Study the genetic variations of Extended Spectrum Beta-Lactamase genes (blaSHV and blaCTX-M) in Klebsiella pneumoniae isolated from clinical samples.

Klebsiella pneumoniae exhibits notable multidrug resistance in burn patients; genomic characterization of resistance determinants is pivotal for elucidating resistance mechanisms and guiding precise therapeutic interventions. The aim of this study to investigate genetic variation among Klebsiella pneumonia isolates obtained exclusively from burn wound infections by analyzing blaSHV, blaCTX-M genes. Between November 2023 and March 2024, 95 burn swabs were collected from male and female patients in five Baghdad hospitals. After culturing and DNA extraction, PCR was performed, and three amplicons (blaSHV, blaCTX-M)were Sanger-sequenced by Macrogen- Korea. Of the 95 burn swab samples, 44% were identified as Klebsiella pneumoniae using the VITEK 2 Compact System, with isolates obtained from 43% male and 57%female patients. A high level of resistance was observed against Ceftriaxone, Ceftazidime, Cefepime, and Cefotaxime, whereas Imipenem and Meropenem exhibited complete efficacy, with no detected resistance. Molecular analysis of the blaSHV and blaCTX-M genes was conducted on ten multidrug-resistant isolates. The blaSHV gene was detected in 100% of isolates, while blaCTX-M was present in 30%. Gene sequences for (JH85, JH86, JH93) submitted to Gen Bank showed high similarity (99–100%). One mutation (G→A at position 78) was noted in the blaCTX-M sequence from isolate JH93. Phylogenetic analysis linked this variant to CTX-M-14. The study highlights a high prevalence of ESBL genes, especially blaSHV and blaCTX-M genes, underscoring the need for continuous surveillance and proper treatment of resistant K. pneumoniae in burn patients