English

Abstract

BACKGROUND: Metallo-β-Lactamase (MBL) mediated resistance to various antibiotics is an emerging threat in Pseudomonas aeruginosa isolates. The present study was undertaken to detect MBL producing isolates of Pseudomonas aeruginosa from various clinical specimen by four different phenotypic methods. OBJECTIVE: To evaluate the various methods for the detection of Metallo-β-Lactamase in clinical isolates of Pseudomonas aeruginosa in a teaching hospital of rural Gujarat - India. STUDY SETTING: Department of Microbiology, P.S. Medical College & Shree Krishna Hospital, Karamsad, Gujarat. STUDY DESIGN: Prospective observational. MATERIALS AND METHODS: Total 50 isolates of Pseudomonas aeruginosa isolated & identified from different clinical specimens as per the standard guidelines. Screening for MBL production was done by Imipenem- EDTA combined disc test, Imipenem-EDTA double disc synergy test (DDST), EDTA disc potentiation using four cephalosporins, MBL E-test. RESULT: Of 50 imipenem sensitive or resistant isolates, 24 were MBL positive, Of which 12(24%) were MBL positive by Imipenem-EDTA combined disc test and Imipenem-EDTA double disc synergy test (DDST), 2(4%) were MBL positive by EDTA disc potentiation using four cephalosporins and 19(63.33%) were MBL positive by MBL E-test method. CONCLUSION: Imipenem-EDTA combined disc test and Imipenem-EDTA double disc synergy test (DDST) are equally effective for MBL detection while MBL E-test is more effective for MBL detection but given the cost-constraints, combined disc test and DDST can be used as a convenient screening method in the clinical microbiology laboratory.