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.

Background: 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. Materials and Methods: 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. Results: 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). Conclusion: 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.

10-DEBC Hydrochloride as a Promising New Agent against Infection of Mycobacterium abscessus.

Mycobacterium abscessus (M. abscessus) causes chronic pulmonary infections. Its resistance to current antimicrobial drugs makes it the most difficult non-tuberculous mycobacteria (NTM) to treat with a treatment success rate of 45.6%. Therefore, there is a need for new therapeutic agents against M. abscessus. We identified 10-DEBC hydrochloride (10-DEBC), a selective AKT inhibitor that exhibits inhibitory activity against M. abscessus. To evaluate the potential of 10-DEBC as a treatment for lung disease caused by M. abscessus, we measured its effectiveness in vitro. We established the intracellular activity of 10-DEBC against M. abscessus in human macrophages and human embryonic cell-derived macrophages (iMACs). 10-DEBC significantly inhibited the growth of wild-type M. abscessus and clinical isolates and clarithromycin (CLR)-resistant M. abscessus strains. 10-DEBC's drug efficacy did not have cytotoxicity in the infected macrophages. In addition, 10-DEBC operates under anaerobic conditions without replication as well as in the presence of biofilms. The alternative caseum binding assay is a unique tool for evaluating drug efficacy against slow and nonreplicating bacilli in their native caseum media. In the surrogate caseum, the mean undiluted fraction unbound (fu) for 10-DEBC is 5.696. The results of an in vitro study on the activity of M. abscessus suggest that 10-DEBC is a potential new drug for treating M. abscessus infections.

Clomiphene Citrate Shows Effective and Sustained Antimicrobial Activity against Mycobacterium abscessus.

Mycobacterium abscessus (M. abscessus) causes chronic pulmonary infections and is the most difficult non-tuberculous mycobacteria (NTM) to treat due to its resistance to current antimicrobial drugs, with a treatment success rate of 45.6%. Thus, novel treatment drugs are needed, of which we identified the drug clomiphene citrate (CC), known to treat infertility in women, to exhibit inhibitory activity against M. abscessus. To assess the potential of CC as a treatment for M. abscessus pulmonary diseases, we measured its efficacy in vitro and established the intracellular activity of CC against M. abscessus in human macrophages. CC significantly inhibited the growth of not only wild-type M. abscessus strains but also clinical isolate strains and clarithromycin (CLR)-resistant strains of M. abscessus. CC's drug efficacy did not have cytotoxicity in the infected macrophages. Furthermore, CC worked in anaerobic non-replicating conditions as well as in the presence of biofilm. The results of this in vitro study on M. abscessus activity suggest the possibility of using CC to develop new drug hypotheses for the treatment of M. abscessus infections.

Biobank for multidrug-resistant tuberculosis research: importance of sequential samples.

Since 2013, Masan National Tuberculosis Hospital has collected standardized specimens from its tuberculosis patients, which include a large number of multidrug-resistant strains. The repository collects matched participants and their bacilli samples, compiling sequential samples from the beginning of treatment. The repository aims to provide resources for in-depth international research.