摘要：
Lipoarabinomannan (LAM) is an important virulent factor secreted by mycobacteria, which generally elicit a strong immune response in the host. In this study, the structural difference of LAMs from three mycobacterial strains, Mycobacterium tuberculosis H37Rv, Mycobacterium smegmatis mc(2)155 and a newly discovered clinical isolate, M. sp. QGD101, was analyzed and further evaluated whether these LAMs can induce DC maturation and promote the immunomodulatory properties. The results reveal that the major structural difference of these LAMs is the amount of mannosyl residues, especially at the terminal end of LAM, which play a key role in determining the divergent response of DCs after mycobacterial infection. Also, this study indicates an important relevance between the glycosylated structure of LAM and its immunomodulatory property, which is helpful to develop a potential approach for identification of different mycobacteria and also lays a foundation for the development of a novel polysaccharide immunological strategy against tuberculosis.
摘要：
The polymyxin colistin is known as a "last resort" antibacterial drug toward pandrug-resistant enterobacteria. The recently discovered plasmid-encoded mcr-1 gene spreads rapidly across pathogenic strains and confers resistance to colistin, which has emerged as a global threat. The mcr-1 gene encodes a phosphoethanolamine transferase (MCR-1) that catalyzes the transference of phosphoethanolamine to lipid A moiety of lipopolysaccharide, resulting in resistance to colistin. Development of effective MCR-1 inhibitors is crucial for combating MCR-1-mediated colistin resistance. In this study, MCR-1 catalytic domain (namely cMCR-1) was expressed and co-crystallized together with D-xylose. X-ray crystallographic study at a resolution of 1.8 angstrom found that cMCR-1-d-xylose co-crystals fell under space group P2(1)2(1)2(1), with unit-cell parameters a = 51.6 angstrom, b = 73.1 angstrom, c = 82.2 angstrom, alpha = 90 degrees, beta = 90 degrees, gamma = 90 degrees. The asymmetric unit contained a single cMCR-1 molecule complexed with d-xylose and had a solvent content of 29.13%. The structural model of cMCR-1-d-xylose complex showed that a D-xylose molecule bound in the putative lipid A-binding pocket of cMCR-1, which might provide a clue for MCR-1 inhibitor development.
摘要：
The incidence of non-tuberculous mycobacteria (NTM)-related death has increased globally recently. To obtain information of the species and characterization of pathogens involved in NTM pulmonary infection in Southern-central China, we identified 160 non-tuberculous infection cases from 3995 acid-fast bacilli (AFB)-positive tuberculous suspects. We then randomly selected 101 non-tuberculous patients, isolated bacteria from their sputa and genotyped the pathogens using the 16S rRNA gene and 16S-23S rRNA internal transcribed spacer sequences. M. intracellulare (32.67%, 33/101), M. abscessus (32.67%, 33/101) and M. fortuitum (7.92%, 8/101) are identified in these isolates. Surprisingly, non-mycobacteria including Gordonia (8.91%, 9/101), Nocardia (5.94%, 6/101) and Tsukamurella (0.99%, 1/101) are also discovered, and the case of Tsukamurella pulmonis infection is first discovered in Southern-central China. Moreover, species of M. mucogenicum group, M. chubuense, M. kansasii, M. gastri, M. avium, M. porcinum and M. smegmatis are identified. In addition, nine immune compromised cases (8.91%, 9/101), including type two diabetes mellitus and HIV/AIDS are found to be infected with non-tuberculous bacteria. This study revealed the distribution and characteristics of non-tuberculous AFB pathogen infection occurred in Southern-central China, and suggested that physicians should be alert of the emerging of NTM and non-mycobacteria infection in AFB positive cases and take caution when choosing chemotherapy for tuberculosis-like pulmonary infections. Generally, this study may help with the development of new strategy for the diagnosis and treatment of mycobacterial infection.
作者机构：
State Key Laboratory of Genetic Engineering,Institute of Genetics,School of Life Science,Fudan Unive;School of Biology and Pharmaceutical Engineering,Wuhan Polytechnic University,68 Xuefu south Road,Ch;Department of Medical Microbiology and Parasitology,Shanghai Jiao Tong University School of Medicine;Baio Technology Limited Company,Shanghai 200233,PR China
摘要：
The widespread occurrence of drug-resistant Mycobacterium tuberculosis places great importance on the detection of TB drug susceptibility.Conventional drug susceptibility testing (DST) is a lengthy process, thus rapid drug resistance testing methods are needed.We developed a novel enzymatic color-reaction based biochip detection assay for the identification of M.tuberculosis (TB) and non-tuberculosis mycobacteria (NTM) and the drug resistance of TB towards isoniazid (INH) and rifampicin (RIF).The process includes asymmetric multiplex PCR /templex PCR, biochip hybridization and an enzymatic color reaction, with specific software used for data acquisition and automated interpretation.The assay contained probes specific for most of the frequently observed mutations.A sensitivity of 50 copies per PCR reaction was achieved, and allele sequences could be detected in mixed samples at a proportion as low as 10%.The templex PCR technique was applied in sample preparation to avoid interference between the different primers that is observed when using conventional multiplex-PCR.The whole testing process takes four and a half hours.We applied this assay to 294 clinical specimens, including 254 M.tuberculosis and 40 non-tuberculosis mycobacteria specimens.The results were compared with those obtained using DNA sequencing and the DST method.The results showed a concordance rate of 91.34% (232/254) for RIF resistance detection (sensitivity 89.15%, specificity 93.6%) and 78.74% (200/254) for INH resistance detection (sensitivity 78.57%, specificity 78.85%).The assay is rapid, sensitive and specific, and can be used for testing of mixed samples.It can be a reliable tool of TB clinical diagnosis and treatment.
会议名称：
Global Conference on Civil, Structural and Environmental Engineering / 3rd International Symp on Multi-field Coupling Theory of Rock and Soil Media and its Applications
会议时间：
OCT 20-21, 2012
会议地点：
China Three Gorges Univ, Yichang, PEOPLES R CHINA
会议主办单位：
China Three Gorges Univ
会议论文集名称：
Advanced Materials Research
关键词：
Assessment for nutrient status;Correlation weighted;Phytoplankton;Sediment;The three gorges reservoir
摘要：
Regression models between the chlorophyll a and other nutrient factors were established elementarily for the characteristic that the Three Gorges Reservoir is a channel reservoir.The nutritional quality of water body was assessed using correlation weighted comprehensive nutritional index.The result was compared with that of assessment based on the nutrient status index of lakes in order to make it closer to the actual environment and embody the feasibility of this method to assess nutrient status in the channel reservoir.
摘要：
Tuberculosis (TB) is still one of the greatest health care problems in the world. In order to identify antigens that may be used in the serodiagnosis of active tuberculosis, a short fragment from Rv3391 (fRv3391) of Mycobacterium tuberculosis was cloned and expressed. Its molecular weight and secondary structure elements were identified by mass spectrometry and circular dichroism. And its immunological nature was also evaluated by enzyme-linked immunosorbent assay (ELISA). The fRv3391 was expressed in Escherichia coli BL21 (DE3) with the molecular weight of 42.5kDa and the secondary structure elements 36.2% α-helix, 0.0% β-sheet, 32.6% β-turn, and 31.3% random coil. Evaluation of fRv3391 as an ELISA solid-phase antigen on a set of human sera from well-characterized TB cases and healthy subjects revealed that there was strong serum antibody reactivity to fRv3391 in many human TB patients. Taken together, a short fragment from Rv3391 of Mycobacterium tuberculosis was cloned and expressed and the ELISA results showed that the protein may be useful as an immunodominant antigen for the serodiagnosis of active TB. Keywords Rv3391 – Mycobacterium tuberculosis –Serodiagnosis–Antigen–Gene expression–Circular dichroism
作者机构：
[张朝宝; 余晓丽; 陈平] School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China;[郭晓奎; 张舒林] Department of Medical Microbiology and Parasitology, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China;[沈建国] Nanyang Institute of Technology, Nanyang 473004, China;[唐神结] Department of Tuberculosis, Pulmonary Hospital Affiliated to Tongji University, Shanghai 200433, China;[温子禄] School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China<&wdkj&>Department of Medical Microbiology and Parasitology, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
通讯机构：
School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, China
