title: Study of the synergism between carbapenems and vancomycin or teicoplanin against MRSA, focusing on S-4661, a carbapenem newly developed in Japan.
abstract: S-4661 is a methylcarbapenem antibiotic newly developed in Japan. We evaluated the combined actions of carbapenems, including S-4661 and vancomycin or teicoplanin, against 27 strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated from the blood of patients admitted to Keio University Hospital, using the checkerboard technique. The minimum inhibitory concentrations (MICs) were determined by the Mueller-Hinton agar method. Most of the strains were highly resistant to carbapenems. Synergy with S-4661, panipenem, meropenem or imipenem, and vancomycin was detected against 92% of the strains tested. Synergy with S-4661, panipenem, meropenem or imipenem, and teicoplanin was detected against 74% of the strains tested. The results of our study suggest that combination therapy of vancomycin or teicoplanin with any of S-4661, panipenem, meropenem, or imipenem would be effective for severe infections due to MRSA strains that are resistant to carbapenems.
authors.affiliation: Division of Clinical Microbiology, Department of Clinical Laboratories, Keio University Hospital, 35 Shinano-machi, Tokyo 160-8582, Japan. umiyama@sc.itc.keio.ac.jp
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000382:microbiology; D015780:Carbapenems / Q000494:pharmacology*; D000077726:Doripenem; D024881:Drug Resistance, Bacterial; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D006801:Humans; D007564:Japan; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000379:methods; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects*; D017334:Teicoplanin / Q000494:pharmacology*; D014640:Vancomycin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D017334:Teicoplanin; D014640:Vancomycin; D000077726:Doripenem