Molecular detection of antibiotic resistance and virulence gene determinants of Enterococcus species isolated from coastal water in the Eastern Cape Province, South Africa

Abstract

Enterococci are a group of significant disease-causing bacteria, which have developed resistance to several conventionally used antibiotics. Of the 67 confirmed Enterococcus species from Kidd’s Beach, 40 (59.7%) were E. faecium, 19 (28.4%) were E. faecalis. The highest level of resistance was observed against rifampicin (83.6%) followed by erythromycin (64.2%), tetracycline (52.2%), linezolid (46.3%), tetracycline (46.3%), and vancomycin (32.8%). Ninety-six per cent of the Enterococcus spp. was found to be multi-drug resistant. MAR indices vary from 0.3 to 0.9. Two virulence determinants (ace and gelE) were detected and six resistance determinants were identified as follows: ermB (19%), tetM (30%), tetL (19%), gyrA (13%), ampC (1.5%) and Van C2/3 (4.5%). The presence of enterococci (E. faecium and E. faecalis) in Kidd’s Beach waters harbouring virulence genes that facilitate multiple antibiotic resistance signifies a possible health threat for beach goers.