Isolamento, identificação molecular e detecção de genes de virulência de yersinia enterocolitica em amostras de leite bovino de tanques de expansão de propriedades do Centrooeste Paulista
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Data
2018-04-12
Autores
Bertolini, Amanda Bezerra
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Universidade Estadual Paulista (Unesp)
Resumo
O leite e seus derivados são bons meios para o desenvolvimento de microorganismos patogênicos e deteriorantes, exigindo cuidados rigorosos com a ordenha, processamento e armazenamento. Entre os vários grupos de bactérias que podem ser desenvolvidas em leite refrigerado cru, Yersinia enterocolitica, um enteropatógeno invasivo para humanos, é uma delas. Esta bactéria pode causar a uma série de sintomas clínicos intestinais e extraintestinais, variando de gastroenterite leve a linfadenite mesentérica, semelhante a apendicite. Para avaliar a prevalência de Yersinia enterocolitica patogênica no leite cru de tanques de expansão localizados no estado de São Paulo, foram avaliadas 102 amostras de leite bovino, pelas análises microbiológicas, seguido de provas bioquímicas; a Reação em Cadeia de Polimerase (PCR) e sequenciamento genético. Não houve o isolamento de Yersinia enterocolitica pelas provas microbiológicas. A análise de PCR revelou seis (6) amostras positivas para Yersinia enterocolitica (5,9%), confirmadas por sequenciamento genético. Somente o gene inv, foi detectado, presente em cepas virulentas e avirulentas. Portanto, ainda que o patógeno estudado não represente um risco potencial nas amostras de leite analisadas neste estudo, foram observados diversos fatores de risco nas fazendas visitadas e uma grande contaminação da microbiota presente no leite, podendo-se afirmar que a qualidade do leite cru em tanques de expansão das fazendas avaliadas é de risco para a saúde pública.
Milk and its byproducts are good means for the development of pathogenic and deteriorating microorganisms, demanding rigorous care with milking, processing and storage. Among the various groups of bacteria that can be grown in raw refrigerated milk, Yersinia enterocolitica, an invasive enteropathogen for humans, is one of them. This bacterium can cause a number of intestinal and extraintestinal clinical symptoms, ranging from mild gastroenteritis to mesenteric lymphadenitis, similar to appendicitis. To evaluate the prevalence of pathogenic Yersinia enterocolitica in raw milk from bulk tanks milk located in the state of São Paulo, 102 bovine milk samples were evaluated by microbiological analysis, followed by biochemical tests; the Polymerase Chain Reaction (PCR) and genetic sequencing. There was no isolation of Yersinia enterocolitica by microbiological tests. PCR analysis revealed six (6) positive samples for Yersinia enterocolitica (5.9%), confirmed by genetic sequencing and later, identification of virulence genes by PCR. Only the inv gene, present in virulent and avirulent strains, was found. Therefore, although the pathogen studied does not present a potential risk in the milk samples analyzed in this study, several risk factors were observed in the farms visited and a great contamination of the microbiota present in the milk, and it can be stated that the quality of raw milk in tanks of the farms evaluated is a risk to public health.
Milk and its byproducts are good means for the development of pathogenic and deteriorating microorganisms, demanding rigorous care with milking, processing and storage. Among the various groups of bacteria that can be grown in raw refrigerated milk, Yersinia enterocolitica, an invasive enteropathogen for humans, is one of them. This bacterium can cause a number of intestinal and extraintestinal clinical symptoms, ranging from mild gastroenteritis to mesenteric lymphadenitis, similar to appendicitis. To evaluate the prevalence of pathogenic Yersinia enterocolitica in raw milk from bulk tanks milk located in the state of São Paulo, 102 bovine milk samples were evaluated by microbiological analysis, followed by biochemical tests; the Polymerase Chain Reaction (PCR) and genetic sequencing. There was no isolation of Yersinia enterocolitica by microbiological tests. PCR analysis revealed six (6) positive samples for Yersinia enterocolitica (5.9%), confirmed by genetic sequencing and later, identification of virulence genes by PCR. Only the inv gene, present in virulent and avirulent strains, was found. Therefore, although the pathogen studied does not present a potential risk in the milk samples analyzed in this study, several risk factors were observed in the farms visited and a great contamination of the microbiota present in the milk, and it can be stated that the quality of raw milk in tanks of the farms evaluated is a risk to public health.
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análise microbiológica, diagnóstico molecular, leite bovino, saúde pública, yersiniose