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Research Paper | Molecular Biology | Bangladesh | Volume 13 Issue 5, May 2024 | Rating: 4.9 / 10
Molecular Detection of Carbapenemase Genes among Carbapenem Resistant Gram-Negative Bacilli in Tertiary Care Hospital, Bangladesh
Dr. Nurun Nahar Mawla | Marynatun Nessa [2] | Prakash Nandi [2] | Md. Mustafizur Rahman [2] | Binod Saha [2] | Md. Omar Faruk [2]
Abstract: Background: Multi-drug resistance among gram negative bacteria with special interest to carbapenem resistance has been increasingly noticed worldwide leaving very few treatment options and associated with high morbidity and mortality. The rapid and accurate detection of several carbapenemase genes in these bacteria is important for both clinicians and infection control practitioners. In this work, we used a multiplex PCR assay for simultaneous detection of 5 carbapenemase genes among GNBs in a single run within a short time. Objectives: Use of Multiplex PCR for early detection of plasmid-borne carbapenemase genes among carbapenem resistant gram-negative bacteria isolated from various clinical samples of patients in community and hospital. Methods: This observational study was conducted at microbiology and molecular laboratory of a Tertiary care hospital in Dhaka, Bangladesh from June to July, 2023. Fresh culture colonies of 30 Carbapenem resistant and 04 Carbapenem sensitive gram-negative bacteria from different clinical samples were tested for carbapenem resistance by both Kirby-bauer disc diffusion and automated MIC detection as per CLSI guidelines. A multiplex PCR assay was done with Unimedica Multiplex Real time PCR Kit for identification of KPC, NDM, VIM, IMP and OXA-48 Carbapenem Resistance Genes and results were analyzed by software. Results: Among total tested 34 clinical isolates, 16 were Klebsiella pneumoniae, 04 E. coli, 08 Pseudomonas aeruginosa and 06 Acinetobacter baumannii. Of them, 24(71%) MDR-GNBs showed the presence of NDM and OXA-48 gene on Multiplex PCR. Both NDM and OXA-48 were co expressed predominantly in 50% isolates, while 33.3% NDM and 16.7% OXA-48 were detected solitarily. No KPC, VIM, IMP were determined. Minocycline (50%), tigecycline, fosfomycin and gentamicin (30%) & cotrimoxazole (25%) were sensitive for NDM encoded carbapenem resistant GNBs, however no sensitivity found to ceftazidime-avibactam. OXA-48 harbouring CR-GNBs showed 25% Fosfomycin & Ceftazidime-avibactam sensitivity and 100% resistance to all other tested antibiotics. Combined NDM & OXA 48 genes were positive in 60% K. pneumoniae, 50% E coli and 28.60% Pseudomonas aeruginosa. They were 33% sensitive to tigecycline, minocycline & fosfomycin, 17% to gentamicin and 8% to ceftazidime-avibactam & cotrimoxazole. All isolates were 100% sensitive to colistin and polymyxin B. Though having high MIC, no resistance genes were present in 6 carbapenem resistant Acinatobacter baumannii. Conclusion: Multiplex PCR overcome the limitations of the phenotypic methods and automated systems in identification of carbapenemase genes that enable physicians to select the most appropriate antibiotics. Our study has shown the co-existence of multiple genes in a single bacteria pointing out that different carbapenmases enzymes are utilized by the bacteria to inactive the carbapenem drugs. We recommend routine testing for carbapenem resistance genes among the MDR-GNB infections which will contribute in preserving carbapenems, the last resort antibiotics.
Keywords: Carbapenem-resistant gram-negative bacteria; Multidrug resistance; Carbapenemases; NDM, KPC, OXA-48, VIM, IMP genes; Co-expression of genes
Edition: Volume 13 Issue 5, May 2024,
Pages: 265 - 274