Metallo-Beta-Lactamase Producing Isolates of Escherichia coli and Klebsiella pneumoniae and their Resistance Profiles in Enugu, Nigeria: A Threat to Public Health

Background: A potential threat to public health is the rapidly spreading enterobacteriaceae, especially Escherichia coli and Klebsiella pneumoniae which produce metallo-beta-lactamases (MBL). This study evaluated the prevalence of metallo-beta-lactamase (MBL) from clinical and non-clinical sources in Enugu Metropolis.

Methodology: The study was conducted in the Microbiology Laboratory of the University of Nigeria Teaching Hospital, Ituku-Ozalla between October 2020 and July 2021. A total of 150 isolates including 85 and 65 isolates of Escherichia coli and Klebsiella pneumoniae respectively was recovered. Standard microbiology procedures were used to identify and characterize the isolates. Antimicrobial susceptibility was done using the Kirby-Bauer disc diffusion technique. Phenotypic detection of Metallo-beta-lactamase production was determined using Combined Disk Tests.

Results: Imipenem resistance was detected in 22 (25.9%) isolates of E. coli and 18 (27.7%) isolates of K. pneumoniae. Of the 22 strains of E. coli that were imipenem resistant, 8 (9.4%) and 14 (16.5%) were found to be MBL producers and non-MBL respectively. Of the 18 strains of Klebsiella pneumoniae that were imipenem resistant, 10 (15.4%) were MBL producers and 8 (12.3%) were non-MBL producers. The highest prevalence of MBL was recovered from urine sources in both E. coli and K. pneumonieae. All MBL-producing isolates were multidrug resistant.

Conclusion: The overall prevalence of MBL in this study was 12.0%. Public health is at risk due to the occurrence of metallo-beta-lactamase. Antimicrobial stewardship and the implementation of infection control strategies are required to halt the spread of these resistant bacteria in the environment. The use of antibiotics should be with utmost prudence.