The discovery of Helicobacter hepaticus and its role in hepatitis, hepatocellular carcinoma, typhlocolitis, and lower-bowel carcinoma in murine colonies was followed by the isolation and characterization of other Helicobacter spp. involved in enterohepatic disease. Colonization of mouse colonies with members of the family Helicobacteriaceae has become an increasing concern for the research comm...

Current bacterial detection techniques are relatively slow, require bulky instrumentation, and usually require some form of specialized training. The gold standard for bacterial detection is culture testing, which can take several days to receive a viable result. Therefore, simpler detection techniques that are both fast and sensitive could greatly improve bacterial detection and identification...

Hydrogen-oxidizing hydrogenase activity was detected in Helicobacter hepaticus and compared to the activity in Helicobacter pylori for characteristics associated with hydrogen uptake respiratory hydrogenases. Intact whole cells could couple H(2) oxidation to oxygen uptake, and no H(2) uptake was observed without oxygen available to complete the respiratory pathway. The H. hepaticus enzyme coupl...

Various Helicobacter species have been isolated from the stomach, intestinal tract and liver of a variety of mammalian and some avian species, and Helicobacter DNA has been detected in human bile and liver samples. An immunoblot assay was established to analyse serum antibody responses to non-gastric Helicobacter species in patients with autoimmune liver diseases, in comparison with healthy ind...

Enterohepatic Helicobacter species infect the intestinal tracts and biliary trees of various mammals, including mice and humans, and are associated with chronic inflammatory diseases of the intestine, gallstone formation, and malignant transformation. The recent analysis of the whole genome sequence of the mouse enterohepatic species Helicobacter hepaticus allowed us to perform a functional ana...

Helicobacter hepaticus expresses a member of the cytolethal distending toxin (CDT) family of bacterial cytotoxins. To investigate the role of CDT in the pathogenesis of H. hepaticus, transposon mutagenesis was used to generate a series of isogenic mutants in and around the cdtABC gene cluster. An H. hepaticus transposon mutant with a disrupted cdtABC coding region no longer produced CDT activit...

Helicobacter hepaticus contaminating nonfrozen tumors was transmissible to severe combined immunodeficient (SCID) mice, but the organism in cryopreserved samples was not. This suggests that H. hepaticus has the ability to spread via biomaterials and that freezing-thawing is able to reduce the numbers of organisms to levels insufficient for subcutaneous infection of SCID mice.

AIM The aim of current study is to investigate whether tonsillar and/or adenoid tissue of patients with chronic adenotonsillitis plays a reservoir role for Helicobacter pylori (H. pylori) or Helicobacter hepaticus (H. hepaticus). BACKGROUND Recently, there have been arguments ragarding Helicobacter pylori (H. pylori) being reserved in adenotonsillar tissue. PATIENTS AND METHODS This study w...

Persistent murine infection with Helicobacter hepaticus leads to chronic gastrointestinal inflammation and neoplasia in susceptible strains. To determine the role of the virulence factor cytolethal distending toxin (CDT) in the pathogenesis of this organism, interleukin-10-deficient (IL-10-/-) mice were experimentally infected with wild-type H. hepaticus and a CDT-deficient isogenic mutant. Bot...

In a long-term rodent bioassay evaluating the carcinogenicity of triethanolamine, there was equivocal evidence of carcinogenic activity in male B6C3F1 mice, based on a marginal increase in the number of hepatocellular adenomas and hepatoblastomas. Interpretation was complicated by the presence of Helicobacter hepaticus in selected silver-stained liver sections which also had histological eviden...