Genotypic Analysis of Klebsiella pneumoniae among Patients Admitted in Critical Care Settings in a Tertiary Care Center of Bangladesh

Objective: Klebsiella pneumoniae, a multidrug-resistant pathogen, is a leading cause of respiratory infections in critically ill patients, particularly those in intensive care units (ICUs). The increasing prevalence of carbapenemase-producing strains, including KPC, NDM, and OXA-48, has significantly limited treatment options and contributed to high mortality rates. This study aims to investigate the antibiotic resistance patterns of K. pneumoniae and identify the responsible resistance genes. Methods: A single-center cross-sectional study was conducted at Chittagong Ma-O-Shihsu Medical College, Bangladesh, from January to March 2024. Endotracheal aspirates were collected from ICU patients undergoing mechanical ventilation. Biochemical assays and phenotypic tests were used for bacterial identification, and antimicrobial susceptibility was assessed using the modified Kirby-Bauer disc diffusion method. Conventional polymerase chain reaction (PCR) was employed to detect resistance genes (KPC, OXA-48, NDM, QnrB, AacB, and Sul-2). Data were analyzed using SPSS version 25. Results: A high prevalence of antibiotic resistance was observed, particularly against ampicillin, cefuroxime, and cefotaxime. Ceftazidime-avibactam exhibited a lower resistance rate, while colistin resistance was minimal. Carbapenemase gene production was detected in 86% (KPC), 96% (OXA-48), and 74% (NDM) of isolates. Additional resistance genes, including qnrb (80%) and sul-2 (88%), were also prevalent. Mortality among infected patients was approximately 50%. Conclusion: The study highlights the severe antibiotic resistance pattern and high mortality rate associated with K. pneumoniae infections in ICU patients in Bangladesh. The findings underscore the urgent need for stringent antibiotic stewardship and enhanced surveillance to curb the further spread of resistance.