PHENOTYPIC DETECTION OF METALLO-BETA-LACTAMASES PRODUCTION IN IMIPENEM RESISTANT ISOLATES OF Escherichia coli AND Klebsiella species ISOLATED FROM HOSPITAL AND ENVIRONMENTAL SOURCES IN NSUKKA, ENUGU STATE, NIGERIA

This study analyzed the prevalence of metallo-beta-lactamases (MBLs) in carbapenem (imipenem) resistant E. coli and Klebsiella spp isolated from hospital and environmental sources in Nsukka between October 2012 and December 2013. One hundred and seventy nine bacteria isolates from hospital and community sources were analyzed. Antimicrobial susceptibility and Metallo- β-Lactamase production were determined using Disk Diffusion method and EDTA Double Disk Synergy Test respectively. Results showed that carbapenems had the highest activity against the bacteria tested. Among the 66 strains of E. coli from hospital patients, 2(3.0%) were resistant to imipenem and were found to be MBL producers. Out of the 47 Klebsiella spp (hospital isolates) tested, 5(10.6%) were resistant to imipenem, and were subsequently found to be MBL producers. Only 1(2.6%) E. coli was resistant to imipenem among the environmental isolates. It was also found to be an MBL producer. Overall, MBL prevalence of 7(6.2%) and 1(1.5%) were recorded from hospital and environmental isolates respectively. Highest prevalence of carbapenemase in hospital were found in Klebsiella spp 5(10.6%). Sputum and sewage samples were found to have MBLs prevalence of 4(11.1%) and 1(5.3%) respectively. Distribution of MBLs producers based on sex shows that 2(5.2%) of the 38 males tested harbored MBL producers while 5(6.7%) out of 75 females tested harbored MBLs producers. Age distribution of MBLs producers showed prevalence of 2(33.3% of 6 isolates) from individuals 51 years and above. Occurrence of Metallo-β-Lactamase in E. coli and Klebsiella spp from hospital and environmental sources is a threat from the public health view point and routine tests and detection in clinical samples will be is a tool for the containment and is hereby advocated.