Analysis of the Major Histocompatibility Complex Class I Antigen Presentation Machinery in Human Lung Cancer

다국어 초록 (Multilingual Abstract)

Susceptibility of 61 strains of Helicobacter pylori to metronidazole was examined by both the disk diffusion method using a cut-off of 15㎜ for resistance and the E test with a cut-off of 8㎎/l. The MIC_50 and MIC_90 by the E test were 2㎎/l and 256㎎/l, respectively. Metronidazole resistance was found in 22(36%) out of the 61 H. pylori strains by the E test and in three additional strains by the disk diffusion method. Amongst the latter three isolates, the MICs by the E test were 4㎎/l, 6㎎/l, and 6㎎/l, respectively. These figures are one log_2 or half log_2 dilution lower than the cut-off of 8㎎/l recommended as resistance for the E test. All 22 metronidazole resistant H. pylori isolates by the E test that were subjected to random amplified polymorphic DNA (RAPD) fingerprinting showed different DNA fingerprints. Interestingly, >90% of resistant isolates possess two common DNA bands of 0.4 and 0.9kb. This study demonstrates that the results of the disk diffusion method for testing H. pylori susceptibility to metronidazole correlates well with that of the E test. The criteria for interpretation need to be internationally standardized so that the results from different centers can be compared.