In the present study we compared the inoculation of swine gastric mucus into the stomach of mice, the ureas test and carbolfuchsin-stained smears for the diagnosis of the infection with "Gastrospirillum suis" ("Helicobacter heilmannii" type 1), an uncultivated tightly spiralled gastric bacterium. Fragments obtained from the antral and oxyntic mucosa of the stomach of 50 slaughtered pigs were us...

The hydrolysis of urea by urease enzyme of oral bacteria is believed to have a major impact on oral microbial ecology and to be intimately involved in oral health and diseases. To begin to understand the biochemistry and genetics of oral ureolysis, a study of the urease of Streptococcus salivarius, a highly ureolytic organism which is present in large numbers on the soft tissues of the oral cav...

Helicobacter pylori survives and grows at low pHs via acid acclimation mechanisms that enable periplasmic pH homeostasis. Important components include a cytoplasmic urease; a pH-gated urea channel, UreI; and periplasmic α-carbonic anhydrase. To allow the rapid adjustment of periplasmic pH, acid acclimation components are recruited to the inner membrane in acid. The ArsRS two-component system, i...

The development of microbial enzymes was a crucial event in the industrial sectors as result tremendous growth biotechnology recent years. Popularity waste management and bioremediation processes have both made extensive use microorganisms’ whole cells their enzymes. pharmaceutical, textile, food, cosmetics, leather, paper, energy, biomaterials, fine chemicals, cellulose, detergent are some use...

The urease enzyme of Campylobacter pylori was studied and compared with that of a related spiral-shaped bacterium, St1, isolated from the rodent ileum. Both bacteria possessed constitutive urease enzymes with activities up to 20-70 times that of Proteus vulgaris. This activity was retained on SDS-polyacrylamide gels. A major catalytic subunit of mol. wt 300,000 was located for all (six) strains...

Most members of the genus Brucella show strong urease activity. However, the role of this enzyme in the pathogenesis of Brucella infections is poorly understood. We isolated several Tn5 insertion mutants deficient in urease activity from Brucella abortus strain 2308. The mutations of most of these mutants mapped to a 5.7-kbp DNA region essential for urease activity. Sequencing of this region, d...

Corynebacterium urealyticum is a common skin colonizer with potent urease activity. It is clinically recognized as an opportunistic pathogen causing urinary tract infections. The annotated genome sequence of strain DSM 7111, isolated from the urine of a young boy with an ectopic kidney, provides new insights into the pathomechanisms of this bacterium.

Extreme pHs, especially acidic pHs, are among the environmental stresses that some bacteria face. The most important strategies that bacteria employ for acid adaptation include either production of acidophilic proteins, or raising the pH of the microenvironment by secretion of basic compounds including ammonia produced by the action of urease. Considering the importance of acid-neutralizing bac...

ureI encodes an integral cytoplasmic membrane protein. It is present in the urease gene cluster of Helicobacter pylori and is essential for infection and acid survival, but its role is unknown. To determine the function of UreI protein, we produced H. pylori ureI deletion mutants and measured the pH dependence of urease activity of intact and lysed bacteria and the effect of urea on the membran...

Dental caries results from prolonged plaque acidification that leads to the establishment of a cariogenic microflora and demineralization of the tooth. Urease enzymes of oral bacteria hydrolyze urea to ammonia, which can neutralize plaque acids. To begin to examine the relationship between plaque ureolytic activity and the incidence of dental caries, recombinant, ureolytic strains of Streptococ...