Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Urease and glutamine synthetase activities in Selenomonas ruminantium strain D were highest in cells grown in ammonia-limited, linear-growth cultures or when certain compounds other than ammonia served as the nitrogen source and limited the growth rate in batch cultures. Glutamate dehydrogenase activity was highest during glucose (energy)-limited growth or when ammonia was not growth limiting. A positive correlation (R = 0.96) between glutamine synthetase and urease activities was observed for a variety of growth conditions, and both enzyme activities were simultaneously repressed when excess ammonia was added to ammonia-limited, linear-growth cultures. The glutamate analog methionine sulfoximine (MSX), inhibited glutamine synthetase activity in vitro, but glutamate dehydrogenase, glutamate synthase, and urease activities were not affected. The addition of MSX (0.1 to 100 mM) to cultures growing with 20 mM ammonia resulted in growth rate inhibition that was dependent upon the concentration of MSX and was overcome by glutamine addition. Urease activity in MSX-inhibited cultures was increased significantly, suggesting that ammonia was not the direct repressor of urease activity. In ammonia-limited, linear-growth cultures, MSX addition resulted in growth inhibition, a decrease in GS activity, and an increase in urease activity. These results are discussed with respect to the importance of glutamine synthetase and glutamate dehydrogenase for ammonia assimilation under different growth conditions and the relationship of these enzymes to urease.
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PMID:Regulation of urease and ammonia assimilatory enzymes in Selenomonas ruminantium. 611 7

Even 70 years ago Gram-negative coccobacilli had been recognized in vaginal discharge and were cultured 30 years ago. The need to have blood in agar medium for cultivation suggested that the organisms might be a Haemophilus species. Later, however, growth characteristics and other features resulted in their being placed in the genus Corynebacterium, before it was realized that this was inappropriate and they were transferred to a new genus and species Gardnerella vaginalis. The organisms are Gram-variable, non-sporing, non-flagellate, non-motile coccobacilli of average size 0.4 X 1-1.5 microns. The cell wall is laminated and some strains possess pili. G. vaginalis is fermentative and dextrose, fructose, galactose, glucose, maltose, mannose, ribose and starch are most likely to be metabolized. However, published patterns of the sugars fermented vary widely and most workers do not rely on such tests as a means of identification. Of many other features exhibited by G. vaginalis, the following are outstanding: it does not produce catalase, cytochrome oxidase, hydrogen sulphide, indole, or urease. Nor does it degrade aesculin, liquefy gelatin, reduce nitrate, or decarboxylate arginine, lysine or ornithine. On the other hand, it is sensitive to hydrogen peroxide, often causes beta-haemolysis and usually hydrolyses hippurate and starch. G. vaginalis is serologically heterogeneous and causes haemagglutination which is mannose resistant. It is resistant to several antibiotics, including amphotericin, colistin, nalidixic acid and gentamicin, which may be incorporated in selective media.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The bacteriology of Gardnerella vaginalis. 639 9

Flurofamide, a potent inhibitor of urease, at concentrations of 0.0007 to 0.001 mg/l inhibited the multiplication of three ureaplasma strains of human genital origin (one tetracycline-resistant) and two and three strains of marmoset genital and oral origin, respectively. However, a more than 1000-fold greater concentration of the drug was required to kill the organisms. Flurofamide did not inhibit the growth of arginine-hydrolysing or glucose-fermenting mycoplasmas, indicating its specificity for ureaplasmas. When it was given orally in a dose of 25 mg twice on one day and 25 mg on one further day to marmosets infected naturally with ureaplasmas in their throats, the organisms disappeared rapidly. The animals remained ureaplasma-free for 42 to 106 days, at which time they were successfully infected experimentally.
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PMID:The inhibitory effect of flurofamide on ureaplasmas and their elimination from marmosets by its use. 644 Aug 84

Quantitative transformation of streptomycin resistance marker was carried out with strains of Acinetobacter calcoaceticus. Standard recipient strain was the competent BD4-Ss. Transformation proceeded in a liquid system with a concentration of 20 micrograms/ml of streptomycin resistant DNA (Sr-DNA) from BD4, 17 reference strains of Acinetobacter, and 42 recent clinical isolates of the acid forming variant (anitratus) and 12 of the non-acid forming variant (lwoffi) as donors of Sr-DNA. The exposure time was 20 min before interruption with DNase and quantitated plating. Among the strains examined were differentiated 16 biotypes as based on oxidative acid production from glucose and lactose, haemolysis, urease, gelatinase, and growth with citrate as the sole carbon source. Autologous transformation gave a transformation of 2.94 (+/- 0.66)% of the recipient cells (quantitated by colony forming units). Sr-DNA from 50 of 63 strains were able to transform BD4-Ss. The transformation ratio was 0.06-6.4% of autologous BD4 transformation. Two further recent clinical isolates were weakly transformation competent. Competence was only found in autologous transformation. The major portion (50/63) of the strains belong to the BD4 genotype of A. calcoaceticus, but the taxonomic position of the 13 non-donors in respect to BD4 could not be evaluated by transformation because of lack of a competent recipient. The strains transforming BD4 belonged to both the glucose acidifyers and the non-acidifyers without genetic distinction. The results are consistent with recognition of both as belonging to the same species, but with their recognition as species variants: A calcoaceticus var, anitratum and A. calcoaceticus var. lwoffi.
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PMID:Taxonomic implications of quantitative transformation in Acinetobacter calcoaceticus. 658 37

This study was conducted to study chemically and serologically the characteristics of the Ureaplasmas isolated from the human oral cavity. Two hundred and fifty-one healthy and 12 periodontitis subjects were examined for the incidence of the isolation of Ureaplasmas from their oral cavity. A total of twenty-six strains was isolated from the healthy human saliva. But no strains could be isolated from a variety of clinical specimens obtained from the patients. The serological properties of the isolates were tested by the method of metabolism inhibition test (MI test). Seven out of 26 isolates were serologically identical with either one of the ATCC standard strains. However, the serological types of the other strains could not be demonstrated by the MI test. The biological characteristics of 4 isolates and ATCC strains were tested by the usual method. The isolates did not metabolize glucose and arginine, while all strains hydrolyzed urea. On the other hand, none of the isolates lysed skimmed milk and gelatin. The proteolytic activity of the isolates could be demonstrated by using casein and horse serum proteins as substrates. Zymogram patterns from one of the isolates and Streptococcus salivarius were obtained by polyacrylamide gel electrophoresis of the cells lysed with digitonin or cell protein extracts. On the basis of the gel electrophoresis patterns, it is clear that the urease of the Ureaplasma is different from that of the Streptococcus salivarius.
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PMID:Biochemical and serological studies on oral ureaplasma. 659 16

A small, fastidious gram-negative anaerobe was isolated from men with non-gonococcal urethritis (NGU). The isolates are described as NGU-associated anaerobes because they were extremely rare in men with urethritis other than NGU, and in asymptomatic men. They showed twitching motility, had many polar pili and appeared to be a homogenous group culturally, morphologically and biochemically. None of the strains fermented or utilised carbohydrates or organic acids as sole sources of carbon for energy and growth. However, growth of all strains was stimulated by formate and fumarate in liquid and solid media, especially in the former where growth seemed dependent on these growth factors. Unlike most anaerobes they produced cytochrome enzyme(s) that might be involved in oxidation-reduction reactions in the presence of oxygen as some of the strains were capable of growing in 5% oxygen. However, growth and energy generally resulted from anaerobic phosphorylation. Strains of this anaerobe seemed to require a low redox-potential (Eh) for survival during transportation but this was not essential for growth. Comparative studies with the other asaccharolytic anaerobes showed some similarity between the NGU-associated anaerobe, Bacteroides ureolyticus and Wolinella succinogenes. Like these, some NGU-associated strains pitted agar media and all produced urease. However, unlike these anaerobes, strains of the NGU-associated anaerobe produced enzymes for the hydrolysis of arginine, and the decarboxylation of lysine and ornithine. They also produced oxidase and some strains haemolysed sheep red cells. However, lactic acid was not an end-product of the metabolism of glucose by any of the strains. The NGU-associated anaerobes are strikingly different from anaerobic vibrios, B. praeacutus and B. asaccharolyticus.
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PMID:Characteristics of a gram-negative anaerobe isolated from men with non-gonococcal urethritis. 670 82

Ninety-seven strains of clinically isolated Corynebacterium strains, probably identical with Corynebacterium JK, are described especially in regard to growth in relation to different lipid substances. The corynebacteria formed a homogeneous group of strict aerobic slow-growing, catalase-positive, urease-and-nitrate-negative typical coryneform rods. Acid was produced from glucose and maltose. Growth was stimulated in the presence of different lipid substances and lipodependence was suggested by satellite growth only around oleic acid drops on otherwise lipid-depleted agar plates. Generally the isolated corynebacteria were resistant to clinically achievable concentrations of penicillins, cephalosporines and aminoglucosides but uniformly sensitive to vancomycin and rifamycin.
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PMID:Multiresistant lipophilic corynebacteria from clinical specimens. Biochemical reactions and antimicrobial agents susceptibility. 671 4

Six strains of a new species, Legionella sainthelensi, were isolated from freshwater in areas affected by the volcanic eruptions of Mt. St. Helens in the state of Washington. Strains of L. sainthelensi are culturally and biochemically similar to other legionellae. They grow on buffered charcoal yeast agar but not on media that lack cysteine. They are gram-negative, nonsporeforming, motile rods that are positive in reactions for catalase, oxidase, gelatin liquefaction, and beta-lactamase. They are negative in reactions for urease, hydrolysis of hippurate, reduction of nitrates, fermentation of glucose, and blue-white autofluorescence. Their cell wall fatty acid composition is qualitatively similar to those of other legionellae, with 50 to 62% branched-chain fatty acids. They contain the isobranched-chain 14- and 16-carbon acids and anteisobranched-chain 15- and 17-carbon acids and relatively large amounts of straight-chain 16-carbon acid. All strains of L. sainthelensi contain approximately equal amounts of ubiquinones Q9, Q10, Q11, and Q12, a pattern similar to those of Legionella bozemanii, Legionella dumoffi, and Legionella longbeachae. Serological cross-reactions were observed between L. sainthelensi, both serogroups of L. longbeachae, and Legionella oakridgensis. Three strains of L. sainthelensi were greater than 90% related by DNA hybridization. The type strain of L. sainthelensi, Mt. St. Helens 4, was 36% related to the type strain of L. longbeachae and 3 to 14% related to the other nine described Legionella species.
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PMID:Legionella sainthelensi: a new species of Legionella isolated from water near Mt. St. Helens. 671 10

Day-old pigs were individually fed a low nickel (0.16 ppm) liquid milk-based diet supplemented with either 0, 5 or 25 ppm nickel on a dry matter basis for a 21-day period. At the end of the liquid feeding period, five pigs per treatment were killed, and the remaining five were fed a dried skim milk-based diet (0.12 ppm nickel) with similar levels of added nickel for an additional 28 days. Dietary nickel did not affect animal gain, liver cholesterol, serum protein concentrations or bacterial urease activity in the gastrointestinal tract. The addition of 5 ppm nickel to the basal dry diet reduced ammonia concentrations in the cecum by 33%. Pigs receiving the high level of nickel had decreased serum alkaline phosphatase and increased serum glucose at 49 days, compared to controls. Animals receiving 5 ppm nickel had higher liver iron and zinc concentrations than controls at 21 days but not at 49 days. Control pigs had lower kidney and lung nickel concentrations than animals receiving 5 ppm nickel at 21 days but not at 49 days. Increasing dietary nickel from 5 to 25 ppm resulted in increased concentrations of nickel in serum, kidney, lung, spleen and muscle. These results suggest that 0.12-0.16 ppm nickel is adequate for growth of neonatal pigs fed milk-based diets. However, additional nickel may improve the iron and zinc status of the young pig.
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PMID:Effect of dietary nickel on growth, urease activity, blood parameters and tissue mineral concentrations in the neonatal pig. 672 54

Simple solid-phase optoelectronic sensors for penicillin, urea, and glucose are described. Triphenylmethane dyes such as bromcresol green and bromthymol blue were derivatized with glutathione and co-immobilized with appropriate enzymes to a transparent membrane sandwiched between a red-light-emitting diode and a silicon photodiode with integral amplifier. In the presence of the corresponding substrates, catalytic action in the enzyme-dye membrane perturbs the local pH and causes characteristic color changes in the membrane which are monitored as a rise or fall in the output voltage of the detector system. With enzymes such as penicillinase, urease, and glucose oxidase, the response of the optoelectronic sensors is extremely reproducible over the concentration range 0-10 mM penicillin G, urea, or D-glucose, respectively. This report describes the construction and operation of these simple, inexpensive, and reagentless optoelectronic sensors.
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PMID:Solid-phase optoelectronic sensors for biochemical analysis. 674 21


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