Introduction: Enterococci are opportunistic pathogens which represent one of the leading agents of nosocomial infections, especially urinary tract infections (UTI) in hospitalized patients. The aim of the present study was to determine the resistance pattern and the type of resistance genes in vancomycin-resistant Enterococcus isolated from an educational hospital in Iran.
Materials and methods: From February 2012 till February 2013, one hundred and eighty six clinical isolates from different department of educational hospitals were collected and identified as Enterococci and specified by biochemical tests. Identification was confirmed by specific PCR. Antibiotic resistance properties of strains were examined by Kerby-bauer method. PCR was performed for ddlE, ddlF, vanA and vanB genes.
Results: One hundred and six (57%) isolates were identified as E. faecalis and 80 (43%) of the isolates were identified as E. faecium. 24 isolates had vanA gene and 19 isolates had vanB genes. In E. faecalis isolates, 15 isolates had vanB and 4 isolates had vanA gene. In E. faecium isolates, 20 isolates had vanA and 4 isolates had vanB gene. Prevalence of van genes between E. faecalis and E. faecium were significantly different for both vanA and vanB (p<0.01, p<0.041, respectively). VRE isolates were sensitive to Linezolid, Nitrofurantoin and Tigecyclin.
Discussion: The overall prevalence of VRE was 23.65%, which shows an increase in VRE isolation in our region. Also, prevalence of E. faecium dramatically increased from 9% to 43% in the present study. Also increase in Gentamicin resistant isolates observed, but VRE isolates were sensitive to Linezolid, Tigecyclin and Nitrofurantoin. Stewardships for antibiotic usage in hospitals, especially for last option antibiotics, can prevent the spread of resistant isolates and losing all treatment options in the future.
Keywords: Antibiotic; E. faecalis; E. faecium; Iran; VRE; resistance; vancomycin.