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)

Estimates were made of the numbers of viable bacteria in the rumens of sheep receiving different rations. Representative colonies were isolated and tested for urease production. Some urease-positive isolates were characterized and identified. The ureolytic activities of the urease-producing isolates were determined and compared with the activity of rumen fluid. The rations fed to the sheep did not exert a significant influence on the relative numbers of the urease-producting organisms in the rumen. No obligately anaerobic ureolytic bacteria were found. All urease-positive isolates were facultatively anaerobic, Gram-positive, catalase-positive cocci. Out of ten isolates, nine were identified as Staphylococcus saprophyticus and one as Micrococcus varians. The total urease activity of the different isolates based on the lowest numbers in which they were present in the rumen, compared favourably with the urease activity of rumen fluid. The facultatively anaerobic Gram-positive cocci were probably responsible for a large proportion of the urease activity of the rumen fluid. Conditions prevailing in the rumen were found to be conducive to urease production by the isolates tested.
J Gen Microbiol 1975 Dec
PMID:Ureolytic bacteria in sheep rumen. 123 88

"Mycobacterium genavense" is a proposed new species recently reported to cause disseminated infections in 18 patients with AIDS in Europe. We have recovered "M. genavense" as slowly growing fastidious mycobacteria in blood cultures of seven patients with AIDS. In the original studies of "M. genavense," the fastidious organism grew only in BACTEC 13A vials. The Seattle, Washington, isolates of "M. genavense" also failed to grow when subcultured from 13A vials to routine solid media, but dysgonic colonies were produced on Middlebrook 7H11 agar supplemented with mycobactin J. The mycolic acid pattern of patients' isolates closely resembled that of the type strain of Mycobacterium simiae when analyzed by one- and two-dimensional thin-layer chromatography and by high-performance liquid chromatography. Whole-cell fatty acid analyses by gas-liquid chromatography distinguished the isolates from M. simiae but misidentified them as Mycobacterium fortuitum. Sequence determinations of the hypervariable regions of the 16S rRNA gene indicate that these organisms belong to the recently proposed new species "M. genavense." Growth from Middlebrook 7H11 agar supplemented with mycobactin J consistently yielded positive tests for catalase (semiquantitative and at 68 degrees C), pyrazinamidase, and urease which enable mycobacteriology laboratories to presumptively identify "M. genavense" without nucleic acid analyses. The failure of "M. genavense" to grow on conventional mycobacterial solid media suggests that mycobacterial blood cultures should include a broth medium incubated for at least 8 weeks.
J Clin Microbiol 1992 Dec
PMID:Laboratory aspects of "Mycobacterium genavense," a proposed species isolated from AIDS patients. 128 Jun 52

Some staphylococcus and enterococcus strains were used to investigate the effect of culture medium on bacteriocin production. Staphylococcus cohnii SC7, Staphylococcus sp. ZTJ 151, S. saprophyticus SS 877, Enterococcus faecium EF1 and E. faecalis EFG2 were isolated from the rumen wall and contents of lambs, calves and fallow deer, Enterococcus gallinarum EG10 and E. avium EA12 were isolated from the caecum of Japanese quail. The tested bacteria belong to producers with a wide antimicrobial effectiveness spectrum, they have low to medium adherence and urease activity (Tab. III). These culture media were used to test the effect of culture medium on bacteriocin production: nutrient agar no. 2 and VL agar enriched with 2% of glucose and lactose (ZAG, ZAL, VLG, VLL), agar for isolation of faecal streptococci (SA) and the base for blood agar no. 4 and no. 2 (KA4, KA2). The strains Streptococcus bovis AO 24/85 and Staphylococcus aureus Oxford 209 P were used as indicator bacteria. Tables I and II show the results of these tests. The tested strains produced the widest inhibition zones (6 mm) with both indicators on SA medium, and this indicates massive bacteriocin production. On ZAG medium, the zones of enterococci with the AO 24/85 strain were larger size than those of staphylococci, but the zones were dim. All strains with the 209P indicator produced dim zones of the 2mm size. The larger inhibition zones (2-5mm) in comparison with staphylococci were observed in enterococci on the ZAL medium with the AO24/85 strain. The production of tested strains was balanced on VLG agar with respect to the use of both indicators.(ABSTRACT TRUNCATED AT 250 WORDS)
Vet Med (Praha) 1992 Dec
PMID:[The effect of culture media on bacteriocin production in various strains of bacteria]. 129 43

Helicobacter pylori (H.p.) is a microorganism involved in peptic ulcer disease. To clarify the role of human dental plaque as a reservoir of H.p. and to compare different methods of investigation the authors studied 20 patients, 17 males main age 56 +/- 12 and 3 females 52 +/- 7, gastro-duodenal H.p. positive. The trial was carried out by cultural, biochemical and microscopical plaque analysis. Cultural and microscopical method were H.p. positive in 80% patients, urease in 100%, alkaline phosphatase in 80%, gamma glutamyltransferase in 70%, nitrate in 70%. To minimize the possibility of false results in H.p. plaque analysis it is necessary to use the three methods simultaneously. Further trials both on human plaque and on food and beverages will be useful to clarify the role of H.p. in human pathology.
Boll Soc Ital Biol Sper 1992 Dec
PMID:Comparison of three different methods for evaluation of Helicobacter pylori (H.P.) in human dental plaque. 130 23

O-serotypes, biotypes, and drug resistance of Serratia marcescens strains isolated from various clinical specimens in Showa University Fujigaoka Hospital were investigated: period I (1979. 1-1982.3), 122 strains; period II (1983. 1-1985. 3), 198; period III (1985. 4-198. 3), 129; period IV (1989. 1-1991. 3), 99. The frequency of serotype O 3 was higher than those of the other serotypes after the period II and ranged 17 to 37%. The isolation frequency (27%) of serotype O 4 was higher than those of other serotypes in the period I. However, this frequency decreased in the period II to III and, in the period IV (10%), was higher than in the period III. The isolation frequency of serotype O 17 suddenly increased in the period II (27%) alone, and 42% of the biotypes, obtained with API 20E, showed 5305701. The isolation frequency of non-typable strains ranged 9 to 14% through all periods. The group including 5317721 and 5307721 clustered by the furthest neighbor method, more frequently appeared through all periods. The former code of urease positive more frequently appeared in the period II to IV. The isolation frequency of the latter code of urease negative reduced to a minimum (18%) in period II, though it increased in the period II to IV. The isolation frequency (22%) of the pigmented strains in the period IV increased much higher than in the period I to III (ranged 2 to 4%). The frequency of the pigmented strains of serotype O 3, not belonged to the Grimont's biotype, was 27% of all pigmented strains isolated in the period IV.(ABSTRACT TRUNCATED AT 250 WORDS)
Rinsho Byori 1992 Dec
PMID:[O-serotypes, biotypes, and antimicrobial susceptibility of Serratia marcescens isolates from clinical specimens: 3rd report]. 130 37

Helicobacter pylori has been shown to be the cause of chronic active gastritis and the evidence that it is involved in the development of peptic ulcer disease and gastric cancer is compelling. Narrow host range, tissue specificity, and chronic inflammation are hallmarks of infection. The study of virulence determinants has just begun but it seems likely that urease, adhesins, cytotoxins, and mediators of inflammation will prove to be important.
Infect Agents Dis 1992 Dec
PMID:Helicobacter pylori and gastroduodenal disease: pathogenesis and host-parasite interaction. 134 68

DNA sequence diversity among 60 independent isolates of the gastric pathogen Helicobacter pylori was assessed by testing for restriction fragment length polymorphisms (RFLPs) in several PCR-amplified gene segments. 18 Mbol and 27 HaeIII RFLPs were found in the 2.4 kb ureA-ureB (urease) segment from the 60 strains; this identified 44 separate groups, with each group containing one to four isolates. With one exception, each isolate not distinguished from the others by RFLPs in ureA-ureB was distinguished by Mbol digestion of the neighboring 1.7 kb ureC-ureD segment. The 1.5 kb flaA (flagellin) gene, which is not close to ure gene cluster, was also highly polymorphic. In contrast, isolates from initial and followup biopsies yielded identical restriction patterns in each of the three cases tested. The potential of this method for detecting population heterogeneity was tested by mixing DNAs from different strains before amplification: the arrays of restriction fragments obtained indicated co-amplification from both genomes in each of the five pairwise combinations tested. These results show that H. pylori is a very diverse species, that indicate PCR-based RFLP tests are almost as sensitive as arbitrary primer PCR (RAPD) tests, and suggest that such RFLP tests will be useful for direct analysis of H. pylori in biopsy and gastric juice specimens.
Nucleic Acids Res 1992 Dec 11
PMID:PCR-based RFLP analysis of DNA sequence diversity in the gastric pathogen Helicobacter pylori. 136 82

The urease enzymes of Helicobacter pylori, H. mustelae, H. felis, and H. nemestrinae have been purified to homogeneity by affinity chromatography and characterized. The native urease enzymes of the four organisms were found to be almost identical, with a pI of 6.1 and molecular masses of 480 to 500 kDa, as determined by electrophoretic mobility in nondenaturing polyacrylamide gels. Transmission electron microscopy of the native urease showed it to be a molecule approximately 13 nm in diameter, with hexagonal symmetry. Denaturation studies indicated that each urease enzyme molecule was composed of two nonidentical subunits with molecular masses of approximately 64 and 30 kDa. The subunits were present in a 1:1 ratio, suggesting a hexameric stoichiometry for the native molecule. The predicted molecular mass of H. pylori urease, based on subunit molecular weight and stoichiometry, is 568 kDa. N-terminal amino acid sequencing of the enzyme subunits from the four species revealed high levels of homology. The large subunits (UreB) were found to be 92 to 100% homologous, and the small subunits (UreA) were 75 to 95% homologous over the first 12 to 20 residues. The high degree of homology suggests a common ancestral origin and an important role for the urease enzymes of these organisms.
Infect Immun 1992 Dec
PMID:Purification and characterization of the urease enzymes of Helicobacter species from humans and animals. 145 59

Two urease-based tests--the urease slide test and the radiolabeled urea breath test, are commonly used for the diagnosis of Helicobacter pylori infection of the stomach. The reliability of these tests in chronic uremia was compared with serological tests for H pylori antibodies, and with direct detection of the organism by microscopy or culture of gastric antral biopsies. Twenty-seven patients with chronic renal failure and dyspepsia underwent upper gastrointestinal endoscopy. Twelve of these patients (46%) were judged to be infected with H pylori on the basis of identification of the organism on microscopy or culture of antral biopsy. Both urease-based tests were able to determine H pylori status, despite the markedly increased concentrations of urea in the gastric juice found in chronic renal failure. The urease slide test performed on antral biopsies obtained at endoscopy proved reliable in determining H pylori status with no false-positive nor false-negative results after 20 minutes and 24 hours of incubation. The 14C-urea breath test also differentiated the infected from the uninfected patients. The 20-minute 14CO2 excretion (kg %dose/mmol CO2 x 100) ranged from 50 to 834 in the H pylori-infected patients, compared with 0.3 to 27 in the H pylori-noninfected patients (P < 0.0001); the 90-minute values ranged from 88 to 398 in the former, compared with 1 to 79 in the latter (P < 0.0001). The excretion of 14CO2 (derived from bacterial hydrolysis of ingested 14C-urea) was higher in all the uremic patients compared with nonuremic controls, and in half of the H pylori-noninfected uremic patients there was a late increase in 14CO2 excretion.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Kidney Dis 1992 Dec
PMID:The diagnosis of Helicobacter pylori infection in uremic patients. 146 85

Two pilot studies were performed to determine whether aluminium-containing antacids may have a place in the treatment of Helicobacter pylori infection. The urease activity of H. pylori is cytopathic to gastric epithelium, and inhibition of this enzyme may have therapeutic potential. In the first study 24 subjects, 12 of which were infected with H. pylori, were given 1 tablet of chewable aluminium hydroxide-containing antacids 10 min before a 14C-urea breath test. Gastric urease activity was suppressed by 33.3% (p = 0.02) in the H. pylori-positive subjects (none became negative) within 40 min after administration of the tablet. Gastric H. pylori infection can be effectively eradicated by triple regimens containing bismuth salts, tetracycline, and metronidazole. Owing to adverse effects of this treatment and concern for possible neurotoxicity of bismuth, a bismuth substitute is warranted. Hence, in the second study, 20 subjects infected with H. pylori were treated with 1 antacid tablet 4 times daily between meals, plus 500 mg oxytetracycline and 200 mg metronidazole 4 times daily with meals for 2 weeks. Individual H. pylori status was assessed by the 14C-urea breath test. Four weeks after cessation of treatment, H. pylori was eradicated in 45% (9 of 20) of the subjects (95% confidence interval, 23.1-68.5%). Thirty per cent (6 of 20) observed one or more adverse effect regarded as moderate or severe, of which loose stools and headache were the most common.(ABSTRACT TRUNCATED AT 250 WORDS)
Scand J Gastroenterol 1992 Dec
PMID:Is there a place for antacids in the treatment of Helicobacter pylori infection? 147 15


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