Virulence Genotyping of Enterococcus species isolated from meat and milk products

Abstract

Enterococci have recently emerged as nosocomial pathogens. Their ubiquitous nature determines their frequent findingin foods as contaminants. As little is known about their virulence potential, this study aimed to investigate the frequencyof five potential virulence determinants in Enterococcus species isolated from various foodstuffs in Sharkia and DakahliaGovernorates, Egypt. A total of 59 enterococci isolates (59%) were recovered according to standard microbiologicalmethods, with milk and meat being most contaminated (76 and 60%, respectively). Species-specific PCR of tenenterococci isolates identified by 16S rDNA revealed the presence of E. faecalis, E. faecium and unidentified enterococciin 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 allthe identified isolates were found to carry one or more virulence-encoding genes, with two or three being the mostcommon 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 isolatesshowed different patterns of virulence determinants; esp, gelE, ace and asa1 genes were more prevalent in E. faeciumthan E. faecalis. Simultaneous presence of virulence markers was observed among the analyzed isolates. Therefore, theresults of this study showed that food can play an important role in the spread of enterococci with virulence potentialthrough the food chain to the human population