PREVALENCE OF CARBAPENAMASE PRODUCING GRAM NEGATIVE BACTERIA

ABSTRACT

Carbapenemases are β-lactamases with hydrolytic capabilities. They are capable of hydrolyzing penicillins, cephalosporins, monobactams, and carbapenems. Bacteria producing these β-lactamases may cause serious infections in which the carbapenemase activity renders many β-lactams ineffective, hence, resistant to β-lactams. Carbapenemases are members of the molecular class A, B, and D β-lactamases. Class A and D enzymes have a serine-based hydrolytic mechanism, while class B enzymes are metallo-β-lactamases that contain zinc in the active site. The aim of this study was to determine the prevalence of carbapenemase producing Gram negative bacilli isolated from a tertiary hospital environment in Benin City, Nigeria. A total of 200 isolates of Gram negative bacilli were isolated from the hospital environment in Benin City. Identification of the isolates was done using standard microbiological techniques. Antimicrobial susceptibility test was performed using Kirby- Bauer’s method. Detection of carbapenemase production was performed using the Simplified Carbapenemase Inhibition Method (sCIM). The detection of Metallo – Beta lactamase producers was performed using the EDTA disk synergy test. A prevalence rate of 18.0% zinc- type carbapenemase and 9.2% serine- type carbapenemase making an overall prevalence of 27.02% carbapenemase production among isolates from hospital environment specimen was recorded in this study.