Plasmid DNA mediated vancomycin-resistant <i>Staphylococcus aureus</i> (VRSA) from cases of urinary tract infection

Abstract

Vancomycin resistance commonly occurs with Staphylococcus aureus, a pathogen that exhibits intrinsic virulence. Sixty isolates of Staphylococcus aureus tested positive as vancomycin possessive isolates on Brain Heart Infusion Agar medium fortified with 6 μg/mL vancomycin from 100 clinical samples of urine from patients with cases of UTIs via agar diffusion method. Standard 30 μg vancomycin disc served as control. Increase in zones of growth inhibition in relation to vancomycin concentrations was noticed in some of the isolates while it was reversed in others, despite the increase in concentration. Typed strain was susceptible to six concentrations of vancomycin exposed and to the control. Thirty one of the sixty isolates were resistant to vancomycin control. Resistant isolates from standard vancomycin discs were then subjected to molecular investigation. Of the 31 isolates exposed to gel electrophoresis, 14 (47%)elicited plasmids of varied molecular weights ranging from 0.79-23.13 kb. The magnitudes of vancomycinresistant isolates from the clinical samples studied, coupled with some incoherent zones of inhibition and the plasmid DNA obtained from the resistant isolates, suggest the need for infection control practitioners and epidemiologist to devise strategies to curtail the spread of this pathogen both in hospital and community settings.