Listeria Monocytogenes Pathogenicity
Mostrando 1-12 de 33 artigos, teses e dissertações.
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1. In vitro detection of pathogenic Listeria monocytogenes from food sources by conventional, molecular and cell culture method
Among current in vitro methods for identification of pathogenic Listeria monocytogenes (L. monocytogenes) rely on growth in culture media, followed by isolation, and biochemical and serological identification. Now PCR (Polymerase Chain Reaction) has been used for the rapid, sensitive and specific detection of pathogenic L. monocytogenes. The pathogenicity of
Braz. J. Microbiol.. Publicado em: 2013-09
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2. Identificação molecular de bactérias ácido láticas isoladas de leite cru e queijo, e pesquisa de genes de bacteriocinas / Molecular identification of lactic acid bacteria isolated from raw milk and cheese, and detection of bacteriocin genes
Considering the importance of the lactic acid bacteria (LAB) as biopreservatives, and their inhibitory potencial against pathogens and spoilage microrganisms, the aim of this study was identify using molecular methodologies LAB isolates obtained from raw milk and soft cheese, and to conduct a detailed study about the presence of bacteriocin codifying genes.
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/02/2011
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3. Comparative analysis of rat hepatocytes invasion process by Listeria monocytogenes and Salmonella Typhimurium: Morphological characterization, quantification of TNF-alpha release and cellular death by apoptosis / Análise comparativa do processo de invasão de hepatócitos de rato por Listeria monocytogenes e Salmonella Typhimurium: caracterização morfológica, quantificação da liberação de TNF-alfa e da morte celular por apoptose
INTRODUÇÃO: Os hepatócitos apresentam papel potencial em iniciar e amplificar a resposta inflamatória aguda no fígado, através da liberação de citocinas pró-inflamatórias, em papel complementar ao exercido pelas células de Kupffer e endoteliais. A invasão bacteriana da célula hepática é um estímulo para que o hepatócito produza citocinas com
Publicado em: 2009
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4. Molecular phylogeny and comparative genomics of Gram- positive bacteria of the gastrointestinal tract / Filogenia molecular e genômica comparativa de bactérias Grampositivas do trato gastrointestinal
Recent information on the complete genome of probiotic lactic acid bacteria and Listeria monocytogenes, and the elucidation on those caused on large clusters of virulence genes, denominated pathogenicity islands (PAIs) present in L. monocytogenes, have brought the attention to the likely existence of gene sequences common to both groups, probiotic and entero
Publicado em: 2007
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5. Pathogenicity of nonstressed, heat-stressed, and resuscitated Listeria monocytogenes 1A1 cells.
The pathogenicity of nonstressed, heat-stressed, and resuscitated cells of Listeria monocytogenes 1A1 was assayed in immunocompromised mice. Cells were stressed by heating them at 56 degrees C for 20 min and were resuscitated by incubation in tryptic soy broth at 25 degrees C. A dose of 10(2) nonstressed and resuscitated cells per mouse was required for path
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6. Natural Atypical Listeria innocua Strains with Listeria monocytogenes Pathogenicity Island 1 Genes
Identification of bona fide Listeria isolates into the six species of the genus normally requires only a few tests. Aberrant isolates do occur, but even then only one or two extra confirmatory tests are generally needed for identification to species level. We have discovered a hemolytic-positive, rhamnose and xylose fermentation-negative Listeria strain with
American Society for Microbiology.
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7. Pathogenicity of Listeria monocytogenes grown on crabmeat.
The pathogenicity of Listeria monocytogenes as influenced by growth on crabmeat at 5 and 10 degrees C was studied. Crabmeat was inoculated with L. monocytogenes V7 (ca. 10(4) CFU/g) and incubated for up to 14 days at 5 and 10 degrees C. At selected incubation times, L. monocytogenes was removed from crabmeat by washing with 0.1 M potassium phosphate buffer (
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8. Routine test for in vitro differentiation of pathogenic and apathogenic Listeria monocytogenes strains.
The exosubstance of Rhodococcus equi in a prepurified form strongly enhanced the hemolytic effect of certain strains of Listeria monocytogenes. The strains which produced positive synergic hemolysis with this exosubstance were also pathogenic for guinea pigs and white mice. The other strains, which remained nonhemolytic in the presence of the R. equi. exosub
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9. Separation of pathogenic from apathogenic Listeria monocytogenes by three in vitro reactions.
One-hundred-twelve isolants of Listeria monocytogenes cultured from clinical and nonclinical sources were examined for hemolytic activity by means of the CAMP phenomenon and tested for acidification of xylose and rhamnose. The reactions of the isolants were noted and correlated with the pathogenicity of the organisms. All of the CAMP-negative (nonhemolytic)
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10. Course of infection and development of immunity in experimental infection of mice with Listeria serotypes.
NMRI mice were experimentally infected with Listeria monocytogenes serotypes 1/2b, 3a, 4b, and 4d and Listeria innocua serotype 6b by different means. The course of infection was monitored, using bacteriological and histological methods. The following typical features of experimental infection with the various L. monocytogenes and L. innocua serotypes were o
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11. Pathogenicity test for Listeria monocytogenes using immunocompromised mice.
The lethality of Listeria isolates was determined with normal adult mice and mice that were immunocompromised by treatment with 20 mg of carrageenan per kg. The mean 50% lethal doses (LD50s) of the pathogenic isolates were significantly lower (alpha = 0.05) in the immunocompromised mice than in the untreated mice, with an average reduction of 5.8 log10 units
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12. Frozen stored murine hybridoma cells can be used to determine the virulence of Listeria monocytogenes.
Murine hybridoma cells, designated Ped-2E9, when stored up to 60 days at -196 degrees C or up to 48 days at -80 degrees C, gave results equivalent to those for freshly grown murine hybridoma cells in an in vitro pathogenicity assay of Listeria species. Thus, laboratories do not need to have their own tissue culture facilities to maintain the hybridoma cells