نتایج جستجو برای: urease gene urec
تعداد نتایج: 1144991 فیلتر نتایج به سال:
Helicobacter pylori mutants devoid of urease activity fail to colonize the gastric mucosa of mice; however, the effect of decreased levels of urease on colonization has not been examined. The nixA gene, required for full urease activity, encodes a cytoplasmic membrane nickel transporter that imports nickel ions and leads to incorporation of nickel ions into apourease. A nixA mutant of the Sydne...
Background and Aim: As one of the factors of gastric ulcers and cancer, Helicobacter pylori can live in the acidic environment of stomach for many years due to having urease enzyme. This enzyme requires Ni2+ and a group of auxiliary proteins such as ureE for its catalytic activity. Urease is not only a requisite factor to colonize the Helicobacter pylori but it is also pathogenic with diff...
BACKGROUND AND OBJECTIVES Invasive and non-invasive techniques are used to diagnose H. pylori infection. Some factors influence the choice of a diagnostic test, such as the sensitivity and specificity of the tests, the clinical circumstances and the cost-effectiveness of the testing strategy. The aim of this study was to reveal the relationship between different H. pylori infection diagnosis me...
The isolation of halophilic urease-producing bacteria and the study of their nano-crystal production
Urease-producing bacteria can precipitate calcite nano-crystals by producing urease in the presence of urea and calcium. Calcite precipitation resulting from microbial activity is a process which causes cementation of soil particles in nature. The purpose of this study was to isolate urease-producing halophilic bacteria in order to precipitate calcite in saline soil. Natural samples, including ...
Helicobacter pylori urease requires nickel ions in the enzyme active site for catalytic activity. Nickel ions must, therefore, be actively acquired by the bacterium. NixA (high-affinity nickel transport protein)-deficient mutants of H. pylori retain significant urease activity, suggesting the presence of alternate nickel transporters. Analysis of the nucleotide sequence of the H. pylori genome ...
PCR is recognized as a promising method for the detection of Helicobacter pylori in gastric biopsy specimens. However, detection of PCR products by gel electrophoresis is difficult to implement in routine clinical laboratories. The aim of this study was to compare three new DNA enzyme immunoassays with the standard method in their ability to detect PCR products. The three assays were based on t...
Urea nitrogen has been proposed to contribute significantly to nitrification by marine thaumarchaeotes. These inferences are based on distributions of thaumarchaeote urease genes rather than activity measurements. We found that ammonia oxidation rates were always higher than oxidation rates of urea-derived N in samples from coastal Georgia, USA (means ± SEM: 382 ± 35 versus 73 ± 24 nmol L-1 d-...
background and objectives: invasive and non-invasive techniques are used to diagnose h. pylori infection. some factors influence the choice of a diagnostic test, such as the sensitivity and specificity of the tests, the clinical circumstances and the cost-effectiveness of the testing strategy. the aim of this study was to reveal the relationship between different h. pylori infection diagnosis m...
Helicobacter pylori infection causes chronic active gastritis that after many years of infection can develop into peptic ulceration or gastric adenocarcinoma. The bacterium is highly adapted to surviving in the gastric environment and a key adaptation is the virulence factor urease. Although widely postulated, the requirement of urease expression for persistent infection has not been elucidated...
Corynebacterium propinquum is a Gram-positive rod occasionally recovered from clinical infections which, according to 16S rRNA gene sequencing, is most closely related (>99% sequence similarity) to Corynebacterium pseudodiphtheriticum. The two species are very similar biochemically, commonly differentiated by a single test, the detection of urease, where strains of C. propinquum are described a...
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