High frequency of vancomycin resistant Enterococcus faecalis in children: an alarming concern


Introduction: Enterococcus spp. is considered as important etiological agents of nosocomial infections. However, a little is known about the epidemiology of vancomycin resistant Enterococcus faecalis (VREF). The aim of this study was to investigate the frequency of  VREF and detecting of two prevalent resistance genes (vanA, vanB) in pediatric population in an Iranian referral pediatric Hospital.

Material and methods: During January 2013 to December 2013, 180 E. faecalis was isolated from clinical samples of hospitalized children at Children Medical Center Hospital, tertiary care and teaching hospital in Tehran, Iran. Antimicrobial testing was performed by Kirby-Bauer disk diffusion and E-test method according to Clinical Laboratories Standards Institute (CLSI). Two prevalent resistance genes (vanA, vanB) were investigated in VREF isolates.

Results: Cephalosporin resistance was found in majority of E. faecalis isolates. There were no linezolid-resistant E. faecalis among all isolates. Teicoplanin resistance was observed in 13.8% of E. faecalis (n=25). MIC ≥32 µg/ml for vancomycin was found in 29 isolates (16%) and vanA gene was detected in 21 (72%) VREF strains, while vanB gene was not detected in any of these isolates. The mortality rate of all cases was 3.4% and 10% of patients with VREF infection died.

Conclusion: This study reveals high rate of multidrug-resistant as well as vancomycin resistance in E. faecalis strains. Thus periodic surveillance of antibacterial susceptibilities is recommended to detect emerging resistance.