Ceftazidime-avibactam resistance among clinical isolates of Citrobacter freundii, Morganella morganii, Providencia spp. and Serratia marcescens across five continents: Data from the Antimicrobial Testing Leadership and Surveillance (ATLAS) programme, 2016-2023.
Journal
International Journal of Antimicrobial Agents
Journal Volume
67
Journal Issue
1
Start Page
Article Number : 107669
ISSN
1872-7913
Date Issued
2026-01
Author(s)
Abstract
Objective The aim of this study is to investigate the trends in ceftazidime-avibactam (CZA) resistance among clinical isolates of Citrobacter freundii, Morganella morganii, Providencia spp., and Serratia marcescens globally using the database from Antimicrobial Testing Leadership and Surveillance (ATLAS) programme, 2016–2023. Methods A total of 18,908 isolates (4,231 C. freundii , 4658 M. morganii , 3,570 Providencia spp ., and 6449 S. marcescens ) from five continents were analysed. Antimicrobial susceptibility testing of these isolates was conducted using the broth microdilution method. Results The CZA resistance rate was the highest in Providencia spp. (8.8%), followed by C. freundii (3.4%), S. marcescens (1.5%), and M. morganii (0.6%). An increasing resistance trend was noted in C. freundii (R² = 0.817) and S. marcescens (R² = 0.995) during the study period. The resistance rate in Providencia spp. peaked in 2020–2021 (R² = 0.610), while that in M. morganii remained sporadically low. Regionally, the biannual resistant rate of C. freundii rose from 6.7% to 13.0% in Asia, 0% to 7.8% in Latin America, and 0% to 7.0% in East Asia (2016–2017 vs . 2022–2023). Furthermore, among carbapenem-resistant isolates, CZA resistance was noted in 91.1% of Providencia spp., 78.8% of C. freundii , 34.9% of S. marcescens , and 60% of M. morganii. The predominant carbapenemase gene was bla NDM in Providencia spp. (82.6%), M. morganii (69.2%), and C. freundii (42.0%), and bla KPC in S. marcescens (45.3%) among carbapenemase-producing isolates. Conclusions CZA resistance is emerging across diverse Enterobacterales species, and exhibits geographic and temporal variability, and warrants continued global surveillance.
Subjects
Antimicrobial Testing Leadership and Surveillance programme
Carbapenemase genes
Ceftazidime-avibactam resistance
Citrobacter freundii
Morganella morganii
Providencia spp.
Serratia marcescens
Publisher
Elsevier B.V.
Type
journal article