title: Comparison of drug resistance genotypes between Beijing and non-Beijing family strains of Mycobacterium tuberculosis in Korea.
abstract: The frequency of resistance genotypes among Beijing and non-Beijing strains was compared using a reverse blot hybridization assay to detect mutations within genes associated with rifampicin (rpoB) and isoniazid (katG, inhA, and ahpC) resistance. Of the 743 Mycobacterium tuberculosis isolates, 569 (77%) belonged to Beijing family. The proportion of Beijing strains was significantly higher among MDR-TB isolates than among drug-susceptible strains (82% vs. 72%, p<0.01). Genotype analysis of the rpoB gene revealed significantly lower rates of the Ser531Leu mutation rate among Beijing vs. non-Beijing MDR-TB strains (41% vs. 66%, p<0.005). While the mutation for Ser315Thr in the katG gene was more common among Beijing vs. non-Beijing family strains (65% vs. 50%, p<0.01), the mutation rate of promoter region of the inhA gene was lower among Beijing strains compared with non-Beijing strains (14% vs. 25%, p<0.05). Reverse hybridization successfully detected over 80% of isoniazid-resistant strains and over 92% of rifampicin-resistant strains among Korean isolates. Significant differences in mutation rates in the rpoB, katG, and inhA genes between Beijing strains and non-Beijing strains could explain discrepancies in mutation rates of genotypes in different countries. Reverse hybridization was useful for rapid detection of isoniazid and rifampicin resistant strains.
authors.affiliation: Korean Institute of Tuberculosis, Seoul 137-900, South Korea. ypark7@empal.com
authors.forename: Young Kil
authors.initials: YK
authors.lastname: Park
authors.forename: Sonya
authors.initials: S
authors.lastname: Shin
authors.forename: Sungweon
authors.initials: S
authors.lastname: Ryu
authors.forename: Sang Nae
authors.initials: SN
authors.lastname: Cho
authors.forename: Won-Jung
authors.initials: WJ
authors.lastname: Koh
authors.forename: O Jung
authors.initials: OJ
authors.lastname: Kwon
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Shim
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Lew
authors.forename: Gill Han
authors.initials: GH
authors.lastname: Bai
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002681:China; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000187:drug effects* / Q000235:genetics; D015995:Prevalence; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology* / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins