Frequency and antibiotic resistance pattern in gram positive uropathogenes isolated from hospitalized patients with urinary tract infection in Tehran, Iran

Background: Urinary tract infection (UTI) is one of the most frequent types of nosocomial infections. The main purpose of this study was to determinate the frequency of gram positive cocci in urine obtained from hospitalized patients and their susceptibility patterns to antimicrobial agents. Material & Methods: During a 12 months study, 316 clinical isolates of gram positive cocci were recovered from 765 urine specimens of hospitalized patients with UTI. In vitro susceptibility of gram positive cocci isolates to 10 antimicrobial agents Ampicilin; Cephalothin; Ceftriaxone; Nitofurantoin; Erythromycin; Norfloxacin; Gentamicin; Vancomycin; Sulfamethoxazole-trimethoprim and Chloramphenicol was performed using the Kirby-Bauer’s Disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) criteria. Results: Out of 3233 urine samples of hospitalized patients 765 (23.7%) patients were showed to be urine culture positive. The frequency of Staphylococcus aureus, Enterococcus spp, Coagulase-negative staphylococci (CoNS) and Streptococcus group B were 24.7%; 8.7%, 4.1% and 3.6%. All of gram-positive cocci with the exception of Enterococcus spp (11.9%) were sensitive to vancomycin. All of Streptococcus group B and CoNS isolates were sensitive to nitrofurantoin. Conclusion: The present study exhibited that Staphylococcus aureus is the most common causative agents of nosocomial UTI. Vancomycin and nitrofurantoin seem to be the most effective drugs for treatment of gram positive cocci causing UTI.