Antibiotic Susceptibility and Molecular Typing of Enterococcus faecalis from Retail Pork Meat Products in Korea

Enterococci have been used as starter cultures and probiotics. They also have been considered as indicator organisms for antibiotic resistance due to their ability to harbor and to easily acquire antibiotic resistance. This study aimed to show the antimicrobial resistance profiles and genotyping of Enterococcus faecalis in retail pork meat products in Korea. Enterococcus spp. were analyzed for 124 collected samples, which included minced pork meat, marinated pork meat with soy sauce or kochujang (fermented hot pepper-soybean paste), and frozen processed pork meat products. The isolates of E. faecalis (n =36) were resistant to tetracycline (58.3%), erythromycin (11.1%), and nitrofurantoin (2.8%). No vancomycin resistant enterococci were observed in the present study. Most of the E. faecalis isolates were sensitive to all antibiotics or resistant to single antibiotics. As a result of the automated repetitive-sequence-based PCR (rep-PCR), which was used as an approach for genotyping enterococci, 7 out of 36 isolates of E. faecalis were assigned to one cluster with a similarity >95%, and all isolates were found to have originated from minced pork meat, suggesting that this clone might circulate in minced pork meat products. Given the importance of antimicrobial resistance of enterococci in food safety as well as in public health, our results on the occurrence, antimicrobial resistance, and genotyping could provide useful information to derive risk management options.