title: Synergistic effects of vancomycin and β-lactams against vancomycin highly resistant Staphylococcus aureus.
abstract: We previously reported isolating vancomycin (VAN) highly resistant Staphylococcus aureus (VRSA) strains from clinical methicillin-resistant S. aureus strains by repeating steps of in vitro mutagenesis and VAN selection. Here we describe that the in vitro susceptibility of these VRSA strains to VAN was markedly increased by combined treatment with β-lactams such as ceftriaxone and oxacillin. Furthermore, in an in vivo silkworm infection model with VRSA, a combination of VAN and ceftriaxone exhibited therapeutic effects, whereas a combination of VAN and oxacillin did not. These findings suggest that combining VAN with an appropriate β-lactam, such as ceftriaxone, is therapeutically effective against infectious diseases caused by VRSA.
authors.affiliation: Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Tabuchi
authors.affiliation: Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.|Institute of Medical Mycology, Teikyo University, Tokyo, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Matsumoto
authors.affiliation: Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ishii
authors.affiliation: Department of Infection Control and Prevention, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Tatsuno
authors.affiliation: Department of Medical Technology, School of Health Sciences, Tokyo University of Technology, Tokyo, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Okazaki
authors.affiliation: Department of Infection Control and Prevention, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Sato
authors.affiliation: Department of Infection Control and Prevention, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Kyoji
authors.initials: K
authors.lastname: Moriya
authors.affiliation: Laboratory of Microbiology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.|Institute of Medical Mycology, Teikyo University, Tokyo, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Sekimizu
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D012831:Bombyx; D002443:Ceftriaxone / Q000008:administration & dosage / Q000494:pharmacology; D004195:Disease Models, Animal; D004357:Drug Synergism; D008826:Microbial Sensitivity Tests; D010068:Oxacillin / Q000008:administration & dosage / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects*; D014640:Vancomycin / Q000008:administration & dosage / Q000494:pharmacology*; D020713:Vancomycin Resistance; D047090:beta-Lactams / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D014640:Vancomycin; D002443:Ceftriaxone; D010068:Oxacillin