Emergence of Ceftazidime–Avibactam Resistance and Decreased Virulence in Carbapenem-Resistant ST11 Klebsiella pneumoniae During Antibiotics Treatment

Abstract

Introduction

Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a serious threat to human public health. Ceftazidime–avibactam (CZA) is currently one of the few effective antibiotics for carbapenem-resistant Enterobacteriaceae (CRE).

Methods and Results

Here, we analyzed two longitudinal Klebsiella pneumoniae clinical isolates (FK8578, FK8695) that were isolated from an ICU patient during antimicrobial treatment. Broth microdilution method, whole-genome sequencing (WGS) and comparative genomic analysis were used to elucidate the dynamics and mechanisms of antibiotic resistance. String test, quantification of capsule, biofilm inhibition test and Galleria mellonella (G. mellonella) infection model were used to explore the changes in virulence of the two clinical isolates. During antibiotic treatment, CRKP FK8578 underwent a series of drug resistance and virulence changes, including CZA resistance, carbapenem susceptibility and virulence attenuation. The results of WGS showed that mutation of bla_KPC-2 to bla_KPC-33 was responsible for the change of drug resistance phenotype between FK8578 and FK8695. pLVPK-like virulence plasmid without siderophore synthesis operon was identified in the two strains. On the other hand, the loss of hypermucoviscosity phenotype in the FK8695 strain may be related to a single nucleotide deletion of the rmpA gene, which would further lead to a decrease in virulence. Virulence results showed that compared with FK8578, FK8695 was negative in the string test, with decreased capsular production, smaller amounts of biofilm formation and higher survival rate of G. mellonella.

Conclusion

This is the first report of CZA resistance and decreased virulence in ST11 CRKP strains during antimicrobial treatment. It is urgent to monitor CZA resistance and timely adjust anti-infective treatment strategies.

Keywords:

• ceftazidime–avibactam
• carbapenem-resistantKlebsiella pneumoniae
• whole-genome sequencing
• hypermucoviscosity
• pLVPK-like plasmid
• virulence attenuation

Date Availability Statement

The datasets generated are available from the corresponding author on reasonable request.

Ethical Approval

This study was approved by the First Affiliated Hospital of Wenzhou Medical University Ethics Committee (Issuing No. 2022R140). Written informed consent for publication of their details was obtained from the patient.

Acknowledgments

We acknowledge the First Affiliated Hospital of Wenzhou Medical University for its help.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

This work was funded by Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province (2022E10022) and the Planned Science and Technology Project of Wenzhou (no. Y2020974).