Enterococci have recently emerged as nosocomial pathogens. Their ubiquitous nature determines their frequent finding in foods as contaminants. As little is known about their virulence potential, this study aimed to investigate the frequency of five potential virulence determinants in Enterococcus species isolated from various foodstuffs in Sharkia and Dakahlia Governorates, Egypt. A total of 59 enterococci isolates (59%) were recovered according to standard microbiological methods, with milk and meat being most contaminated (76 and 60%, respectively). Species-specific PCR of ten enterococci isolates identified by 16S rDNA revealed the presence of E. faecalis, E. faecium and unidentified enterococci in 70, 20 and 10% of the isolates, respectively. PCR screening for esp (enterococcal surface protein), gelE (gelatinase), asa1 (aggregation substance), hyl (hyaluronidase) and ace (collagen binding antigen) virulence factors showed that all the identified isolates were found to carry one or more virulence-encoding genes, with two or three being the most common pattern. The esp and gelE were the predominant virulence traits among all investigated enterococci isolates (80% each), followed by ace, asa1 and hyl genes (50, 30 and 10%, respectively). Notably, E. faecalis and E. faecium isolates showed different patterns of virulence determinants; esp, gelE, ace and asa1 genes were more prevalent in E. faecium than E. faecalis. Simultaneous presence of virulence markers was observed among the analyzed isolates. Therefore, the results of this study showed that food can play an important role in the spread of enterococci with virulence potential through the food chain to the human population. |
