Milk and its derivatives are good substrates for the proliferation of pathogenic and quality-deteriorating microorganisms, demanding rigorous care with milking, processing, and storage. Among the various bacteria that can grow in raw refrigerated milk, Yersinia enterocolitica, is an invasive enteropathogen of humans. 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 milk tanks located in the State of São Paulo, 102 bovine milk samples (one per dairy farm) were evaluated by microbiological analyses, followed by biochemical tests PCR and genetic sequencing. Microbiological testing did not isolate Y. enterocolitica. However, PCR analysis revealed six samples that were positive for Y. enterocolitica (5.9%), confirmed by genetic sequencing. Only the inv gene was detected, which is present in virulent and avirulent Y. enterocolitica strains. There was great difficulty in microbiological isolation due to the difficulty of competitiveness of Y. enterocolitica in a very rich microbiota of raw milk. Although virulence genes known to be present in potentially pathogenic strains of Y. enterocolitica have not been identified, the presence of this pathogen in milk from expansion tanks, identified through PCR and confirmed by genetic sequencing, suggests that Y. enterocolitica may be a risk to public health, especially if milk and its derivatives are consumed without heat treatment. ResumoO leite e seus derivados possuem substratos que favorecem o desenvolvimento de micro-organismos patogênicos e deteriorantes, devido a isso, cuidados rigorosos são exigindo durante a ordenha, processamento e seu armazenamento. Dentre os vários grupos de bactérias que podem contaminar o leite refrigerado cru está Yersinia enterocolitica. Esta bactéria pode causar a uma série de sintomas clínicos intestinais e extraintestinais, variando de gastroenterite leve a linfadenite mesentérica, semelhante à apendicite. Para avaliar a prevalência de Y. enterocolitica patogênica no leite cru de tanques de expansão localizados no estado de São Paulo, foram avaliadas 102 amostras de leite bovino, por análises microbiológicas, seguido de provas bioquímicas; a Reação em Cadeia de Polimerase (PCR) e sequenciamento genético. Não houve o isolamento de Y. enterocolitica pelas provas microbiológicas clássicas. No entanto, a análise de PCR, realizada diretamente do leite, revelou seis (6) amostras positivas para Y. enterocolitica (5,9%), confirmadas por sequenciamento genético. Somente o gene inv, foi detectado, que pode estar presente em cepas virulentas e avirulentas. Houve dificuldade de isolamento microbiológico devido à dificuldade de competitividade da Y. enterocolitica em uma microbiota muito rica do leite cru. Ainda que não tenham sido identificados os genes de virulência que sabidamente estão presentes em cepas de Y. enterocolitica potencialmente pat...

Leptospirosis is considered a bacterial zoonosis of public health importance. It is common in tropical areas, especially in developing countries with scarce health and sanitation resources. This study evaluated the presence of Leptospira spp. in slaughtered bovine in a slaughterhouse in the Midwest region of São Paulo, Brazil, as well as identified positive animals both in serology and by molecular analysis. Biological samples of blood, liver and kidneys from 150 cattle were investigated by the technique of Microscopic Agglutination Test (MAT) and conventional Polymerase Chain Reaction (cPCR). The serological results showed that of the 150 animals, 71 (47.3%) were reactive. The molecular results showed the presence of Leptospira spp. in kidneys of 21 (14%) animals, in liver of five (3.3%) animals, in liver and kidneys in two animals (1.3%) and in blood, in one (0.7%) animal. These results indicate a warning about the health of beef cattle due to the possibility of these animals being the source of infection and the importance of the occupational characteristic of this disease. It was also verified the importance of complementing serological and molecular techniques.