toxins. Killer proteins are classified into 11 typical types (K1-K11). These toxins have different killing mechanisms on sensitive cells. Some of them hydrolyze major cell wall component, beta-1,3- glucans. As mammalian cells lack cell walls research and development of novel highly selective antifungals are mostly focused on the agents which target the components of the fungal cell wall. K5 type killer protein was characterized in our labarotory previously. This protein is an exo beta-1,3-glucanase which is stable at pH&
#8217
s and temperatures appropriate for its biocontrol usage. Beta-1,3-glucan hydrolyzing activity of the K5 type killer protein highlighted the potential use of this protein as a selective antifungal agent. According to CLSI methodology, antifungal activity of the K5 type yeast killer protein was tested against 6 fungal strains causing postharvest spoilage in citrus fruits and found to be effective on Botrytis cinerea, Penicillium digitatum, Penicillium italicum whereas non effective on Colletotrichum gloeosporoides, Phythophythora citrophthora, Alternaria citri. The MIC values of the toxin for B.cinerea, P.digitatum, P.italicum were found to be 16 mikrogram/ml while IC 50 values of the toxin were 2.12, 3.31, 2.57 mikrogram/ml respectively. The results showed that K5 type yeast killer protein would be used as a novel and selective agent against B.cinerea, P.digitatum and P.italicum.
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Avsaroglu, M. Dilek. "Isolation, Molecular Characterization Of Food-borne Drug Resistant Salmonella Spp. And Detection Of Class 1 Integrons." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608844/index.pdf.

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In this study, 59 epidemiologically unrelated Salmonella strains isolated from foods in Tü
rkiye and 49 Salmonella strains obtained from National Salmonella Reference Laboratories of Germany were analysed. For the characterization of strains, analyses such as serotyping, phage typing, antibiotyping and molecular biological characterization were done. The strains exhibited 17 different serotypes with S. Enteritidis serotype and PT21 phage type being the most prevalent in Turkish isolates. The highest antimicrobial resistance was observed against NAL for Turkish strains, whereas it was against SUL for strains from German origin. Molecular typing of all strains exhibited different plasmid profiles and PFGE patterns. There were 1-4 plasmids/profile for Turkish strains and 1-7 plasmids/profile for German strains. The PFGE patterns revealed 42 different subgroups, having two major clusters with 44,3% arbitrary homology. Among 72 resistant strains, the most prevalent resistance genotypes were observed as blatem-1 (%56, AMP resistance)
floR (%100, CHL and FFC resistance)
aphA1 (%100, KAN and NEO resistance)
tet(A) (%53, TET resistance)
aadA1 (%82, SPE and STR resistance)
sulI (%78, SUL resistance). The class I integron variable region analyses exhibited 700 bp (1 strain), 1000 bp (37 strain), 1200 bp (16 strain) and 1600 bp (3 strain) integrons.
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Davutluoglu, Ayten. "Detection Of Helminth Eggs And Protozoan Cysts In Wastewaters." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605921/index.pdf.

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The withdrawal of water sources concluded the reuse of treated wastewaters, especially for non-potable purposes. Agricultural use of the reclaimed wastewaters is one of the reuse options. However health considerations of the reuse of reclaimed wastewaters for public related purposes are underestimated, since wastewaters contain a variety of microbial pathogens, which may be transmitted to workers and consumers through the crops irrigated. Of these, parasitic eggs have a special place, as they are capable of surviving in the soil for months or even years, depending on environmental conditions. There is insufficient accumulated information on the health related criteria for the reuse of treated wastewaters in Turkey. The aim of this study was therefore to determine the helminthic eggs in raw sewage and in effluents of ASKi municipal wastewater treatment plant in Ankara. The study involved examining to decide whether these organisms exist in the wastewaters at all, and if so in what concentrations. Modified Bailenger&rsquo
s method, which published in the &ldquo
WHO Laboratory Manual of Parasitological and Bacteriological Techniques&rdquo
and &ldquo
U.S.EPA ICR Microbial Laboratory Manual&rdquo
were used in developing the specific methods used in this study.
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Gokduman, Kurtulus. "The Development Of Molecular Genetic Tools For Detection Of Salmonella Pathogen." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614501/index.pdf.

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Although traditional microbiological methods are accepted standard for Salmonella detection, they are labor intensive and time consuming. Therefore, for food industry and public health, finding sensitive and rapid methods is required. As a rapid and reliable tool, Real-Time PCR is one of the most common methods in molecular detection and research area. The aim of the current study is to develop rapid, sensitive and quantitative Salmonella detection method using Real-Time PCR technique based on inexpensive, easy to produce, convenient and standardized plasmid based positive control for the first time. To achieve this, two plasmids were constructed as reference molecules by cloning two most commonly used Salmonella specific target regions &lsquo
invA and ttrRSBC&rsquo
into them. Standard curves were constructed for the plasmids and reproducibility, PCR efficiency, amplification efficiency values were calculated. To illustrate the applicability of the developed method, enriched (as used commonly for Salmonella detection with Real-Time PCR) 105 to 100 CFU/ml level (estimated by standard plate counts before enrichment) S. Typhimurium ATCC 14028 cultures were tried to detect and quantify, also compared with traditional culture method. In addition, detection limits of the developed technique were determined by serial dilution of DNA extracted from 105 CFU/ml level. The results revealed much faster detection ability of the developed plasmid based Salmonella detection method (in comparison to traditional culture method, ISO 6579:2004) allowing quantitative evaluation with perfect reproducibility, sensitivity (except for lower concentrations for invA target), detection limit, PCR efficiency, amplification efficiency for both invA and ttrRSBC targets. The detection and quantification ability of the method developed by using S. Typhimurium ATCC 14028 cultures were tested also with 15 Salmonella species using milk as a representative food. The results also revealed much faster (in comparison to traditional culture method, ISO 6579:2004) quantitative detection ability of the developed method. Thus, the developed method has great potential to be used in food industry for rapid and quantitative Salmonella detection.
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Books on the topic "Pathogenic Organisms"

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Robinson, Mark W., and John P. Dalton, eds. Cysteine Proteases of Pathogenic Organisms. Boston, MA: Springer US, 2011. http://dx.doi.org/10.1007/978-1-4419-8414-2.

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Cysteine proteases of pathogenic organisms. New York: Springer Science+Business Media, 2011.

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Yeasts and yeast-like organisms. Weinheim, Federal Republic of Germany: VCH, 1990.

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Smith, Mary M. Genus and species of pathogenic organisms: A spelling guide to medical binomial terminology. Jefferson, N.C: McFarland, 1991.

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H, Collins C., and Grange John M, eds. Isolation and identification of micro-organisms of medical and veterinary importance. London: Academic Press, 1985.

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U.S.-Japan Meeting on Aquaculture (29th 2000 Ise, Mie, Japan). Pathogenic organisms and disease prevention: Proceedings of the twenty-ninth U.S.-Japan Meeting on Aquaculture, Ise, Mie, Japan, November 7 and 8, 2000. [Mie, Japan]: National Research Institute of Aquaculture (NRIA) and Fisheries Agency, 2001.

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M, Smulders Frans J., ed. Elimination of pathogenic organisms from meat and poultry: Proceedings of the International Symposium : Prevention of Contamination, and Decontamination in the Meat Industry, Zeist, The Netherlands, 2-4 June 1986. Amsterdam: Elsevier, 1987.

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Association, American Water Works, ed. Waterborne pathogens. 2nd ed. Denver, CO: American Water Works Association, 2006.

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Campbell, R. E. Biological control of microbial plant pathogens. Cambridge: Cambridge University Press, 1989.

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Molecular detection of human bacterial pathogens. Boca Raton, FL: Taylor & Francis/CRC Press, 2011.

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Book chapters on the topic "Pathogenic Organisms"

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An Chen, Tseh. "Serology of Mycoplasma-Like Organisms." In Plant Pathogenic Bacteria, 301–5. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3555-6_64.

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Liao, Zhen, Kristian Persson Hodén, and Christina Dixelius. "Small talk and large impact: the importance of small RNA molecules in the fight against plant diseases." In RNAi for plant improvement and protection, 86–93. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789248890.0009.

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Abstract This short and general chapter summarizes how plants and pathogens communicate using not only proteins for recognition and signal transduction or other metabolites but also RNA molecules where small RNAs with sizes between 21 to 40 nt are most important. These small RNAs can move between plants and a range of interacting pathogenic organisms in both directions, that is, a 'cross-kingdom' communication process. The first reports on RNA-based communications between plants and plant pathogenic fungi appeared about 10 years ago. Since that time, we have learnt much about sRNA biology in plants and their function in different parasitic organisms. However, many questions on the processes involved remain unanswered. Such information is crucial in order to sustain high crop production. Besides giving a brief background, we highlight the interactions between the potato late blight pathogen and its plant host potato.
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Liao, Zhen, Kristian Persson Hodén, and Christina Dixelius. "Small talk and large impact: the importance of small RNA molecules in the fight against plant diseases." In RNAi for plant improvement and protection, 86–93. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789248890.0086.

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Abstract This short and general chapter summarizes how plants and pathogens communicate using not only proteins for recognition and signal transduction or other metabolites but also RNA molecules where small RNAs with sizes between 21 to 40 nt are most important. These small RNAs can move between plants and a range of interacting pathogenic organisms in both directions, that is, a 'cross-kingdom' communication process. The first reports on RNA-based communications between plants and plant pathogenic fungi appeared about 10 years ago. Since that time, we have learnt much about sRNA biology in plants and their function in different parasitic organisms. However, many questions on the processes involved remain unanswered. Such information is crucial in order to sustain high crop production. Besides giving a brief background, we highlight the interactions between the potato late blight pathogen and its plant host potato.
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Jiang, Y. P., and T. A. Chen. "Purification of Mycoplasma-Like Organisms from Lettuce Affected with Aster Yellows Agent." In Plant Pathogenic Bacteria, 375. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3555-6_76.

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Kirkpatrick, B. C., D. C. Stenger, T. J. Morris, and A. H. Purcell. "Detection of X-Disease Mycoplasma-Like Organisms in Plant and Insect Hosts Using Cloned, Disease Specific DNA." In Plant Pathogenic Bacteria, 982. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3555-6_211.

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Laver, Nora V., and Charles S. Specht. "Pathogenic Properties of Infectious Organisms and Tissue Reactions." In The Infected Eye, 13–35. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-42840-6_2.

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Urdea, M. S. "Controlled Synthetic Oligonucleotide Networks for the Detection of Pathogenic Organisms." In Rapid Methods and Automation in Microbiology and Immunology, 1–5. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-76603-9_1.

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Sharma, Indu, Sagolsem Yaiphathoi, and Parijat Hazarika. "Pathogenic Escherichia coli: Virulence Factors and Their Antimicrobial Resistance." In Model Organisms for Microbial Pathogenesis, Biofilm Formation and Antimicrobial Drug Discovery, 159–73. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-1695-5_10.

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St Arnaud, Marc, and Annemie Elsen. "Interaction of Arbuscular Mycorrhizal Fungi with Soil-Borne Pathogens and Non-Pathogenic Rhizosphere Micro-Organisms." In Soil Biology, 217–31. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/3-540-27331-x_12.

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Sanchez-Trincado, Jose L., and Pedro A. Reche. "Generation of Variability-Free Reference Proteomes from Pathogenic Organisms for Epitope-Vaccine Design." In Methods in Molecular Biology, 255–63. New York, NY: Springer US, 2020. http://dx.doi.org/10.1007/978-1-0716-0389-5_13.

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Conference papers on the topic "Pathogenic Organisms"

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Sinha, S., T. Stander, and J. du Preez. "Inactivating pathogenic micro-organisms through microwave sterilization technology." In 2013 International Symposium on Electrodynamic and Mechatronic Systems (SELM). IEEE, 2013. http://dx.doi.org/10.1109/selm.2013.6562981.

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Wallace, William H., Michael V. Henley, and Gary S. Sayler. "Detection of pathogenic organisms in food, water, and body fluids." In AeroSense 2002, edited by Patrick J. Gardner. SPIE, 2002. http://dx.doi.org/10.1117/12.472259.

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Bastola, Dhundy R., Scott McGrath, Sanjukta Bhowmick, and Ishwor Thapa. "A Comparison of Computational Approaches in the Molecular Identification of Pathogenic Organisms." In 2012 IEEE Second International Conference on Healthcare Informatics, Imaging and Systems Biology (HISB). IEEE, 2012. http://dx.doi.org/10.1109/hisb.2012.23.

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Masychev, Viktor I., and Olga N. Risovannaya. "The effect of selective photosuppression of sensitized pathogenic microflora: Part I. Influence on pathogenic organisms causing pyoinflammatory processes in oral cavity." In Biomedical Optics 2005, edited by Peter Rechmann and Daniel Fried. SPIE, 2005. http://dx.doi.org/10.1117/12.588988.

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Crucean, Stefan. "Principalii dăunători ale culturii nucifere din clasa Arachnida și manifestarea efectelor negative ale acestora." In International Scientific Symposium "Plant Protection – Achievements and Prospects". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2020. http://dx.doi.org/10.53040/9789975347204.04.

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This material results from the research of the nut culture in order to identify pathogenic organisms of the class Arachnida and to represent the effects of these organisms on tree organs. The research was made at the Botanical Garden Institute, Chișinău on a number of 300 trees. This paper includes the identification of the main pests of the class Arachnida, namely: the gall mite of walnut leaves (Aceria tristriata) and the disease named walnut blister mine caused by Aceria erinea. At the same time, the methods of pest control and the negative effects of their presence are exposed here.
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Xu, Xiaohong, Chundu Wu, and Degang Ning. "Detection Analysis of Pathogenic Organisms in Municipal Sewage with PCR-Based 16S rDNA Technique." In 2010 4th International Conference on Bioinformatics and Biomedical Engineering (iCBBE 2010). IEEE, 2010. http://dx.doi.org/10.1109/icbbe.2010.5518027.

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Sinha, Ashok, Ranjan Ganguly, and Ishwar K. Puri. "Immunomagnetic Separation in Microchannels: From MEMS to BioNEMS." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81569.

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Conventional methods of monitoring and testing water quality involve collection of the sample to be tested and its subsequent analysis in a research laboratory for which some procedures may not be feasible or even accessible under certain field situations. Therefore, next generation sensors are required. Herein, an innovative concept that combines a micromixer and microparticle trap is proposed that should enable more rapid pathogen detection in contaminated water. In it, immunomagnetic separation (a procedure [1,2] that is well practiced in the field of immunochemistry) is scaled down from the benchtop to the microscale. Our design is generic, i.e., design is not limited to the detection of waterborne biological agents, but can be used for other forms of chemical analysis. Testing for waterborne bacteria requires analysis methods that must meet a number of challenging criteria. Time and sensitivity of analysis are the more important limitations. Bacterial detection methods have to be rapid and very sensitive since the presence of even a small pathogenic sample may sometimes constitute an infectious or otherwise harmful dose. Selective detection is also required because small numbers of pathogenic bacteria are often present in a complex biological environment along with many other nonpathogenic organisms. As an example, the infectious dosage of a pathogen such as E. coli O157:H7 or Salmonella is as low as 10 cells and the existing coliform standard for E. coli in water is 4 cells: 100 ml [3].
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Dolgov, V. V. "The influence of phytophages insects on the distribution and development of major sunflower diseases." In Растениеводство и луговодство. Тимирязевская сельскохозяйственная академия, 2020. http://dx.doi.org/10.26897/978-5-9675-1762-4-2020-99.

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The increase in demand for oilseeds in the Russian Federation has led to the problem of oversaturation of crop rotations with sunflower. Currently, the tendency to expand the sown areas of culture continues. In combination with the changed weather and climatic conditions, this leads to a change in the species composition of insects and pathogens of sunflower diseases, which provokes a deterioration in the phytosanitary state of the agrocenosis of the crop. The harm caused by insects can be not only direct, but also indirect - pathogenic organisms penetrate through the damage left by insects. Sunflower plants damaged by phytophagous insects are more often affected by diseases, viruses and phytoplasmas, which leads to a decrease in yield. Therefore, the study of the influence of phytophagous insects on the spread and development of the main diseases of sunflower is relevant.
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Ovchinnikov, Ilya S., Valery V. Tuchin, Krill I. Ivanov, and Vladimir A. Titorenko. "Preclinical and clinical studies of photodynamic action on some pathogenic micro-organisms of the oral cavity." In International Symposium on Photonics and Applications, edited by Arthur E. T. Chiou, Halina Podbielska, and Steven L. Jacques. SPIE, 2001. http://dx.doi.org/10.1117/12.446644.

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van der Zee, H., B. Wit, and E. de Boer. "Pathogenic bacteria and indicator organisms for anti-microbial resistance in pork meat at retail level in The Netherlands." In Second International Symposium on Epidemiology and Control of Salmonella in Pork. Iowa State University, Digital Press, 2003. http://dx.doi.org/10.31274/safepork-180809-474.

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Reports on the topic "Pathogenic Organisms"

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Bercovier, Herve, and Paul Frelier. Pathogenic Streptococcus in Tilapia: Rapid Diagnosis, Epidemiology and Pathophysiology. United States Department of Agriculture, October 1994. http://dx.doi.org/10.32747/1994.7568776.bard.

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Within the project "Pathogenic Streptococcus in Tilapia", gram positive cocci pathogens of fish in Israel and in the United States were characterized. We showed that Streptococcus shiloi, the name for an agent causing septicemic infection in fish, is a junior synonym of Streptococcus iniae and that Enterococcus seriolicida is a junior synonym of Lactococcus garvieae, a causative agent of septicemia and meningo-encephalitis in fish. Molecular epidemiology studies on these two pathogens, based on 16S rDNA sequences and ribotyping showed that although each country had specific clones, S. iniae originated probably from the U.S. and L. garvieae from Japan. PCR assays were developed for both pathogens and applied to clinical samples. S. agalactiael S. difficile was also recognized for the first time in the U.S. in tilapia. Our histopathological studies explained the noted paradox (abundant in vitro growth often accompanied by scant to small numbers of organisms within the meninges in histologic sections of brain) in diagnostic of fish streptococcus. The greatest concentration of cocci were consistently observed within macrophages infiltrating the extrameningeal fibroadipose tissue surrounding the brain within the calvarium. These results also suggests that the primary route of meningeal infection may be extension from the extrameningeal connective tissue rather than meningeal vascular emigration of cocci-containing macrophages. Our work has resulted in a cognizance of streptococcus as fish pathogen which goes beyond the pathology observed in tilapia and is already extended to many aquaculture fish species in Israel and in the United States. Finally, our data suggest that vaccines (bivalent or trivalent) could be developed to prevent most of the damages caused by streptococcus in aquaculture.
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Harman, Gary E., and Ilan Chet. Discovery and Use of Genes and Gene Combinations Coding for Proteins Useful in Biological Control. United States Department of Agriculture, September 1994. http://dx.doi.org/10.32747/1994.7568787.bard.

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The objectives of the research in this proposal were to (A) identify synergy among proteins that provide enhanced activity over single proteins for control of plant pathogenic fungi, (B) clone and characterize genetic sequences coding for proteins with ability to control pathogenic fungi, (C) produce transgenic organisms with enhanced biocontrol ability using genes and gene combinations and determine their efficiency in protecting plants against plant pathogenic fungi. A related objective was to produce disease-resistant plants. Fungal cell wall degrading enzymes from any source are strongly synergistic with any membrane active compound and, further, different classes of cell wall degrading enzymes are also strongly synergistic. We have cloned and sequenced a number of genes from bacterial and fungal sources including five that are structurally unrelated. We have prepared transgenic fungi that are deficient in production of enzymes and useful in mechanistic studies. Others are hyperproducers of specific enzymes that permit us, for the first time, to produce enzymes from T. harzianum in sufficient quantity to conduct tests of their potential use in commercial agriculture. Finally, genes from these studies have been inserted into several species of crop plants were they produce a high level of resistance to several plant pathogenic fungi.
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Harman, Gary E., and Ilan Chet. Enhancing Crop Yield through Colonization of the Rhizosphere with Beneficial Microbes. United States Department of Agriculture, December 2001. http://dx.doi.org/10.32747/2001.7580684.bard.

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At the start of this project, fungi in the genus Trichoderma were known to be potent biocontrol agents, and their primary mechanism was considered to via direct effects upon the target fungi. Due in large part to the efforts of the two PIs, we now know that this view is far too limited; while Trichoderma spp. do indeed have direct effects on pathogenic fungi, they have very far reaching effects directly upon plants. Indeed, these fungi must be considered as opportunistic plant symbionts; they provide a number of benefits to plants and themselves are favored by large numbers of healthy roots. Research under this BARD grant has demonstrated that These fungi induce resistance mechanisms in plants. They increase root development and depth of rooting; Bradyrhizobium enhances this effect in soybean. They enhance uptake of plant nutrients. They have abilities to solubilize nutrients, such as oxidized metals and insoluble phosphorus compounds by a variety of different mechanisms and biochemicals. This is a marked expansion of our knowledge of the abilities of these organisms. This knowledge has direct implications for understanding of basic plant responses and abilities, and already is being used to improve plant productivity and reduce pollution of the environment.
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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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Irudayaraj, Joseph, Ze'ev Schmilovitch, Amos Mizrach, Giora Kritzman, and Chitrita DebRoy. Rapid detection of food borne pathogens and non-pathogens in fresh produce using FT-IRS and raman spectroscopy. United States Department of Agriculture, October 2004. http://dx.doi.org/10.32747/2004.7587221.bard.

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Rapid detection of pathogens and hazardous elements in fresh fruits and vegetables after harvest requires the use of advanced sensor technology at each step in the farm-to-consumer or farm-to-processing sequence. Fourier-transform infrared (FTIR) spectroscopy and the complementary Raman spectroscopy, an advanced optical technique based on light scattering will be investigated for rapid and on-site assessment of produce safety. Paving the way toward the development of this innovative methodology, specific original objectives were to (1) identify and distinguish different serotypes of Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Bacillus cereus by FTIR and Raman spectroscopy, (2) develop spectroscopic fingerprint patterns and detection methodology for fungi such as Aspergillus, Rhizopus, Fusarium, and Penicillium (3) to validate a universal spectroscopic procedure to detect foodborne pathogens and non-pathogens in food systems. The original objectives proposed were very ambitious hence modifications were necessary to fit with the funding. Elaborate experiments were conducted for sensitivity, additionally, testing a wide range of pathogens (more than selected list proposed) was also necessary to demonstrate the robustness of the instruments, most crucially, algorithms for differentiating a specific organism of interest in mixed cultures was conceptualized and validated, and finally neural network and chemometric models were tested on a variety of applications. Food systems tested were apple juice and buffer systems. Pathogens tested include Enterococcus faecium, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus, Yersinia enterocolitis, Shigella boydii, Staphylococus aureus, Serratiamarcescens, Pseudomonas vulgaris, Vibrio cholerae, Hafniaalvei, Enterobacter cloacae, Enterobacter aerogenes, E. coli (O103, O55, O121, O30 and O26), Aspergillus niger (NRRL 326) and Fusarium verticilliodes (NRRL 13586), Saccharomyces cerevisiae (ATCC 24859), Lactobacillus casei (ATCC 11443), Erwinia carotovora pv. carotovora and Clavibacter michiganense. Sensitivity of the FTIR detection was 103CFU/ml and a clear differentiation was obtained between the different organisms both at the species as well as at the strain level for the tested pathogens. A very crucial step in the direction of analyzing mixed cultures was taken. The vector based algorithm was able to identify a target pathogen of interest in a mixture of up to three organisms. Efforts will be made to extend this to 10-12 key pathogens. The experience gained was very helpful in laying the foundations for extracting the true fingerprint of a specific pathogen irrespective of the background substrate. This is very crucial especially when experimenting with solid samples as well as complex food matrices. Spectroscopic techniques, especially FTIR and Raman methods are being pursued by agencies such as DARPA and Department of Defense to combat homeland security. Through the BARD US-3296-02 feasibility grant, the foundations for detection, sample handling, and the needed algorithms and models were developed. Successive efforts will be made in transferring the methodology to fruit surfaces and to other complex food matrices which can be accomplished with creative sampling methods and experimentation. Even a marginal success in this direction will result in a very significant breakthrough because FTIR and Raman methods, in spite of their limitations are still one of most rapid and nondestructive methods available. Continued interest and efforts in improving the components as well as the refinement of the procedures is bound to result in a significant breakthrough in sensor technology for food safety and biosecurity.
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Yogev, David, Ricardo Rosenbusch, Sharon Levisohn, and Eitan Rapoport. Molecular Pathogenesis of Mycoplasma bovis and Mycoplasma agalactiae and its Application in Diagnosis and Control. United States Department of Agriculture, April 2000. http://dx.doi.org/10.32747/2000.7573073.bard.

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Mycoplasma bovis and M. agalactiae are two phylogenetically related mycoplasmas which cause economically significant diseases in their respective bovine or small ruminant hosts. These organisms cause persistent asymptomatic infections that can result in severe outbreaks upon introduction of carrier animals into susceptible herds. Little is known about the mechanisms underlying mycoplasma-host interaction, variation in virulence, or of the factors enabling avoidance of the host immune system. In recent years it has become apparent that the ability of pathogenic microorganisms to rapidly alter surface antigenic structures and to fine tune their antigenicity, a phenomena called antigenic variation, is one of the most effective strategies used to escape immune destruction and to establish chronic infections. Our discovery of a novel genetic system, mediating antigenic variation in M. bovis (vsp) as well as in M. agalactiae (avg) served as a starting point for our proposal which included the following objectives: (i) Molecular and functional characterization of the variable surface lipoproteins (Vsp) system of M. bovis and comparison with the Vsp-counterpart in M. agalactiae (ii) Determination of the role of Vsp proteins in the survival of M. bovis when confronted by host defense factors, (iii) Assessment of Vsp-based genetic and antigenic typing of M. bovis and M. agalactiae for epidemiology of infection and (iv) Improvement of diagnostic tests for M. bovis and M. agalactiae based on the vsp-and vsp-analogous systems. We have carried out an extensive molecular characterization of the vsp system and unravelled the precise molecular mechanism responsible for the generation of surface antigenic variation in M. bovis. Our data clearly demonstrated that the two pathogenic mycoplasma species possess large gene families encoding variable lipoprotein antigens that apparently play an important role in immune evasion and in pathogen-host interaction during infection. Phase variable production of these antigens was found to be mediated by a novel molecular mechanism utilizing double site-specific DNA inversions via an intermediate vsp configuration. Studies in model systems indicate that phase variation of VspA is relevant in interaction between M. bovis and macrophages or monocytes, a crucial stage in pathogenesis. Using an ELISA test with captured VspA as an antigen, phase variation was shown to occur in vivo and under field conditions. Genomic rearrangements in the avg gene family of M. agalactiae were shown to occur in vivo and may well have a role in evasion of host defences and establishment of chronic infection. An epidemiological study indicated that patterns of vsp-related antigenic variation diverge rapidly in an M. bovis infected herd. Marked divergence was also found with avg-based genomic typing of M. agalactiae in chronically infected sheep. However, avg-genomic fingerprints were found to be relatively homogeneous in different animals during acute stages of an outbreak of Contagious Agalactiae, and differ between unrelated outbreaks. These data support the concept of vsp-based genomic typing but indicate the necessity for further refinement of the methodology. The molecular knowledge on these surface antigens and their encoding genes provides the basis for generating specific recombinant tools and serological methods for serodiagnosis and epidemiological purposes. Utilization of these methods in the field may allow differentiating acutely infected herds from chronic herds and disease-free herds. In addition the highly immunogenic nature of these lipoproteins may facilitate the design of protective vaccine against mycoplasma infections.
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Shpigel, Nahum, Raul Barletta, Ilan Rosenshine, and Marcelo Chaffer. Identification and characterization of Mycobacterium paratuberculosis virulence genes expressed in vivo by negative selection. United States Department of Agriculture, January 2004. http://dx.doi.org/10.32747/2004.7696510.bard.

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Mycobacterium avium subsp. paratuberculosis (MAP) is the etiological agent of a severe inflammatory bowel disease (IBD) in ruminants, known as Johne’s disease or paratuberculosis. Johne’s disease is considered to be one of the most serious diseases affecting dairy cattle both in Israel and worldwide. Heavy economic losses are incurred by dairy farmers due to the severe effect of subclinical infection on milk production, fertility, lower disease resistance and early culling. Its influence in the United States alone is staggering, causing an estimated loss of $1.5 billion to the agriculture industry every year. Isolation of MAP from intestinal tissue and blood of Crohn's patients has lead to concern that it plays a potential pathogenic role in promoting human IDB including Crohn’s disease. There is great concern following the identification of the organism in animal products and shedding of the organism to the environment by subclinically infected animals. Little is known about the molecular basis for MAP virulence. The goal of the original proposed research was to identify MAP genes that are required for the critical stage of initial infection and colonization of ruminants’ intestine by MAP. We proposed to develop and use signature tag mutagenesis (STM) screen to find MAP genes that are specifically required for survival in ruminants upon experimental infection. This research projected was approved as one-year feasibility study to prove the ability of the research team to establish the animal model for mutant screening and alternative in-vitro cell systems. In Israel, neonatal goat kids were repeatedly inoculated with either one of the following organisms; MAP K-10 strain and three transposon mutants of K-10 which were produced and screened by the US PI. Six months after the commencement of inoculation we have necropsied the goats and taken multiple tissue samples from the jejunum, ileum and mesenteric lymph nodes. Both PCR and histopathology analysis indicated on efficient MAP colonization of all the inoculated animals. We have established several systems in the Israeli PI’s laboratory; these include using IS900 PCR for the identification of MAP and using HSP65-based PCR for the differentiation between MAV and MAP. We used Southern blot analysis for the differentiation among transposon mutants of K-10. In addition the Israeli PI has set up a panel of in-vitro screening systems for MAP mutants. These include assays to test adhesion, phagocytosis and survival of MAP to/within macrophages, assays that determine the rate of MAPinduced apoptosis of macrophages and MAP-induced NO production by macrophages, and assays testing the interference with T cell ã Interferon production and T cell proliferation by MAP infected macrophages (macrophage studies were done in BoMac and RAW cell lines, mouse peritoneal macrophages and bovine peripheral blood monocytes derived macrophages, respectively). All partners involved in this project feel that we are currently on track with this novel, highly challenging and ambitious research project. We have managed to establish the above described research systems that will clearly enable us to achieve the original proposed scientific objectives. We have proven ourselves as excellent collaborative groups with very high levels of complementary expertise. The Israeli groups were very fortunate to work with the US group and in a very short time period to master numerous techniques in the field of Mycobacterium research. The Israeli group has proven its ability to run this complicated animal model. This research, if continued, may elucidate new and basic aspects related to the pathogenesis MAP. In addition the work may identify new targets for vaccine and drug development. Considering the possibility that MAP might be a cause of human Crohn’s disease, better understanding of virulence mechanisms of this organism might also be of public health interest as well.
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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, January 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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Dickman, Martin B., and Oded Yarden. Regulation of Early Events in Hyphal Elongation, Branching and Differentiation of Filamentous Fungi. United States Department of Agriculture, 2000. http://dx.doi.org/10.32747/2000.7580674.bard.

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In filamentous fungi, hyphal elongation, branching and morphogenesis are in many cases the key to successful saprophytic and pathogenic fungal proliferation. The understanding of the fungal morphogenetic response to environmental cues is in its infancy. Studies concerning the regulation of fungal growth and development (some of which have been obtained by the participating collaborators in this project) point to the fact that ser/thr protein kinases and phosphatases are (i) involved in the regulation of such processes and (ii) share common structural and functional features between saprophytes and pathogens. It is our objective to combine a pharmaceutical and a genetic approach in order to identify, characterize and functionally dissect some of the regulatory factors involved in hyphal growth, branching and differentiation. Using an immunohistochemical approach, a ser/thr protein kinase involved in hyphal elongation in both Neurospora crassa and Colletotrichum trifolii has been localized in order to identify the physical arena of regulation of hyphal elongation. The analysis of additional kinases and phosphatases (e.g. Protein kinase C, cAMP-dependent kinase, lipid-activated protein kinase, components of the type 2A protein phosphatase) as well as a RAS-related gene (an additional key participant in signal transduction) has been performed. In order to succeed in advancing the goals of this project, we have taken advantage of available elongation/branching mutants in N. crassa and continuously combined the accumulated information obtained while studying the two systems in order to dissect the elements involved in these processes. The various inhibitors/effectors analyzed can serve as a basis for modification to be used as anti-fungal compounds. Understanding the regulation of hyphal proliferation is a key requirement for identifying novel target points for either curbing fungal growth (as in the case of pathogenesis) or affecting growth patterns in various biotechnological processes. The major objective of our joint project was to advance our understanding of regulation of hyphal growth, especially during early events of fungal germination. Towards achieving this goal, we have coupled the analysis of a genetically tractable organism (N. crassa) with a plant pathogen o economic importance (C. trifolii). As the project progressed we believe that the results obtained have provided a reinforcement to our basic approach which called for combining the two fungal systems for a joint research project. On the one hand, we feel that much of the advance made was possible due to the amenability of N. crassa to genetic manipulations. The relevance of some of the initial findings obtained in Neurospora have been proven to be relevant to the plant pathogen while unique features of the pathogen have been identified in Colletotrichum. Most of the results obtained from this research project have been published. Thus, the main volume of this report is comprised of the relevant publications describing the research and results obtained.
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MacDonald, James D., Aharon Abeliovich, Manuel C. Lagunas-Solar, David Faiman, and John Kabshima. Treatment of Irrigation Effluent Water to Reduce Nitrogenous Contaminants and Plant Pathogens. United States Department of Agriculture, July 1993. http://dx.doi.org/10.32747/1993.7568092.bard.

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The contamination of surface and subterranean drinking water supplies with nitrogen-laden agricultural wastewater is a problem of increasing concern in the U.S. and Israel. Through this research, we found that bacteria could utilize common organic wastes (e.g. paper, straw, cotton) as carbon sources under anaerobic conditions, and reduce nitrate concentrations in wastewater to safe levels. Two species of bacteria, Cellulomonas uda and a Comamonas sp., were required for dentitrification. Celulomonas uda degraded cellulose and reduced nitrate to nitrite. In addition, it excreted soluble organic carbon needed as a food source by the Comamonas sp. for completion of denitrification. We also found that recirculated irrigation water contains substantial amounts of fungal inoculum, and that irrigating healthy plants with such water leads to significant levels of root infection. Water can be disinfected with UV, but our experiments showed that Hg-vapor lamps do not possess sufficient energy to kill spores in wastewater containing dissolved organics. Excimer lasers and Xenon flashlamps do possess the needed power levels, but only the laser had a high enough repetition rate to reliably treat large volumes of water. Ozone was highly efficacious, but it's use as a water treatment is probably best suited to moderate or low volume irrigation systems. This research provides critical data needed for the design of effective water denitrification and/or pathogen disinfection systems for different growing operations.
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