Co-occurrence of Carbapenemase Genes bla_NDM, bla_VIM, bla_KPC, and bla_OXA-48 in Pseudomonas aeruginosa Clinical Isolates

Pseudomonas aeruginosa, a gram-negative bacterium, is notorious for its innate resistance to many antibiotics. Carbapenems are broad-spectrum antibiotics often used to treat severe P. aeruginosa infections. However, the emergence and proliferation of carbapenem-resistant P. aeruginosa (CRPA) strains have become a grave global health concern. This study examined the co-occurrence of four major carbapenemase genes, namely bla(NDM), bla(VIM), bla(KPC), and bla(OXA-48), in clinical isolates of P. aeruginosa. Using standard microbiological methods,150 P. aeruginosa clinical isolates were collected and identified, and antimicrobial susceptibility testing was conducted following Clinical and Laboratory Standards Institute guidelines. Polymerase chain reaction (PCR) with gene-specific primers was used to detect the presence of carbapenemase genes. Among the 150 P. aeruginosa clinical isolates, 62(41.3%) were found to be carbapenem-resistant. The most detected carbapenemase genes were bla(KPC) (49%), bla(NDM) (31%), bla(OXA-48) (22%), and bla(VIM) (9%). Notably 13(12.9%) isolates carried two carbapenemase genes. The combination of bla(KPC) and bla(NDM) genes was found in eight isolates, two isolates carried bla(KPC) and bla(VIM), and three isolates carried bla(OXA-48) and bla(NDM). Four isolates (6.5%) harbored three carbapenemase genes. Co-occurrence of bla(NDM), bla(VIM), bla(KPC), and bla(OXA-48) was observed in four isolates (2.8%). Our findings highlight the alarming prevalence of carbapenemase genes, particularly bla(NDM) and bla(KPC), in clinical isolates of P. aeruginosa. The co-occurrence of multiple carbapenemase genes in the same isolate raises concerns about the potential for horizontal gene transfer and dissemination of multidrug-resistant P. aeruginosa strains in clinical settings. Further research is needed to elucidate the molecular mechanisms underlying the co-occurrence of carbapenemase genes and their impact on the clinical outcomes of P. aeruginosa infections. Urgent measures, such as enhanced surveillance, infection control protocols, and antibiotic stewardship programs, are imperative to combat the emergence and spread of CRPA strains.