High Prevalence of Vancomycin Non-Susceptible and Multi-Drug Resistant Enterococci in Farmed Animals and Fresh Retail Meats in Bangladesh

Abstract The emergence of antimicrobial resistant Enterococcus spp., a leading cause of untreatable nosocomial infection, in food animals and dissemination to humans is a public health concern. The study was conducted to determine the prevalence and antimicrobial resistance, and virulence characteristics of Enterococcus faecalis and Enterococcus faecium in food animals and meats in Bangladesh. Enterococcus spp., were confirmed using sodA gene specific PCR, and antimicrobial resistance and virulence properties were characterized by PCR. Enterococcus spp. were recovered from 57% of the collected samples (n=201/352). Farm samples yielded significantly higher (p≤0.05) prevalence (62%) compared to retail meat samples (41%) and E. faecalis (52%) was most frequently isolated species. High proportions of isolates exhibited resistance to tetracycline (74%), erythromycin (65%) and ciprofloxacin (34%). Fifty-one isolates were vancomycin non-susceptible enterococci (VNSE), of which forty-seven were MDR and 20 were linezolid resistant, a last line drug for VNSE. Virulence factors such as gelatinase (gelE), aggregation factor (asa1) and sex pheromone (cpd) were detected along with vancomycin resistance gene (vanA, vanB and vanC2/C3) in VNSE isolates. The high prevalence of MDR enterococci in food animals and retail meats may lead to infection in consumers with concomitant reduced therapeutic options available for treatment.