Diversity of Ceftazidime-Avibactam Resistance Mechanism in KPC2-Producing Klebsiella pneumoniae Under Antibiotic Selection Pressure

Min Jiang; Bin Sun; Yong Huang; Chengyang Liu; Yan Wang; Yanli Ren; Yuhong Zhang; Yunying Wang; Di Mu

doi:10.2147/IDR.S371285

Diversity of Ceftazidime-Avibactam Resistance Mechanism in KPC2-Producing Klebsiella pneumoniae Under Antibiotic Selection Pressure

Infect Drug Resist. 2022 Aug 18:15:4627-4636. doi: 10.2147/IDR.S371285. eCollection 2022.

Authors

Min Jiang^#¹, Bin Sun^#¹, Yong Huang¹, Chengyang Liu¹, Yan Wang¹, Yanli Ren¹, Yuhong Zhang¹, Yunying Wang¹, Di Mu¹

Affiliation

¹ Department of Laboratory Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.

^# Contributed equally.

Abstract

Purpose: The aim of this study was to understand the resistance mechanism of ceftazidime/avibactam (CZA) in carbapenem-resistant Klebsiella pneumoniae under antibiotic selection pressure.

Patients and methods: Four CZA-resistant Klebsiella pneumoniae strains were isolated from two patients, and six CZA-resistant strains that were produced in vitro were screened from 25 carbapenem-resistant Klebsiella pneumoniae strains. The mechanisms of resistance to CZA of these strains were characterized by PCR and Sanger sequencing.

Results: CZA-resistant Klebsiella pneumoniae with different resistance mechanisms (including upregulation of the expression of efflux pumps and KPC variants (KPC-14, KPC-44)) were isolated from the same patient (patient 1). In patient 2, the resistance mechanism of CZA-resistant Klebsiella pneumoniae was the mutation of KPC-2 to KPC-33. In addition, among the CZA-resistant Klebsiella pneumoniae that were produced in vitro, we found 3 new KPC variants: KPC-86 (D179G), KPC-87 (GT241A) and KPC-88 (G523T).

Conclusion: In this study, although the CZA-resistant bacteria originated from only two clinical patients, four different mechanisms of CZA resistance were detected. In the in vitro induction experiment, the mechanisms of resistance to CZA in strains from different patients were also different. The above result implies that the mechanisms of resistance to CZA are generally random and diverse. Therefore, elucidating the mechanism of resistance to CZA can provide a certain theoretical basis for the effective response of CZA-resistant strains and the selection of antibiotics.

Keywords: KPC mutants; Klebsiella pneumoniae; antibiotic pressure; ceftazidime/avibactam-resistance; resistance mechanisms.

Grants and funding

The work was supported by funds (to Di Mu) from the National Natural Science Foundation of China (82102376) and Kuanren Talents Program of the second affiliated hospital of Chongqing Medical University. This work was supported by funds (to Bin Sun) from the National Natural Science Foundation of China (81802062).