Study of Some Virulence Genes of Enterococci Species Isolated from Raw Milk and Some Milk Products

A total of 150 random samples of raw cow milk and some locally manufactured dairy products including yoghurt, Kareish cheese and ice cream were collected from various dairy shops, and supermarkets in Qena city, Egypt. Samples were examined for the presence of Enterococcus spp. The investigation revealed that 64, 28, 76, 72 and 16 % of the examined raw milk samples, large and small-scale yoghurt, Kareish cheese and ice cream were contaminated with Enterococcus spp., respectively. Isolates were identified as E. faecalis and E. faecium in percentages of (8 & 32), (16 & 0), (8 & 28), (8 & 36), and (4 & 0) in the examined raw milk samples, large and small-scale yoghurt, Kareish cheese and ice cream, respectively. The obtained isolates were screened for presence of some virulence genes gelE, asa1, esp and cylA using multiplex PCR. The results indicated that gelE, asa1, esp and cylA were located in 53.9, 76.9, 69.2, and 30.8% of the total E. faecalis isolates and in 46.9, 71.9, 53.1, and 34.3 % of the total E. faecium isolates, respectively. The asa1 and esp genes were the predominant virulence traits among all investigated enterococci isolates followed by gelE and cylA genes. Therefore, the results of this study showed that milk and dairy products can play an important role in the spread of Enterococci with virulence potential through the food chain to the human population.