Comparison of the
- 1IHMA, Schaumburg, IL, USA
- 2Pfizer, New York, NY, USA
- 3IHMA, Schaumburg, IL, USA; Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada; Corresponding author. Mailing address: IHMA, 2122 Palmer Drive, Schaumburg, IL, 60173, USA.
Abstract
Objectives: To provide a descriptive analysis of the in vitro antimicrobial susceptibility testing results for all 39,661 Pseudomonas aeruginosa isolates collected by the ATLAS global surveillance programme data from 2020 to 2024 with a focus on ceftazidime-avibactam and ceftolozane-tazobactam activities against carbapenem-resistant and DTR (difficult-to-treat resistance) phenotypes. Methods: MICs were determined using reference CLSI broth microdilution testing and interpreted by 2026 CLSI and EUCAST breakpoints. Results: Ceftazidime-avibactam (90.6% susceptible; MIC 90 , 8 µg/mL) and ceftolozane-tazobactam (89.8% susceptible; MIC 90 , 8 µg/mL) demonstrated similar in vitro activities against all P. aeruginosa isolates. Percent susceptible values for ceftazidime-avibactam, ceftolozane-tazobactam, and meropenem were lowest in Africa (ceftazidime-avibactam, 84.6%; ceftolozane-tazobactam, 82.1%; meropenem, 74.0%) and Latin America (86.5%; 84.7%; 69.8%), and highest in North America (94.8%; 95.1%; 81.6%) and the South Pacific (96.2%; 96.3%; 88.9%). Annual percent susceptible values for ceftazidime-avibactam (range, 90.2% in 2023 to 91.6% in 2022) and ceftolozane-tazobactam (range, 89.6% in 2023 to 90.8% in 2022) did not change over the five years studied. Overall, 26.1% of isolates were carbapenem-resistant; 68.0% and 65.6% of carbapenem-resistant isolates were ceftazidime-avibactam-susceptible and ceftolozane-tazobactam-susceptible, respectively. A DTR phenotype was present for 8.0% of isolates; 30.4% and 28.5% of DTR isolates were ceftazidime-avibactam-susceptible and ceftolozane-tazobactam-susceptible, respectively. In total, 4,641 of all 39,661 isolates (11.7%) were ceftazidime-avibactam-resistant and/or ceftolozane-tazobactam-nonsusceptible; 67.5% of these isolates were both ceftazidime-avibactam-resistant and ceftolozane-tazobactam-nonsusceptible, 19.6% were ceftolozane-tazobactam-nonsusceptible and ceftazidime-avibactam-susceptible, and 12.9% were ceftazidime-avibactam-resistant and ceftolozane-tazobactam-susceptible. Conclusion: Approximately 90% of global clinical isolates of P. aeruginosa from 2020 to 2024 remained susceptible to ceftazidime-avibactam and ceftolozane-tazobactam.
BibTeX
@article{estabrook2026comparison,
title = {{Comparison of the}},
author = {Mark A. Estabrook and Gregory G. Stone and Katherine K. Perez and James A. Karlowsky},
journal = {Journal of Global Antimicrobial Resistance},
year = {2026},
month = oct,
doi = {10.1016/j.jgar.2026.10.001},
url = {https://doi.org/10.1016/j.jgar.2026.10.001},
note = {CC BY},
}
RIS
TY - JOUR
TI - Comparison of the
AU - Mark A. Estabrook
AU - Gregory G. Stone
AU - Katherine K. Perez
AU - James A. Karlowsky
PY - 2026
DA - 2026/10/31
JO - Journal of Global Antimicrobial Resistance
DO - 10.1016/j.jgar.2026.10.001
UR - https://doi.org/10.1016/j.jgar.2026.10.001
AB - Objectives: To provide a descriptive analysis of the in vitro antimicrobial susceptibility testing results for all 39,661 Pseudomonas aeruginosa isolates collected by the ATLAS global surveillance programme data from 2020 to 2024 with a focus on ceftazidime-avibactam and ceftolozane-tazobactam activities against carbapenem-resistant and DTR (difficult-to-treat resistance) phenotypes. Methods: MICs were determined using reference CLSI broth microdilution testing and interpreted by 2026 CLSI and EUCAST breakpoints. Results: Ceftazidime-avibactam (90.6% susceptible; MIC 90 , 8 µg/mL) and ceftolozane-tazobactam (89.8% susceptible; MIC 90 , 8 µg/mL) demonstrated similar in vitro activities against all P. aeruginosa isolates. Percent susceptible values for ceftazidime-avibactam, ceftolozane-tazobactam, and meropenem were lowest in Africa (ceftazidime-avibactam, 84.6%; ceftolozane-tazobactam, 82.1%; meropenem, 74.0%) and Latin America (86.5%; 84.7%; 69.8%), and highest in North America (94.8%; 95.1%; 81.6%) and the South Pacific (96.2%; 96.3%; 88.9%). Annual percent susceptible values for ceftazidime-avibactam (range, 90.2% in 2023 to 91.6% in 2022) and ceftolozane-tazobactam (range, 89.6% in 2023 to 90.8% in 2022) did not change over the five years studied. Overall, 26.1% of isolates were carbapenem-resistant; 68.0% and 65.6% of carbapenem-resistant isolates were ceftazidime-avibactam-susceptible and ceftolozane-tazobactam-susceptible, respectively. A DTR phenotype was present for 8.0% of isolates; 30.4% and 28.5% of DTR isolates were ceftazidime-avibactam-susceptible and ceftolozane-tazobactam-susceptible, respectively. In total, 4,641 of all 39,661 isolates (11.7%) were ceftazidime-avibactam-resistant and/or ceftolozane-tazobactam-nonsusceptible; 67.5% of these isolates were both ceftazidime-avibactam-resistant and ceftolozane-tazobactam-nonsusceptible, 19.6% were ceftolozane-tazobactam-nonsusceptible and ceftazidime-avibactam-susceptible, and 12.9% were ceftazidime-avibactam-resistant and ceftolozane-tazobactam-susceptible. Conclusion: Approximately 90% of global clinical isolates of P. aeruginosa from 2020 to 2024 remained susceptible to ceftazidime-avibactam and ceftolozane-tazobactam.
SN - 2213-7165
SN - 2213-7173
ER -