Molecular Detection of Carbapenem Resistant Genes among Gram Negative Bacteria Isolated from Neonatal Sepsis Cases in a Tertiary Care Hospital of Bangladesh

Background: Carbapenem-resistant Gram negative bacteria have emerged as a major cause of neonatal sepsis, posing serious challenges to effective antimicrobial therapy in resource-limited settings. Detection of underlying carbapenemase genes is essential for understanding resistance mechanisms and guiding infection control policies. To identify carbapenem-resistant gram negative bacteria isolated from neonatal sepsis cases and to detect the presence of common carbapenemase encoding genes by conventional PCR. Materials and methods: This cross-sectional study was conducted among neonates with clinically suspected sepsis admitted to the Neonatal Intensive Care Unit (NICU). Blood samples were cultured by BACT/ALERT 3D automated system. Gram negative isolates were identified by standard microbiological techniques. Antimicrobial susceptibility testing was performed by Kirby-Bauer disk diffusion method following CLSI guidelines. Isolates showing reduced susceptibility to carbapenems were screened phenotypically for carbapenemase production using Modified Carbapenem Inactivation Method (mCIM). Genomic DNA was extracted from carbapenem-resistant isolates and polymerase chain reaction (PCR) assays were carried out to detect carbapenemase genes including NDM, KPC and OXA-48. Results: A total 48 Gram negative isolates were recovered, of which 34 (70.83%) exhibited phenotypic resistance to carbapenems. Molecular analysis revealed the predominance of NDM (20.59%)genes among resistant isolates followed by OXA48(14.70%).No KPC was detected in any isolates. Conclusion: The high prevalence of carbapenemase producing Gram negative bacteria, particularly those harboring NDM gene underscores an alarming trend of antimicrobial resistance among neonatal sepsis pathogens in Bangladesh. Continuous molecular surveillance and strict antibiotic stewardship are urgently needed to contain the spread of multi-drug resistant organisms. Chatt Maa Shi Hosp Med Coll J; Vol.25 (2); July 2026; Page 3-9