Resumo

Enterococcus spp. are bacteria that have different technological properties, but its presence in food has been of concern due to its frequent association with various clinical infections. Moreover, these bacteria are suspected of being causal agents of foodborne illnesses. The pathogenicity of Enterococcus is multifactorial and occurs from a sequence of virulence factors. The aim of this study was to determine virulence factors by genotypic and phenotypic tests in Enterococcus sp. isolated from clinical and minas fresh cheese samples. The biological material for this study came from the collection of 30 clinical isolates of enterococci, belonging to the species E. faecalis (7) and E. faecium (23) and 103 isolates of artisan cheeses belonging to the species E. faecalis (38), E. faecium (61) and Enterococcus spp. (4). All isolates were investigated regarding the virulence markers for gelatinase (gelE), adhesin (ace), aggregation substance (asa1)cytolysin (cylA) and sex pheromone (cpd). Phenotypic expression was performed for the enzyme gelatinase and biofilm formation on abiotic surfaces. The virulence genes gelE, ace, asa1, cylA and cpd were found in 45.6%, 58.2%, 76.7%, 0% and 23.3% for isolates of cheese, 60%, 26.7%, 33.3%, 3.3% and 26.7% for clinical isolates, respectively. In food, was a higher percentage of virulence markers for adhesin and aggregation substance, factors related to adherence of bacteria to host cells. However, in clinical isolates, genes for gelatinase was the most frequent, and its activity is related to the degradation of various cellular components. Among the tested isolates, the species E. faecalis was those that showed more virulence markers. The expression of gelatinase found was 21.3% and 23.3% of enterococci clinical and food, respectively. For biofilm formation, a clinical isolate was strongly biofilm-forming, as others were characterized as weakly biofilm-forming. The conclusions of this study are that both the isolates from cheese and clinical samples have virulence markers, gelatinase activity and biofilm formation, demonstrating that food can be considered a route of enterococci dissemination with virulent potential to the food chain.