Molecular characterization and antimicrobial resistance of Enterococcus faecalis isolated from seafood samples

Abstract

Background: Enterococcus faecalis is considered an opportunistic foodborne pathogen.The present study aimed to assess the prevalence, antimicrobial resistance, virulence characters, and molecular typing of E. faecalis strains isolated from seafood samples. Methods: Two hundred and seventy-six seafood samples were collected. E. faecalis was isolated from samples using bacterial culture. Furthermore, the disk diffusion assessed their antimicrobial resistance. Also, the distribution of virulence factors was determined using polymerase chain reaction (PCR) assay. Random amplified polymorphic DNA (RAPD) method was used for their molecular typing.Results: Fifty-six of 276 (20.2%) seafood samples were contaminated with E. faecalis. Fish harboured the highest contamination rate (30.0%). Isolates harboured the highest resistance rate towards oxacillin (100%), tetracycline (100%), erythromycin (100%), cefoxitin (89.2%), cefazolin (87.5%), trimethoprim-sulfamethoxazole (85.7%), rifampin (69.6%), clindamycin (69.6%), and gentamicin (64.2%) antimicrobials. Efa (100%), ebpA (89.2%), ebpB (58.9%), ebpC (53.5%), and esp (51.7%) were the most commonly detected virulence factors among E. faecalis isolates. RAPD-PCR analysis showed 11 different molecular clusters considering the closeness of more than 80%. Conclusion:Seafood samples were considered reservoirs of virulence and resistant E. faecalis strains. Different molecular clusters of isolates may reflect their diverse sources of contamination.