Clinical characteristics and carbapenem resistance gene of Klebsiella pneumonia isolates from children in Chongqing from 2019 to 2024

Objective To investigate the distribution and antibiotic resistance, change of resistance and carbapenem genotype of Klebsiella pneumonia isolated from Chongqing’s four hospitals during the period of Jan 2019-Dec 2024, to provide the reference for reasonable use of antibiotics and preventi on and control of nosocomial infections.Methods Identifications and antibiotic susceptibility tests (AST) of the total 5020 Klebsiella pneumonia isolates were performed by automated system and the conventional Kirby-Bauer method. The AST results were interpreted according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI). Carbapenem resistance genes were detected by using polymerase chain reaction (PCR) technology combined with Sanger sequencing technology.Results Atotal of 5020 Klebsiella pneumonia were isolated, accounting for 5.1%(5020/99063). The maximum number of Klebsiella pneumonia(2970/5020 strains) was isolated from sputum (59.2%). The susceptibility of Klebsiella pneumonia strains were determined as 3.8% for amikacin,10.9% for levofloxacin, 19.1% for imipenem,19.9% for meropenem.The resistance rates of Klebsiella pneumoniae to cefoperazone/sulbactam, piperacillin/tazobactam, ceftazidime, cefotaxime, cefepime, aztreonam, sulfamethoxazole, and levofloxacin showed an increasing trend year by year from 2019 to 2024 (P<0.05), while there was no significant change in the resistance rates of other tested drugs (P>0.05). The carbapenemase genes in children in Chongqing are mainly blaNDM-5, blaNDM-1, and blaKPC-2, with detection rates of 42.2%, 33.9%, and 17.3%, respectively. Patients with KPC-2 Klebsiella pneumoniae (KPC-KP) (median age, 240 days) were older than those with NDM-1 and NDM-5 Klebsiella pneumoniae (NDM-KP) (median age, 40 days) (P<0.05). The detection rate of NDM-KP in neonatal wards was higher than that in KPC-KP (64.6% vs. 26.9%, P<0.05), while the detection rate of NDM-KP in intensive care units (ICU) was lower than that in KPC-KP (6.1% vs. 26.9%, P<0.05).Conclusion The drug resistance of Klebsiella pneumoniae is on the rise, and there are differences in carbapenemase genotypes among children of different ages .