Cefiderocol susceptibility of Achromobacter spp.: study of an accurately identified collection of 230 strains

• Published in: Annals of clinical microbiology and antimicrobials Vol. 23; no. 1; pp. 54 - 13
• Main Authors: Jean-Pierre, Vincent, Sorlin, Pauline, Pantel, Alix, Chiron, Raphaël, Lavigne, Jean-Philippe, Jeannot, Katy, Marchandin, Hélène
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 17-06-2024; BioMed Central; BMC
• Subjects: Achromobacter; Achromobacter - classification; Achromobacter - drug effects; Achromobacter - genetics; Achromobacter - isolation & purification; Analysis; Anti-Bacterial Agents - pharmacology; Antibacterial agents; Care and treatment; Cefiderocol; Cephalosporins - pharmacology; Cystic fibrosis; Cystic Fibrosis - microbiology; Diagnosis; Disease susceptibility; Dosage and administration; Gram-Negative Bacterial Infections - microbiology; Humans; Microbial Sensitivity Tests; Opportunistic pathogen; RNA sequencing; Susceptibility; France; Cystic fibrosis; Cefiderocol; Susceptibility; Opportunistic pathogen; Achromobacter
• ISSN: 1476-0711; 1476-0711
• DOI: 10.1186/s12941-024-00709-z

Achromobacter spp. are opportunistic pathogens, mostly infecting immunocompromised patients and patients with cystic fibrosis (CF) and considered as difficult-to-treat pathogens due to both intrinsic resistance and the possibility of acquired antimicrobial resistance. Species identification remains challenging leading to imprecise descriptions of resistance in each taxon. Cefiderocol is a broad-spectrum siderophore cephalosporin increasingly used in the management of Achromobacter infections for which susceptibility data remain scarce. We aimed to describe the susceptibility to cefiderocol of a collection of Achromobacter strains encompassing different species and isolation sources from CF or non-CF (NCF) patients.
We studied 230 Achromobacter strains (67 from CF, 163 from NCF patients) identified by nrdA gene-based analysis, with available susceptibility data for piperacillin-tazobactam, meropenem and trimethoprim-sulfamethoxazole. Minimal inhibitory concentrations (MICs) of cefiderocol were determined using the broth microdilution reference method according to EUCAST guidelines.
Strains belonged to 15 species. A. xylosoxidans represented the main species (71.3%). MICs ranged from ≤ 0.015 to 16 mg/L with MIC
of ≤ 0.015/0.5 mg/L overall and 0.125/2 mg/L against 27 (11.7%) meropenem-non-susceptible strains. Cefiderocol MICs were not related to CF/NCF origin or species although A. xylosoxidans MICs were statistically lower than those of other species considered as a whole. Considering the EUCAST non-species related breakpoint (2 mg/L), 228 strains (99.1%) were susceptible to cefiderocol. The two cefiderocol-resistant strains (A. xylosoxidans from CF patients) represented 3.7% of meropenem-non-susceptible strains and 12.5% of MDR strains.
Cefiderocol exhibited excellent in vitro activity against a large collection of accurately identified Achromobacter strains, irrespective of species and origin.