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)

Treatment of growing cultures of Mycobacterium smegmatis with alkylating agents (methyl methanesulphonate, ethyl methanesulphonate, nitrogen mustard, or mitomycin C) or with ultraviolet light resulted in enhanced specific activities of a DNA polymerase and of an ATP-dependent deoxyribonuclease. Similar results had previously been obtained with hydroxyurea and with iron limitation. The three of these treatments which were tested (methyl methanesulphonate, mitomycin C and hydroxyurea) produced strand breaks or alkali-labile regions in the DNA of this organism. The increased enzyme activities could be prevented by simultaneous treatment with inhibitors of protein synthesis. In contrast, treatment of the cultures with intercalating agents (ethidium bromide, acridine orange, or proflavine), 5-fluorouracil, caffeine, or nalidixic acid, inhibited DNA synthesis without increasing the enzyme activities. These treatments did not produce strand breaks in the DNA of this organism. The results support the hypothesis that, in M. smegmatis, damage to DNA induces increased synthesis of enzymes associated with DNA repair.
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PMID:Increased DNA polymerase and ATP-dependent deoxyribonuclease activities following DNA damages in mycobacterium smegmatis. 84 85

Irradiation with ultraviolet light (360 nm) of cell-free extracts, electron-transport particles, and soluble components from Mycobacterium phlei resulted in the loss of malate oxidation by the flavine adenine dinucleotide pathway both in cell-free extracts and reconstituted systems. Addition of vitamin K1 restored the loss to the extent of 14% and 11% in cell-free extracts and reconstituted systems respectively. Electron-transport particles from M. phlei upon reduction with malate exhibited electron-paramagnetic resonance signals at g = 2.002 and 1.94, characteristic of napthosemiquinone and nonheme iron protein, respectively. Upon irradiating the particles with ultraviolet light (360 nm) these signals were not observed. Particulate flavine-adenine-dinucleotide-dependent malate dehydrogenase (EC 1.1.1.37) of M. phlei assayed by the 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyl tetrazolium bromide and phenazine methosulfate - 2,6-dichlorophenolindophenol systems, which trap electrons at cytochrome c and at the flavine level respectively, was inhibited by o-phenanthroline. These observations suggest that nonheme iron protein is sensitive to ultraviolet light (360 nm) and participates before or in combination with flavine in the malate (flavine adenine dinucleotide) pathway of M. phlei.
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PMID:Site of action of nonheme iron in the malate (flavine adenine dinucleotide) pathway of Mycobacterium phlei. 96 13

A test based on the polymerase chain reaction (PCR) was developed for the detection of the Mycobacterium tuberculosis complex in clinical samples. In this test, a 245-bp sequence of the insertion element IS986 was amplified and detected by agarose gel electrophoresis in the presence of ethidium bromide and by Southern blot and dot blot hybridization by using a 188-bp digoxigenin-labeled probe. We tested clinical specimens from 227 patients suspected of having tuberculosis. These included 102 cerebrospinal fluid, 48 sputum, 18 pleural fluid, 5 bronchoalveolar lavage, 18 blood, 7 pus, 8 bone marrow, and 6 urine samples and 15 tissue biopsy specimens. We also tested sputum samples from 75 patients with diseases other than tuberculosis. Sputum samples were first decontaminated, and all samples were treated with proteinase K-detergent solution to extract the DNA. Part of each sample was spiked with M. tuberculosis to provide a semiquantitative assay and to control for the loss of mycobacteria or interference with the PCR which may cause false-negative results. One femtogram of M. tuberculosis DNA could be detected. PCR was positive for all 32 culture-positive (for M. tuberculosis) and Ziehl-Neelsen staining (ZN)-positive samples, 10 of 12 culture-positive and ZN-negative samples, and all 4 culture-negative and ZN-positive samples. PCR detected M. tuberculosis complex bacteria in 35 of 178 culture- and ZN-negative samples. Clinical data supported the diagnosis of tuberculosis in the majority of the 35 patients from whom those samples were obtained.
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PMID:Detection of Mycobacterium tuberculosis in clinical samples by using polymerase chain reaction and a nonradioactive detection system. 140 Sep 55

We cloned and sequenced a DNA fragment from Mycobacterium tuberculosis for use in the identification of members of the M. tuberculosis complex. The DNA probe for culture confirmation had a sensitivity and a specificity of 100%. By using primers developed from this probe, the polymerase chain reaction detected 20 mycobacteria by ethidium bromide staining. This polymerase chain reaction system demonstrated 98% sensitivity and 100% specificity for detection of the M. tuberculosis complex in 200 sputum specimens.
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PMID:Characterization of a DNA probe for detection of Mycobacterium tuberculosis complex in clinical samples by polymerase chain reaction. 150 May 29

The polymerase chain reaction (PCR) was employed to detect Pneumocystis carinii in organs of infected rats. Using a pair of oligonucleotides designed to the dihydrofolate reductase (DHFR) gene of rat P. carinii, specific amplification of an expected 415 bp region of P. carinii DHFR DNA of this organism was achieved, while no amplification occurred with the human, Candida albicans, and Mycobacterium avium and tuberculosis DNAs. Using rat P. carinii isolated from in vitro cultures and infected lung homogenates, the minimum detection level by PCR on an ethidium bromide gel was about 200 organisms and by Southern analysis with radiolabelled DHFR probe the detection level improved to 20 organisms. This level of sensitivity is sufficient to detect P. carinii specific band on the gel in infected rat lung and other organs. This PCR technique is potentially useful for detecting P. carinii in bronchoalveolar lavage (BAL) fluids of AIDS patients and for quantifying the organisms in tissues and in in vitro cultures where a high background with conventional stains makes it harder to determine the number of organisms.
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PMID:Detection of Pneumocystis carinii in a rat model of infection by polymerase chain reaction. 151 43

The present study describes the in vitro effect of anti-leprosy drugs on superoxide anion (O2-) production by rat resident peritoneal macrophages. Of the three drugs tested i.e. clofazimine, rifampicin and dapsone, the first was most effective in increasing O2- production in a dose dependent manner, while rifampicin had some stimulatory effect and dapsone exhibited minimal action. Furthermore, when clofazimine and dapsone were added together it was observed that the increase of O2- production by macrophages due to clofazimine was not significantly altered by the addition of dapsone. Moreover, it was found that killed Mycobacterium leprae could induce a lesser amount of O2- production in comparison to that of Staphylococcus aureus and the enhancement of O2- release due to clofazimine was stimulus dependent. This increase of O2- release after addition of clofazimine was inhibited by the addition of p-bromophenacyl bromide. Another interesting finding was that the enhancement of O2- production by clofazimine gradually decreased as clofazimine was exposed to light for days. On further investigation it was found that ultraviolet, NMR, infrared and mass spectra of the light unexposed and exposed drug were similar, but the diffusion current of the polarogram of light exposed drug was remarkably more than that observed in light unexposed drug, indicating, thereby, a possible increase in the electron accepting capacity of the light reacted molecule. As far as we know this is the first report describing the effect of light exposed clofazimine on the respiratory burst activity of macrophages.
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PMID:Effect of anti-leprosy drugs on superoxide anion production by rat peritoneal macrophage with special reference to light exposed clofazimine. 164 74

Acid-fast staining is broadly used for the detection of mycobacteria in smears or pathological preparations, but it does not distinguish viable and non-viable bacteria. Enzymatic hydrolysis of fluorescein diacetate (FDA) was reported as a tool to detect viable mammalian cells or protozoa. We have applied this method to mycobacteria samples to detect viable or non-viable bacteria in the smear. Mycobacterium bovis BCG (Tokyo), 20 mg/ml suspension of standard vaccine, was used as the sample of viable bacteria. A part of the same suspension was heated at 100 degrees C for 30 min and used as the sample of non-viable bacteria. Three samples, viable, non-viable, and 1:1 mixture of the two, were stained with acid-fast staining and FDA-EB (ethidium bromide) mixture, respectively. For FDA/EB staining, stock solution of FDA (5 mg/ml acetone) was diluted 1:50 in PBS and 25 microliters of FDA and 25 microliters of EB (20 micrograms/ml PBS) were mixed with 50 microliters of bacterial suspension. Preparations were observed with either light or fluorescein microscope. Living bacteria were stained in yellow green in FDA/EB staining while non-viable bacteria were red. Mixed sample of live and dead bacilli showed differential staining with green or red in FDA/EB staining, but no difference was shown in acid-fast staining between viable and non-viable bacteria.
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PMID:[Detection of viable or non-viable mycobacteria by hydrolysis of fluorogenic substrate]. 169 50

In the present study we have evaluated the Fluorescein Diacetate/Ethidium Bromide (FDA/EB) staining technique to assess the viability of Mycobacterium leprae obtained from biopsies of leprosy patients under different periods of treatment. Bacillary suspensions were obtained from skin punch biopsies and stained with the FDA/EB solution. The average percentage of green cells seen which were deemed to be viable were: 67.2% of green cells in patients without previous treatment; 45.6% in patients with 1 to 6 months of treatment; 25.9% for patients with 7 to 12 months of treatment and 10.5% in patients with 13 to 24 months of treatment. All the patients studied were on multidrug therapy. The differences obtained in the percentages of green cells in the different groups of patients were statistically significant as determined by the Wilcoxon's test. The decrease in the percentage of green cells observed with increasing periods of treatment suggests that the FDA/EB technique correlates with the actual viability of M. leprae. The application of this technique in the routine procedures performed with Hansen's disease patients could be very useful for monitoring the effectiveness of treatment in leprosy patients.
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PMID:Assessing the viability of Mycobacterium leprae by the fluorescein diacetate/ethidium bromide staining technique. 172 41

The ability of the fluorescein diacetate and ethidium bromide fluorescent staining method to assess the percentage of viable bacterial cells in suspension was compared with the plate counting method. Mycobacterium smegmatis and Escherichia coli bacterial cell suspensions were incubated at 60 degrees C. At different time intervals samples were taken and the percentage of viable cells in each sample was assessed by the fluorescent staining method and compared with the plate counting method. The fluorescent staining method showed a positive correlation with the plate counting method. However, the viable counts by the plate counting method were lower than the staining method when incubated at 60 degrees C, indicating a lag period in the decay of enzymes after bacterial death. Hence, the fluorescent staining technique can be used to assess the trend of bacterial death rather than to assess to exact number of viable bacilli.
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PMID:Fluorescein diacetate and ethidium bromide staining to determine the viability of Mycobacterium smegmatis and Escherichia coli. 172 46

Five alternative methods were used to explore in vitro the effects of normal and activated murine macrophages on the metabolic well-being of intracellular Mycobacterium leprae: fluorescein diacetate-ethidium bromide staining, ATP content, synthesis of phenolic glycolipid 1, and two techniques to quantitate oxidation of palmitic acid. In relatively short-term experiments (7 to 10 days), each of these procedures provided strong evidence that activated macrophages exerted a deleterious effect on the leprosy bacillus. These findings appear to confirm the contention that activated macrophages underlie host resistance to clinical leprosy and limitation of M. leprae growth in paucibacillary leprosy.
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PMID:Effects of activated macrophages on Mycobacterium leprae. 190 24


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