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)

(1) Infections following invasive endoscopy are rare and are usually of endogenous origin. Nevertheless, infections do occur due to inadequate cleaning and disinfection and the use of contaminated rinse water and processing equipment. (2) Rigid and flexible operative endoscopes and accessories should be thoroughly cleaned and preferably sterilized using properly validated processes. (3) Heat tolerant operative endoscopes and accessories should be sterilized using a vacuum assisted steam sterilizer. Use autoclavable instrument trays or containers to protect equipment during transit and processing. Small bench top sterilizers without vacuum assisted air removal are unsuitable for packaged and lumened devices. (4) Heat sensitive rigid and flexible endoscopes and accessories should preferably be sterilized using ethylene oxide, low temperature steam and formaldehyde (rigid only) or gas plasma (if appropriate). (5) If there are insufficient instruments or time to sterilize invasive endoscopes, or if no suitable method is available locally, they may be disinfected by immersion in 2% glutaraldehyde or a suitable alternative. An immersion time of at least 10 min should be adopted for glutaraldehyde. This is sufficient to inactivate most vegetative bacteria and viruses including HIV and hepatitis B virus (HBV). Longer contact times of 20 min or more may be necessary if a mycobacterial infection is known or suspected. At least 3 h immersion in glutaraldehyde is required to kill spores. (6) Glutaraldehyde is irritant and sensitizing to the skin, eyes and respiratory tract. Measures must be taken to ensure glutaraldehyde is used in a safe manner, i.e., total containment and/or extraction of harmful vapour and the provision of suitable personal protective equipment, i.e., gloves, apron and eye protection if splashing could occur. Health surveillance of staff is recommended and should include a pre-employment enquiry regarding asthma, skin and mucosal sensitivity problems and lung function testing by spirometry. (7) Possible alternative disinfectants to glutaraldehyde include peracetic acid (0.2-0.35%), chlorine dioxide (700-1100 ppm) and superoxidized water. These are very effective, killing vegetative bacteria, including mycobacteria, and viruses in 5 min and bacterial spores in 10 min. An endorsement of compatibility with endoscopes, accessories and processing equipment is required from both the solution/device manufacturer and the endoscope manufacturer. Other important considerations are stability, cost and safety from the user and environmental standpoints. (8) Cleaning and disinfection or sterilization should be undertaken by trained staff in a dedicated area, e.g., SSD or TSSU. A suitable training programme is described. (9) If endoscopes are processed by immersion in disinfectants, harmful residues must be removed by thorough rinsing. Sterile or bacteria free water is essential for rinsing all invasive endoscopes and accessories to prevent recontamination. (10) If an automated washer disinfector is used it must be effective, non-damaging, reliable, easy to use and its performance regularly monitored. (11) If used, washer disinfectors and other processing equipment should be disinfected on a regular basis, i.e., between patients or at the start of each session. This will prevent biofilm formation and recontamination of instruments during rinsing. Disinfection should include the water treatment system, if present. (12) To comply with the Medical Devices Directive, manufacturers are obliged to provide full details on how to decontaminate the reusable devices they supply. This should include details of compatibility with heat, pressure, moisture, processing chemicals and ultrasonics. (13) The Infection Control Team should always be involved in the formulation and implementation of decontamination policies. Wherever possible, the national good practice guidelines produced by the Medical Devices Agency and/or professional societies shoul
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PMID:Decontamination of minimally invasive surgical endoscopes and accessories. 1143 15

Mannich bases of norfloxacin were synthesized by reacting them with formaldehyde and several isatin derivatives. The compounds were evaluated in vitro against Mycobacterium tuberculosis H37R(v) at 12.5 microg/ml in BACTEC 12B medium using the BACTEC radiometric system. Among the compounds tested, S-10 showed promising activity, with 100% inhibition at a concentration lower than 6.25 microg/ml.
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PMID:Antituberculous activity of norfloxacin mannich bases with isatin derivatives. 1139 63

Mycothiol (MSH) is a novel thiol comprised of N-acetylcysteine amide-linked to GlcN-alpha(1-1)-Ins. It is the major thiol in most actinomycetes and is produced at millimolar levels in mycobacteria and streptomycetes. MSH biosynthesis occurs by linkage of GlcNAc to Ins, deacetylation to GlcN-Ins, ligation of the latter to L-cysteine, and transacetylation of the cysteinyl residue by CoASAc to produce MSH. The genes encoding the respective enzymes have been designated mshA, mshB, mshC, and mshD; all but mshA have been identified. Mycobacterium smegmatis mutants deficient in mshA, mshC, and mshD have been characterized. MSH plays a significant role in the detoxification of thiol-reactive substances, including formaldehyde, various electrophiles, and antibiotics. Mycothiol S-conjugates derived from electrophiles and antibiotics are cleaved by mycothiol S-conjugate amidase to release GlcN-Ins, used to resynthesize MSH, and a mercapturic acid which is excreted from the cell. A mycothiol-disulfide-selective reductase has been identified and likely helps to maintain cellular MSH in the reduced state. Mycothiol biochemistry has characteristics similar to those of glutathione but also has a variety of unique features.
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PMID:Mycothiol biochemistry. 1242 Jan 57

A microtiter plate assay for UDP-galactopyranose mutase, an essential cell wall biosynthetic enzyme of Mycobacterium tuberculosis, was developed. The assay is based on the release of tritiated formaldehyde from UDP-galactofuranose but not UDP-galactopyranose by periodate and was used to identify a uridine-based enzyme inhibitor from a chemical library.
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PMID:Drug targeting Mycobacterium tuberculosis cell wall synthesis: development of a microtiter plate-based screen for UDP-galactopyranose mutase and identification of an inhibitor from a uridine-based library. 1249 18

The panB gene that encodes ketopantoate hydroxymethyltransferase has been cloned from Mycobacterium tuberculosis, expressed, and purified to homogeneity. 1H NMR spectroscopy was used to determine the rate of (i) tetrahydrofolate-independent hydroxymethyltransferase chemistry between formaldehyde and alpha-ketoisovalerate and (ii) deuterium exchange in the methylenetetrahydrofolate-independent enolization of alpha-ketoisovalerate and other alpha-keto acids, catalyzed by PanB. These studies have demonstrated that substrate enolization by PanB is divalent metal-dependent with a preference of Mg2+ > Zn2+ > Co2+ > Ni2+ > Ca2+. The rate of enolization is pH-dependent with optimal activity in the range of 7.0-7.5. The pH profile was bell-shaped, depending on the ionization state of two ionizable groups with apparent pK values of 6.2 and 8.3. Enolization and isotope exchange occurs with some alpha-keto acids (e.g., pyruvate and alpha-ketobutyrate), resulting in the complete exchange of all beta-hydrogens. Enzyme-catalyzed enolization and isotope exchange occur with other long-chain and branched alpha-keto acids, resulting in the stereospecific exchange of only one of the beta-hydrogen atoms. These results are discussed in the context of steric restrictions present in the enzyme active site and the stereochemistry of base-catalyzed isotope exchange.
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PMID:Mycobacterium tuberculosis ketopantoate hydroxymethyltransferase: tetrahydrofolate-independent hydroxymethyltransferase and enolization reactions with alpha-keto acids. 1251 54

A series of 3,5-disubstituted thiadiazine thiones (4-24) have been synthesized by reaction of primary amines with carbon disulphide followed by cyclocondensation of the resulting intermediate with formaldehyde and primary amines or amino acids. The compounds were screened for antitubercular activity in vitro against Mycobacterium tuberculosis H37Rv. Three compounds 4, 12 and 18 showed antimycobacterial activity with MIC 12.5 microg/mL. Compound 4, was tested in vitro against five multidrug resistant (MDR) strains of M. tuberculosis and was found to be active. Compound 4 also exhibited activity in vivo. While all the mice died in the untreated group, the mean survival time (MST) of the compound treated mice was enhanced, 33% mice were surviving in treated group and the load of bacilli in the lung was considerably less in the compound treated group than in the untreated control group.
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PMID:Synthesis and antimycobacterial activity of 3,5-disubstituted thiadiazine thiones. 1312 74

Yotis, William W. (Loyola University, Chicago, Ill.). Absorption of the antibacterial serum factor by staphylococci. J. Bacteriol. 85:911-917. 1963.-The absorption of antibacterial serum factor by eight bacterial species and one yeast showed good correlation with the sensitivity of the organisms to the serum factor. The serum factor was removed from aqueous solution by coagulase-positive and coagulase-negative strains of staphylococci and Bacillus subtilis, and the oxygen consumption of the bacteria was inhibited by prior exposure to the serum factor. Escherichia coli, Neisseria catarrhalis, Proteus vulgaris, Bacillus megaterium, Mycobacterium phlei, and Saccharomyces cerevisiae failed to absorb the serum factor, and their respiration was not inhibited by prior exposure to 40 mg or more of the serum factor per ml. Staphylococci treated with 0.25 mg per ml of coagulase were almost completely refractory to the antibacterial action of 2 mg of serum factor per ml, and the serum factor was not absorbed. When the staphylococci were first treated with the serum factor, subsequent treatment with coagulase had no effect. Exposure of staphylocci to heat (70 C for 1 hr), 3.6% formaldehyde, 1 n sodium hydroxide, and 1 n hydrochloric acid did not prevent absorption of the serum factor. However, pretreatment with 88% liquefied phenol partially prevented serum factor absorption. The absorption and antibacterial activity of the serum factor were dependent on the concentration, the time and temperature of exposure, and the nature and concentration of salts present.
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PMID:ABSORPTION OF THE ANTIBACTERIAL SERUM FACTOR BY STAPHYLOCOCCI. 1404 62

The microbicidal activity of four different biocides was studied in synthetic metalworking fluid (MWF) against Mycobacterium immunogenum, a suspected causative agent for hypersensitivity pneumonitis, and Pseudomonas fluorescens, a representative for the predominant gram-negative bacterial contaminants of MWF. The results indicated that M. immunogenum is more resistant than P. fluorescens to the tested formaldehyde-releasing biocides (Grotan and Bioban), isothiazolone (Kathon), and phenolic biocide (Preventol). Kathon was effective against mycobacteria at lower concentrations than the other three test biocides in MWF. In general, there was a marked increase in biocidal resistance of both the test organisms when present in MWF matrix compared to saline. Increased resistance of the two test organisms to biocides was observed when they were in a mixed suspension (1:1 ratio). The results indicate the protective effect of the MWF matrix against the action of commonly used biocides on the MWF-colonizing microbial species of occupational health significance, including mycobacteria.
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PMID:Biocidal activity of formaldehyde and nonformaldehyde biocides toward Mycobacterium immunogenum and Pseudomonas fluorescens in pure and mixed suspensions in synthetic metalworking fluid and saline. 1564 Feb 32

The purpose of this study was to prepare various isoniazid derivatives by introducing the isoniazid pharmacophore into several molecules and screening for antimycobacterial activity. Ortho-hydroxy acetophenone reacts with isoniazid to form acid hydrazones. The C-Mannich bases of the above acid hydrazones were prepared by reacting them with formaldehyde and various secondary amines. The synthesized compounds were screened against M. tuberculosis H(37)R(v) using the alamar blue susceptibility test. The synthesized compounds inhibit Mycobacterium tuberculosis strain H(37)R(v) with minimum inhibitory concentrations ranging from 0.56 to 4.61 microM. Compound N'-{1-[2-hydroxy-3-(piperazin-1-ylmethyl)phenyl]ethylidene}isonicotinohydrazide 8 was found to be the most active compound with an MIC of 0.56 microM, and was more potent than isoniazid (MIC of 2.04 microM). After 10 days of treatment, compound 8 decreased the bacterial load in murine lung tissue by 3.7-log10 as compared to controls, which was equipotent to isoniazid. The results demonstrate the potential and importance of developing new isoniazid derivatives against mycobacterial infections.
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PMID:Synthesis and in vitro and in vivo antimycobacterial activity of isonicotinoyl hydrazones. 1611 63

Dendritic cells produce cytokines that regulate the class of the adaptive immune response. Microbial recognition is mediated, at least in part, by pattern recognition receptors such as Toll-like receptors, which influence dendritic cell maturation. In humans it is not yet clear how intact pathogens modulate the developing immune response. To address the effects of intact pathogens on the maturation and effector functions of human dendritic cells, we investigated their responses to a number of microbial pathogens. We studied a range of micro-organisms including Gram-negative bacteria (Escherichia coli and Salmonella enterica sv. typhimurium), Gram-positive cocci (Staphylococcus aureus) and atypical bacteria (Mycobacterium tuberculosis and Mycoplasma hominis) as well as the human protozoal parasite Trichomonas vaginalis. The micro-organisms were fixed in formaldehyde to prevent replication whilst preserving surface morphology. All the pathogens induced similar up-regulation of dendritic cell activation-associated cell surface markers but there was a profound difference in the patterns of cytokines produced by the stimulated dendritic cells. Some pathogens (E. coli, Salmonella enterica sv. typhimurium and S. aureus) induced interleukin-12 (IL-12), IL-10 and interferon-alpha whereas others (M. tuberculosis, Mycoplasma hominis and T. vaginalis) induced only IL-10. This differential effect was not altered by costimulation of the dendritic cells through CD40. These results support the notion that human dendritic cells are plastic in their response to microbial stimuli and that the nature of the pathogen dictates the response of the dendritic cell.
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PMID:Qualitatively distinct patterns of cytokines are released by human dendritic cells in response to different pathogens. 1616 73


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