Antimicrobial Resistance of Acinetobacter Baumannii Isolated from Intensive Care Units of Isfahan Hospitals, Iran

Background: Acinetobacter baumannii is an opportunistic Gram-negative pathogen with increasing relevance in a variety of hospital-acquired infections especially among intensive care unit patients. A. baumannii is mostly a cause of septicaemia, pneumonia and urinary tract infection following hospitalization of patients with more severe illnesses. Multidrug-resistant isolates of A. baumannii have been reported increasingly during the last decade, probably as a consequence of extensive use of antimicrobial agents. The aim of this study was to determine the antimicrobial resistance of Acinetobacter baumannii isolated from intensive care units of Isfahan hospitals, Iran. Methods: In a period of one year (2009-2010) we examined 456 clinical specimens from patients in ICU departments for isolation of Acinetobacter baumannii. Then susceptibility of isolates toward antibiotics was determined by standard disk diffusion method. Findings: A total of 50 Acinetobacter baumannii isolates were cultured from urine, catheter wound, blood, and CSF.  The antimicrobial patterns of isolates showed that 52% of isolates were resistant to Carbapenems (imipenem and meropenem), 66% to Ceftazidime, 64% to Amikacin, 72% to Ciprofloxacin, 90% to trimetoprim sulfametoxazol and 54% were resistant to Piperacillin-Tazobactam. 85% of isolates were resistant to two or more antibiotics. Conclusion: This study showed a high percentage of resistance to antimicrobial agents in Acinetobacter baumannii isolates; therefore, strategies to control the spread of multidrug-resistant strains must be designed and evaluated. In addition, new treatment regimens are clearly necessary. Keywords: Intensive Care Units, Antimicrobial drug resistance, Cross infection