Evaluation of different phenotypic techniques in detection of metallo-betalactamases in pseudomonas aeruginosa

Abstract

Metallo-beta-lactamase (MBL) producing Pseudomonas is a worrisome pathogen to hospital infection control due to production of resistance to multiple antibiotics. So, treatment options are narrowed down to only few antibiotics which will result in high morbidity and mortality. This study was conducted with the aim to detect prevalence of MBL producing Pseudomonas aeruginosa and to compare the different phenotypic methods for the detection of MBL production in Imipenem resistant clinical isolates of Pseudomonas aeruginosa. : In this prospective study total of 14,145 different clinical samples received from different wards. Out of which 804 Pseudomonas aeruginosa were isolated and antibiotic sensitivity testing was done by Kirby-Bauer disc diffusion method using CLSI guidelines. These were evaluated for Carbapenems resistance and MBL production. Imipenem resistant strains were subjected to screening tests like Double-disc synergy test, Combined disc diffusion test (CDT) and Modified-Hodge test. : In our study out of 804 isolates,153(19.02%) isolates are resistant to Imipenem. Out of 153 Imipenem resistant isolates, Combined disc diffusion test was positive in 100%, Double disc synergy test in 76.5% and Modified-hodge test in 84.15% isolates.: Combined disc diffusion test is very sensitive, cost effective and convenient screening test for detection of MBL producing Pseudomonas aeruginosa. So, all Imipenem resistant Pseudomonas isolates should be regularly screened for detection of MBL by Combined disc diffusion test (CDT) to prevent spread of resistance, longer hospital stay and treatment failure.