Resistance pattern and detection of metallo‑beta‑lactamase genes in clinical isolates of Pseudomonas aeruginosa in a central Nigeria Tertiary Hospital

Abstract

Background: Acquired metallo‑β‑lactamases (MBLs) pose serious problem both in terms of treatment and infection control in the hospitals and report across the world showed an increase in their prevalence. However, there is a paucity of data from Africa, and their report is rare in Nigeria.

Aim: This study aimed to determine the prevalence of acquired MBL‑resistant genes in carbapenem‑resistant Pseudomonas aeruginosa in Abuja, North Central Nigeria.

Materials and Methods: Two hundred nonduplicate, consecutive isolates of P. aeruginosa from clinical samples submitted to the Medical Microbiology Laboratory of National Hospital, Abuja were screened for carbapenem resistance using imipenem and meropenem. Phenotypic detection of MBL‑producing strains was determined using Total MBL confirm kits and E‑test strips on isolates that were resistant to both Imipenem and meropenem. The MBL genes were detected using multiplex polymerase chain reaction, while the gene variant was determined by sequencing.

Results: Twenty‑two MBL‑producing strains were detected phenotypically, but only 5 harbored the blaVIM‑1 gene, giving a prevalence of 2.5%. These 5 strains were resistant to all the antipseudomonal antibiotics tested except Aztreonam and Colistin. Other common MBL‑genes were not detected.

Conclusion: The prevalence of MBL‑producing strains of P. aeruginosa which poses serious challenge for therapeutics and infection control is currently low in Abuja, North Central, Nigeria. Therefore, rational use of the carbapenems and other antipseudomonal antibiotics, regular surveillance and adequate infection control measures should be instituted to limit further spread.

Keywords: Abuja, carbapenem‑resistance, metallo‑β‑lactamases, Pseudomonas aeruginosa