Validation and comparative analysis of kogene mycobacterial interspersed repetitive unit-variable number of tandem repeat typing kit and its application on clinically isolated mycobacterium tuberculosis samples from national tuberculosis hospital, Republic of Korea.

Abstract

Tuberculosis (TB) remains a serious public health burden in Korea. Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat (MIRU-VNTR) is preferred for epidemiological TB investigation. Until recently, the difficulty lies in epidemiological TB investigation due to the absence of commercialized MIRU-VNTR in Korea. Here, we have evaluated the newly designed MIRU-VNTR kit by Kogenebiotech, Korea. A total of 200 samples, where 100 are Mycobacrerium tuberculosis (M. tuberculosis), and the other 100 are non-M. tuberculosis, were used. Initially, the Kogenebiotech MIRU-VNTR typing kit (KoMIRU) was compared with Multilocus Variable Number Tandem Repeat Genotyping of M. tuberculosis typing kit (MVNTR) by Philip Supply for validation purpose. Then, Limit of Detection for DNA copies was optimized. Finally, KoMIRU and Genoscreen MIRU-VNTR typing kit (GeMIRU) were tested and comparatively analyzed for its specificity and sensitivity. The study showed that the KoMIRU has slightly higher discriminatory power over MVNTR, 100% versus 97.5%. In comparative analysis, the KoMIRU has shown comparable capability as GeMIRU, showing 100% for sensitivity and specificity with a 95% CI value of 96.38 to 100.00%. Also, no discrepancies were observed on discriminated lineage strains between KoMIRU and GeMIRU. Out of 100, 84 were identified as Beijing strains, and remains were identified as NEW-1 (n = 8), Uganda (n = 6), East African Indian (EAI) (n = 6), Turkey (n = 2), and Haarlem (n = 1). In this study, KoMIRU has shown a comparable capability to GeMIRU. Furthermore, previous researches had suggested an association between lineage strains and drug resistance; hence, the implementation of KoMIRU can help in TB control and prevention.