PREVALENCE OF METALLO-?-LACTAMASE RESISTANT GRAM-NEGATIVE BACILLI IN BENIN CITY, NIGERIA

Abstract

Detection of metallo-?-lactamase (MBL) is crucial in the management and control of difficult to treat infections. This study aims to determine the prevalence of MBL – producing Gram-negative bacilli among imipenem-resistant multi-drug resistant (MDR) clinical isolates. A total of 224 consecutive MDR Gram-negative bacilli consisting of Escherichia coli (78), Klebsiella species (64), Proteus species (40) and Pseudomonas aeruginosa (40) were used for this study. Imipenem disc susceptibility test was performed on all isolates and MBL detection was performed on imipenem-resistant isolates using standard techniques. Of the 224 MDR isolates tested, 37 (16.52%) were imipenem resistant and the prevalence of this resistant isolates was significantly higher in Ps. aeruginosa (35.00%) compared to others (P = 0.005). Among, the imipenem-resistant isolates, the prevalence of MBL production was highest in Ps. aeruginosa (14.29%) followed by Escherichia coli (11.11%), Klebsiella species (10.00%) and Proteus species (0%). However, the difference in prevalence was not statistically significant (P = 0.8807). Conclusively, Ps. aeruginosa was the most prevalent microorganism that was resistant to imipenem. An overall prevalence of 10.81% of MBL producers was observed among imipenem-resistant microbial isolates. Measures to control and prevent the spread of MBL producing and imipenem-resistant microbial isolates are advocated.