Virulence characteristics and phylogenetic background of antibiotic-resistant Enterococcus faecalis from abattoir, poultry and clinical origin in Ado-Ekiti, Nigeria

Enterococcus faecalis is a major cause of nosocomial infection in human and severe extra-intestinal infections in animals. Enterococcus spp possesses the ability to acquire and spread genes linked with antimicrobial resistance which makes them an important nosocomial pathogen. This study aims to determine the distribution of antibiotic resistance and virulence genotype of Enterococcus faecalis in animal, poultry and clinical sources. A total of 150 samples made up of poultry droppings, abattoir and clinical specimens were collected. Standard bacteriological methods were used in the isolation and characterisation of E. faecalis. Fifteen E. faecalis isolates were examined for virulence determinant genes through quantitative Polymerase Chain Reaction analysis, while disc diffusion technique was used in determining the antibiotic-resistant pattern of the isolates. The highest prevalence of Enterococcus faecalis was in poultry droppings (94.0%) and lowest in clinical samples (24.0%). Enterococcal surface protein (Esp) was detected in 2/7, 0/5 and 0/3 of poultry, abattoir and clinical isolates, respectively. Antibiotic susceptibility pattern of the isolates indicated high resistant in poultry, abattoir and clinical samples as follows: Erythromycin (87.2%), (100.0%), (100.0%); Cloxacillin (72.3%), (90.5%), (91.7%); Cefuroxime (68.1%), (100.0%), (66.7%) and Augmentin (63.8%), (81.0%), (66.7%). High prevalence of antibiotic resistance and high virulence potential were observed among the E. faecalis isolated. There is a need for constant epidemiological surveillance and strict enforcement of good hygiene practices in the study areas.