Work

Assessment of carbapenemase genes and antibiotic resistance profiles in ceftazidime–avibactam resistant Klebsiella pneumoniae isolates: A single-center cross-sectional study

Year: 2025

Type: article

Abstract: BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is an urgent global health threat due to its rapid spread and limited treatment options. Ceftazidime-avibactam exhibits broad efficacy against gram-negative bacteria, including CRKp; however, emerging resistance to this agent is increasingly reported. Understanding the prevalence of ceftazidime-avibactam resistance and the underlying carbapenemase genes is critical for optimizing antimicrobial stewardship and guiding clinical management. This study aimed to determine the prevalence of ceftazidime avibactam resistance among CRKp isolates collected from various clinical specimens, and to analyze their associated carbapenemase genes and antibiotic resistance profiles. METHODS: This cross-sectional study analyzed 312 K pneumoniae isolates obtained from various clinical specimens of hospitalized patients at a tertiary care hospital in Turkey. Antibiotic susceptibility testing was performed using the disk diffusion method for ceftazidime-avibactam and broth microdilution for both colistin and ceftazidime-avibactam. Molecular detection of carbapenemase genes was carried out using polymerase chain reaction. RESULTS: Ceftazidime-avibactam resistance was identified in 21.5% (67/312) of CRKp isolates. Among these isolates, 37.3% harbored both OXA-48 and NDM genes, 13.4% carried NDM alone, 10.4% carried OXA-48 alone, and 38.8% lacked these genes. The majority of resistant isolates originated from urine (31.3%), followed by tracheal aspirate (29.9%), and blood (22.4%) specimens. The prevalence of colistin susceptibility among ceftazidime-avibactam-resistant CRKp isolates was 56.7%. CONCLUSIONS: The coexistence of NDM and OXA-48 genes is a major contributor to ceftazidime-avibactam resistance in CRKp isolates, particularly in urinary and respiratory tract infections. These findings underscore the need for ongoing surveillance and tailored antibiotic stewardship programs to control the spread of resistance in hospital settings.

Source: Medicine

DOI: 10.1097/md.0000000000045289

Authors: Ipek Koçer, Hadiye Demirbakan

Institution: Sanko University

Language: English

Topic: Antibiotic Resistance in Bacteria

Subfield: Microbiology (medical)

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $1,950