Abstract - Acinetobacter baumannii isolates in a tertiary care hospital: Antimicrobial resistance and clinical significance

摘要

Objectives To carry out a retrospective study on Acinetobacter baumannii isolates from various clinical samples in a tertiary care hospital in India and analyze its epidemiology, antibiotic susceptibility patterns, pathogenic potential and nosocomial status. Materials and methods The clinical specimens over a period of 14 months from December 2008 to January 2010 were analyzed and the A.baumannii isolates obtained by an automated identification system (Vitek 2 Compact) were segregated for further study. Their antibiograms were studied and a clinical correlation was made to assess their pathogenic status and mode of acquisition. Further, the nosocomial infections acquired during this period were studied and the contribution made by A.baumannii was calculated to assess its nosocomial status. Results A.baumannii was isolated in 155 samples out of 1632 gram negative isolates (9.4% prevalence) from the entire hospital. Maximum isolates were from respiratory secretions (57.4%) followed by blood (23.8%). Prevalence of A.baumannii rose to 22.7% (119 out of 525) in intensive care unit (ICU) and 65 isolates (54.6%) proved to be pathogenic. A.baumannii contributed to 30.4% ventilator associated pneumonia, 35.2% Catheter Associated Blood Stream Infections, 12.5% Surgical Site Infections and 2.94% Catheter Associated Urinary Tract Infections. Overall resistance of A.baumannii towards carbapenems was 90% from all hospital isolates. ICU isolates showed higher resistance (93.2%) as compared to Inpatient Department (82.7%) and Out-patient Department (57.1%). Conclusion In this study, A.baumannii isolates showed a pathogenic potential of around 54.6% and a majority were found to be carbapenem resistant. We must be cognizant of the fact that all A.baumannii isolations doesn’t necessarily mean infection and antibiotics should only be given in clinically proven infections. J Microbiol Infect Dis 2012; 2(2) 57-63  .