Investigating the Presence of <i>bla_CMY</i> and Extended Spectrum Beta-Lactamase Genes in <i>Klebsiella pneumoniae</i> Isolates Identified in the Clinical Samples of Patients in Dhi-Qar, Iraq

Background: Klebsiella pneumoniae is an opportunistic pathogen that can cause nosocomial infections due to its high virulence factors and multiple antimicrobial resistance (AMR) mechanisms. This bacterium can produce various beta-lactamases, including extended-spectrum beta-lactamase (ESBL) and AmpC. This study aimed to investigate the presence of plasmid AmpC and ESBL genes in K. pneumoniae isolates from the clinical samples of patients in Dhi-Qar, Iraq. Methods: A total of 612 clinical samples were collected from different medical centers and laboratories in Dhi-Qar, Iraq, between April 2023 and February 2024. Then, the presence of K. pneumoniae in these samples was evaluated using conventional biochemical and microbiological methods. ESBL production was assessed phenotypically by the synergy double disk (SDD) method. The presence of the blaCTX-M, blaTEM, blaCTX-M-3, blaCMY, and blaSHV genes was analyzed using the polymerase chain reaction. Results: Out of the 612 samples, 180 (29.4%) tested positive for K. pneumoniae. Of these, 40 isolates (22.2%) were positive in the SDD test and were considered ESBL producers. The blaSHV, blaCTX-M-3, blaTEM, and blaCTX-M genes were detected in 8 (20%), 32 (80%), 21 (52.5%), and 22 (55%) isolates, respectively. The blaCMY gene was not found in any of the K. pneumoniae isolates. Conclusion: Our study highlights high resistance against third-generation cephalosporins among K. pneumoniae isolates. The prevalence of ESBL genes, including blaCTX-M, blaTEM, and blaSHV, among these isolates can cause serious challenges in the treatment of bacterial infections.