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1.
Fangui Min Jinchun Pan Ruike Wu Meiling Chen Huiwen Kuang Weibo Zhao 《Experimental Animals》2016,65(1):11-16
Recent evidence indicates that the prevalence of diseases caused by nontuberculous
mycobacteria (NTM) has been increasing in both human and animals. In this study, antibody
profiles of NTM in rhesus monkeys (Macaca mulatta) were determined and
compared with those of monkeys infected with Mycobacterium tuberculosis
complex (MTBC). Antibodies against 10 M. tuberculosis proteins, purified
protein derivative (PPD), and mammalian old tuberculin (MOT) were detected in 14 monkeys
naturally infected with NTM by indirect ELISA. Sera from 10 monkeys infected with MTBC and
10 healthy monkeys were set as controls. All antigens showed high serological reactivities
to MTBC infections and low reactivities in healthy monkeys. NTM infections showed strong
antibody responses to MOT and PPD; moderate antibody responses to 16kDa, U1, MPT64L,
14kDa, and TB16.3; and low antibody responses to 38kDa, Ag85b, CFP10, ESAT-6, and
CFP10-ESAT-6. According to the criteria of MTBC, only CFP10, ESAT-6, and CFP10-ESAT-6
showed negative antibody responses in all NTM infections. Taken together, these results
suggest that positive results of a PPD/MOT-based ELISA in combination with results of
antibodies to M. tuberculosis-specific antigens, such as CFP10 and
ESAT-6, could discriminate NTM and MTBC infections. Two positive results indicate an MTBC
infection, and a negative result for an M. tuberculosis-specific antigen
may preliminarily predict an NTM infection. 相似文献
2.
Nqobile A.C. Ngubane Lionel Gresh Alexander Pym Eric J. Rubin Makobetsa Khati 《Biochemical and biophysical research communications》2014
Tuberculosis (TB), which is caused by Mycobacterium tuberculosis, remains one of the most prevalent infectious diseases worldwide which causes high morbidity and mortality. However, there is still limited understanding of the physiological processes that allow M. tuberculosis to survive in its host environment. One of the challenges is the limited availability of molecular probes that can be used to study some of the complex systems in mycobacteria. One such system is the ESX-3 secretion system, a specialized type VII secretion (T7S) system. This system is essential for optimal growth of pathogenic mycobacteria in low iron environments similar to that encountered by mycobacteria in macrophages during infection. EsxG, a protein of unknown function, is both encoded within the ESX-3 locus and secreted by the ESX-3 system. 相似文献
3.
Aneesh Thakur Mandeep Sharma Vipin C. Katoch Prasenjit Dhar R. C. Katoch 《Indian journal of microbiology》2012,52(2):289-291
Mycobacterium bovis and Mycobacterium tuberculosis infect both animals and humans. The disease epidemiology by these agents differs in developed and developing countries due to the differences in the implementation of the prevention and control strategies. The present study describes the detection of M. bovis and M. tuberculosis from specimens of lungs and pulmonary lymph nodes of four cattle died in an organized herd of 183 cattle in the state of Himachal Pradesh, India, with inconclusive skin test results. Identification and distinction of these closely related mycobacterial species was done by PCR-RFLP targeting hsp65 gene followed by spacer oligonucleotide typing. Mixed infection of M. bovis and M. tuberculosis was detected in one cattle. 相似文献
4.
Low vitamin D levels in human immunodeficiency virus type-1 (HIV) infected persons are associated with more rapid disease progression and increased risk for Mycobacterium tuberculosis infection. We report that physiological concentrations of 1α,25-dihydroxycholecalciferol (1,25D3), the active form of vitamin D, inhibits M. tuberculosis and HIV replication in co-infected macrophages through human cathelicidin microbial peptide-dependent autophagy that requires phagosomal maturation. These findings provide a biological explanation for the importance of vitamin D sufficiency in HIV and M. tuberculosis-infected persons, and provide new insights into novel approaches to prevent and treat HIV infection and related opportunistic infections. 相似文献
5.
Comparative Study of 14C-Labeled Purified Protein Derivative from Various Mycobacteria: II. Skin Cross-Reactivity in Sensitized Guinea Pigs 总被引:1,自引:1,他引:0
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A study on skin cross-reactivity between stabilized 14C-labeled mycobacterial antigens, namely tuberculin purified protein derivative (PPD; from Mycobacterium tuberculosis), PPD-A (M. avium), PPD-Y (M. kansasii), PPD-G (M. scrofulaceum), PPD-B (M. intracellulare), and PPD-F (M. fortuitum), has been carried out in groups of guinea pigs sensitized with one of the following heat-killed mycobacteria: M. tuberculosis, M. avium, M. kansasii, M. scrofulaceum, M. intracellulare, or M. fortuitum. For each type of sensitization, the average response for the corresponding PPD antigen was higher than the average response for any of the other antigens. However, the responses to the heterologous PPD antigens were not necessarily significantly different among themselves, and the significant differences of the heterologous PPD antigens were distributed differently according to the type of sensitization. Therefore, 14C-PPD antigens skin cross-reacted in guinea pigs essentially in the same manner as reported by others for nonradioactive PPD antigens. 相似文献
6.
A microplate-based rapid, inexpensive and robust technique is developed by using tetrazolium salt 2, 3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) and menadione to determine the viability of Mycobacterium tuberculosis, Mycobacterium bovis BCG and Mycobacterium smegmatis bacilli in microplate format. In general, XTT reduction is an extremely slow process which takes almost 24 h to produce a detectable signal. Menadione could drastically induce this reduction to an almost equal extent within a few minutes in a dose dependent manner. The reduction of XTT is directly proportional to the cell concentration in the presence of menadione. The standardized protocol used 200 μM of XTT and 60 μM of menadione in 250 μl of cell suspension grown either in aerobic or anaerobic conditions. The cell suspension of M. bovis BCG and M. tuberculosis were incubated for 40 min before reading the optical density at 470 nm whereas M. smegmatis was incubated for 20 min. Calculated Signal/Noise (S/N) ratios obtained by applying this protocol were 5.4, 6.4 and 9.4 using M. bovis BCG, M. tuberculosis and M. smegmatis respectively. The calculated Z′ factors were > 0.8 for all mycobacterium bacilli indicating the robustness of the XTT Reduction Menadione Assay (XRMA) for rapid screening of inhibitors. The assay protocol was validated by applying 10 standard anti-tubercular agents on M. tuberculosis, M. bovis BCG and M. smegmatis. The Minimum Inhibitory Concentration (MIC) values were found to be similar to reported values from Colony Forming Unit (CFU) and REMA (resazurin microplate assay) assays. Altogether, XRMA is providing a novel anti-tubercular screening protocol which could be useful in high throughput screening programs against different physiological stages of the bacilli. 相似文献
7.
This study investigated the hypothesis that serum antibodies against Mycobacterium tuberculosis present in naturally infected healthy subjects of a tuberculosis (TB) endemic area could create and/or sustain the latent form of infection. All five apparently healthy Indian donors showed high titres of serum antibodies against M. tuberculosis cell membrane antigens, including lipoarabinomannan and alpha crystallin. Uptake and killing of bacilli by the donor macrophages was significantly enhanced following their opsonization with antibody-rich, heat-inactivated autologous sera. However, the capability to opsonize was apparent for antibodies against some and not other antigens. High-content cell imaging of infected macrophages revealed significantly enhanced colocalization of the phagosome maturation marker LAMP-1, though not of calmodulin, with antibody-opsonized compared with unopsonized M. tuberculosis. Key enablers of macrophage microbicidal action—proinflammatory cytokines (IFN-γ and IL-6), phagosome acidification, inducible NO synthase and nitric oxide—were also significantly enhanced following antibody opsonization. Interestingly, heat-killed M. tuberculosis also elevated these mediators to the levels comparable to, if not higher than, opsonized M. tuberculosis. Results of the study support the emerging view that an efficacious vaccine against TB should, apart from targeting cell-mediated immunity, also generate ‘protective’ antibodies. 相似文献
8.
Jeong-Sun Han Tripti Anandan Srinivas Sripathi Sang Hee Lee Choong-Min Kang 《Biochemical and biophysical research communications》2010,400(3):293-298
Toxin-antitoxin systems, ubiquitous in prokaryotic genomes, have been proposed to play an important role in several stress responses. While Mycobacterium tuberculosis contains more than 80 putative TA loci, the roles they play in this pathogen are yet to be studied. Here, we characterize a chromosomal Rv1102c-Rv1103c TA system in M. tuberculosis. We found that the Rv1102c toxin interacts with the Rv1103c antitoxin in a pull-down assay and the yeast two-hybrid system. Rv1102c cleaved the era mRNA in Escherichia coli, and cleavage was inhibited by co-expression of Rv1103c. Heterologous expression of Rv1102c led to growth arrest in E. coli, which was fully recovered only when Rv1103c was co-expressed in cis with Rv1102c, suggesting that the production and assembly of Rv1102c and Rv1103c are tightly linked. Our additional results indicate that translational coupling of the Rv1102c and Rv1103c genes is important for Rv1102c-Rv1103c binding. Finally, we discovered that the expression of Rv1102c induced growth arrest and increased the level of persister cells in Mycobacterium smegmatis. These results suggest that the Rv1102c-Rv1103c TA system could play a role in M. tuberculosis pathogenesis via generating bacilli that survive in the face of multidrug therapy. 相似文献
9.
Adwait Anand Godbole Wareed Ahmed Rajeshwari Subray Bhat Erin K. Bradley Sean Ekins Valakunja Nagaraja 《Biochemical and biophysical research communications》2014
m-AMSA, an established inhibitor of eukaryotic type II topoisomerases, exerts its cidal effect by binding to the enzyme–DNA complex thus inhibiting the DNA religation step. The molecule and its analogues have been successfully used as chemotherapeutic agents against different forms of cancer. After virtual screening using a homology model of the Mycobacterium tuberculosis topoisomerase I, we identified m-AMSA as a high scoring hit. We demonstrate that m-AMSA can inhibit the DNA relaxation activity of topoisomerase I from M. tuberculosis and Mycobacterium smegmatis. In a whole cell assay, m-AMSA inhibited the growth of both the mycobacteria. 相似文献
10.
Cleoni Alves Mendes de Lima Harrison Magdinier Gomes Maraníbia Aparecida Cardoso Oelemann Jesus Pais Ramos Paulo Cezar Caldas Carlos Eduardo Dias Campos Márcia Aparecida da Silva Pereira Fátima Fandinho Onofre Montes Maria do Socorro Calixto de Oliveira Philip Noel Suffys Maria Manuela da Fonseca Moura 《Memórias do Instituto Oswaldo Cruz》2013,108(4):457-462
The main cause of pulmonary tuberculosis (TB) is infection with
Mycobacterium tuberculosis (MTB). We aimed to evaluate the
contribution of nontuberculous mycobacteria (NTM) to pulmonary disease in
patients from the state of Rondônia using respiratory samples and
epidemiological data from TB cases. Mycobacterium isolates were identified using
a combination of conventional tests, polymerase chain reaction-based restriction
enzyme analysis of hsp65 gene and hsp65 gene
sequencing. Among the 1,812 cases suspected of having pulmonary TB, 444 yielded
bacterial cultures, including 369 cases positive for MTB and 75 cases positive
for NTM. Within the latter group, 14 species were identified as
Mycobacterium abscessus, Mycobacterium
avium, Mycobacterium fortuitum,
Mycobacterium intracellulare, Mycobacterium
gilvum, Mycobacterium gordonae,
Mycobacterium asiaticum, Mycobacterium
tusciae, Mycobacterium porcinum,
Mycobacterium novocastrense, Mycobacterium
simiae, Mycobacterium szulgai,
Mycobacterium phlei and Mycobacterium
holsaticum and 13 isolates could not be identified at the species
level. The majority of NTM cases were observed in Porto Velho and the relative
frequency of NTM compared with MTB was highest in Ji-Paraná. In approximately
half of the TB subjects with NTM, a second sample containing NTM was obtained,
confirming this as the disease-causing agent. The most frequently observed NTM
species were M. abscessus and M. avium and
because the former species is resistant to many antibiotics and displays
unsatisfactory cure rates, the implementation of rapid identification of
mycobacterium species is of considerable importance. 相似文献
11.
Ru-Yi Zhu Kou-Xing Zhang Ming-Qiu Zhao Ya-Hong Liu Yun-Yi Xu Chun-Mei Ju Bing Li Jin-Ding Chen 《Journal of microbiological methods》2009,78(3):339-343
Mycobacterium tuberculosis and Mycobacterium bovis are pathogenic bacterial species in the genus Mycobacterium and the causative agents of most cases of tuberculosis (TB). Detection of M. tuberculosis and M. bovis using conventional culture- and biochemical-based assays is time-consuming and laborious. Therefore, a simple and sensitive method for rapid detection has been anxiously awaited. In the present study, a visual loop-mediated isothermal amplification (LAMP) assay was designed from the rimM (encoding 16S rRNA-processing protein) gene sequence and used to rapidly detect M. tuberculosis and M. bovis from clinical samples in South China. The visual LAMP reaction was performed by adding calcein and manganous ion, allowing the results to be read by simple visual observation of color change in a closed-tube system, and which takes less than 1 h at 65 °C. The assay correctly identified 84 M. tuberculosis isolates, 3 M. bovis strains and 1 M. bovis BCG samples, but did not detect 51 non-tuberculous mycobacteria (NTM) isolates and 8 other bacterial species. Sensitivity of this assay for detection of genomic DNA was 1 pg. Specific amplification was confirmed by the ladder-like pattern of gel electrophoresis and restriction enzyme HhaI digestion. The assay successfully detected M. tuberculosis and M. bovis not only in pure bacterial culture but also in clinical samples of sputum, pleural fluid and blood. The speed, specificity, sensitivity of the rimM LAMP, the lack of a need for expensive equipment, and the visual readout show great potential for clinical detection of M. tuberculosis and M. bovis. 相似文献
12.
13.
Heo DR Shin SJ Kim WS Noh KT Park JW Son KH Park WS Lee MG Kim D Shin YK Jung ID Park YM 《Biochemical and biophysical research communications》2011,(3):642-647
Mycobacterium tuberculosis, the etiological factor of pulmonary tuberculosis, causes significant morbidity and mortality worldwide. Activation of host immune responses for containment of mycobacterial infections involves participation of innate immune cells, such as dendritic cells (DCs). In this study, we demonstrated that the gene encoding lipoamide dehydrogenase C (lpdC) from M. tuberculosis, Rv0462, induce maturation and activation of DCs involved in the MAPKs signaling pathway. Moreover, Rv0462-treated DCs activated naïve T cells, polarized CD4+ and CD8+ T cells to secrete IFN-γ in syngeneic mixed lymphocyte reactions, which would be expected to contribute to Th1 polarization of the immune response. Our results suggest that Rv0462 can contribute to the innate and adaptive immune responses during tuberculosis infection, and thus modulate the clinical course of tuberculosis. 相似文献
14.
This review investigates ancient infectious diseases in the Americas dated to the
pre-colonial period and considers what these findings can tell us about the history
of the indigenous peoples of the Americas. It gives an overview, but focuses on four
microbial pathogens from this period: Helicobacter pylori,
Mycobacterium tuberculosis, Trypanosoma cruzi
and Coccidioides immitis, which cause stomach ulceration and gastric
cancer, tuberculosis, Chagas disease and valley fever, respectively. These pathogens
were selected as H. pylori can give insight into ancient human
migrations into the Americas, M. tuberculosis is associated with
population density and urban development, T. cruzi can elucidate
human living conditions and C. immitis can indicate agricultural
development. A range of methods are used to diagnose infectious disease in ancient
human remains, with DNA analysis by polymerase chain reaction one of the most
reliable, provided strict precautions are taken against cross contamination. The
review concludes with a brief summary of the changes that took place after European
exploration and colonisation. 相似文献
15.
Sai-Kam Li Patrick Kwok-Shing Ng Hao Qin Jeffrey Kwan-Yiu Lau Jonathan Pak-Yuen Lau Stephen Kwok-Wing Tsui Ting-Fung Chan Terrence Chi-Kong Lau 《RNA (New York, N.Y.)》2013,19(1):74-84
Gene regulation by small RNAs (sRNAs) has been extensively studied in various bacteria. However, the presence and roles of sRNAs in mycobacteria remain largely unclear. Immunoprecipitation of RNA chaperone Hfq to enrich for sRNAs is one of the effective methods to isolate sRNAs. However, the lack of an identified mycobacterial hfq restricts the feasibility of this approach. We developed a novel method that takes advantage of the conserved inherent sRNAs-binding capability of heterologous Hfq from Escherichia coli to enrich sRNAs from Mycobacterium smegmatis, a model organism for studying Mycobacterium tuberculosis. We validated 12 trans-encoded and 12 cis-encoded novel sRNAs in M. smegmatis. Many of these sRNAs are differentially expressed at exponential phase compared with stationary phase, suggesting that sRNAs are involved in the growth of mycobacteria. Intriguingly, five of the cis-encoded novel sRNAs target known transposases. Phylogenetic conservation analysis shows that these sRNAs are pathogenicity dependent. We believe that our findings will serve as an important reference for future analysis of sRNAs regulation in mycobacteria and will contribute significantly to the development of sRNAs prediction programs. Moreover, this novel method of using heterologous Hfq for sRNAs enrichment can be of general use for the discovery of bacterial sRNAs in which no endogenous Hfq is identified. 相似文献
16.
In this study, we designed a simple and rapid colorimetric detection method, a one-tube loop-mediated isothermal amplification (LAMP)-PCR-hybridization-restriction endonuclease-ELISA [one-tube LAMP-PCR-HY-RE-ELISA] system, to detect resistance to isoniazid, ethambutol and streptomycin in strains of Mycobacterium tuberculosis isolated from clinical specimens. The clinical performance of this method for detecting isoniazid-resistant, ethambutol-resistant and streptomycin-resistant isolates of M. tuberculosis showed 98.9%, 94.3% and 93.8%, respectively. This assay is rapid and convenient that can be performed within one working day. One-tube LAMP-PCR-HY-RE-ELISA system was designed based on hot spot point mutations in target drug-resistant genes, using LAMP-PCR, hybridization, digestion with restriction endonuclease and colorimetric method of ELISA. In this study, LAMP assay was used to amplify DNA from drug-resistant M. tuberculosis, and ELISA was used for colorimetrical determination. This assay will be a useful tool for rapid diagnosis of mutant codons in strains of M. tuberculosis for isoniazid at katG 315 and katG 463, ethambutol at embB 306 and embB 497, and streptomycin at rpsL 43. 相似文献
17.
Manvar A Bavishi A Radadiya A Patel J Vora V Dodia N Rawal K Shah A 《Bioorganic & medicinal chemistry letters》2011,21(16):4728-4731
Control and prevention of tuberculosis is a major challenge, as one-third of the world’s population is infected with Mycobacterium tuberculosis. The resurgence of tuberculosis and the emergence of multidrug-resistance strains of mycobacteria, necessitate the search for new class of antimycobacterial agents. As a part of investigation of new antitubercular agents in this laboratory, we describe the syntheses of various hydrazides of comarins, quinolones and pyrroles and screening against M. tuberculosis (Mtb) H37Rv by using rifampin as a standard drug. Among the designed molecules, the most prominent compounds 2a-g, 4a and 9a showed >90% GI at MIC <6.25 μg/mL. Finally, these studies suggests that compounds 2a-g, 4a and 9a may serve as promising lead scaffolds for further generation of new anti-TB agents. 相似文献
18.
A great challenge is posed to the treatment of tuberculosis due to the evolution of multidrug-resistant (MDR) and extensively drugresistant
(XDR) strains of Mycobacterium tuberculosis in recent times. The complex cell envelope of the bacterium contains unusual
structures of lipids which protects the bacterium from host enzymes and escape immune response. To overcome the drug
resistance, targeting “drug targets” which have a critical role in growth and virulence factor is a novel approach for better
tuberculosis treatment. The enzyme Phosphopantetheinyl transferase (PptT) is an attractive drug target as it is primarily involved
in post translational modification of various types-I polyketide synthases and assembly of mycobactin, which is required for lipid
virulence factors. Our in silico studies reported that the structural model of M.tuberculosis PptT characterizes the structure-function
activity. The refinement of the model was carried out with molecular dynamics simulations and was analyzed with root mean
square deviation (RMSD), and radius of gyration (Rg). This confirmed the structural behavior of PptT in dynamic system.
Molecular docking with substrate coenzyme A (CoA) identified the binding pocket and key residues His93, Asp114 and Arg169
involved in PptT-CoA binding. In conclusion, our results show that the M.tuberculosis PptT model and critical CoA binding pocket
initiate the inhibitor design of PptT towards tuberculosis treatment. 相似文献
19.
The transketolase (TKT) enzyme in Mycobacterium tuberculosis
represents a novel drug target for tuberculosis treatment and has low homology
with the orthologous human enzyme. Here, we report on the structural and kinetic
characterization of the transketolase from M. tuberculosis
(TBTKT), a homodimer whose monomers each comprise 700 amino acids. We show that
TBTKT catalyses the oxidation of donor sugars xylulose-5-phosphate and
fructose-6-phosphate as well as the reduction of the acceptor sugar
ribose-5-phosphate. An invariant residue of the TKT consensus sequence required
for thiamine cofactor binding is mutated in TBTKT; yet its catalytic activities
are unaffected, and the 2.5 Å resolution structure of full-length TBTKT
provides an explanation for this. Key structural differences between the human
and mycobacterial TKT enzymes that impact both substrate and cofactor
recognition and binding were uncovered. These changes explain the kinetic
differences between TBTKT and its human counterpart, and their differential
inhibition by small molecules. The availability of a detailed structural model
of TBTKT will enable differences between human and M.
tuberculosis TKT structures to be exploited to design selective
inhibitors with potential antitubercular activity. 相似文献
20.
Khye Seng Goh 《Journal of microbiological methods》2010,81(2):208-210
Mycobacterium tuberculosis reduces nitrate very strongly as compared to Mycobacterium bovis and M. bovis BCG. Nitrate reductase, in conjunction with niacin accumulation, constitutes one of the major biochemical tests used in clinical microbiology laboratories to differentiate M. tuberculosis from other members of the M. tuberculosis complex, as well as nontuberculous Mycobacteria. Determination of nitrate reductase activity is currently performed using cultures grown on solid media with a slow detection time and the need for large quantities of bacilli, as otherwise the test is not reliable. Hereby, we propose a nitrate reduction test coupled to Bactec MGIT960 system as a simple, rapid and economic method with a total gain of time of about 3 to 4 weeks over the conventional solid medium. In our study, almost all the M. tuberculosis and Mycobacterium canettii strains gave a strongly positive nitrate reductase result within 1 day of positive detection by the MGIT960 system. In contrast, M. bovis, M. bovis BCG and M. africanum strains remained negative even after 14 days of incubation. The possibility to detect nitrate reductase within 1 to 3 days of a positive culture using MGIT960 opens new perspectives with the possibility of confirming M. tuberculosis — starting directly from pathological specimens. 相似文献