In vitro activity of thiamphenicol against Haemophilus influenzae, Streptococcus pneumoniae and Streptococcus pyogenes clinical isolates

Objective. To determine in vitro activity of thiamphenicol and other clinically available antimicrobials against clinical isolates Haemophilus influenzae, Streptococcus pneumoniae pyogenes. Materials Methods. We included the study 875 from 20 Russian cities during 2018–2019. Among tested strains, 126 were H. 389 – S. pneumoniae, 360 Antimicrobial susceptibility testing was performed using broth microdilution method according to ISO 20776-1:2006. AST results interpreted EUCAST v.11.0 breakpoints. Results. The minimum inhibitory concentrations (MICs) did not exceed 2 mg/L for 94.4% influenzae strains (MIC50 MIC90 0.5 1 mg/L, respectively). Thiamphenicol active 76.9% ampicillin-resistant (MIC < mg/L). MIC range 0.06–2 96.7% 90.6% with reduced penicillin > 0.06 mg/L) mg/L. A total 88.1% resistant erythromycin highly susceptible 8 96.1% pyogenes 4 Conclusions. characterized by relatively high activity, comparable that chloramphenicol, pyogenes, including penicillin.