Phenotypic characterization of Acinetobacter species and their resistance pattern in a tertiary care hospital

Abstract

is an emerging opportunistic pathogen and increasingly implicated in hospital acquired infection especially in intensive care unit. The infection caused by spp. is difficult to control due to multi drug resistance which limits its therapeutic options. This study was undertaken to isolate from various clinical samples and to speciate isolates. Efforts were made to study the antimicrobial susceptibility pattern of species and to detect metallo beta lactamase producing strains. Clinical samples blood, urine, sputum, pus, body fluids and ETT sample received in microbiology laboratory were processed according to the standard laboratory procedure. Identification and antimicrobial susceptibility testing was done by VITEK-2 automated method. All the isolates that showed resistance to Imipenem were tested for Metallo – Beta – Lactamase (MBL) production by phenotypic test, Imipenem-EDTA-combined disc test method. Out of total 100 spp isolated from clinical samples, 80 were isolated from critical care units. baumannii was common spp 88 (88%), followed by A.complex 10 (10%). Isolation rate of species was highest from blood (27%) specimens followed by ETT (19%). 44% strains of were isolated from respiratory samples. 84(84%) spp, were carbapenem resistant. Out of 84 carbapenems resistant strains 48 (57%) were MBL positive strains by combined disc test. Emergence of MBLs producing strains of is alarming and reflects excessive use of carbapenems. Therefore early detection and prompt infection control measures is important to prevent further spread of MBLs to other Gram negative bacilli.