Antibiotic-Resistant Enterococcus faecalis Isolated from Food Canteens in Osun States, Nigeria

Abstract

Enterococci have continued to attract considerable importance and attention as pathogens of public health concern both in the hospital and environmental settings. Therefore epidemiological studies of these organisms are now a major research interest. Incidence of multiple antibiotic resistance (MAR) among Enterococcus faecalis recovered from food canteens in Osun States, Nigeria was investigated. In all, 537 samples from canteens including; foods, plates and hand swabs of food handlers, were examined for contamination by E. faecalis. Out of 658 E. faecalis strains recovered from the samples, 71.30% were resistant to cloxacilin, 70.21% to erythromycin, 68.54% to cotrimoxazole, 65.05% to amoxicillin, 65.05% to chloramphenicol, 63.68% to tetracycline, 61.70% to augmentin, 53.04% to gentamicin and 11.7% to vancomycin. Resistance to the fluoroquinolones tested was in the order levofloxacin (34.04%), ciprofloxacin (28.72%), norfloxacin (26.6%), spafloxacin, (24.92%), and perfloxacin (24.32%). About 99.2% of the isolates were multiple resistant to between three and 12 of the antibiotics tested. The most common MAR phenotype was AMX/TET/COT/CLX/GEN/CLO/AUG/LEV/CIP/NOR. Of the ten medicinal plants investigated for antimicrobial activity on selected E. faecalis isolates, sweet acacia (Acacia farneciana) possessed the highest antibacterial activity. Crude methanol extract was most potent than the others (ethanol and aqueous extracts); an indication that the methanol extract probably possessed some active components not contained in the other extracts. This study has revealed that foods vended from a number of canteens and food outlets in Osun State, Nigeria were contaminated with antibiotic-resistant E. faecalis suggesting a possible significant reservoir of antibiotic-resistant bacteria. Hence, urgent and periodic epidemiological evaluation and enforcement of good hygiene practices in the study area are essential. Plant extracts were very effective on AR E. faecalis. Further studies on these plant extracts may provide evidence to confirm their roles as alternatives for the treatment and or control of E. faecalis-associated diseases.