The persistence of the gastric pathogen Helicobacter pylori is due in part to urease and Msr (methionine sulfoxide reductase). Upon exposure to relatively mild (21% partial pressure of O2) oxidative stress, a Δmsr mutant showed both decreased urease specific activity in cell-free extracts and decreased nickel associated with the partially purified urease fraction as compared with the parent str...

Ureaplasma urealyticum is a pathogenic ureolytic mollicute which colonizes the urogenital tracts of humans. A genetic polymorphism between the two biotypes of U. urealyticum at the level of the urease genes was found. The urease gene cluster from a biotype 1 representative of U. urealyticum (serotype I) was cloned and sequenced. Seven genes were found, with ureA, ureB, and ureC encoding the str...

The aim of the study was to determine the response of soil enzymes such as dehydrogenases, urease and acid and alkaline phosphatases to heating oil contaminating (0.0, 0.25, 0.5, 0.75, 1.0, 1.5% of soil) the experimental soil supplemented with lime and used for cultivation of yellow lupine of the Markiz variety. An increasing contamination of soil with heating oil stimulated the activity of deh...

Helicobacter pylori infects nearly 50% of the world's population. This microorganism is accepted as the most important agent of gastritis and as a risk factor for peptic ulcer disease and gastric adenocarcinoma. Currently many diagnostic methods exist for detecting H. pylori, however they all have limitations, thus it is recommend a combination of at least two methods. The aim of this study was...

Inhibition of jack bean activity by 2,5-dichloro-1,4-benzoquinone (DCBQ) was studied in phosphate buffer, pH 7.0. It was found that DCBQ acted as a strong, time and concentration dependent inactivator of urease. Under the experimental conditions obeyed the terms of pseudo-first-order reaction, urease was totally inactivated. Application of Wilson-Kitz method proved that the urease-DCBQ interact...

This study investigated the influence of urease-positive non-Helicobacter pylori bacteria on the results of a urea breath test (UBT) to evaluate the diagnostic utility of a UBT using film-coated [(13)C]urea tablets. The UBT was performed in 102 patients treated with a proton pump inhibitor and antibiotics for the eradication of H. pylori. Urease-producing bacteria other than H. pylori were isol...

Acidic media trigger cytoplasmic urease activity of the unique human gastric pathogen Helicobacter pylori. Deletion of ureI prevents this activation of cytoplasmic urease that is essential for bacterial acid resistance. UreI is an inner membrane protein with six transmembrane segments as shown by in vitro transcription/translation and membrane separation. Expression of UreI in Xenopus oocytes r...

Cryptococcus neoformans is a pathogenic basidiomycete with a defined sexual cycle involving mating between haploid yeast cells with a transient diploid state. We examined F1 progeny from a crossing between the urease-negative strain (environmental isolate, serotype A, mating type alfa, haploid) and a tester strain (B 3502 from NIH of USA; urease-positive, serotype D, mating type a, haploid) for...

Shiga toxin-producing Escherichia coli (STEC) is a food-borne pathogen with a low infectious dose that colonizes the colon in humans and can cause severe clinical manifestations such as hemolytic-uremic syndrome. The urease enzyme, encoded in the STEC chromosome, has been demonstrated to act as a virulence factor in other bacterial pathogens. The NH(3) produced as urease hydrolyzes urea can aid...

Enterohemorrhagic Escherichia coli (EHEC) is a food-borne pathogen that can cause severe health complications and utilizes a much lower infectious dose than other E. coli pathotypes. Despite having an intact ure locus, ureDABCEFG, the majority of EHEC strains are phenotypically urease negative under tested conditions. Urease activity potentially assists with survival fitness by enhancing acid t...