Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026918 (Mycobacterium)
 52,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vaccination of mice with Mycobacterium bovis culture filtrate proteins (CFP), prepared in a variety of adjuvants (aluminum hydroxide, Quil-A, and dimethyldioctyldecyl ammonium bromide [DDA]), provided significant protection against an aerosol challenge of virulent M. bovis. Additionally, vaccination with CFP in DDA or Quil-A did not sensitize mice to M. bovis purified protein derivative.
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PMID:Effective, nonsensitizing vaccination with culture filtrate proteins against virulent Mycobacterium bovis infections in mice. 974 17

The mmr gene, cloned from Mycobacterium tuberculosis, was shown to confer to Mycobacterium smegmatis resistance to tetraphenylphosphonium (TPP), erythromycin, ethidium bromide, acriflavine, safranin O, and pyronin Y. The gene appears to code for a protein containing four transmembrane domains. Studies of [3H]TPP intracellular accumulation strongly suggest that the resistance mediated by the Mmr protein involves active extrusion of TPP.
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PMID:mmr, a Mycobacterium tuberculosis gene conferring resistance to small cationic dyes and inhibitors. 981 72

Background: Diverse mutations in an 81 bp region of the rpoB gene are found in approximately 95% of rifampin-resistant (RIFr) Mycobacterium tuberculosis isolates. Various methods to detect these mutations have been evaluated for their usefulness as rapid screens for rifampin resistance. Methods and Results: Two nonradioactive variations of single-strand conformation polymorphism (SSCP) electrophoresis were optimized and evaluated for their ability to distinguish nine rpoB mutations present in a collection of 51 RIFr M. tuberculosis isolates. One of the methods used polymerase chain reaction products (128 bp) encompassing the 81 bp region of the rpoB gene, which were denatured in the presence of methyl mercury hydroxide, subjected to polyacrylamide gel electrophoresis (PAGE) and detected by staining with ethidium bromide. For the second method, fluorogenically labeled primers were used to generate products that were electrophoresed in an ABI Model 310 Genetic Analyzer equipped with a 3% GeneScan Polymer Column (Applied Biosystems Inc; Foster City, CA). Mobility shifts for all nine mutations were clearly discernible from the wild-type pattern by methods when tested in blind analyses. When an additional 30 isolates were tested by both SSCP methods in a blinded fashion, correlations with RIF susceptibility testing were complete for susceptible and homogeneously resistant isolates. Among three isolates with heterogeneously resistant populations, however, two were correctly identified by fluorescent SSCP compared with one by the PAGE SSCP method. Subpopulations of the His 526-->Tyr rpoB mutant, which is frequently encountered among RIFr strains, could be detected using templates prepared from mixtures of broth cultures with a susceptible strain. Conclusions: SSCP electrophoresis is useful for rapid screening for RIF resistance in susceptible and fully resistant isolates of M. tuberculosis. However, conventional susceptibility testing is still necessary for two reasons: (1) <100% of RIF strains have mutations in the 81 bp hotspot rpoB genomic region, and (2) SSCP may not offer sufficient sensitivity to detect clinically important emergent mutant subpopulations, especially those present as <10% of the total population in a sample. Whereas PAGE SSCP is less costly than fluorescent SSCP, the latter method is somewhat easier to perform and generates quantitative data.
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PMID:Comparison of Two Nonradioactive, Single-Strand Conformation Polymorphism Electrophoretic Methods for Identification of rpoB Mutations in Rifampin- Resistant Isolates of Mycobacterium tuberculosis. 1002 58

Standardisation and control of the live Mycobacterium bovis BCG (BCG) vaccine is performed as specified by the World Health Organisation (WHO) and the European Pharmacopoeia (EP). The conventional viable count for control of potency of BCG vaccine is performed by culturing on solid medium. This assay method is not only time consuming but may give variable results. A tetrazolium salt assay has been developed and evaluated as a potential additional, or replacement, test for determining number of viable organisms. The tetrazolium salts 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 2,3-bis-(2-methoxy-4-nitro-5-sulphenyl)-(2H)-tetrazolium-5-carb oxanilide (XTT) used as alternative substrates in the assay both gave more rapid and reproducible results than the conventional viable count. XTT showed greater sensitivity than MTT with a lower detection limit of about 7x10(4) colony forming units (c.f.u.) ml(-1). The XTT assay has proven effective for determining viability of suspensions prepared from several BCG vaccine substrains, covering a range of viable units, without the need for modification. This assay is easily performed and takes just 48 h to produce an estimate of viable cell content compared with 3 weeks for the conventional method.
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PMID:Development of a tetrazolium salt assay for rapid determination of viability of BCG vaccines. 1039 24

The immunoprotective behaviour of the 30-kDa secretory glycoprotein of Mycobacterium tuberculosis H37Rv has been investigated in different adjuvant systems in two mouse strains, NMR1 and C57BL/6J. In comparison with Freund's incomplete adjuvant (FIA) and dimethyldioctadecyl ammonium bromide (DDA), the 30-kDa glycoprotein complexed with polylactide-co-glycolide microparticles (PLG-MPs) induced maximum immunoreactivity in the two mouse strains. As compared with controls, immunisation with 30-kDa-PLG-MPs resulted in significantly greater protection in animals challenged with 1 x LD50 of M. tuberculosis H37Rv on the basis of survival rates and number of cfu in the infected organs 30 days after challenge. The degree of protection provided by 30-kDa-PLG-MPs was similar to that obtained with 30-kDa-FIA and higher than BCG immunisation. These findings suggest that biodegradable PLG microparticles can be used as an efficient carrier system for the key immunoprotective 30-kDa secretory protein antigen of M. tuberculosis H37Rv.
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PMID:Adjuvant modulation of T-cell reactivity to 30-kDa secretory protein of Mycobacterium tuberculosis H37Rv and its protective efficacy against experimental tuberculosis. 1045 Sep 99

The firefly luciferase assay of ATP is a rapid and convenient technique for monitoring growth of mycobacteria. The time needed to obtain a drug susceptibility pattern can be reduced to less than 1 week as compared to 4 weeks with conventional methods. The ATP assay is simple and reliable. However, the extraction of bacterial ATP is not a trivial problem. Lysing the cells will immediately activate ATP-degrading enzyme systems. The extractant must therefore lyse the cells and simultaneously inactivate ATP-degrading enzyme systems. Only by comparing the ATP yields obtained with different extractants we will know something about the intracellular ATP level. In the present study various extractants were compared for the extraction of ATP from Mycobacterium bovis (BCG) cultures. Dodecyl trimethyl ammonium bromide (DTAB) in Tris-buffer with EDTA resulted at 100 degrees C in an ATP yield that was approximately twice as high as the same buffer without DTAB. The optimum temperature was 80-100 degrees C. With the optimized extraction procedure the coefficient of variation for the entire assay of ATP in BCG cultures was 5%. The analytical interference from DTAB with the firefly reaction was obviated by neutralization with alpha-cyclodextrin, making it possible to increase the sensitivity by assaying 0.5 mL rather than 0.01 mL extract.
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PMID:Improved extraction and assay of mycobacterial ATP for rapid drug susceptibility testing. 1051 89

We examined the role of cytokines in the development of gamma interferon (IFN-gamma)-secreting protective T cells following immunization with a culture filtrate subunit vaccine against Mycobacterium tuberculosis containing the adjuvant dimethyldioctadecylammonium bromide (DDA). Depletion of either interleukin-6 (IL-6) or IL-12 with specific neutralizing antibodies during vaccination reduced the priming of T cells for antigen-specific proliferation and IFN-gamma secretion. Such reduction was also observed in IL-6 gene-disrupted mice as compared to wild-type animals. IL-6 was found to play a role in the initial differentiation of Th1 cells but not in their expansion. The defect found after IL-6 depletion or in IL-6-knockout mice was compensated by the inclusion of recombinant mouse IL-12 in the vaccine. The induction of protective immunity against an intravenous or an aerosol challenge with live, virulent M. tuberculosis was markedly reduced by neutralizing either IL-6 or IL-12 during immunization with the vaccine. Likewise, the effects of IL-6 neutralization were partially reversed by including IL-12 in the vaccine. Our data point to an important role of IL-6 and IL-12 in the generation of cell-mediated immunity to tuberculosis.
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PMID:Interleukin-6 and interleukin-12 participate in induction of a type 1 protective T-cell response during vaccination with a tuberculosis subunit vaccine. 1053 Dec 24

In the present prospective study, a dot immunobinding assay (Dot-Iba) was standardized to measure the circulating mycobacterial antigen in cerebrospinal fluid (CSF) specimens for the laboratory diagnosis of tuberculous meningitis (TBM). Immunoglobulin G antibody specific for Mycobacterium tuberculosis in a CSF specimen from a patient with culture-proven TBM was isolated and was coupled with activated cyanogen bromide-Sepharose 4B. By immunosorbent affinity chromatography, a 14-kDa antigen was isolated from the culture filtrate of M. tuberculosis. Antibody to the 14-kDa mycobacterial antigen was raised in rabbits. The Dot-Iba in this study gave no false-positive results with CSF specimens from patients with nontuberculous neurological diseases. The assay gave positive results for all five patients with culture-proven TBM. The Dot-Iba described in the present report is simple, rapid, sensitive, specific, and, more importantly, suitable for routine application in laboratories in developing countries.
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PMID:Rapid diagnosis of tuberculous meningitis by a dot immunobinding assay To detect mycobacterial antigen in cerebrospinal fluid specimens. 1056 8

Principal Component Analysis (PCA) and Artificial Neural Network (ANN) were used to analyze the relationship between the structure and the activities of a series of nine biphenyl-phenyl methanone derivatives against Mycobacterium tuberculosis in vitro. Both PCA and ANN were able to classify these derivatives in two categories: low active and highly active compounds. Empirical and theoretical descriptors were used in the classification process. The descriptors selected by PCA indicated that the reactivity plays an important role in the determination of antimycobacterial activity of biphenylphenyl methanone derivatives (BPM). The BPM showed a moderate activity against the M. tuberculosis strain tested with the exception of chloride-, bromide- and nitroderivatives (when X = Cl, Br, NO2) which were the most actives against M. tuberculosis in vitro among all the methanones studied.
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PMID:Structure-activity relationship analysis of 4'-bromo-[1,1'-biphenyl]-4-yl 4-X-phenyl methanone derivatives and activity against Mycobacterium tuberculosis. 1063 49

The ESAT-6 antigen from Mycobacterium tuberculosis is a dominant target for cell-mediated immunity in the early phase of tuberculosis (TB) in TB patients as well as in various animal models. The purpose of our study was to evaluate the potential of ESAT-6 in an experimental TB vaccine. We started out using dimethyl dioctadecylammonium bromide (DDA), an adjuvant which has been demonstrated to be efficient for the induction of cellular immune responses and has been used successfully before as a delivery system for TB vaccines. Here we demonstrate that, whereas immune responses to both short-term-culture filtrate and Ag85B are efficiently induced with DDA, this adjuvant was inefficient for the induction of immune responses to ESAT-6. Therefore, we investigated the modulatory effect of monophosphoryl lipid A (MPL), an immunomodulator which in different combinations has demonstrated strong adjuvant activity for both cellular and humoral immune responses. We show in the present study that vaccination with ESAT-6 delivered in a combination of MPL and DDA elicited a strong ESAT-6-specific T-cell response and protective immunity comparable to that achieved with Mycobacterium bovis BCG.
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PMID:ESAT-6 subunit vaccination against Mycobacterium tuberculosis. 1063 47


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