[Differences in susceptibility of Helicobacter pylori to macrolide and other antibiotics in tests using blood agar and albumin agar].

Minimum inhibitory concentrations (MICs) of penicillin G, cefazolin, tetracycline, chloramphenicol, four aminoglycosides, and seven macrolides against Helicobacter pylori strains were determined on Brucella agar supplemented with bovine serum albumin fraction V (albumin agar) and compared with those on blood agar. MICs of the macrolides against H. pylori determined on albumin agar were markedly lower than those found with blood agar. The susceptibilities of 26 H. pylori strains to the macrolides were estimated from the MIC50 values determined on blood agar and albumin agar, which were 0.39 and < or = 0.05 micrograms/ml for erythromycin, midecamycin and rokitamycin, 3.13 and 0.10 micrograms/ml for clindamycin, 1.56 and < or = 0.05 micrograms/ml for josamycin, 1.56 and 0.10 micrograms/ml for kitasamycin, and 0.10 and < or = 0.05 micrograms/ml for roxithromycin, respectively. However, the MICs of other antibiotics against H. pylori and of all antibiotics against two reference Campylobacter strains differed minimally between values obtained on blood agar and albumin agar.