Background: Drug resistant tuberculosis poses a great challenge for tuberculosis control worldwide. Timely determination of drug resistance and effective individual treatment are essential for blocking the transmission of drug resistant Mycobacterium tuberculosis. We aimed to establish and evaluate the accuracy of a reverse dot blot hybridization (RDBH) assay to simultaneously detect the resistance of four anti-tuberculosis drugs in M. tuberculosis isolated in China. Methods: In this study, we applied a RDBH assay to simultaneously detect the resistance of rifampicin (RIF), isoniazid (INH), streptomycin (SM) and ethambutol (EMB) in 320 clinical M. tuberculosis isolates and compared the results to that from phenotypic drug susceptibility testing (DST) and sequencing. The RDBH assay was designed to test up to 42 samples at a time. Pearson’s chi-square test was used to compute the statistical measures of the RDBH assay using the phenotypic DST or sequencing as the gold standard method, and Kappa identity test was used to determine the consistency between the RDBH assay and the phenotypic DST or sequencing. Results: The results showed that the concordances between phenotypic DST and RDBH assay were 95% for RIF, 92.8% for INH, 84.7% for SM, 77.2% for EMB and the concordances between sequencing and RDBH assay were 97.8% for RIF, 98.8% for INH, 99.1% for SM, 93.4% for EMB. Compared to the phenotypic DST results, the sensitivity and specificity of the RDBH assay for resistance detection were 92.4 and 98.5% for RIF, 90.3 and 97.3% for INH, 77.4 and 91.5% for SM, 61.4 and 85.7% for EMB, respectively; compared to sequencing, the sensitivity and specificity of the RDBH assay were 97.7 and 97.9% for RIF, 97.9 and 100.0% for INH, 97.8 and 100.0% for SM, 82.6 and 99.1% for EMB, respectively. The turnaround time of the RDBH assay was 7 h for testing 42 samples. Conclusions: Our data suggested that the RDBH assay could serve as a rapid and efficient method for testing the resistance of M. tuberculosis against RIF, INH, SM and EMB, enabling early administration of appropriate treatment regimens to the affected drug resistant tuberculosis patients.

: Leprosy is an infectious disease caused by Mycobacterium leprae. China was once one of the countries with severe leprosy epidemics, but its incidence has remained low in recent years. Despite this, there has been no decrease in its incidence more recently, and it is still a public health problem which needs to be controlled. In this study, we analyzed the epidemiological characteristics and trends in the detection rate of new cases of leprosy in China between 2004 and 2016. There were 4,519 cases of leprosy in 28 provinces, municipalities, and autonomous regions between 2004 and 2016, and the total incidence was 0.02815 (per 100,000 individuals) and 21 deaths. The overall incidence of leprosy showed an inverted “V” distribution (i.e., an increase followed by a decrease). Yunnan, Sichuan, Guangdong, Guizhou, and Guangxi were the top five regions with the highest incidence rates, and they accounted for 68.7% of the total cases. There were more male patients than female patients, and peasants accounted for 71.7% of the leprosy cases. The patients with leprosy in China were mainly concentrated in the age-group 15–44 years, as this group accounted for 57.2% of the total cases. The purpose of this study is to explore the epidemiology of leprosy in China. This analysis will be useful for future monitoring of leprosy and establishment of public health measures in China, in keeping with the “Programme for the Elimination of Leprosy in China 2011–2020.”

Background: MPT64 and PstS1 are the earliest known immune-dominant antigens of Mycobacterium tuberculosis and have been commonly used as candidates in the diagnosis of tuberculosis. Methods: We constructed recombinant plasmids pET-32a-Rv0934 and pET-32a-Rv1980c to express both wild and mutant forms of MPT64 and PstS1 and purified them. From November 9 to December 9, 2016, and November 9 to December 10, 2017, 96 patients with tuberculosis, 53 patients without tuberculosis, and 96 healthy volunteers were enrolled in this study. We used the purified proteins as antigens to perform T-spot and enzyme-linked immunosorbent assay (ELISA) for samples obtained from healthy volunteers and tuberculosis patients. Results: Regarding T-spot, the area under the curve (AUC) values for MPT64-wild protein (MPT64-H37Rv) and MPT64-mutant protein (MPT64-FJ05395) were 0.723 and 0.750, respectively. The AUC values for PstS1-H37Rv, PstS1-FJ05132, and PstS1-JL06035 were 0.817, 0.796, and 0.745, respectively. With regard to ELISA, the AUC values for MPT64-H37Rv and MPT64-FJ05395 were 0.525 and 0.528, respectively, while those for PstS1-H37Rv, PstS1-FJ05132, PstS1-JL06035 were 0.588, 0.509, and 0.560, respectively. There was no difference between wild and mutant proteins when we used them as antigens to perform T-spot and ELISA assays. Conclusion: MPT64 and PstS1 are likely candidate diagnostic antigens for M tuberculosis T-spot test, at least in combination with other proteins. Polymorphisms of MPT64 and PstS1 had little effect on cell-mediated and humoral immunity in the host.