title: In Vitro Activities of Tedizolid and Linezolid against Gram-Positive Cocci Associated with Acute Bacterial Skin and Skin Structure Infections and Pneumonia.
abstract: Tedizolid is a novel, expanded-spectrum oxazolidinone with potent activity against a wide range of Gram-positive pathogens. A total of 425 isolates of Gram-positive bacteria were obtained consecutively from patients with acute bacterial skin and skin structure infections (ABSSSIs) or pneumonia. These isolates included methicillin-susceptible Staphylococcus aureus (MSSA) (n = 100), methicillin-resistant Staphylococcus aureus (MRSA) (n = 100), Streptococcus pyogenes (n = 50), Streptococcus agalactiae (n = 50), Streptococcus anginosus group (n = 75), Enterococcus faecalis (n = 50), and vancomycin-resistant enterococci (VRE) (Enterococcus faecium) (n = 50). The MICs of tedizolid and linezolid were determined by the agar dilution method. Tedizolid exhibited better in vitro activities than linezolid against MSSA (MIC90s, 0.5 versus 2 μg/ml), MRSA (MIC90s, 0.5 versus 2 μg/ml), S. pyogenes (MIC90s, 0.5 versus 2 μg/ml), S. agalactiae (MIC90s, 0.5 versus 2 μg/ml), Streptococcus anginosus group (MIC90s, 0.5 versus 2 μg/ml), E. faecalis (MIC90s, 0.5 versus 2 μg/ml), and VRE (MIC90s, 0.5 versus 2 μg/ml). The tedizolid MICs against E. faecalis (n = 3) and VRE (n = 2) intermediate to linezolid (MICs, 4 μg/ml) were 1 μg/ml and 0.5 μg/ml, respectively. The tedizolid MIC90s against S. anginosus, S. constellatus, and S. intermedius were 0.5, 1, and 0.5 μg/ml, respectively, and the rates of susceptibility based on the U.S. FDA MIC interpretive breakpoints to the isolates were 16%, 28%, and 72%, respectively. Tedizolid exhibited 2- to 4-fold better in vitro activities than linezolid against a variety of Gram-positive cocci associated with ABSSSIs and pneumonia. The lower susceptibilities of tedizolid against isolates of S. anginosus and S. constellatus than against those of S. intermedius in Taiwan were noted.
authors.affiliation: Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan Department of Clinical Pathology, Tri-Service General Hospital Songshan Branch, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Ko-Hung
authors.initials: KH
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Yu-Tsung
authors.initials: YT
authors.lastname: Huang
authors.affiliation: Department of Internal Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Chun-Hsing
authors.initials: CH
authors.lastname: Liao
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Wang-Hui
authors.initials: WH
authors.lastname: Sheng
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan hsporen@ntu.edu.tw.
authors.forename: Po-Ren
authors.initials: PR
authors.lastname: Hsueh
mesh_terms: D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000254:growth & development; D016984:Enterococcus faecium / Q000187:drug effects / Q000254:growth & development; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology / Q000473:pathology; D006801:Humans; D000069349:Linezolid / Q000494:pharmacology*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D010755:Organophosphates / Q000494:pharmacology*; D010080:Oxazoles / Q000494:pharmacology*; D018410:Pneumonia, Bacterial / Q000382:microbiology / Q000473:pathology; D013207:Staphylococcal Skin Infections / Q000382:microbiology / Q000473:pathology; D013290:Streptococcal Infections / Q000382:microbiology / Q000473:pathology; D013292:Streptococcus agalactiae / Q000187:drug effects / Q000254:growth & development; D034366:Streptococcus anginosus / Q000187:drug effects / Q000254:growth & development; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000254:growth & development; D013624:Taiwan; D065507:Vancomycin-Resistant Enterococci / Q000187:drug effects / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D010755:Organophosphates; D010080:Oxazoles; D000069349:Linezolid; C515040:tedizolid phosphate