Abstract

BETA LACTAMASES CONTRIBUTING CARBAPENEM RESISTANT MECHANISMS IN GRAM NEGATIVE BACILLI

Sibin P. S.* and Anuranjini C.

Abstract

Carbapenem group of antibiotics are mainly use to treat severe bacterial infections. Phenotypic detection of this study shows that carbapenem resistance is mediated not only through enzymatic activity (carbapenemase), impermeability and efflux action, but also it is mediated through beta lactamase mechanisms such as ESBL and Amp C production along with Carbapenem resistance mechanisms. Objectives: The study was mainly analyze combination of beta lactamase resistant mechanisms contributing carbapenem resistance mechanisms. Method: On the basis of CLSI guidelines and VITEK Automation system differentiate prevalence of carbapenem resistance. Modified hodge test is used to differentiate carbapenemase and non carbapenemase producers. The non carbapenemase producers were further screened for their resistance due to efflux or impermeability by using Augmented in vitro susceptibility test by using EDTA and detection of Efflux by Ethedium bromide agar cartwheel method. Each type of carbapenem resistant strains isolated from samples were further screened for the detection of beta lactamase production by using different generations of Cephalosporin antibiotic discs. Result: Klebsiella and E.coli were the predominant organisms isolated from the clinical samples. Phenotypic characterization of this study shows that beta lactamases contribute resistance in each level of resistant mechanisms in carbapenem resistance.

Keywords: Modified hodge test, Klebsiella and E.coli.