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)

Strains of Mycobacterium tuberculosis were obtained from 65 patients with pulmonary tuberculosis resident in Uganda, and from pulmonary and extrapulmonary tuberculosis in 42 British patients of European ethnic stock and in 67 Asian immigrants, often from Uganda, resident in Britain. The bacteriophage-type patterns of the African, British and Asian strains were different. The pattern for the Asian strains resembled that found previously in patients from South India, suggesting that there has been little interchange of organisms between the Asian community and the African and British communities alongside whom they have lived. The patterns for pulmonary and extra-pulmonary tuberculosis were similar. Strains of bacteriophage type 1, mainly obtained from Asians, were characterized by a greater susceptibility to the bactericidal activity of hydrogen-peroxide and/or a greater sensitivity to thiophen-2-carbonic acid hydrazide than strains of other types.
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PMID:Comparison of strains of Mycobacterium tuberculosis from British, Ugandan and Asian immigrant patients: a study in bacteriophage typing, susceptibility to hydrogen peroxide and sensitivity to thiophen-2-carbonic acid hydrazide. 41 98

One hundred strains of Mycobacterium tuberculosis isolated from cases of pulmonary tuberculosis in Nepalese villagers were typed with the World Health Organization set of bacteriophages. The number of strains in the 3 major phage types A, I, and B were 19, 53, and 28 respectively. This distribution is significantly different from those described in other geographical regions. In particular there was a relatively low incidence of type A strains and, in common with South India, there was a high proportion of type I strains. All the strains in this study were resistant to 5-Furan-2 carbonic acid hydrazine and 34 were highly resistant to isoniazid. Representative strains of the 3 phage types, including 4 isoniazid-resistant type I strains, did not differ in their virulence in the guinea pig; thus the type I strains found in Nepal may not be of the same origin as those of this phage type from India which are usually attenuated in the guinea pig. This study provides further evidence for the existence of geographical differences in the types of tubercle bacilli.
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PMID:Bacteriophage typing of strains of Mycobacterium tuberculosis from Nepal. 640 18

The molecular basis by which organisms detect and respond to fluctuations in inorganic carbon is not known. The cyaB1 gene of the cyanobacterium Anabaena sp. PCC7120 codes for a multidomain protein with a C-terminal class III adenylyl cyclase catalyst that was specifically stimulated by bicarbonate ion (EC50 9.6 mm). Bicarbonate lowered substrate affinity but increased reaction velocity. A point mutation in the active site (Lys-646) reduced activity by 95% and was refractory to bicarbonate activation. We propose that Lys-646 specifically coordinates bicarbonate in the active site in conjunction with an aspartate to threonine polymorphism (Thr-721) conserved in class III adenylyl cyclases from diverse eukaryotes and prokaryotes. Using recombinant proteins we demonstrated that adenylyl cyclases that contain the active site threonine (cyaB of Stigmatella aurantiaca and Rv1319c of Mycobacterium tuberculosis) are bicarbonate-responsive, whereas adenylyl cyclases with a corresponding aspartate (Rv1264 of Mycobacterium) are bicarbonate-insensitive. Large numbers of class III adenylyl cyclases may therefore be activated by bicarbonate. This represents a novel mechanism by which diverse organisms can detect bicarbonate ion.
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PMID:A defined subset of adenylyl cyclases is regulated by bicarbonate ion. 1282 12

Large-scale vaccination with BCG, the live attenuated strain of Mycobacterium bovis, is being adopted around the world, although sporadic complications have occurred after the procedure. Lymphadenopathy is not uncommon especially in babies under one year (0.73% of vaccinated infants), but the swelling subsides within 2 months in most cases, with no medical or surgical treatment. Brazil adopted BCG vaccination program earlier in the seventies and by 1995 more than 96% of the infant population received this immunization. We report here the occurrence of lymphadenopathy in a two-year-old child vaccinated with the Brazilian BCG strain. The diagnosis was made using a lymph node biopsy and intestinal aspirates that yielded a positive mycobacterial culture. The isolate was resistant to isoniazid, rifampicin, pyrazinamide and thiophen-2-carbonic acid hydrazide, sensitive to streptomycin, ethambutol, and p-nitrobenzoic acid, and reacted positively to cyclo-serine and negatively to niacin. The pncA gene involved in bacterial activation of pyrazinamide contains in M. bovis a point mutation that renders pyrazinamidase unable to catalyze drug activation. Therefore, this polymorphism is a good option for developing methods to differentiate M. bovis and M. tuberculosis. Taking advantage of this difference we further analyzed the isolates by single-stranded conformation polymorphism electrophoresis of DNA following PCR of the pncA gene. The isolate identity was confirmed by RFLP electrophoretic analysis of the amplified fragment following Eco065I digestion, which selectively cleaves M. tuberculosis DNA. From this result it is proposed that RFLP of pncA gene represents an alternative for differential diagnosis of M. bovis.
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PMID:BCG lymphadenopathy detected in a BCG-vaccinated infant. 1510 32

The development of diagnostic tests to differentiate between vaccinated animals and those infected with Mycobacterium bovis is required so that test and slaughter control strategies can continue alongside vaccination. In this work, the peptide antigen, ESAT-6, p45, derived from the N-terminal sequence of the ESAT-6 protein, was adsorbed onto a range of microparticulate and nanoparticulate substrates to enhance the in vitro immune response of blood lymphocytes previously sensitised to M. bovis. Two types of hydroxyapatite (HA) nanoparticles (both approximately 300 nm in linear dimension), carbonate hydroxyapatite nanospheres (CHA, approximately 50 nm), two sizes of polystyrene nanospheres ( approximately 500 and 40 nm), calcium carbonate microparticles (0.3-1.0 microm) and glass microspheres (1.0-3.0 microm) were incubated in a solution of the peptide in PBS. Peptide adsorption increased on the nanoparticle carriers in the order HA (2.5+/-0.12%w/w), CHA (4.9+/-0.12) polystyrene (500 nm, 6.8+/-0.15%, 40 nm, 9.2+/-0.07) and these systems exhibited fairly low levels of desorption (approximately 10-15% peptide release) over a 24-h incubation period in PBS at 37 degrees C. HA, CHA and polystyrene carriers with adsorbed peptide were subsequently tested in the BOVIGAM assay to investigate the efficiency of the immune response of blood lymphocytes in terms of interferon-gamma (IFN-gamma) production. A general elevation of IFN-gamma production resulted for particle-bound peptide relative to free peptide at high peptide concentrations (>10 microg/ml). Only HA-adsorbed peptide resulted in consistently higher immune responses at low peptide concentration (<0.1 microg/ml) compared with the free peptide, indicating that peptide antigens adsorbed to hydroxyapatite nanoparticles may be useful, in diagnostic assays, for differentiating between tuberculosis (TB)-infected and vaccinated animals.
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PMID:Improving peptide-based assays to differentiate between vaccination and Mycobacterium bovis infection in cattle using nanoparticle carriers for adsorbed antigens. 1568 Oct 78

Because many membrane-associated proteins represent potential drug targets, diagnostic probes, and components of vaccines, we have chosen to study the membrane proteins of Mycobacterium tuberculosis H37Rv. To remove cytosolic proteins and facilitate access to the integral membrane proteins, membrane fractions of M. tuberculosis H37Rv were intensely washed with 5 M urea and high pH carbonate solution. One-dimensional SDS-PAGE, followed by enzymatic hydrolysis and nanoLC electrospray ionization MS/MS, proved to be the most efficient way to identify the proteins contained within the membrane fraction. Here we report 349 protein identifications in total, validated by at least two tryptic peptide matches and MOWSE scores greater than 75. Of those 349 proteins, 100 are integral membrane proteins with at least one predicted transmembrane alpha helix (excluding the possible signal sequence). 84 M. tuberculosis H37Rv proteins, including 42 integral membrane proteins, are described for the first time.
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PMID:Identification of Mycobacterium tuberculosis H37Rv integral membrane proteins by one-dimensional gel electrophoresis and liquid chromatography electrospray ionization tandem mass spectrometry. 1595 32

Alkylation of 2-hydroxydibenzofuran with 3-chloro-3-methyl-1-butyne, followed by Claisen rearrangement, gave access to 3,3-dimethyl-3Hbenzofuro[3,2-f][1]-benzopyran. Several derivatives modified at the pyran 1,2-double bond were prepared, including the corresponding dihydro compound and (+/-)-cis-diol, which was converted into diacetate and cyclic carbonate upon acylation. Both 3,3-dimethyl-3Hbenzofuro[3,2-f][1]benzopyran and 1,2-dihydro-3,3-dimethyl-3Hbenzofuro[3,2-f][1]benzopyran displayed significant activities when tested against Mycobacterium tuberculosis H37Rv and Beijing strains, with MIC99 in the range of 1-10 microg/ml. Further biological studies demonstrated good activities against drug-resistant mycobacterial strains. These compounds appear as promising specific antitubercular agents, since they exhibited neither significant cytotoxicity against mammal cells, nor effect on the growth of various bacteria and fungi.
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PMID:Benzofuro[3,2-f][1]benzopyrans: a new class of antitubercular agents. 1661 4

Mycobacterial plasma membrane proteins play essential roles in many cellular processes, yet their comprehensive proteomic profiling remains challenging. This is mainly due to obstacles related to their extraction and solubilization. To tackle this problem, we have developed a novel procedure to selectively enrich mycobacterial plasma membrane proteins based on alkaline sodium carbonate washing of crude membranes followed by Triton X-114 phase partitioning. The present study assesses the efficiency of this method by proteome analysis of plasma membrane proteins from Mycobacterium bovis BCG. Extracted proteins were separated in parallel by 1-D SDS-PAGE and 2-DE and then analyzed by LC-MS/MS and MALDI-MS/MS. Our study revealed 125 proteins, of which 54 contained 1-14 predicted transmembrane domains (TMD) including nine novel proteins. The 1-D SDS-PAGE-based proteome analysis identified 81 proteins, of which 49 (60.5%) harbored TMD. This approach also revealed many hydrophobic membrane-associated/periplasmic proteins lacking TMD, but only few soluble proteins. The identified proteins were characterized with regard to biological functions and physicochemical properties providing further evidence for the high efficiency of the prefractionation method described herein.
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PMID:An improved strategy for selective and efficient enrichment of integral plasma membrane proteins of mycobacteria. 1743 67

The plasma membrane of Mycobacterium tuberculosis is likely to contain proteins that could serve as novel drug targets, diagnostic probes or even components of a vaccine against tuberculosis. With this in mind, we have undertaken proteome analysis of the membrane of M. tuberculosis H37Rv. Isolated membrane vesicles were extracted with either a detergent (Triton X114) or an alkaline buffer (carbonate) following two of the protocols recommended for membrane protein enrichment. Proteins were resolved by 2D-GE using immobilized pH gradient (IPG) strips, and identified by peptide mass mapping utilizing the M. tuberculosis genome database. The two extraction procedures yielded patterns with minimal overlap. Only two proteins, both HSPs, showed a common presence. MALDI-MS analysis of 61 spots led to the identification of 32 proteins, 17 of which were new to the M. tuberculosis proteome database. We classified 19 of the identified proteins as 'membrane-associated'; 14 of these were further classified as 'membrane-bound', three of which were lipoproteins. The remaining proteins included four heat-shock proteins and several enzymes involved in energy or lipid metabolism. Extraction with Triton X114 was found to be more effective than carbonate for detecting 'putative' M. tuberculosis membrane proteins. The protocol was also found to be suitable for comparing BCG and M. tuberculosis membranes, identifying ESAT-6 as being expressed selectively in M. tuberculosis. While this study demonstrates for the first time some of the membrane proteins of M. tuberculosis, it also underscores the problems associated with proteomic analysis of a complex membrane such as that of a mycobacterium.
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PMID:Proteome analysis of the plasma membrane of Mycobacterium tuberculosis. 1862 50

Ultrasound is widely used to disinfect drinking water and wastewater due to its strong physical and chemical effects on microorganisms. The aim of this study was to investigate the effect of ultrasound on the destruction of Mycobacterium strain 6PY1. Ultrasound waves (20 kHz or 612 kHz) were used to treat aqueous suspensions of Mycobacterium at different volumes, initial bacterial concentrations, and power densities. At the same power density and the same exposure time, sonication at high frequency resulted in a lower destruction of Mycobacterium sp. 6PY1 (35.5%) than sonication at low frequency (93%). The percentage of removal was not significantly affected by the volume of the irradiated suspension (150-300 ml) or the initial cell concentration (2.15 x 10(-3)-1.4 x 10(-2)mg protein L(-1)). At low frequency, the removal percentage of Mycobacterium sp. 6PY1 increased with increasing the power density, with a constant level reached after a certain power density. At high frequency, the removal percentage of Mycobacterium sp. 6PY1 increased with increasing the power density. The mechanism of cell killing was investigated by examining the effects of OH() radical scavengers such as sodium carbonate. At high frequency the presence of sodium carbonate suppressed the removal process. However, at low frequency the removal process was not affected, thus indicating that OH() radicals have a negligible role in this case. The latter result was supported by ten time's H(2)O(2) production at high frequency greater than that at low frequency.
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PMID:Effectiveness of ultrasound for the destruction of Mycobacterium sp. strain (6PY1). 1945 Oct 14


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