Prevalence of carbapenemase genes in Klebsiella pneumoniae and Escherichia coli isolated from intensive care unit patients in Iran: a systematic review (2014-2025)

This systematic review aimed to analyze the prevalence of the most common globally occurring carbapenemase genes (bla(OXA), bla(NDM), bla(KPC), bla(IMP), bla(VIM), and bla(GES)) in Klebsiella pneumoniae and Escherichia coli isolated from Iranian ICUs between 2014 and 2025. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The search was conducted in Embase, PubMed/MEDLINE, and Scopus databases to find relevant studies. The search resulted in 931 records; after removing articles according to the inclusion/exclusion criteria, only 10 articles were included in this study. According to the results of this review, carbapenemase-encoding bla(OXA) (47%) and bla(NDM) (33.6%) were most prevalent in K. pneumoniae, while bla(OXA) was the sole gene detected in E. coli isolates, with a prevalence of 12.1%. The comparison revealed that K. pneumoniae had an OR of 6.4 (95% CI: 2.9-14.5; p-value < 0.001) for bla(OXA) prevalence compared to E. coli, indicating a significantly higher pooled prevalence of bla(OXA) in K. pneumoniae. Moreover, antibiotic resistance rates to carbapenems, aminoglycosides, fluoroquinolones, and cephalosporins were significantly higher in K. pneumoniae compared to E. coli isolates. The findings emphasize the importance of finding new inhibitors to cover OXA and NDM carbapenemases and infection control strategies in the ICU setting to address the significantly high prevalence of carbapenemases in Iranian ICUs.