Comparative Analysis of Prevalence and Antibiotic Resistance in Vancomycin-Resistant Enterococcus from Clinical Samples – Demographics and Phenotypes

Background: Of all enterococci species, the most renowned clinically as multidrug-resistant pathogens areEnterococcus faecium and Enterococcus faecalis. Vancomycin-resistant Enterococcus (VRE) species are theprincipal cause of opportunistic hospital-acquired infections, due to numerous resistance mechanisms.Methods: In this study, the prevalence and antibiotic resistance profiles of VRE according to clinical sourcesfrom three selected hospitals in Southwest-Nigeria were investigated. Altogether, ۴۳۱ samples (urine, rectal,and wound swabs - caesarian section (CS), automobile accidents, and other skin lesions and abrasions) werecollected from three selected hospitals in Osun State, Nigeria. Established techniques were employed for therecovery of enterococci and screening for VRE while antibiotic susceptibility tests were carried out by discdiffusion technique.Results: Altogether, ۲۰۸ (۴۸.۳%) enterococci strains were recovered from which ۸۵ (۴۰.۹%) were VRE.E. faecium predominated at ۷۱.۸% (۶۱/۸۵) and E. faecalis at ۲۸.۲% (۲۴/۸۵) as determined by phenotypiccharacterization. VRE isolates exhibited ۱۰۰%, ۹۷.۶%, and ۹۲.۹% resistance to ampicillin, clindamycin, andquinupristin-dalfopristin (Q/D) respectively. The least resistance in-vitro was to tigecycline (۲۷.۱%). None of theantibiotics exhibited ۱۰۰% activity against all the isolates. vanA resistant phenotype was prevalent at ۶۵.۹%.E. faecium from all study locations displayed higher levels of resistance than E. faecalis. Multiple antibioticresistance (MAR) indices in all VRE isolates were ≥۰.۲, all being multidrug-resistant.Conclusions: The high prevalence rate along with the high level of multidrug resistance observed in the presentstudy is worrisome and poses a continuous threat in the therapy of illnesses triggered by VRE as vancomycin wasperceived as a drug of choice to curb enterococcal infections.

Keywords:

Enterococci , Vancomycin-resistance , Prevalence , Multidrug-resistance , Van phenotypes