Isolation, molecular identification and detection of virulence genes of Yersinia enterocolitica in bulk tank milk samples of properties from Midwest Region of São Paulo State

Abstract

There is still a belief, for much of the population, that raw milk as well as tastier is more healthy, nutritious and yet has a lower price, as well as the processed milk has preservatives and chemicals that can affect the health of those who consuming. These arguments are used by people who consume raw milk in various states of Brazil. However, milk and dairy products are great means for the development of pathogenic and spoilage microorganisms, necessitating the need for strict care of milking, processing and storage. Among the various groups of bacteria that may develop in the refrigerated raw milk, there are the psychrotrophic, since multiply at temperatures below 7 °C, and thus represent a high risk for the consumer of cold raw milk. Among these psychrotrophic bacteria, Yersinia enterocolitica, which is an invasive enteropathogen of humans, causes a series of intestinal clinical symptoms and extra-intestinal disorders, ranging from mild gastroenteritis to a mesenteric lymphadenitis, may mimic appendicitis above and, in rare cases, progression to septicemia, and can lead to immunological sequelae, including glomerulonephritis, arthritis and erythema nodosum. Yersinia enterocolitica has been identified in Brazil in fecal material of human patients and animals, the environment in meat and processed pork, as well as in ice used for human consumption; but it is unknown its actual prevalence in refrigerated raw milk. This work aims to detect and identify the presence of Yersinia enterocolitica in 101 samples of bovine milk coming from bulk tanks of properties located in the Midwest region of Sao Paulo State, by inoculating in three different culture media, followed by biochemical and use evidence API 20E identification system, identification of biotypes and serogroups and the conventional Polymerase Chain Reaction (cPCR), both of milk samples from the tank as the suspected isolated colonies; as well as the presence of virulence genes of pathogenic species of Yersinia enterocolitica: inv, ail , YadA, virF, ystA e ystB. It will also be performed antimicrobial susceptibility profile of the isolates and comparison of different diagnostic methods for identification of Y. enterocolitica.