Rapid Drug Susceptibility Testing for Isoniazid and Rifampicin by Reverse Hybridization Assay.

Park, Young Kil; Yu, Hee Kyoung; Ryu, Sung Weon; Bai, Gill Han

doi:2003.55.5.440

Tuberc Respir Dis > Volume 55(5); 2003 > Article

Original Article

Tuberculosis and Respiratory Diseases 2003;55(5):440-448.
DOI: https://doi.org/10.4046/trd.2003.55.5.440 Published online November 1, 2003.

Rapid Drug Susceptibility Testing for Isoniazid and Rifampicin by Reverse Hybridization Assay.

Young Kil Park, Hee Kyoung Yu, Sung Weon Ryu, Gill Han Bai

Korean Institute of Tuberculosis, Seoul, Korea. gbai@hotmail.com

Abstract

BACKGROUND
Development of rapid drug susceptibility testing provides the opportunity for rapid identification of individuals with drug resistant tubercle bacilli, allowing selection of appropriate therapeutic regimens. METHODS: A total of 502 drug resistant isolates were subjected to reverse blot hybridization assay to detect mutations within genes (rpoB, katG, inhA, and ahpC) associated with rifampicin (RMP) and isoniazid (INH) resistance. RESULTS: Among the 264 RMP resistant strains (RMPR) tested, the most prevalent mutation was the Ser531Leu seen in 121 strains (46%). The second common mutation occurred in 84 strains (32%) at codon 526. And 27 strains (10%) showed the mutation at codon 516. Among all 469 INH resistant strains (INHR), the katG mutation was responsible for INH. The inhA mutation was present in 88 strains (19%). In 11 isolates (2%), coexisting of the katG and inhA mutations were identified. Reverse hybridization assay successfully detected over 80% of INHR and over 92% of RMPR among Korean isolates. CONCLUSION: Reverse hybridization was useful for rapid detection of INHR and RMPR.

Key Words: Mycobacterium tuberculosis, Korea, Beijing family, genotypes, rpoB, katG, inhA