ارزیابی پروفایل میکروارگانیسم های دخیل در پنومونی بیمارستانی و الگوی مقاومت آنتی بیوتیکی آن ها در بخش های مراقبت های ویژه

Background and purpose: Hospital-acquired pneumonia (HAP) is the most commonly-acquired infection in patients in intensive care units and related to a high mortality rate. Due to differences in type of microorganisms and their resistance pattern, this study was conducted to determine profile of microorganisms and their resistance pattern for initiation of more effective empirical therapy. Materials and methods: All patients admitted to three intensive care units (ICUs) of Imam Khomeini Hospital between January 2011 and August2012 were studied prospectively for the occurrence of Sample collection for microbiological analysis was done by ETA ((endotracheal aspiration)) and BAL (bronchoalveolar lavage) methods. Antimicrobialsusceptibility test were determined by “Disk Diffusion” and “Broth Dilution”methods according to CLSI (Clinical and Laboratory Standards Institute) guidelines. Results: Three hundred and eight patients from three ICUs were included in the study. Incidence of nosocomial pneumonia was 11.4%, including 91.4% VAP (ventilator-associated pneumonia) and 8.6% Non-VAP. The most common microorganisms isolated wasAcinetobacterspp (22%) and Staphylococcus aureus (14.6%), respectively. Thirty percent of Acinetobacterspp were resistant to all antimicrobial agents. Ceftazidime was the most effective antibiotic (rate of Resistance 22.2%). All isolated Acinetobacters were resistant to ciprofloxacin and ceftriaxone. Regarding the Staphylococcus aureus isolates, 50% and 33.3% were resistant to vancomycin with “Disk Diffusion” and Broth Dilution” respectively. Conclusion: Due to high prevalence of Acinetobacter spp. andstapylococusaureus (14.6%), based on the culture/sensitivity results, the most effective antibiotics was Ceftazidime, Tobramycin and Ofloxacin. Ceftriaxone and Ciprofloxacin should not be used until their efficacy would be documented in the future studies.