title: Epigallocatechin gallate synergy with ampicillin/sulbactam against 28 clinical isolates of methicillin-resistant Staphylococcus aureus.
abstract: Compared with ampicillin, oxacillin, cefmetazole and imipenem, the combination of ampicillin and sulbactam at a constant ratio of 2:1 showed the greatest effect against 28 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), but MICs of ampicillin/sulbactam were still above the resistance breakpoint. When ampicillin/sulbactam was further combined with epigallocatechin gallate (EGCg, a main constituent of tea catechins), the MIC90 of ampicillin/ sulbactam was reduced to 4 mg/L, the susceptibility breakpoint. The fractional inhibitory concentration indices were between 0.19 and 0.56 in combination with 6.25 and 25 mg/L EGCg, respectively, indicating that ampicillin/sulbactam and EGCg combination may be effective against MRSA infections.
authors.affiliation: Department of Microbiology and Immunology, Showa University School of Medicine, Tokyo, Japan. zqhu@med.showa-u.ac.jp
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Hu
authors.forename: W H
authors.initials: WH
authors.lastname: Zhao
authors.forename: Y
authors.initials: Y
authors.lastname: Hara
authors.forename: T
authors.initials: T
authors.lastname: Shimamura
mesh_terms: D000667:Ampicillin / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects*; D013407:Sulbactam / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D000667:Ampicillin; D002392:Catechin; C045651:epigallocatechin gallate; D013407:Sulbactam