Tuberculosis caused 20% of all human deaths in the Western world between the 17th and 19th centuries, and remains a cause of high mortality in developing countries. In analogy to other crowd diseases, the origin of human tuberculosis has been associated with the Neolithic Demographic Transition, but recent studies point to a much earlier origin. Here we used 259 whole-genome sequences to reconstruct the evolutionary history of the Mycobacterium tuberculosis complex (MTBC). Coalescent analyses indicate that MTBC emerged about 70 thousand years ago, accompanied migrations of anatomically modern humans out of Africa, and expanded as a consequence of increases in human population density during the Neolithic. This long co-evolutionary history is consistent with MTBC displaying characteristics indicative of adaptation to both low- and high host densities.

Summary Background Multidrug-resistant tuberculosis (MDR-TB) is a significant threat to tuberculosis elimination worldwide. Understanding the transmission pattern is crucial for its control. We used a genomic epidemiological approach to assess the recent transmission of MDR-TB and potential risk factors for transmission. Methods In a population-based retrospective study, we performed variable-number-of-tandem-repeat (VNTR) genotyping, followed by whole-genome sequencing (WGS) of isolates from all MDR-TB patients in Shanghai, China, 2009-2012. We measured strain diversity within and between genomically clustered patients. Genomic and epidemiologic data were combined to construct transmission networks. Findings 367 (5%) of 7982 patients with tuberculosis had MDR tuberculosis and 324 (88%) of these had isolates available for genomic analysis. 103 (32%) of the 324 MDR strains were in 38 genomic clusters that differed by 12 or fewer single nucleotide polymorphisms (SNPs), indicating recent transmission of MDR strains. Patients who had delayed diagnosis or were older than 45 years had high risk of recent transmission. 235 (73%) patients with MDR tuberculosis probably had transmission of MDR strains. Transmission network analysis showed that 33 (87%) of the 38 clusters accumulated additional drug-resistance mutations through emergence or fixation of mutations during transmission. 68 (66%) of 103 clustered MDR strains had compensatory mutations of rifampicin resistance. Interpretation Recent transmission of MDR strains, with increasing drug-resistance, helps drive the MDR-TB epidemic in Shanghai, China. WGS provides a measure of the heterogeneity of drug-resistant mutations within and between hosts and enhances our ability to determine the transmission patterns of MDR-TB. Funding National Science and Technology Major Project, National Natural Science Foundation of China, and US National Insitutes of Health.

M. tuberculosis population within patients exhibited considerable genetic diversity, which underwent selections for most fit resistant mutant. These findings have important implications and emphasize the need for early diagnosis of tuberculosis to decrease the chance of evolving highly fit drug-resistant strains.

The Beijing family is the most successful genotype of Mycobacterium tuberculosis and responsible for more than a quarter of the global tuberculosis epidemic. As the predominant genotype in East Asia, the Beijing family has been emerging in various areas of the world and is often associated with disease outbreaks and antibiotic resistance. Revealing the origin and historical dissemination of this strain family is important for understanding its current global success. Here we characterized the global diversity of this family based on whole-genome sequences of 358 Beijing strains. We show that the Beijing strains endemic in East Asia are genetically diverse, whereas the globally emerging strains mostly belong to a more homogenous subtype known as “modern” Beijing. Phylogeographic and coalescent analyses indicate that the Beijing family most likely emerged around 30,000 y ago in southern East Asia, and accompanied the early colonization by modern humans in this area. By combining the genomic data and genotyping result of 1,793 strains from across China, we found the “modern” Beijing sublineage experienced massive expansions in northern China during the Neolithic era and subsequently spread to other regions following the migration of Han Chinese. Our results support a parallel evolution of the Beijing family and modern humans in East Asia. The dominance of the “modern” Beijing sublineage in East Asia and its recent global emergence are most likely driven by its hypervirulence, which might reflect adaption to increased human population densities linked to the agricultural transition in northern China.

Manganese oxide has been recognized as one of the most promising gaseous heterogeneous catalysts due to its low cost, environmental friendliness, and high catalytic oxidation performance. Mn-based oxides can be classified into four types: (1) single manganese oxide (MnOx), (2) supported manganese oxide (MnOx/support), (3) composite manganese oxides (MnOx-X), and (4) special crystalline manganese oxides (S-MnOx). These Mn-based oxides have been widely used as catalysts for the elimination of gaseous pollutants. This review aims to describe the environmental applications of these manganese oxides and provide perspectives. It gives detailed descriptions of environmental applications of the selective catalytic reduction of NOx with NH, the catalytic combustion of volatile organic compounds, Hg oxidation and adsorption, and soot oxidation, in addition to some other environmental applications. Furthermore, this review mainly focuses on the effects of structure, morphology, and modified elements and on the role of catalyst supports in gaseous heterogeneous catalytic reactions. Finally, future research directions for developing manganese oxide catalysts are proposed.

Hg0 capture by sorbents was a promising technology to control Hg0 emission from coal-fired power plants and smelters. However, the design of a high performance sorbent and the predicting of the extent of Hg0 adsorption were both extremely limited due to the lack of adsorption kinetics and structure–activity relationship. In this work, the adsorption kinetics of gaseous Hg0 onto MoS3/TiO2 was investigated and kinetic parameters were obtained by fitting breakthrough curves. According to the kinetic parameters, the removal efficiency, the adsorption rate and the capacity for Hg0 capture were accurately predicted. Meanwhile, the structure–activity relationship of metal sulfides for gaseous Hg0 adsorption was built. The chemical adsorption rate of gaseous Hg0 was found to mainly depend on the amount of surface adsorption sites available for the physical adsorption of Hg0, the amount of surface S2 2– available for Hg0 oxidation and gaseous Hg0 concentration. As MoS3/TiO2 showed a superior performance for capturing high concentrations of Hg0 due to the large number of surface adsorption sites for the physical adsorption of gaseous Hg0, it has promising applications in recovering Hg0 from smelting flue gas.

Cross-priming amplification (CPA) technology for tuberculosis diagnosis from sputum specimens was evaluated. The sensitivity of CPA from smear-and liquid culture-positive specimens was 96.9%, and that from smear-negative and liquid culture-positive specimens was 87.5%. The specificity of CPA in culture-negative specimens was 98.8%.The diagnosis of tuberculosis (TB) is based on phenotypic and genotypic methods. Light microscopy for the detection of acid-fast bacilli (AFB) in sputum smears is a rapid and specific tool commonly used all over the world, but it only detects 30% to 40% of TB patients (10). While the sensitivity of Löwen-stein-Jensen (L-J) solid or liquid culture methods is higher than that of AFB microscopy, culture-based methods require several weeks of incubation time. Several genotypic assays, mostly based on nucleic acid amplification tests, have been developed for rapid TB diagnosis, including the GenProbe amplified Mycobacterium tuberculosis direct test, Roche Amplicor MTB test, Cobas Amplicor test, Abbott LCx test, and the BD-ProbeTec (strand displacement amplification) test (1,2,5,8,12). However, the cost of equipment needed for these methods is a barrier to their widespread use, especially in developing countries. A sensitive, accurate, rapid, and affordable diagnostic tool that will work in resource-limited settings is urgently needed.Cross-priming amplification (CPA) technology is a recent invention from an isothermal DNA amplification system by Ustar Biotechnologies Co., Ltd. Using multiple cross-linked primers (six to eight primers), a DNA target sequence can be amplified at a constant temperature (Fig. 1). The detection of amplified products is performed on a lateral flow strip housed in an enclosed, sealed plastic device to prevent the leakage of amplicons (4, 7). In this study, we evaluated the CPA isothermal amplification and detection kit (Ustar Biotech, Hangzhou, China) to determine whether it could accurately detect M. tuberculosis in clinical sputum specimens from a variety of different types of patients. Sputum specimens from 180 persons who were suspected of having TB, based on their clinical symptoms and presentation, were obtained from three hospitals in Shanghai. Sputum specimens were also collected from 98 non-TB patients (with lung cancer, lung edema, and other pulmonary illnesses) presenting at the same hospitals. For comparison with the CPA assay results, all of the clinical specimens in our study were also processed for AFB smear microscopy, L-J solid medium, and BacT/Alert 3D liquid culture following standard protocols (11). Bacterial genomic DNA was extracted by boiling, as previously described (9). The CPA method was performed according to the manufacturer's instructions, using primers targeting the gyrB gene of M. tuberculosis ( Fig. 2A). The result of each CPA assay was determined by observing the presence (positive result) or absence (negative result) of visible bands on the test strips (Fig. 2B).The detection rates of mycobacteria in the 180 sputum specimens used ...

The utilization of HSO, produced using SO from nonferrous metal smelting flue gas as a source of S, is extremely restricted due to Hg contamination; therefore, there is great demand to remove Hg from smelting flue gas. Although the ability of Cu/TiO to capture Hg is excellent, its resistance to HO and SO is very poor. In this study, Cu/TiO was treated with HS to improve its resistance to HO and SO for capturing Hg. The chemical adsorption of Hg on Cu/TiO was primarily through the HgO route, which was almost suppressed by HO and SO due to the transformation of CuO into CuSO. Besides the HgO route, the HgS route also contributed to the chemical adsorption of Hg on modified Cu/TiO. As the CuS on modified Cu/TiO was inert to HO and SO, the chemical adsorption of Hg on modified Cu/TiO through the HgS route was barely inhibited. Meanwhile, the HgS route was predominant in the chemical adsorption of Hg on modified Cu/TiO. Therefore, modified Cu/TiO exhibited an excellent resistance to HO and SO, and its Hg capture capacity from simulated flue gas was up to 12.7 mg g at 100 °C.