Detection of CTX-M and SHV genes in Extended Spectrum Beta- Lactamase producing Klebsiella pneumoniae and Pseudomonas aeruginosa in a tertiary hospital in north-central Nigeria

Abstract

Background: Antimicrobial resistance (AMR) is an emerging threat to global health security. Globally, an estimated 700,000 deaths are attributed to AMR annually. Annual deaths due to AMR are projected to reach 10 million by 2050 if current trends persist. Extended Spectrum β-Lactamases (ESBLs) have the ability to hydrolyse penicillins, cephalosporins up to the third generation, and monobactams, but not β-lactamase inhibitors such as clavulanic acid. ESBLs undergo continuous mutation, leading to the development of new enzymes with over 400 different ESBL variants described. This study aimed to detect selected CTX-M genes, SHV, and TEM genes in Extended Spectrum Beta-Lactamase producing Klebsiella pneumoniae and Pseudomonas aeruginosa in Jos, Nigeria.

Methodology: A total of 110, non-replicated isolates of Klebsiella pneumonia and 125 isolates of Pseudomonas aeruginosa were identified phenotypically from clinical specimens of patients at a tertiary hospital in Jos, Northcentral Nigeria. The isolates were screened for ESBL production using the disk diffusion method of the Clinical Laboratory Standard Institute (CLSI) breakpoints. Phenotypic confirmation of ESBL production was done using the double-disc synergy test. Multiplex PCR was used to detect ESBL genes.

Results: Fifty (45.5%) of the 110 isolates of Klebsiella pneumoniae and 9(7.2%) of the 125 isolates of Pseudomonas aeruginosa were ESBL-positive. Typing of 20 representative ESBL isolates (17 Klebsiella and 3 Pseudomonas spp) showed the presence ofblaCTX-M1, blaCTX-M9, and blaSHV genes in these isolates. All 20 (100%) isolates had the blaCTX-M1 gene. The blaSHV gene was detected in 16(80%) while CTX-M9 was detected in 6(30%) of the isolates studied.

Conclusion: The study showed that there is a high prevalence of ESBL genes among isolates of Klebsiella pneumoniae and Pseudomonas aeruginosa in North-central Nigeria. This emphasizes the need for continuous surveillance and coordinated infection prevention and control to curtail its spread.