title: Micro-broth dilution method with air-dried microplate for determining MICs of clarithromycin and amoxycillin for Helicobacter pylori isolates.
abstract: MICs of clarithromycin and amoxycillin for 253 isolates of Helicobacter pylori were measured by an air-dried microplate method and compared with the results obtained by the agar plate dilution method. The air-dried microplate method is performed by coating each well of a 96-well microplate with the test antibiotic and air-drying it. There were no marked differences between the air-dried microplate method and agar plate dilution methods in the MIC(50) and MIC(90) values or MIC ranges of clarithromycin obtained for the 253 isolates of H. pylori. More specifically, the MICs of clarithromycin for 114 (45.1 %) of the 253 isolates were the same by the air-dried microplate method as the agar plate dilution method, and the differences in the MICs of clarithromycin for a further 114 isolates (45.1 %) varied within one twofold dilution. The MICs of amoxycillin by the former method were in close agreement with the MICs obtained by the latter method: MICs of amoxycillin for 199 (78.7 %) of the 253 isolates were the same by both methods, and the differences in the MICs of amoxycillin for 42 isolates (16.6 %) varied within one twofold dilution. These results indicate that the air-dried microplate method is a useful method for determination of MICs, because the results obtained were in close agreement with those obtained by the standard agar plate dilution method. The air-dried microplate method is, therefore, a convenient and reliable method for determining the MICs of clarithromycin and amoxycillin for H. pylori isolates.
authors.affiliation: Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories, Inc., Tokyo, Japan 2,3Department of General Medicine2 and Second Department of Internal Medicine3, Oita University Faculty of Medicine, Oita, Japan.
authors.forename: Intetsu
authors.initials: I
authors.lastname: Kobayashi
authors.affiliation: Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories, Inc., Tokyo, Japan 2,3Department of General Medicine2 and Second Department of Internal Medicine3, Oita University Faculty of Medicine, Oita, Japan.
authors.forename: Hiroe
authors.initials: H
authors.lastname: Muraoka
authors.affiliation: Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories, Inc., Tokyo, Japan 2,3Department of General Medicine2 and Second Department of Internal Medicine3, Oita University Faculty of Medicine, Oita, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Saika
authors.affiliation: Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories, Inc., Tokyo, Japan 2,3Department of General Medicine2 and Second Department of Internal Medicine3, Oita University Faculty of Medicine, Oita, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Nishida
authors.affiliation: Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories, Inc., Tokyo, Japan 2,3Department of General Medicine2 and Second Department of Internal Medicine3, Oita University Faculty of Medicine, Oita, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Fujioka
authors.affiliation: Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories, Inc., Tokyo, Japan 2,3Department of General Medicine2 and Second Department of Internal Medicine3, Oita University Faculty of Medicine, Oita, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Nasu
mesh_terms: D000658:Amoxicillin / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017291:Clarithromycin / Q000494:pharmacology*; D003470:Culture Media; D005756:Gastritis / Q000382:microbiology; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000295:instrumentation / Q000379:methods*; D010437:Peptic Ulcer / Q000382:microbiology; D012015:Reference Standards
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D000658:Amoxicillin; D017291:Clarithromycin