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

Enzyme-linked immunoassays have been employed in this work to measure antibodies against either pertussigen or filamentous hemagglutinin, using a urease-conjugated second antibody system. Pertussigen and filamentous hemagglutinin were obtained from the supernatants of Bordetella pertussis cultures by chromatographic procedures, and were shown to be essentially free of other proteins. Further checks have established the specificity of the enzyme-linked immunoassay-systems. Anti-pertussigen and anti-filamentous hemagglutinin antibody titers, in a pilot study of sera from normal adults, showed little correlation with the donors' pertussis contact, infection or vaccination histories. Nevertheless, the titers did correlate with the ability of the sera to neutralize the biological actions of pertussigen in mice and the haemagglutinating activity of filamentous haemagglutinin, respectively. Antibody titers of sera from patients with suspected or confirmed pertussis infection fell within the range covered by sera from normal adults. Sera from unvaccinated children (less than two months old) also showed some anti-pertussis activity that was probably maternal in origin. Further selected adult plasma samples have been compared for anti-pertussis activity by enzyme-linked immunoassays and agglutination. These samples also have been evaluated for their abilities to protect mice passively against intra-nasal and intra-cerebral challenge with Bordetella pertussis.
 ...
PMID:Specific anti-Bordetella pertussis activities in human blood examined by enzyme-linked immunoassay and biological assay. 287 23

Bordetella bronchiseptica is a ureolytic mammalian respiratory pathogen. We have investigated the regulation of urease in B. bronchiseptica and the potential role of this enzyme in eukaryotic invasion and intracellular survival. Our results indicate urease is a bordetella virulence repressed gene. Urease activity in virulent B. bronchiseptica BB7865 is up-regulated from basal levels by 5 gl1 magnesium sulphate at 37 degrees C. At 30 degrees C, urease activity remained at basal levels, even in the presence on magnesium sulphate, suggesting a second temperature dependent mechanism of urease regulation was also operating. Urease was not inducible by 10 mM urea nor up-regulated in nitrogen limiting conditions. To evaluate the role of urease in intracellular invasion and survival urease-negative mutants of B. bronchiseptica BB7865 and B. bronchiseptica BB7866 were created by transposon mutagenesis, and compared to the urease-positive parental strains in a HeLa cell invasion assay. We demonstrate that increasing the concentration of urea in the assay increased survival of the urease-positive but not urease-negative strains after 24 h, suggesting that urease does have a role in intracellular survival. Partial DNA sequence analysis of an 11.0 kb EcoRI DNA fragment encoding urease activity revealed an open reading frame containing 50%, 45%, 45%, and 41% homology to the UreA urease subunit protein of Klebsiella aerogenes, Proteus vulgaris, Helicobacter pylori and Proteus mirabilis respectively. We also show Bordetella pertussis to contain sequences homologous with a DNA probe containing the gene encoding UreA of B. bronchiseptica indicating the possible presence of cryptic urease genes in this species.
 ...
PMID:Molecular analysis of the bvg-repressed urease of Bordetella bronchiseptica. 893 44

During the pertussis clinical trials, the best conditions for isolating B. pertussis were determined. Isolation is higher if two nasopharyngeal aspirates are collected, transport is carried out at ambient temperature and takes no longer than 48 hours, Reagan Lowe or Bordet Gengou selective and non-selective plates are used and incubated at 36 degrees C for seven days. Identification must include Gram stain and urease, oxidase and nitrate reactions. Confirmation is obtained with specific anti-B. pertussis antiserum. Characterization of the isolates can be performed by using the polymerase chain reaction, serotyping and pulsed-field gel electrophoresis.
 ...
PMID:Isolation, identification and characterization of Bordetella pertussis. 927 55

Bordetella bronchiseptica is a common ureolytic mammalian respiratory pathogen. The urease operon of this organism is encoded within an 8.9 kb DNA fragment which contains the structural genes (ureA, ureB and ureC) and accessory genes (ureD and ureG) homologous to other urease genes. Uniquely, the ureE and ureF genes are fused to form a hybrid protein, UreEF, which may result in tighter coordination of the putative functions of the individual accessory genes, nickel donation to the urease active site, and prevention of nickel incorporation until correct formation of the active site, respectively. The operon contains an additional open reading frame, UreJ, found only also in the Alcaligenes eutrophus urease operon. UreJ is also 37% homologous with HupE from Rhizobium leguminosarum bv. viciae, and may potentially be involved in nickel transport. A transcriptional activator, designated Bordetella bronchiseptica urease regulator (BbuR), is located directly upstream and in the opposite orientation to the urease operon. BbuR shares homology with members of the LysR regulatory protein family. LysR proteins have been shown to regulate urease in Klebsiella aerogenes (NAC), and catalase in Escherichia coli (OxyR), which offers the intracellular bacterium protection from phagolysosome damage. A putative BbuR binding site (5'-ATA-N9-TAT-3'), identical to the NAC-binding consensus sequence, was found 27 bp upstream of the urease promoter in B. bronchiseptica. We hypothesise that BbuR controls urease expression which is involved in protection of intracellular B. bronchiseptica from phagolysosomal damage. Comparison of the urease promoter regions of B. bronchiseptica, Bordetella parapertussis ATCC15311 and the urease-negative strain B. pertussis Tohama I revealed no differences in the ureD open reading frame between each species. A cluster of mutations in both B. pertussis and B. parapertussis was found upstream of the urease promoter, in a region proximal to the putative bbuR promoter. The inability of B. pertussis to produce urease may therefore reflect mutations in regulatory elements, and not mutations in the urease locus itself.
 ...
PMID:Characterisation of the urease gene cluster in Bordetella bronchiseptica. 952 76

Chronic active gastritis of the antral mucosa is a characteristic feature of infection with Helicobacter pylori and interactions between bacterial components and inflammatory cells are believed to play an important pathogenic role. Neutrophils stimulated with H. pylori sonicate were demonstrated to release L-selectin (CD62L) expressed on the cellular surface, with a subsequent up-regulation of the beta2-integrins CD11b and CD11c, both in a dose- and time-dependent manner, reaching maximum levels after 45-60 min of stimulation. No changes were observed for the CD11a receptor upon stimulation. The activating properties of H. pylori sonicates on neutrophils were heat-labile and susceptible to protease attack, indicating the protein nature of the activating factor. After size fractionation, the major neutrophil-inducing activity was detected in the high molecular weight fraction exhibiting urease activity. Pertussis toxin was unable to inhibit neutrophil activation by the H. pylori protein(s). We conclude that proteins from H. pylori have a potent inflammatory effect on the surface membrane molecules CD62L, CD11b and CD11c essential for transendothelial migration of neutrophils to areas of inflammation. The neutrophil-activating protein(s) act via a pertussis toxin-insensitive mechanism.
 ...
PMID:Inflammatory activation of neutrophils by Helicobacter pylori; a mechanism insensitive to pertussis toxin. 1116 1

The genomes of three closely related bordetellae are currently being sequenced, thus providing an opportunity for comparative genomic approaches driven by an understanding of the comparative biology of these three bacteria. Although the other strains being sequenced are well studied, the strain of Bordetella parapertussis chosen for sequencing is a recent human clinical isolate (strain 12822) that has yet to be characterized in detail. This investigation reports the first phenotypic characterization of this strain, which will likely become the prototype for this species in comparison with the prototype strains of B. pertussis (Tohama I), B. bronchiseptica (RB50), and other isolates of B. parapertussis. Multiple in vitro and in vivo assays distinguished each species. B. parapertussis was more similar to B. bronchiseptica than to B. pertussis in many assays, including in BvgS signaling characteristics, presence of urease activity, regulation of urease expression by BvgAS, virulence in the respiratory tracts of immunocompromised mice, induction of anti-Bordetella antibodies, and serum antimicrobial resistance. In other assays, B. parapertussis was distinct from all other species (in pigment production) or more similar to B. pertussis (by lack of motility and cytotoxicity to a macrophage-like cell line). These results begin to provide phenotypes that can be related to genetic differences identified in the genomic sequences of bordetellae.
 ...
PMID:Comparative phenotypic analysis of the Bordetella parapertussis isolate chosen for genomic sequencing. 1206 21

The purpose of the work was to assess the state of bacteriological diagnosis of diphtheria infection in Russia in order to establish possible reasons for the decrease in the release of C. diphtheriae. The Reference Center for Monitoring the Pathogens of Measles, Rubella, Mumps, Pertussis and Diphtheria in 2018 in 85 subjects of Russia conducted a questionnaire of laboratories of medical organizations and the Centers for Hygiene and Epidemiology of Rospotrebnadzor, carrying out bacteriological studies for diphtheria infection. It was found that the number of studies conducted over the five-year period decreased by 1.2 times. The tendency to decrease the number of bacteriological studies for diphtheria is observed in the territories of almost all federal districts. In 99% and 29% of cases, the institutions of the FBUZ Centers for Hygiene and Epidemiology and medical organizations (MO) and use in their work documents regulating bacteriological studies for diphtheria infection. In a number of territories, the list of documents used includes documents that are invalid or do not define such studies. Most organizations use dry tampons when examining for diphtheria, however, 13.1% and 53.4% of FBUZ Centers for Hygiene and Epidemiology and medical organizations (respectively) use commercial transport environments, which does not comply with regulatory documentation. Analysis of the quality of work of bacteriological laboratories showed shortcomings at the stage of preparation of media (use of donor blood, or absence of addition of blood and potassium tellurite), Elek tests (addition of horse serum or absence of serum to the medium), setting of incomplete biochemical series (absence of tests for urease and nitrate reductase), absence of standard control strains, incomplete volume of internal laboratory quality control. Given the continuing circulation of the pathogen in various countries of the world and in our country, as well as the possibility of imported cases of infection from endemic regions, the analysis was aimed at drawing the attention of specialists to the problem of improving the quality of laboratory diagnosis of diphtheria in Russia.
 ...
PMID:Status and problems of bacteriological diagnosis of diphtheria infection in the Russian Federation. 3330 63