MOLECULAR AND IN-SILICO CHARACTERIZATION OF BLANDM IN CARBAPENEM-RESISTANT KLEBSIELLA PNEUMONIAE ISOLATED FROM IMMUNOCOMPROMISED CANCER PATIENTS

Abstract

The emergence of New Delhi metallo-β-lactamase (blaNDM) variants makes carbapenem-resistant klebsiella pneumonaie (CRKP) a critical threat to immunocompromised cancer patients, using in-silico 3D modeling and integrated molecular diagnostics, this study showed the frequency of structural changes and genetic mutations of the blaNDM gene in clinical CRKP strains isolated from cancer patients. The obtained and identified carbapenem resistance from the screened clinical K. pneumoniae isolates was amplified by PCR to detect the blaNDM gene, then examined by Sanger sequencing, and simulated using AlphaFold 3 and PyMOL to assess localized structural modifications. In 75.00% of sequenced blaNDM isolates, genetic variation was detected, along with carrying multiple substitutions with 66.33%. In 100.00% of the mutated isolates, the non-synonymous alterations was seen A>C (Met154Leu), whereas the alteration of the G>T (Val88Leu) was found in 83.33% of mutated strains, showing a transition toward the highly effective NDM-5 phenotype. The overall globular fold remained unchanged despite the localized loop rearrangement happened next to positions 88 and 154 according to in-silico 3D modeling. The given study shows the high regional frequency of the optimized NDM-5 phenotype, the affinity of the zinc is known to be enhanced by the observed mutations. In the host-induced zinc starvation, this modification in the structure of carbapenemase maintains its function and preserve it, and this highlights the critical need for quick molecular diagnosis in oncology surveillance and monitoring.