Some Virulence Genes of Pathogenic Enterococci Isolated from Raw Milk and Some Milk Products

Abstract

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.

Characteristics of High-Level Aminoglycoside-Resistant Enterococcus faecalis Isolated from Bulk Tank Milk in Korea

“…In this study, HLAR E. faecalis showed a high prevalence of genes such as ace (99.5%), efa A (98.9%), cad 1 (98.4%), gel E (85.9%), and asa 1 (61.6%). This result was in accordance with the high prevalence of virulence genes of E. faecalis from buffalo milk in Brazil [47] and E. faecalis from dairy products in Egypt [48]. Although the presence of virulence genes does not increase pathogenicity, virulence factors promote tissue colonization in the hosts.…”

Dairy Products: A Potential Source of Multidrug-Resistant Enterococcus faecalis and Enterococcus faecium Strains

“…The reactions proceeded as follows: initial activation was at 94 °C for 3 min, 25 cycles were run of denaturation at 94 °C for 60 s, annealing at temperatures indicated in Supplementary Table S1 , and extension at 72 °C for 1 min, and the reaction was completed with one cycle at 72 °C for 10 min. The extracted DNA was screened also for the presence of the esp, asa1 , gelE, and cylA genes [ 23 ] using a PCR with the corresponding primers ( Supplementary Table S1 ). The reaction proceeded as follows: initial activation was at 95 °C for 10 min, 30 cycles were run of denaturation at 94 °C for 60 s, annealing at temperatures indicated in Supplementary Table S1 , and extension at 72 °C for 1 min, and the reaction was completed with one cycle at 72 °C for 10 min.…”

Wybrane Zoonozy Bakteryjne Przenoszone przez Mleko Surowe

“…Odsetek krów, wydalających paciorkowce, był niewiele niższy -ok. 90%, Wśród izolatów zidentyfikowano co najmniej 10 gatunków tych bakterii w tym m.in. E. hirae, E. faecalis i E. faecium [29,41].…”

“…Badania przeprowadzone przez Shafeek i wsp. [41] wskazują na obecność Enterococcus spp. aż w 64% próbek mleka surowego.…”