Listeria monocytogenes in expansion tank milk assessed in Alagoas state counties, Brazil

Résumé

Foodborne diseases represent a global public health issue and dairy products are closely related to it, since the quality of the milk produced in several Brazilian regions is unsatisfactory due to the presence of microorganisms in it. Listeria monocytogenes is a serious problem linked to food safety and, when it comes to milk, it represents a potential danger because it can withstand food storage temperatures, among other characteristics. The significant participation of Alagoas State in this the dairy production sector and the importance of producing safe food led to the aim of the present study, namely: investigating Listeria monocytogenes in expansion tank milk in Alagoas State counties. Milk samples were collected from tanks in 30 milk-processing unit suppliers. Next, they were taken to the Meat and Milk Inspection Laboratory (LICAL - UFRPE). The ISO 11290-1: 1996 / Amd.1: 2004 method, with adaptations, was used in the analyses. Bluish colonies, with or without halo formation, were identified according to their morpho-tintorial and biochemical characteristics. Listeria monocytogenes were detected in 20% of the samples (6/30), and such rate represents a public health risk. Thus, monitoring this microorganism and mastitis in the herd, as well as pre- and post-dipping, equipment and storage tank sanitation, and milk collection through refrigerated trucks at the appropriate time is a relevant procedure to prevent contamination and to assure safe food provision to the population.