Antibiotics
In Vitro Activity of Eravacycline, Aztreonam-Avibactam, and Cefiderocol Against Multidrug-Resistant Gram-Negative Clinical Isolates from a Romanian Tertiary Hospital
By Baicus A, Sisu VD, Tatar AD and 4 others.
Abstract
Background/objectives
Carbapenem-resistant Gram-negative bacteria-especially NDM- and OXA-48-producing Klebsiella pneumoniae and carbapenem-resistant Acinetobacter baumannii (CRAB)-have limited treatment options, and in vitro data from Eastern Europe on the reserve agents eravacycline, aztreonam-avibactam, and cefiderocol are scarce. We evaluated their in vitro activity against consecutive multidrug-resistant (MDR) Gram-negative isolates from a Romanian tertiary hospital, stratified by species and carbapenemase profile.
Methods
Seventy-seven consecutive, non-duplicate MDR Gram-negative isolates were collected over a 12-week period (January-March 2026) at a single tertiary center and tested by gradient diffusion (Liofilchem MIC Test Strip). MTS was used as an exploratory screening method; reference broth microdilution (BMD) remains the standard for categorical susceptibility confirmation. MICs were interpreted using FDA and EUCAST v16.0 breakpoints. Carbapenemases were detected by immunochromatography (18 isolates), and carbapenemase-encoding genes were detected by Xpert Carba-R PCR (40 isolates of K. pneumoniae). Susceptibility is reported with Wilson 95% confidence intervals.