Detection of Listeria monocytogenes in frescal cheese traded in the northwestern region of the state of Paraná

ABSTRACT Listeria monocytogenes is responsible for listeriosis, a food-borne zoonosis causing food poisoning episodes throughout the world. It lives in the soil, vegetation, silage, nasal discharge and also in the intestinal flora of many animals. Its transmission takes place through material contaminated with feces, urine, aborted fetuses, uterine discharge, milk and its derivatives, mainly frescal cheese, since they are manufactured with non-pasteurized milk, are not cured, present a low percentage of salt and a high humidity, factors that are favorable for the quick microbial growth and consequent food poisoning to its consumers. Frescal cheese is widely consumed due to its low cost, palatability and in-natura state, meeting the growing demand for minimally processed food. This paper had the purpose of detecting the presence of Listeria monocytogenes in frescal cheese traded in the northwestern region of the state of Parana. A total of 21 samples of frescal cheese traded in different establishments were purchased. The samples were stored in thermal boxes and duly identified. They were then forwarded to the Laboratory of Food and Water Quality Control and Inspection (LACOMA) at Universidade Federal do Parana (UFPR), Palotina campus, where the analyses were performed. All of the 21 samples analyzed were absent for Listeria monocytogenes in a 25-gram sample, in compliance with the microbiological standard for high-humidity cheese (55%) as defined by the Brazilian National Health Surveillance Agency (Agencia Nacional de Vigilância Sanitaria - ANVISA).