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)

Seventy-four cases of miliary tuberculosis were studied retrospectively. Most common symptoms and findings were fever (97.3%), elevated serum alkaline phosphatase (67.6%), and nodular shadows in the chest X-ray films (98.6%). The other findings were enlarged mediastinal lymph node (17.6%), lung cavities (23.0%), consolidation (35.1%), and pleural effusion (27.0%). Sputum cultures and urine cultures were positive for Mycobacterium tuberculosis in 76.8% and 58.6% respectively. Biopsies were positive for bone marrow aspiration (61.5%), lymph node biopsies (83.3%), liver biopsies (100%), and lung biopsies (100%). Though antituberculosis therapy was successful in most of the patients, seven patients died of miliary tuberculosis, of whom four developed adult respiratory distress syndrome.
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PMID:[Miliary tuberculosis]. 988 25

AIDS patients are open to many opportunistic infections which often present as fever. The cases of 25 men and 3 women with AIDS of mean age 34 years, with fever of unknown origin who underwent 31 liver biopsies in Taiwan from December 1995 to May 1997, are presented. The biochemical tests most often showed moderate to markedly elevated alkaline phosphatase concentrations, but normal or mildly elevated aminotransferase concentrations. The most common histopathologic finding was macrosteatosis, noted in 15 of the 28 patients, while granuloma was found in 11 patients. The histochemical stain and culture of liver specimens yielded Mycobacterium avium complex (MAC) in 8 patients, Mycobacterium tuberculosis in 2 patients, Histoplasma capsulatum in 1 patient, and cytomegalovirus in 1 patient with concomitant MAC infection. A definitive diagnosis in AIDS patients with fever of unknown origin was therefore made in 11 of the 28 cases with the assistance of liver biopsy. During follow-up, late extrahepatic involvement by the same infectious agents was found in 6 patients. Hepatic manifestations could therefore be a harbinger of disseminated opportunistic infections in AIDS patients.
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PMID:Opportunistic hepatic infections in AIDS patients with fever of unknown origin. 1006 67

Improved enzyme-linked immunosorbent assay (ELISA) methods have been developed for the determination of femtomole amounts of mycothiol (MSH), the main low-molecular-weight thiol in mycobacteria. The immunoassays utilize an affinity-purified rabbit polyclonal antibody that is highly specific for the pseudodisaccharide moiety of MSH. MSH was first biotinylated by the thiol-specific reagent 3-(N-maleimidopropionyl)biocytin. The MSH-biotin adduct was then captured with immobilized avidin and detected with anti-MSH antibody (biotin-capture ELISA) or was captured with immobilized anti-MSH antibody and detected with alkaline phosphatase-labelled avidin (MSH-capture ELISA). The MSH-capture ELISA was the most sensitive method, measuring as little as 0.3 fmol of MSH. Methods for biotinylating MSH directly from Mycobacterium spp. are described. The MSH-capture ELISA was tested for the detection of M. avium seeded in human urine or cerebrospinal fluid samples and for screening mutant M. smegmatis strains to detect MSH production.
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PMID:Improved methods for immunoassay of mycothiol. 1036 78

Proteins which are secreted or associated with the cell envelope of Mycobacterium tuberculosis may contain protective T-cell epitopes. Prior to this study, a recombinant clone bank of enzymatically active M. tuberculosis-alkaline phosphatase fusions, were screened for immunogenicity in a murine T-cell model. Five of these were selected for further study, and the IFN-gamma secretion and proliferation of human PBMC from purified protein derivative- (PPD)-positive and PPD-negative donors were measured in response to oligopeptides, Mtb-PhoA fusions and one full-length protein. Epitopes from four of the five selected antigens were immunoreactive in the human model and corresponded to cytochrome d ubiquinol oxidase, cytochrome c oxidase subunit II, MTV005.02 and MTV033.08. Thus, this strategy identified novel human immunogenic peptides as possible candidates for a subunit vaccine.
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PMID:Identification of novel immunogenic Mycobacterium tuberculosis peptides that stimulate mononuclear cells from immune donors. 1043 30

Non-specific phosphomonoesterase activities (alkaline phosphatase (EC 3.1.3.1) and acid phosphatase (EC 3.1.3.2)) were examined at the cell surface of Mycobacterium bovis BCG. Using p-nitrophenylphosphate as the substrate, peaks of phosphatase activity were detected at pH 6.0, pH 10.0 and pH 12.0, suggesting the presence of one acid phosphatase and two alkaline phosphatases with distinct optimum pH values. Contrary to the situation observed in several other microorganisms, the expression of these enzymes is not regulated by the environmental inorganic phosphate concentration.
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PMID:The cell surface associated phosphatase activity of Mycobacterium bovis BCG is not regulated by environmental inorganic phosphate. 1117 39

The functionality of the putative Mycobacterium tuberculosis phosphate transport operon was studied by operon- lacZ promoterless fusions in Mycobacterium smegmatis. The expression of the operon genes was evaluated in transformed M. smegmatis growing in medium with low and high phosphate concentration. Although the gene fusions expressed beta-galactosidase in medium with phosphate, a higher activity was detected in bacteria growing in medium with low phosphate. In contrast, alkaline phosphatase activity from M. smegmatis was detected only in bacteria growing in medium with low phosphate. The expression of the operon genes was driven by a promoter located 5' upstream from the start codon of the pstB gene. A second putative internal promoter 5' upstream of the pstS-1 gene was also detected. Furthermore, comparative analysis between the native and recombinant PstS-1 proteins showed that they were very similar. Like the native protein, the recombinant protein was also secreted to the culture medium as a glycosylated band. The results show that M. smegmatis recognized phosphate regulatory signals of the M. tuberculosis phosphate transport operon genes, and open the possibility to study gene phosphate regulation in mycobacteria.
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PMID:Molecular analysis of Mycobacterium tuberculosis phosphate specific transport system in Mycobacterium smegmatis. Characterization of recombinant 38 kDa (PstS-1). 1137 23

Tuberculosis is the single most serious infectious disease worldwide. The respiratory tract is the primary site of infection by Mycobacterium tuberculosis(MTB). A number of immunogenic components of the cell wall of MTB, if delivered to the lungs as aerosols, can be used to study the local immune response. The site of deposition of these aerosols can be employed to control their residence time in the lungs. Muramyl dipeptide (MDP) aerosols were delivered to alveolar macrophages in the lungs of rodents. Guinea pig macrophages harvested by bronchoalveolar lavage were examined by differential interference contrast microscopy for morphological changes indicative of activation. Bronchoalveolar lavage fluid was analyzed for the presence of alkaline phosphatase, lactate dehydrogenase, N-acetyl-glucosaminidase (NAG), and total protein content. Rat alveolar macrophages were studied for the production of nitric oxide, by induction of nitric oxide synthase. Twenty-four hours following exposure to an aerosol of MDP, alveolar macrophages exhibited morphological characteristics (spreading and pseudopodia), enzyme activity (NAG 50% above control), and production of the reactive intermediate nitric oxide. Rat macrophages subjected to aerosol exposure to MDP when challenged with a second dose of MDP or lipopolysaccharide exhibited a linear dose response as measured by nitric oxide production. These studies indicate that the topical delivery of an MTB bacterial cell wall component, muramyl dipeptide, results in activation of alveolar macrophages. This approach may be useful in elucidating elements of the immune response to MTB.
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PMID:Aerosol delivery of muramyl dipeptide to rodent lungs. 1174 Dec 41

Dolichol phosphate-mannose (Dol-P-Man) is a mannose donor in various eukaryotic glycosylation processes. So far, two groups of Dol-P-Man synthases have been characterized based on the way they are stabilized in the endoplasmic reticulum membrane. Enzymes belonging to the first group, such as the yeast Dpm1, are typical integral membrane proteins harboring a transmembrane segment (TMS) at their C terminus. In contrast, mammalian Dpm1, enzymes of the second group, lack the typical TMS and require the association with the small hydrophobic proteins Dpm3 to be properly stabilized in the endoplasmic reticulum membrane. In Mycobacterium tuberculosis, the Polyprenol-P-Man synthase MtPpm1 is involved in the biosynthesis of the cell wall-associated glycolipid lipoarabinomannan. MtPpm1 is composed of two domains. The C-terminal catalytic domain is homologous to eukaryotic Dol-P-Man synthases. The N-terminal domain of MtPpm1 contains six TMS that anchor the enzyme in the cytoplasmic membrane. In contrast, in Mycobacterium smegmatis, orthologs of the two domains of MtPpm1 are encoded by two distinct open reading frames, Msppm1 and Msppm2, organized as an operon. No TMS are predicted in MsPpm1, and subcellular fractionation experiments indicate that this enzyme is cytosolic when produced in Escherichia coli. Computer-assisted topology predictions and alkaline phosphatase insertions showed that MsPpm2 is an integral membrane protein. Using a recently developed bacterial two-hybrid system, it was found that MsPpm2 interacts with MsPpm1 to stabilize the synthase MsPpm1 in the bacterial membrane. This interaction is reminiscent of that of mammalian Dpm1 with Dpm3 and mimics the structure of MtPpm1 as demonstrated by the capacity of the two domains of MtPpm1 to spontaneously interact when co-expressed in E. coli.
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PMID:In vivo interaction between the polyprenol phosphate mannose synthase Ppm1 and the integral membrane protein Ppm2 from Mycobacterium smegmatis revealed by a bacterial two-hybrid system. 1242 59

Although alkaline phosphatases are common in a wide variety of bacteria, there has been no prior evidence for alkaline phosphatases in Mycobacterium smegmatis. Here we report that transposon insertions in the pst operon, encoding homologues of an inorganic phosphate transporter, leads to constitutive expression of a protein with alkaline phosphatase activity. DNA sequence analysis revealed that M. smegmatis does indeed have a phoA gene that shows high homology to other phoA genes. The M. smegmatis phoA gene was shown to be induced by phosphate starvation and thus negatively regulated by the pst operon. Interestingly, the putative M. smegmatis PhoA has a hydrophobic N-terminal domain which resembles a lipoprotein signal sequence. The M. smegmatis PhoA was demonstrated to be an exported protein associated with the cell surface. Furthermore, immunoprecipitation of PhoA from [(14)C]acetate-labeled M. smegmatis cell lysates demonstrated that this phosphatase is a lipoprotein.
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PMID:Identification of a regulated alkaline phosphatase, a cell surface-associated lipoprotein, in Mycobacterium smegmatis. 1289 18

Thirty-six consecutive cases of liver abscess seen at the BP Koirala Institute of Health Sciences Hospital, Dharan, Nepal, from 1995 to 1998, were reviewed. Twenty-one cases were male and 15 female, with a mean age of 42 years. Twenty-four cases (66.7%) were amebic, 7 (19.4%) pyogenic, 3 (8.3%) indeterminate and 2 (5.5%) tuberculous. The most frequent clinical features included fever (88%), leukocytosis (66.7%), abnormal level of serum albumin (44.4%) and alkaline phosphatase (38.9%). The liver abscess was single in 61.1%, multiple in 27.8%, and in 66.7% of cases the abscess was present in the right lobe of the liver. Ultrasonography was diagnostic in all cases. A positive culture of the abscess was obtained in 7 cases (19.4%). The most frequent bacteria found were Klebsiella pneumoniae (4;11.1%), followed by Escherichia coli (3;8.3%). Two cases were due to Mycobacterium tuberculosis and none had malignancy. Percutaneous drainage was performed in 27 patients (75%). Mortality attributable to the abscess was 5.5%. We found percutaneous needle aspiration of liver abscess helpful in confirming diagnosis, as it provides a better bacteriological culture yield, gives a good outcome, and may uncover clinically unsuspected conditions like malignancy and tuberculosis. These two conditions should certainly be considered possible causes in our part of the world when an abscess fails to respond to standard treatment. In developing countries like Nepal, the clinical presentation of liver abscess has not varied over time. At present, rapid diagnosis and image-guided percutaneous drainage offer a better prognosis for liver abscess. We also recommend routine cytological examination of aspirated abscess materials, as well as stains and cultures for acid-fast bacilli.
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PMID:Liver abscess in the tropics: an experience from Nepal. 1569 Nov 50


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