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Are New β-Lactam/β-Lactamase Inhibitor Combinations Promising Against Carbapenem-Resistant K. pneumoniae Isolates?
Ayşe Nur Ceylan1, Selda Kömeç1, Kamuran Şanlı1
1Department of Medical Microbiology, Basaksehir Çam and Sakura City Hospital, University of Health Science, Istanbul 34480, Türkiye.
Background/Objectives:
Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections present a significant clinical challenge due to limited therapeutic options and high transmission potential. This study aimed to identify the resistance genes associated with carbapenemase production in CRKP isolates and evaluate the in vitro activity of ceftazidime/avibactam (CZA) and meropenem/vaborbactam (MEV), among other β-lactam/β-lactamase inhibitor combinations.
Methods:
Between October 2021 and June 2022, a total of 504 CRKP isolates were grown from patient samples in intensive care units. When duplicate patient samples were removed, the remaining 89 isolates were included in the study. Bacterial identification and antimicrobial susceptibility testing were per-formed using MALDI-TOF, Phoenix M50, and disk diffusion methods, following EUCAST guidelines. PCR analyses identified carbapenemase genes such as OXA-48, NDM, and KPC.
Results:
The most prevalent carbapenemase gene was OXA-48 (79.8%), followed by NDM (21.4%) and KPC (17.9%). The susceptibility rate to CZA was 82.0%, significantly higher than MEV (10.1%). All isolates were resistant to piperacillin/tazobactam and ceftolozane/tazobactam. Among MEV-resistant isolates, most carried the OXA-48 gene, while NDM was common in CZA-resistant isolates.
Conclusions:
CZA demonstrates high efficacy against OXA-48-producing CRKP, making it a viable treatment option in settings where OXA-48 predominates. The limited activity of MEV in this study underscores the need for molecular surveillance of resistance mechanisms to guide empirical therapy.
Insights
Ceftazidime/avibactam (CZA) shows high efficacy against OXA-48 carbapenem-resistant Klebsiella pneumoniae (CRKP) infections. Meropenem/vaborbactam (MEV) had limited activity, highlighting the need for resistance surveillance in CRKP treatment.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a significant global health threat due to limited treatment options.
- Understanding resistance mechanisms and evaluating novel antibiotic combinations are crucial for effective CRKP management.
Purpose of the Study:
- To identify carbapenemase genes in CRKP isolates.
- To assess the in vitro activity of ceftazidime/avibactam (CZA) and meropenem/vaborbactam (MEV) against CRKP.
Main Methods:
- Collected 504 CRKP isolates from intensive care units between October 2021 and June 2022.
- Identified isolates and performed antimicrobial susceptibility testing using MALDI-TOF, Phoenix M50, and disk diffusion.
- Utilized PCR to detect carbapenemase genes, including OXA-48, NDM, and KPC.
Main Results:
- OXA-48 was the most prevalent carbapenemase gene (79.8%), followed by NDM (21.4%) and KPC (17.9%).
- Ceftazidime/avibactam (CZA) exhibited an 82.0% susceptibility rate, significantly higher than meropenem/vaborbactam (MEV) at 10.1%.
- All isolates were resistant to piperacillin/tazobactam and ceftolozane/tazobactam.
Conclusions:
- CZA is a highly effective treatment option against OXA-48-producing CRKP.
- The low activity of MEV necessitates ongoing molecular surveillance to guide empirical CRKP therapy.
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