Objective: Antibiotic-resistant bacteria are major global threats to public health. Our study aims to demonstrate the carbapenemase enzymes responsible for the resistance and the clonal relationship among carbapenemresistant strains of Escherichia coli, Enterobacter cloacae, and Proteus mirabilis isolated in our hospital.

Methods: We included carbapenem-resistant strains that were obtained between 2015 and 2022. The polymerase chain reaction (PCR) method was used to investigate resistance genes KPC, NDM, OXA-48, VIM, and IMP. “Enterobacterial repetitive intergenic consensus” (ERIC) PCR was performed to find clonal relationships.

Results: We identified 31 strains of carbapenem-resistant E. coli (CREsc), 43 strains of carbapenem-resistant E. cloacae (CREnt), and 21 strains of carbapenem-resistant P. mirabilis (CRPro). Of these strains, 16 of the CREsc strains (52%) carried the NDM gene, 5 (16%) carried the OXA-48 gene, 3 (10%) carried the KPC gene, 2 (6%) carried both NDM and OXA-48 genes, and one strain each carried the IMP, VIM, and NDM+KPC+OXA-48 resistance genes. Among CREnt strains, 39 (91%) carried the NDM gene, 2 (5%) carried the VIM gene, and one strain each carried the IMP and VIM+OXA-48 resistance genes. In CRPro strains, 17 (81%) carried the OXA-48 gene, and 4 (19%) carried the NDM resistance genes. We found 21 different clones among 31 CREsc strains, seven different clones in 43 CREnt strains, and five different clones in 21 CRPro strains.

Conclusion: Our study highlights the increasing prevalence of carbapenem-resistant strains in other enteric bacteria. Monitoring these strains is crucial for determining treatments and obtaining epidemiological data.