Abstract
OBJECTIVE: To determine the epidemiological cut-off (ECOFF) values of etimicin against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus. METHODS: We selected 1500 isolates from five hospitals throughout five cities in China spanning from January 2018 to December 2021 in the study. Minimal inhibit concentrations (MICs) of etimicin were determined using the broth microdilution method. ECOFFs of etimicin against six species were calculated using ECOFFinder software and visual estimation following EUCAST principles. RESULTS: MICs of etimicin were distributed from 0.064 to >128 mg/L for S. aureus, from 0.125 to >128 mg/L for P. aeruginosa, from 0.25 to >128 mg/L for K. pneumoniae, P. mirabilis and A. baumannii, and from 0.5 to >128 mg/L for E. coli. The MIC ECOFF of etimicin was 2 mg/L for K. pneumoniae, 8 mg/L for E. coli and P. mirabilis, 16 mg/L for P. aeruginosa and A. baumannii, and the tentative ECOFF (TECOFF) of etimicin was 2 mg/L for S. aureus. CONCLUSIONS: (T)ECOFFs of etimicin against E. coli, K. pneumoniae, P. mirabilis, P. aeruginosa, A. baumannii and S. aureus were determined, which will be helpful to differentiate wild-type strains.