Chronic gastric infection by the Gram-negative bacterium Helicobacter pylori (H. pylori) is strongly associated with gastritis, gastric ulcer and the development of distal gastric carcinoma and gastric mucosal lymphoma in humans. Antibiotic treatment of H. pylori is becoming less effective because of increasing antibiotic resistance; other treatment approaches such as specifically targeted meth...

We characterized 38 Helicobacter isolates, including 22 from gastric biopsy samples obtained from 14 rhesus monkeys and single isolates from 16 monkeys in a different colony. Biochemical profiles of these isolates were nearly identical to that of Helicobacter pylori ATCC 43504. Restriction fragment length polymorphism (RFLP) analysis indicated that each infected monkey harbored one to four stra...

The nickel-containing enzyme urease is an essential colonization factor of the gastric pathogen Helicobacter pylori, as it allows the bacterium to survive the acidic conditions in the gastric mucosa. Although urease can represents up to 10% of the total protein content of H. pylori, expression of urease genes is thought to be constitutive. Here it is demonstrated that H. pylori regulates the ex...

The effect of high salt environments on biological characteristics of Helicobacter pylori is still unclear. In the present study, we therefore investigated biological characteristics of the bacterium exposed to high salt concentrations. H. pylori strain, L301, was cultured in media supplemented with different concentrations (3%, 15% and 30%) of sodium chloride (NaCl) under microaerophilic condi...

The outcome of H. pylori infection is closely related with bacteria's virulence factors and host immune response. The association between T cells and H. pylori infection has been identified, but the effects of the nine major H. pylori specific virulence factors; cagA, vacA, oipA, babA, hpaA, napA, dupA, ureA, ureB on T cell response in H. pylori infected patients have not been fully elucidated....

Helicobacter pylori urease, a nickel-requiring metalloenzyme, hydrolyzes urea to NH3 and CO2. We sought to identify H. pylori genes that modulate urease activity by constructing pHP8080, a plasmid which encodes both H. pylori urease and the NixA nickel transporter. Escherichia coli SE5000 and DH5alpha transformed with pHP8080 resulted in a high-level urease producer and a low-level urease produ...

Helicobacter pylori (H. pylori) infects more than half of the world's population, causing chronic gastritis, peptic ulcers and gastric cancer. Urease B subunit (UreB), a conserved protein of H. pylori, is capable of inducing specific CD4(+) T-cell responses and provides protection against this infection. Previous studies have confirmed the effectiveness of rUreB subunit vaccines in generating C...

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 method of recovering Helicobacter pylori DNA or viable cells absorbed on a string that a person has swallowed and that is retrieved an hour later (string test) should be a useful alternative to traditional analysis of cells or DNA obtained by endoscopy, which is invasive, uncomfortable, relatively costly, and ill-suited for community-based and pediatric studies. Here we assayed the sensitiv...

Helicobacter pylori is a global health problem which has encouraged scientists to find new ways to diagnose, immunize and eradicate the H. pylori infection. In silico studies are a promising approach to design new chimeric antigen having the immunogenic potential of several antigens. In order to obtain such benefit in H. pylori vaccine study, a chimeric gene containing four fragments of FliD se...