Antimicrobial Activity of Sulbactam-Durlobactam Against Acinetobacter baumannii-Calcoaceticus Complex Strains Causing Non-Respiratory and Non-Bloodstream Infections From the United States (2023–2025)

Authors

• Elizabeth Cyr
• Jill Argotsinger
• Eric T Beck
• Robin R Chamberland
• Andrew E Clark
• Anne R Daniels
• Rachael Liesman
• Mark Fisher
• Philip Gialanella
• Jonathan Hand
• Amanda T Harrington
• Romney M Humphries
• Holly Huse
• Robert Hamilton-Seth
• Julia D Hankins
• Wesley D Kufel
• Scott W Riddell
• Meera Mehta
• Ryan Demkowicz
• A Brian Mochon
• Hossein Salimnia
• Ayesha Khan
• Virginia M Pierce
• Raghava Potula
• Tsigereda Tekle
• Patricia J Simner
• Robert J Tibbetts
• Christine Vu
• Lilian M Abbo
• Octavio Martinez
• Rebekah E Dumm
• Manohar B Mutnal
• Timothy C Jenkins
• Violeta Chávez
• Paulette Pinargote
• Jennifer Bowling
• Erik Munson
• Daniel V Zurawski
• David P Nicolau
• Tomefa E Asempa
• On behalf of the Acinetobacter baumannii Complex National Biorepository (ACNBio) Study Group

Language

English

Publication Date

3-23-2026

Journal

Microbiology Spectrum

DOI

10.1128/spectrum.03289-25

PMID

41869812

PMCID

PMC13141879

PubMedCentral® Posted Date

3-23-2026

PubMedCentral® Full Text Version

Post-print

Abstract

Acinetobacter baumannii most often causes pneumonia in critically ill patients. However, A. baumannii is also an important cause of a broader range of infections, including skin/wound and urinary tract infections. This study aims to evaluate the in vitro activity of sulbactam-durlobactam and comparator antibiotics, including meropenem and cefiderocol against A. baumannii-calcoaceticus complex isolates from non-respiratory and non-bloodstream sources. Samples included 285 A. baumannii-calcoaceticus complex isolates enriched for carbapenem resistance collected across 17 states in the United States (January 2023–May 2025). Antimicrobial susceptibility tests were conducted by manual broth microdilution and interpreted according to Clinical and Laboratory Standards Institute (CLSI) and Food and Drug Administration (FDA) (cefiderocol) standards. A. baumannii complex isolates were primarily cultured from skin/wound (58.6%), urinary tract (31.6%), and other sources (9.8%), including cerebrospinal and peritoneal fluid. Carbapenem resistance was observed in approximately 70% of isolates and more common among skin/wound cultures. Sulbactam-durlobactam was observed to be highly active (96.9% susceptible [S]; MIC90 4 mg/L) and demonstrated greater activity than sulbactam (37.9% S; MIC90 32 mg/L). Sulbactam-durlobactam also displayed high susceptibility rates across isolate sources, ranging from 96.4 (skin/wound) to 97.8% (urine). Cefiderocol demonstrated similar in vitro activity across culture sources and patient location, inhibiting >90 and >80% of isolates at CLSI and FDA susceptible breakpoints, respectively. Minocycline susceptibility was 69.1%, while tigecycline and eravacycline MICs50/90 were 1/4 and 0.5/1 mg/L, respectively. The observed data are consistent with results from surveillance studies among respiratory and bloodstream isolates and show that sulbactam-durlobactam demonstrates potent in vitro activity against clinical A. baumannii complex isolates from a variety of culture sources.

Keywords

Acinetobacter, meropenem, CRAB, sulbactam-durlobactam

Published Open-Access

yes

Recommended Citation

Cyr, Elizabeth; Argotsinger, Jill; Beck, Eric T; et al., "Antimicrobial Activity of Sulbactam-Durlobactam Against Acinetobacter baumannii-Calcoaceticus Complex Strains Causing Non-Respiratory and Non-Bloodstream Infections From the United States (2023–2025)" (2026). Faculty, Staff and Student Publications. 4069.
https://digitalcommons.library.tmc.edu/uthmed_docs/4069