Current Pattern of Antibiotic Resistance in Clinical Isolates of Acinetobacter Baumannii from Intensive Care Units of Tertiary Care Hospital

Purpose: To determine the pattern of antibiotic resistance in clinical isolates of Acinetobacter baumannii from ICU's of tertiary care hospital in Karachi. Study Design: A case control study. Methods: Three hundred and fifteen clinical isolates of Acinetobacter baumannii collected from different ICUs were evaluated during 1 year period. The isolates were identified by morphology, growth and biochemical characteristics, susceptibility to a panel of antimicrobial agents in disc diffusion assay and molecular characterization by PCR using glt A and gyr B genes. Results: 94% of Acinetobacter spp were detected as multi drug resistant (MDR) and sensitive to Polymixin B only. About 6% Acinetobacter spp were also MDR but sensitive to Polymixin B, Meropenem and Salbactum + Cefoperazone. All tested isolates exhibited differing resistance representation, as establish by medium incorporation - replica method, against different tested antibiotics, as follows: Amoxicillin - Calvulanic acid, Tazobactam, Ceftriaxone, Ceftazidime, Meropenem, Imipenem, Gentamicin, Amikacin, Chloramphenicol, Co-trimoxazole, Tobramycin, Salbactam, Cefoperazone, Gentamicin and Amikacin. All the isolates of Acinetobacter baumannii were PCR positive for glt A and gyr B. Conclusions: Acinetobacter baumannii is the most frequently isolated and alarming pathogen in the health care system specifically for the patients in intensive care units (ICUs). Its survival in hospital environment is because of tolerance the antibiotics and antiseptic pressures. Multi drug resistance made this pathogen the lethal pathogen of this century to infect debilitated patients. There is a strict need to monitor the surveillance of global clones at institutional and or intra-institutional level for accurate treatment, precise prevention and batter control.