Linezolid vancomycin resistant Enterococcus isolated from clinical samples in Tehran hospitals

Background: Vancomycin-resistant enterococci pose an emerging health risk. The limitation in therapeutic options has resulted in the development of new drugs such as quinupristin/ dalfopristin and linezolid. Aim, Setting and Design: This study investigated the species prevalence and antibacterial resistance among enterococci isolated in selected Tehran hospitals. Materials and Methods: Between March 2006 and August 2007, 200 enterococcal isolates from urine, blood, stool and wound were recovered in 2 teaching hospitals of Tehran province. Susceptibility of all isolates was tested against vancomycin, teicoplanin and linezolid antibiotics by disk diffusion and agar dilution method. Results and Conclusion: Seventeen (8.5%), 6 (3%) and 4 (2%) of the isolates were resistant to vancomycin, teicoplanin and linezolid, respectively. Within the vancomycin-resistant isolates, 6 (35.2%), 4 (25%) and 1 (5.88%) showed vanA, vanB and vanC genotype patterns, respectively. Four (23.5%) of VRE isolates were resistant to linezolid with minimum inhibitory concentrations between 16 and 32 μg/mL. Two linezolid vancomycin resistant enterococci were E. faecium.