Analysis of the Association Between Antimicrobial Resistance Genes and Virulence Factors in ST11 and Non-ST11 CR-KP Bloodstream Infections in the Intensive Care Unit

Yanye Tu; Hui Gao; Rongqing Zhao; Jiliang Yan; Diyu Wu

doi:10.2147/IDR.S478156

Analysis of the Association Between Antimicrobial Resistance Genes and Virulence Factors in ST11 and Non-ST11 CR-KP Bloodstream Infections in the Intensive Care Unit

Infect Drug Resist. 2024 Sep 16:17:4011-4022. doi: 10.2147/IDR.S478156. eCollection 2024.

Authors

Yanye Tu¹, Hui Gao¹, Rongqing Zhao¹, Jiliang Yan¹, Diyu Wu²

Affiliations

¹ Clinical Laboratory of Ningbo Medical Centre Lihuili Hospital, Ningbo University, Ningbo, Zhejiang Province, People's Republic of China.
² School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, People's Republic of China.

Abstract

Objective: This study aims to investigate the association between antimicrobial resistance genes and virulence factors in ST11 and non-ST11 types of CR-KP in bloodstream infections in the intensive care unit, providing a theoretical basis for infection control and clinical diagnosis and treatment.

Methods: From January 2021 to June 2023, samples of Klebsiella pneumoniae from bloodstream infections were collected at our hospital, focusing on those resistant to carbapenems. The resistance genes, housekeeping genes, and virulence genes were identified through PCR and analyzed using the GrapeTree software to perform MLST-based minimum spanning tree typing.

Results: Among the 85 CR-KP cases, 61.18% were of the ST11 type, predominantly of the KL64 capsular type; non-ST11 types were mainly ST15, accounting for 25.88%, predominantly of the KL5 capsular type. The carriage rates of virulence genes such as rmpA2, entB, silS, kpn, iucA, peg-344, and terB were significantly higher in the ST11 group than in the non-ST11 group. The primary carbapenemase identified was class A enzyme bla _KPC-2, with a higher carriage rate in the ST11 group. Drug susceptibility tests showed that the resistance rates for cefepime, ertapenem, nitrofurantoin, amikacin, and gentamicin were also higher in the ST11 group, consistent with the resistance genotype findings.

Conclusion: The study reveals that ST11 type CR-KP in intensive care unit bloodstream infections exhibits stronger resistance and higher virulence compared to non-ST11 types, posing significant challenges to clinical treatment. Thus, strict control over the use of carbapenem antibiotics is essential to prevent the spread of resistant plasmids.

Keywords: Non-ST11 CR-KP; ST11 CR-KP; bloodstream infections; intensive care unit; resistance genes; virulence genes.

Grants and funding

This work was supported by the research grants from Zhejiang Medical and Health Science and Technology Plan (NO.2023KY1042) and Ningbo Municipal Natural Science Fund (No. 2022J255).