Comparison of drug resistance genotypes between Beijing and non-Beijing family strains of Mycobacterium tuberculosis in Korea.
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.
Park
Young Kil
YK
Korean Institute of Tuberculosis, Seoul 137-900, South Korea. ypark7@empal.com
Shin
Sonya
S
Ryu
Sungweon
S
Cho
Sang Nae
SN
Koh
Won-Jung
WJ
Kwon
O Jung
OJ
Shim
Young Soo
YS
Lew
Woo Jin
WJ
Bai
Gill Han
GH
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
D000995:Antitubercular Agents; D001426:Bacterial Proteins