Thirty bovine ground meat samples from several markets from Niterói, RJ, were analyzed, in order to observe the frequency of bacterias of the genus Listeria spp. A USDA revised methodology as applied in this research. Fifty percent of the samples were contaminated by Listeria spp.. L. innocua species as the most isolated, followed by L. monocytogenes. In serological typification, the greatest prevalence was that of sorotype 4b L. monocytogenes (50%), however the ½ c sorotype was also identified. Samples contaminated by L. monocytogenes are potentially capable of causing diseases through food consumption.
Microbiology; red meat; listeriosis