Activity of Nitrofurantoin Against Urinary Tract Infection (UTI) Isolates of Vancomycin-Resistant Enterococci (VRE): A Three-Year Survey in an Iranian Hospital

Background and Objective: Vancomycin-resistant enterococci (VRE) are major causative agents of urinary tract infections (UTIs) in hospitalized patients. The aim of this study was to determine prevalence of UTI caused by VRE in an Iranian 1000-bed hospital and to assess the activity of commonly used antibiotics including nitrofurantoin against VRE isolates. Material and Methods: This study was carried out between April 2002 and April 2006 in Milad Hospital (Tehran). Only patients who had puria and significant bacteriuria included in our study. All isolates performed identification to species level and susceptibility testing performed by disk diffusion method as recommended by Clinical Laboratory Institute Standards (CLSI). Results: In total, 837 enterococcus species were isolated from UTIs that 668 (79.8%) and 169 (20.2%) isolates were E. faecalis and E. faecium respectively. Analysis of the collected data revealed that 9.43% of vancomycin-resistant strains were resistant to nitrofurantoin as well (6 out of 65), while 84.9% of the isolated enterococci (54 out of 65) were vancomycin-resistant and nitrofurantoinsensitive. The obtained data also showed that both vancomycin- and nitrofurantoin-resistant isolates had higher frequency rate in admitted patients compared with out-patients. Conclusion: It is concluded that susceptibility of approximately 85% of VRE to nitrofurantoin indicates that this antibiotic still is the suitable alternative drug for treatment of urinary tract infections caused by VRE.