Evaluation of the GenoType® MTBDRsl assay in Korean patients with MDR or XDR tuberculosis

Abstract

Background This study used the GenoType® MTBDRsl assay (MTBDRsl, Hain Lifescience, Nehren, Germany), an assay for anti-tuberculosis drug susceptibility testing, for the detection of resistance of 40 tuberculosis strains to fluroquinolones (FLQ), injectable drugs (amikacin or capreomycin) and ethambutol to identify multi-drug resistant and extensively drug-resistant tuberculosis patients previously identified by solid drug susceptibility test (DST). Methods These tuberculosis strains were analysed by both DNA sequencing and conventional drug susceptibility testing on solid medium. Results The overall agreement rates of the MTBDRsl assay and phenotypic drug susceptibility testing for the detection of ofloxacin (OXF), moxifloxacin (MXF), amikacin (AMK), capreomycin (CPM) and ethambutol (EMB) susceptibility in clinical strains were 87.5% (35/40), 87.5% (35/40), 97.5% (39/40), 60.0% (24/40) and 65.0% (26/40), respectively. Conclusions This study reconfirmed 37 extensively drug-resistant tuberculosis strains using the MTBDRsl assay and these strains were verified by phenotypic drug susceptibility testing. After identification with the MTBDRsl assay, the results were analysed by DNA sequencing with specific primers. From the various mutations identified in the DNA sequencing results, this study found new mutations that characterised EMB-resistant strains, namely, R507K and G406T mutations, which had not been previously reported.

Keywords:

• GenoType® MTBDRsl
• MDR
• XDR
• tuberculosis
• anti-tuberculosis drug susceptibility testing

Acknowledgements

This research was partially supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology (2010-0025229). This research was partially supported by the National Research Foundation of Korea (NRF), funded by the Ministry of Health and Welfare, Republic of Korea (HI13C0866, HI13C1468). This research was partially supported by the Pioneer Research Center Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT & Future Planning (NRF-2012-0009555). This research was partially supported by Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2015K1A4A3047345).

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.