Bacteriological profile and antimicrobial resistance pattern of Acinetobacter species isolated from patients of tertiary care hospital of Gujarat

Introduction: Acinetobacter spp. is an emerging important nosocomial pathogen. This opportunistic bacterium is quickly becoming resistant to commonly prescribed antimicrobials. Emergence of MBLs and ESBLs is becoming a therapeutic challenge as these enzymes leads to degradation of higher generation antibiotics. Aim and Objectives: The study aimed at identification and antimicrobial resistance pattern of the common Acinetobacter species prevalent in our setup and to correlate with different clinical conditions. Materials and methods: All the specimens received in a Clinical Microbiology Laboratory for bacterial culture processed to obtain Acinetobacter during period of June 2014 to May 2015. Identification and species differentiation of Acinetobacter was done by different biochemical tests. They were performed according to standard procedures. Antibiotic susceptibility test was done by Modified Kirby Bauer disk diffusion technique. The ESBL production was examined by phenotypic confirmatory disk diffusion method (PCDDT) and phenotypic expression of MBL was examined by combined disc diffusion test (CDDT). Results: All the clinical samples received in Clinical Microbiology Laboratory for bacterial culture were included in our study. These samples were processed to obtain Acinetobacter during period of June 2014 to May 2015. A total of 64 Acinetobacter were identified from 360 non-lactose fermenting bacteria isolated from various specimens. Out of 64 isolates, 61 were A. baumannii, 2 were A. lwoffii and 1 was A. calcoaceticus. Most of the isolates were resistant to Cefuroxime (96.87%) followed by Amoxicillin-clavulanic acid (95.31%), Amikacin (93.75%), Cefoxitin (93.75%), Ciprofloxacin (90.62%), Cefepime (90.62%), Cefotaxime (90.62%), Co-trimaxazole (90.62%) and Gentamicin (78.12%). Isolates showed minimum resistance of 37.5% against Imipenem. In the present study 12% Acinetobacter were found to be MBL producer and 8% were found to be ESBL producer. Conclusion: In the present study, Out of 64 Acinetobacter spp. 53.12% were from medical wards including ICU. While surgical wards contributed for 20.31% rest from other wards. Most common infective site for Acinetobacter infection was respiratory followed by operative and urinary tract. However maximum Acinetobacter isolated from Pus sample. The incidence of isolates possessing MBL activity in the present study represents an emerging threat of higher resistance to carbapenems and other commonly prescribed drugs among Acinetobacter spp. in India.