The survey of antibiotic resistance in gram negative bacilli, isolated from urine culture specimens, Kermanshah Imam Reza Hospital

Abstract

<h3>Aim</h3> Antimicrobial resistance among bacterial pathogens is a worldwide problem. Although in many cases, the selection of initial treatment is made on an empirical basis, susceptibility testing is important in modifying therapy, if indicated, especially for treatment of common bacterial pathogens. Accordingly, we decided to determine the antimicrobial susceptibility of Gram negative pathogens found in urine cultures of patients admitted to Imam Reza Hospital, Kermanshah. <h3>Methods</h3> All urine specimens submitted for culture in the central laboratory of Imam Reza Hospital (KUMS) during a 12 month period (2006–2007) were selected. All of the specimens were cultured on MacConkey agar, blood agar and differential media for Gram negative bacteria according to NCCLS recommendations. After diagnosis and isolation of Gram negative bacteria, proper inoculum was used for susceptibility testing. Susceptibility testing was done by disk diffusion test (Kirby-Bauer method) and interpreted according to NCCLS recommendations. <h3>Results</h3> Of 10492 cultured urine, 1815 (17.29%) specimens had positive results, 1239 (68.2%) cases were positive for Gram negative bacteria and the most common pathogen was <i>Escherichia coli</i> (66.3%). Antibiotic susceptibility results reveal that Gram negative bacteria have greatest susceptibility to imipenem (67.9%) and the greatest resistance to ampicillin (91.6%). Pseudomonas species was an exception that was resistant to all antibiotics except for imipenem (100%) and ciprofloxacin (69%). <h3>Conclusion</h3> According to our results, it is apparent that antimicrobial susceptibility tests of bacteria may differ by geographic region. So after determination of this pattern empirical therapy should be based on it.