Enterococcus species are known as opportunistic pathogens and are a leading cause of nosocomial infections. As normal commensals of the human gastrointestinal tract, Enterococci are routinely exposed to a myriad of antibiotics in the course of contemporary medical treatment and enterococcal resistance plays a key role in the ecological dynamics that occur during and after antibiotic therapy. This study focused to determine the frequency and distribution of vancomycin resistant Enterococci, their phylogenetic relationship using 16S rRNA sequence and the presence of virulence genes in isolates. Random sampling was employed in the collection of 120 fecal samples of cattle, poultry, and piggery, and human clinical isolates. Standard bacteriological methods were employed in the isolation and characterization of Enterococcus species and disk diffusion method was used in determining the antibiotic resistance profile of the isolates. Results showed highest prevalence of Enterococcus species in cattle (100%), clinical isolates (80%), piggery and poultry both recording the least at 67%. Vancomycin resistance was observed in Enterococcus species at 80%, 0%, 90%, 41% from cattle, piggery, human clinical isolates, and poultry respectively. Multidrug resistance was also observed among isolates resulting in twelve resistance profiles. Sequences from the 16S rRNA identified E. faecalis, E.faecium, E. olivae, E. diestrammenae, E. bulliens, and E. diestrammenae. Isolates from cattle samples were most probable source of clinical isolates at 79% homologous conserved regions. Three virulence determinant genes Asa1 (66.6%), Cyl (16.6%) and GelE (8.3%) were detected among the isolates. Healthy and professional practices among animal farmers in regard to antibiotic usage, as well as hygienic and preventive measures among hospital workers are here recommended.
Keywords: enterococci, vancomycin, antibiotic resistance, virulence genes