title: In vitro evaluation of AZD2563, a new oxazolidinone, tested against beta-haemolytic and viridans group streptococci.
abstract: Linezolid was the first clinically applied agent from the oxazolidinone class, and AZD2563, a new agent, is described here. Five hundred and twenty-five streptococcal isolates were tested, including beta-haemolytic (266) and viridans group (259) species. MIC(50)/MIC(90)/% susceptible (susceptibility breakpoint <2 mg/L of AZD2563) results were, for beta-haemolytic species: AZD2563 (1/2/100), linezolid (1/2/100), quinupristin-dalfopristin (0.25/0.25/100), vancomycin (0.25/0.5/100) and levofloxacin (0.5/1/99); for viridans group species: AZD2563 (0.5/1/100), linezolid (1/1/100), quinupristin-dalfopristin (0.5/1/99), vancomycin (0.5/0.5/100) and levofloxacin (1/1/98). The modal MICs of AZD2563 and linezolid were 0.5 or 1 mg/L and 1 mg/L, respectively. AZD2563 activity screening against these non-pneumococcal streptococci indicated a slightly greater potency of AZD2563 when compared with linezolid. All AZD2563 MICs were <2 mg/L.
authors.affiliation: The Jones Group/JMI Laboratories, North Liberty, IA 52317, USA.
authors.forename: Tamara R
authors.initials: TR
authors.lastname: Anderegg
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Biedenbach
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
mesh_terms: D004353:Drug Evaluation, Preclinical / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000706:statistics & numerical data; D023303:Oxazolidinones / Q000494:pharmacology*; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000302:isolation & purification; D034363:Viridans Streptococci / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D023303:Oxazolidinones; C453362:posizolid