TREHALOSE PLAYS AN IMPORTANT ROLE IN MYCOBACTERIA, PERFORMING VARIOUS FUNCTIONS SUCH AS BEING THE CARRIAGE OF MYCOLIC ACIDS AND IN THE FUNCTIONALIZATION OF MYCOLIC ACIDS INTO OM GLYCOLIPIDS. EARLIER WORK DONE BY THE AUTHOR SUGGESTED THAT NEW TYPES OF MYCOLIC ACID INTERMEDIATES ARE ACCUMULATING IN BOTH THE PRESENCE AND ABSENCE OF EXOGENOUS TREHALOSE IN A MYCOBACTERIUM SMEGMATIS STRAIN THAT IS AN AUXOTROPH FOR TREHALOSE. HOWEVER, THE IDENTITIES OF THESE INTERMEDIATES HAVE YET TO BE CHARACTERIZED.IN THIS WORK, WE AIMED TO CHARACTERIZE THESE MYCOLIC ACID INTERMEDIATES BY FIRST VERIFYING THEIR IDENTITIES AS MYCOLATES. THEREAFTER, WE TRIED TO CHARACTERIZE THEIR INTERMEDIATES FURTHER TO ELUCIDATE THEIR IDENTITIES. HOWEVER, WE WERE UNSUCCESSFUL IN OUR ATTEMPTS. FURTHER OPTIMIZATION OF THE EXPERIMENTS PERFORMED HAS BEEN PLANNED. DATA FROM THESE CHARACTERIZATIONS STUDIES THAT WILL BETTER OUR UNDERSTANDING OF HOW TREHALOSE COULD REGULATE MYCOLIC ACID BIOSYNTHESIS ...
Mycolic acids are essential components of the mycobacterial cell envelope and their biosynthetic pathway is a well-known source of antituberculous drug
The bulk of my research output has been involved with synthetic organic chemistry and specifically with the preparation of mycolic acid derivatives, which are found as complex mixtures in the cell walls of bacteria, most notably the TB causing Mycobacterium tuberculosis. As a result of overseeing the first total synthesis of each of the major classes of these mycolic acids, I have been involved in multiple collaborations seeking to exploit these compounds in diagnostic tests or as adjuvants. This work has led to multiple publications and several patents. I have also been involved in the development of efficient routes to the synthesis of cyclopropenes, including cyclopropene fatty acids, which has led to collaborations with research groups investigating their biological activity. I am also involved in the extraction of bioactive components from plants with two current ongoing projects in the area, one as part of the Beacon+ project.. Collaborations:. I have been a partner in 6 international ...
You know the TB cells having a kind of acidic fat cell wall coating makes me think that alkaline based attack profiling would diffuse the issue, lime and lemon... and other natural foods that produce alkaline environments within the body cavities and vascular systems,lungs etcetra ...
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Structure and mass spectrometry fragmentation of the mycolic acid species present in Mycobacterium tuberculosis complex (MTBC). (A) Alpha-mycolates harbor both
Resp.Sir,. Isoniazid(INH):. Only actively growing tubercle bacilli are susceptible to the bactericidal property of INH. The major action of INH is on the cell wall of the bacillus, where it prevents the synthesis of mycolic acid.. Other commonalty used drugs are:. ...
Batt, S.M and Bingle, Lewis E. H. and Dafforn, T.R and Thomas, Christopher M. (2009) Bacterial Genome Partitioning: N-Terminal Domain of IncC Protein Encoded by Broad-Host-Range Plasmid RK2 Modulates Oligomerisation and DNA Binding. Journal of Molecular Biology, 385 (5). pp. 1361-1374. ISSN 0022-2836. Mikhailov, Victor A. and Cooper, Helen J. (2008) Activated Ion Electron Capture Dissociation (AI ECD) of proteins: synchronization of infrared and electron irradiation with ion magnetron motion. Journal of the American Society for Mass Spectrometry, 20 (5). pp. 763-771. ISSN 1044-0305. Bhatt, Apoorva and Brown, Alistair K. and Singh, Albel and Minnikin, David E. and Besra, Gurdyal S (2008) Loss of a Mycobacterial Gene Encoding a Reductase Leads to an Altered Cell Wall Containing β-oxo- Mycolic Acid Analogs and Accumulation of Ketones. Chemistry and Biology, 15 (30). pp. 930-939. ISSN 1074-5521. Creese, Andrew J. and Cooper, Helen J. (2008) The Effect of Phosphorylation on the Electron Capture ...
Comparison of gene expression fold change in key genes associated with mycolate biosynthesis pathway.Genes associated with mycolate biosynthesis were identified
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TY - JOUR. T1 - Production of antibodies against glycolipids from the Mycobacterium tuberculosis cell wall in aerosol murine models of tuberculosis. AU - Cardona, P. J.. AU - Julián, E.. AU - Vallès, X.. AU - Gordillo, S.. AU - Muñoz, M.. AU - Luquin, M.. AU - Ausina, V.. PY - 2002/5/30. Y1 - 2002/5/30. N2 - Evolution of antibodies against glycolipids from the Mycobacterium tuberculosis cell wall has been studied for the first time in experimental murine models of tuberculosis induced by aerosol, in which infection, reinfection, reactivation, prophylaxis and treatment with antibiotics have been assayed. Results show a significant humeral response against these antigens, where diacyltrehaleses (DAT) and sulphelipid I (SL-I) elicited higher antibody levels than protein antigens like antigen 85 protein complex (Ag85), culture filtrate proteins (CFP) and purified protein derivative (PPD). Only immunoglobulin M (IgM) antibodies have been detected against DAT and SL-I. Their evolution has a ...
Cord factor, or trehalose dimycolate, is a glycolipid molecule found in the cell wall of Mycobacterium tuberculosis and similar species. It is the primary lipid found on the exterior of M. tuberculosis cells. Cord factor influences the arrangement of M. tuberculosis cells into long and slender formations, giving its name. Cord factor is virulent towards mammalian cells and critical for survival of M. tuberculosis in hosts, but not outside of hosts. Cord factor has been observed to influence immune responses, induce the formation of granulomas, and inhibit tumor growth. A cord factor molecule is composed of a trehalose sugar, a disaccharide, that is esterified to two mycolic acid residues. One of the two mycolic acid residues is attached to the sixth carbon of one monosaccharide, while the other mycolic acid residue is attached to the sixth carbon of the other monosaccharide. Therefore, cord factor is also named trehalose-6,6-dimycolate. The carbon chain of the mycolic acid residues vary in ...
Antituberculosis Drugs Isoniazid MOA: inhibits mycolic acid synthesis in the wall Side Effects: peripheral neuropathies (prevent with treatment with pyridoxine), hepatitis, hepatotoxicity Rifampin MOA: blocks the beta subunit of bacterial RNA polymerase thus stopping bacterial RNA synthesis Side Effects: urine and sweat turn red, induces P450, hepatitis Pyrazinamide MOA: nicotinamide analog with unknown mechanism Side Effects: hepatitis, hyperuricemia with gouty arthritis. Is never used alone because of rapid resistance Ethambutol MOA: inhibits mycolic acid synthesis in bacterial cell wall Side Effects: reversible retrobulbar neuritis, loss of central vision
Inhibition of mycolic acid transport across the Mycobacterium tuberculosis plasma membrane. Anna Grzegorzewicz, Ha Pham, Vijay Gundi, Michael Scherman1, Elton North, Tamara Hess, Victoria Jones, Veronica Gruppo, Sarah Born, Jana Korduláková, Sivagami Sundaram Chavadi, Christophe Morisseau, Anne J Lenaerts, Richard Lee, Michael McNeil & Mary Jackson. Nature Chemical Biology 8: 334-341 April 2012. There are many important unexplained mysteries in life, from the Bermuda triangle to why they decided to only put a single elevator in the Micro Bldg. Somewhere in between this range of conundrums lies another head scratcher - what is the transporter that moves mycolic acids from their cytoplasmic site of synthesis through the plasma membrane and out to the cell wall in Mycobacterium tuberculosis? Despite the fact that mycolic acids may make up ~ half the dry weight of the bacteria, 30+ years of work has not provided any substantial clues to solve this mystery. Its enough to make hard working TB ...
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Radhika Pothi (2013); Anti-Oxidant enzyme levels and quantification of Reactive oxygen species in Mycobacterium aurum Int. J. of Adv. Res. (8). 0] (ISSN 2320-5407). www.journalijar.com. ...
Taxonomic studies were performed on a phenotypically homogeneous group of 13 mycobacteria isolated from clinical, veterinary and stream-water samples. The methods applied included chromatographic analyses of bacterial lipids, biochemical tests and sequencing of the 16S rDNA and the internal transcribed spacer 1 (ITS1) region. Positive results in urease, Tween 80 hydrolysis and pyrazinamidase tests and a negative result in a semi-quantitative catalase test, combined with the ability to grow at 42 degrees C, distinguished this group among the yellow-pigmented, slowly growing mycobacteria. Unique fatty acid and mycolic acid profiles in chromatographic analyses and the results of gene sequencing indicated that the novel isolates represent a previously undescribed species, for which the name Mycobacterium palustre sp. nov. is proposed. The fatty acid profile obtained by GLC was characterized by the presence of several methyl-branched fatty acid markers. The most prominent markers were 2-methyleicosanoic,
Acid-fastness is a physical property of certain bacterial and eukaryotic cells, as well as some sub-cellular structures, specifically their resistance to decolorization by acids during laboratory staining procedures.[1][2] Once stained as part of a sample, these organisms can resist the acid and/or ethanol-based decolorization procedures common in many staining protocols, hence the name acid-fast.[2]. The mechanisms of acid-fastness vary by species, although the most well-known example is in the genus Mycobacterium, which includes the species responsible for tuberculosis and leprosy. The acid-fastness of Mycobacteria is due to the high mycolic acid content of their cell walls, which is responsible for the staining pattern of poor absorption followed by high retention. Some bacteria may also be partially acid-fast, such as Nocardia. Acid-fast organisms are difficult to characterize using standard microbiological techniques, though they can be stained using concentrated dyes, particularly when the ...
In this investigation, we have used transposon mutagenesis to identify a novel mycobacterial protein that is associated with phenotypic changes in the parent strain that alter the adhesive properties of the mycobacteria. Recently, a similar BCG transposon library was used to identify a mycolic acid cyclopropane synthetase as a virulence factor in M. tuberculosis by screening for variants that are deficient in cord formation (20). For our investigation, we reasoned that a mutant which exhibited a nonaggregative morphology may identify a gene that influences the interaction of mycobacteria with other cells, since there is evidence that adhesins can also induce autoaggregation of bacteria (9, 32). In fact, it has previously been shown that the mycobacterial adhesin HBHA promotes bacterial aggregation (16, 31, 33).. In this study, after screening more than 1,900 BCG transposon insertion mutants, one mutant strain, mc21525, was singled out for demonstrating an obvious difference in clumping ...
Mycobacterium tuberculosis: Mycobacteria are waxy celled, pleomorphic rods, which range from 2-4 micrometers in length, and .2-.5 um in width. These bacilli cells also have a high concentration of lipids in them, called mycolic acids. Because of this, they have a resistance to many antibiotics. Also, these lipids are hydrophobic and affect the permeability, allowing of liquids or gases to pass through, in the cell wall. These are found in habitats such as water or soil. This specific TB causing bacteria has been causing harm since before human times. Evidence shows that this transferred over to humans through cows in 8000-4000 B.C., through milk consumption. For more information on this bacteria, go to this website ...
The World Health Organisation in 1997 recognised the need for the development of new drugs to combat the imminent threat of mass infection by multi-drug resistant strains of pathogenic micro-organisms that spread diseases such as tuberculosis (TB). With this in mind, the work covered in this thesis focused on the preparation of novel carbohydrate-based compounds as potential anti-bacterial agents, in particular targeted to mycobacterial infection. An essential cell wall structural component of various mycobacteria (including M. tuberculosis) is the galactofuranose (Galf) residue, which forms part of the polysaccharide connection between the mycolic acids and the peptidoglycan layer. Interference with the incorporation of Galf into this polysaccharide was expected to compromise the physical integrity of the bacterial cell wall leading to cell death. With minimal projected side-effects, owing to the lack of Galf residues in mammalian systems, hydrolytically-stable Galf analogues were selected as ...
ID A0A075TZV8_9CORY Unreviewed; 570 AA. AC A0A075TZV8; DT 29-OCT-2014, integrated into UniProtKB/TrEMBL. DT 29-OCT-2014, sequence version 1. DT 27-SEP-2017, entry version 25. DE RecName: Full=Chromosomal replication initiator protein DnaA {ECO:0000256,HAMAP-Rule:MF_00377, ECO:0000256,RuleBase:RU000577}; GN Name=dnaA {ECO:0000256,HAMAP-Rule:MF_00377}; GN ORFNames=CATYP_00005 {ECO:0000313,EMBL:AIG63362.1}; OS Corynebacterium atypicum. OC Bacteria; Actinobacteria; Corynebacteriales; Corynebacteriaceae; OC Corynebacterium. OX NCBI_TaxID=191610 {ECO:0000313,EMBL:AIG63362.1, ECO:0000313,Proteomes:UP000028504}; RN [1] {ECO:0000313,EMBL:AIG63362.1, ECO:0000313,Proteomes:UP000028504} RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=R2070 {ECO:0000313,EMBL:AIG63362.1, RC ECO:0000313,Proteomes:UP000028504}; RA Tippelt A., Mollmann S., Albersmeier A., Jaenicke S., Ruckert C., RA Tauch A.; RT "Complete genome sequence of Corynebacterium atypicum DSM 44849: RT identifiction of the mycolic acid ...
the nanorobotic device brings their surfaces into intimate contact, allowing reversible binding sites on the microbivore hull to recognize and weakly bind to the bacterium. Binding sites can already be engineered [77, 78]. Bacterial membranes are quite distinctive, including such obvious markers as the family of outer-membrane trimeric channel proteins called porins in gram-negative bacteria like E. coli [79, 80] and other surface proteins such as Staphylococcal protein A [81] or endotoxin (lipopolysaccharide or LPS), a variable-size carbohydrate chain that is the major antigen of the outer membrane of gram-negative bacteria. Mycobacteria contain mycolic acid in their cell walls [82]. And only bacteria employ right-handed amino acids in their cellular coats, which helps them resist attack by digestive enzymes in the stomach and by other organisms. Peptidoglycans, the main structural component of bacterial walls, are cross-linked with peptide bridges that contain several unusual nonprotein amino ...
PA 824: nitroimidazopyran derived from 5-nitroimidazoles; a prodrug that requires activation by a bacterial F420-depedent glucose-6-phosphate dehydrogenase (Fgd) and nitroreductase to activate components that then inhibit bacterial mycolic acid and protein synthesis; structure in first source
In 3, the vertical plane that passes through the red broken line perpendicular to the plane of the cyclopropane ring bisects the molecule into halves that are mirror images of each other. Therefore, it is a plane of symmetry.. Mastery Check. ...
BEAMAN, B. L; MORING, S. E; IONEDA, T. Effect of growth stage on mycolic acid structure in cell walls of nocardia asteroides guh-2. Journal of Bacteriology, Baltimore, v. 170, n. 3, p. 1137-42, 1988. DOI: 10.1128/jb.170.3.1137-1142.1988 ...
A previously undescribed, slowly growing, non-chromogenic mycobacterium, isolated from a Korean patient with a symptomatic pulmonary infection, is described as representing a novel species. Its 16S rRNA gene sequence was unique and phylogenetic analysis based on 16S rRNA gene sequences showed that this organism belonged to the Mycobacterium terrae subclade. Phenotypically, the strain was generally similar to M. terrae and Mycobacterium nonchromogenicum, but its growth rate was slower than those of other M. terrae complex strains. A unique mycolic acid profile and phylogenetic analysis based on two different alternative chronometer molecules, hsp65 and rpoB, confirm the taxonomic status of this strain as a representative of a novel species. The name Mycobacterium senuense sp. nov. is proposed, with the type strain 05-832T (=DSM 44999T =KCTC 19147T).
article{8174192, author = {Tima, Hermann Giresse and Al Dulayymi, Jumaa Raheem and Denis, Olivier and Lehebel, Pauline and Baols, Klarah Sherzad and Mohammed, Mohsin Omar and LHomme, Laurent and Sahb, Mohaned Mohammed and Potemberg, Georges and Legrand, Sylvie and Lang, Roland and Beyaert, Rudi and Piette, Jacques and Baird, Mark Stephen and Huygen, Kris and Romano, Marta}, issn = {1662-811X}, journal = {JOURNAL OF INNATE IMMUNITY}, keyword = {Mycobacterium tuberculosis,Glycolipids,Trehalose dimycolate,Trehalose monomycolate,Glucose monomycolate,Arabinose monomycolate,Inflammasome,Adjuvant,CORD FACTOR,ACIDS,MICE,RECEPTOR,MINCLE,ACTIVATION,CYCLOPROPANATION,RECOGNITION,MACROPHAGES,MONOESTERS}, language = {eng}, number = {2}, pages = {162--180}, title = {Inflammatory properties and adjuvant potential of synthetic glycolipids homologous to mycolate esters of the cell wall of Mycobacterium tuberculosis}, url = {http://dx.doi.org/10.1159/000450955}, volume = {9}, year = {2017 ...
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Unlike its genome structure, the cell structure of the strain PDB9T is well analyzed for its taxonomic position. The major components of its cell wall include meso-diaminopimelic acid, mycolic acids (36-46 carbon atoms), and arabinose and galactose as major carbohydrates. Glycosyl is present as the acyl type in the beta-1,4-N acetylmuramic acid. These distinctive chemotaxonomic markers have attributed to the differential of the strain PDB9T from other type strains of R. pyridinivorans. As it is stated above, the strain PDB9T is able to degrade pyridine, however, the exact mechanism of pyridine biodegradation has not been studied well (10). The genome sequence of R.pyridinivorans strain AK37 has identified several key enzymes involved in the six pathways of monocyclic aromatic compound biodegradation: protocatechuate 3,4-dioxygenase, benzoate 1,2-dioxygenase, 3-ketosteroid-9α-hydroxylase, 3-ketosteroid-σ-dehydrogenase, and so on. Some of these enzymes seem to be widely distributed among ...
General Information: Like other closely related Actinomycetales, such as Nocardia and Corynebacterium, mycobacteria have unusually high genomic DNA GC content and are capable of producing mycolic acids as major components of their cell wall. This bacterium is the causative agent of tuberculosis - a chronic infectious disease with a growing incidence worldwide. It infects 1.7 billion people a year (~33% of the entire world population) and causes over 3 million deaths/year. This bacterium does not form a polysaccharide capsule, and is an extremely slow growing obligate aerobe. This bacterium does not form a polysaccharide capsule, and is an extremely slow growing obligate aerobe. This bacterium does not form a polysaccharide capsule, and is an extremely slow growing obligate aerobe. The sluggish growth rate is a result of the tough cell wall that resists the passage of nutrients into the cell and inhibits waste products to be excreted out of the cell. The specialized cell envelope of this organism ...
Corynebacterineae is a suborder of the Actinomycetales, and includes most of the acid-fast bacteria. It is a high G+C gram positive bacteria. It causes Tuberculosis and leprosy. ...
A nicotinamide derivative, with antibacterial activity, used to treat tuberculosis. Although the exact mechanism of action of ethionamide is unknown, it may inhibit the synthesis of mycolic acid, a saturated fatty acid found in the bacterial cell wall, thereby inhibiting bacterial cell wall synthesis. This eventually leads to bacterial cell wall disruption and cell lysis. Ethionamide may be bacteriostatic or bactericidal in action, depending on the concentration of the drug at the site of infection and the susceptibility of the organism involved.
Group 1 Compact disc1 substances, Compact disc1a, CD1c and CD1b, present lipid antigens from (Mtb) to Capital t cells. acids, which make the bacterias much less vulnerable to antibiotics. These substances also help the bacterias to subvert and after that conceal from the immune system program. The frequency of the disease and the raising issue of antibiotic level of resistance possess sparked the search for an effective vaccine against tuberculosis. While many attempts possess concentrated on using proteins pieces in tuberculosis vaccines, some proof suggests that human being immune system cells can understand fatty substances such as mycolic acids and that these cells could help manage and control attacks. Nevertheless, it provides been tough to determine whether these resistant cells sincerely buy 1208315-24-5 play a defensive function against the disease because most vaccine analysis uses mouse versions and rodents perform not really have got an similar of these resistant cells. Today, Zhao ...
Published studies indicate that mycobacterial lipid antigens may stimulate CD1-restricted T cells. However, the pool of studied mycobacterial antigenic lipids is small compared with the diversity of the lipid components of the M. tuberculosis envelope. So far, only three classes of molecules were shown to stimulate CD1b-restricted T cells: free mycolic acids (13), mycoloyl glycolipids such as glucose monomycolate (17), and phosphoglycolipids represented by lipoarabinomannan (19), lipomannan (19), and PIM (20). These molecules are commonly present in the envelope of both virulent and nonvirulent mycobacteria. Their immunogenicity during infection with virulent or avirulent strains has not been compared.. In these studies we have characterized the structure of a novel mycobacterial glycolipid, a diacylated sulfoglycolipid (Ac2SGL), presented by CD1b on the cell surface of M. tuberculosis-infected APCs. This antigen stimulates bactericidal CD8+ T cells and evokes strong responses in healthy PPD+ ...
Mycobacterium gordonae ATCC ® 35760D-5™ Designation: Genomic DNA from Mycobacterium gordonae strain TMC 1327 TypeStrain=False Application:
Mycobacterium gordonae ATCC ® 35760D-5™ Designation: Genomic DNA from Mycobacterium gordonae strain TMC 1327 TypeStrain=False Application:
Fighting Mycobacterium tuberculosis can seem like an escalating arms race. The bacterium, which causes tuberculosis (TB), is a master at outmaneuvering drugs designed to kill it. Each year there are 450,000 new cases of TB that are resistant to multiple drugs, and nearly a third of TB-related deaths can be attributed to antimicrobial resistance. One TB target that scientists have long had in their sights is the enzyme phosphopantetheinyl transferase (PptT). PptT plays a role in the biosynthesis of mycolic acids that make up the bacteriums cell wall and virulence lipids that the bacterium needs to suppress its hosts immune reactions. After years of trying, researchers have identified a compound that fights TB by inhibiting PptT. Known as 8918, the small molecule kills the bacterium in a petri dish and also prevents it from reproducing itself in the lungs of mice infected with TB. A team led by Weill Cornell Medicines Carl Nathan and Texas A&M Universitys James Sacchettini made the discovery ...
General Information: This strain was isolated from a diary herd in Wisconsin, USA in the 1970s. Environmental organism which causes infections in birds and humans. This genus comprises a number of Gram-positive, acid-fast, rod-shaped aerobic bacteria and is the only member of the family Mycobacteriaceae within the order Actinomycetales. Like other closely related Actinomycetales, such as Nocardia and Corynebacterium, Mycobacteria have unusually high genomic DNA GC content and are capable of producing mycolic acids as major components of their cell wall. Mycobacterium avium is ubiquitous in the environment, and can be found in stagnant waters and soils. This organism causes tuberculosis in birds and disseminated infections in immunocompromized humans (the elderly, children, and especially patients with AIDS). Infection results in a characteristic pulmonary disease which requires expensive drug therapy for successful treatment. Most prevalent colony morphotypes are smooth opaque, smooth ...
Meike Niggemann and co-workers at RWTH Aachen University have reported in ACIE on a calcium catalyzed cyclopropanation reaction. ACIE paper
A 23 days NOECrepro value of 7.8 µg/L has been determined for the effects of pentadecan-1 -ol on cumulative number of offsprings of the freshwater invertebrate D. magna. This is the lowest reliable value available for this endpoint and has been selected as key. A study report is available with the closely related substance pentadecanol branched (a single methyl branch group in the 2-position).This type of branched structure is termed essentially linear and the physicochemical, toxicological and ecotoxicological properties and behaviour do not differ significantly between such structures and their linear analogues. It is therefore possible to read-across between the two substances. Additionally these isomeric substances have an identical molecular weight. The difference in composition is dependent on the manufacturing process which may create linear alcohols or simple mono-branched structures. Direct read-across from pentadecanol branched to pentadecanol (CAS 629-76-5) is scientifically ...
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Leprosy is a chronic and degenerative infectious disease caused by Mycobacterium leprae, a Gram-positive and acid-fast bacterium. Recently, the number...
The present invention provides methods for catalyzing the conversion of an olefin to any compound containing one or more cyclopropane functional groups using heme enzymes. In certain aspects, the present invention provides a method for producing a cyclopropanation product comprising providing an olefinic substrate, a diazo reagent, and a heme enzyme; and admixing the components in a reaction for a time sufficient to produce a cyclopropanation product. In other aspects, the present invention provides heme enzymes including variants and fragments thereof that are capable of carrying out in vivo and in vitro olefin cyclopropanation reactions. Expression vectors and host cells expressing the heme enzymes are also provided by the present invention.
Mycobacterium chelonae-like organisms are nonpigmented rapidly growing mycobacteria whose clinical significance is unknown. We evaluated 87 sporadic isolates encountered in a clinical laboratory. Most isolates (62%) were respiratory; only 2 of 54 (4%) (both from patients with AIDS) were clinically significant. Among 33 nonrespiratory isolates, 20 of 33 (or 61%) were clinically significant. Clinical diseases included posttraumatic wound infections and catheter-related sepsis. Routine biochemical features included growth inhibition by 5% NaCl (100%), a smooth colony morphology (94%), positive 3-day arylsulfatase reaction (84%), no color or a light tan color on iron uptake (100%), and variable nitrate reduction (45%). Additional characteristics that helped to separate this group from M. chelonae and Mycobacterium abscessus were susceptibility to cephalothin (90%) and ciprofloxacin (100%), utilization of mannitol (94%) and citrate (83%) as carbon sources, and unique patterns of mycolic acid esters ...
Contamination of clinical specimens by Mycobacterium gordonae is a significant endemic problem in many laboratories. To investigate this problem, 84 cases at 1 hospital were retro-spectively identified during 20 months. The overall rate of specimen contamination was 2.4%, and 72 of the contaminated specimens were respiratory. A case-control comparison showed that the risk of respiratory specimen contamination was significantly increased if the specimen was expectorated (odds ratio [OR], 3.62; 95% confidence interval [CI], 1.36-9.50) or if the patient consumed fluids within 2 days before specimen collection (OR, 8.92; 95% CI, 1.40-71.20). Cultures of tap water, ice, and iced drinking water all yielded M. gordonae at 10−2-100 cfu/mL. A culture survey of consenting patients showed contamination of 8 (24%) of 34 sputum specimens collected immediately after a tap water mouth rinse. These findings demonstrate that endemic specimen contamination arises from mycobacteria in hospital tap water and ...
To the editor: We recently treated a patient with the acquired immunodeficiency syndrome and disseminated infection due to Mycobacterium gordonae. Infection with this organism has not previously been reported in association with the syndrome.. A 41-year-old man who abused intravenous drugs developed Pneumocystis carinii pneumonia in November 1981. He responded to treatment with intravenous sulfamethoxazole and trimethoprim. In July 1982 he developed esophageal candidiasis which was treated with ketoconazole. The next month, a sputum specimen showed acid-fast bacilli on stain. He was treated by his physician with isoniazid. In November 1982, because of persistent fever and weakness, a bone marrow ...
Tuberculosis was declared a global emergency by the WHO in 1993. Nevertheless, this infectious disease is still one of the most devastating bacterial diseases worldwide, with high rates of morbidity and mortality, and of increasing concern related to the emergence of MDR and XDR strains [15, 16]. Rational development of new anti-TB agents will benefit from the use of new approaches to understand the genetics and physiology of M. tuberculosis. The availability of the genome sequence of M. tuberculosis [17] and powerful genetic tools has provided valuable information about some potential drug targets. M. marinum [18] and M. smegmatis [19] are already used as model species to study the genetics and physiology of M. tuberculosis, and for drug discovery. The use of a new model strain for drug discovery could help identify to new targets and pathways involved in mycobacterial drug resistance. M. aurum is a fast-growing mycobacterium with a doubling time of ~3 h and does not require biosafety level 3 ...
Ethambutol: ethambutol, pyrazinamide, and ethionamide are synthetic chemicals used in treating tuberculosis. Isoniazid, ethionamide, and pyrazinamide are similar in structure to nicotinamide adenine dinucleotide (NAD), a coenzyme essential for several physiological processes. Ethambutol prevents the synthesis of mycolic acid, a