Isolation and characterization of the first strain of Helicobacter hepaticus in China / 南方医科大学学报

Helicobacter hepaticus is nongastric helicobacter that can reside in the hepatobiliary and intestinal systems of many animal hosts, leading to proliferative hepatitis, hepatocellular carcinoma, typhlitis, and colonitis. In this study, the intestinal mucosa was isolated from BALB/c mice to prepare tissue homogenate and spread onto selective C jejuni blood agar plates for incubation in the presence of trimethoprim, vancomycin, and polymyxin at 37 degrees Celsius; under microaerobic conditions in vented jars containing 5% O2, 10%CO2, and 85% N2. The bacteria were identified morphologically and biochemically. Gene sequence analysis of the 16s rRNA confirmed the presence of Helicobacter hepaticus, and the success in isolating this bacteria may have significant implications for studies of nongastric helicobacter.

Immunization with catalase and UreB two-valence vaccine for preventing Helicobacter pylori infection in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of the two-valence vaccine consisting of Helicobacter pylori (H. pylori) catalase and urease subunit UreB in preventing H. pyloriinfection in mice.</p><p><b>METHODS</b>C57BL/6 mice were divided into 7 groups and immunized with intragastric administration of catalase and UreB (both 100 microg) plus cholera toxin (CT, 2 microg), catalase (100 microg) plus CT (2 microg), UreB (100 microg) plus CT (2 microg), catalase (100 microg), UreB (100 microg), CT (2 microg), or PBS, respectively, once a week for 4 consecutive weeks. Two weeks after the last immunization, all the mice were challenged by live H. pylori, and sacrificed 4 weeks after the challenge to obtain the gastric mucosa samples for detecting H. pylori using semi-quantitative bacterial culture assay.</p><p><b>RESULTS</b>The total protection rate in mice immunized with the two-valence vaccine, single-valence vaccine of catalase, and single-valence vaccine of UreB was 83.3% (20/24), 41.7% (10/24) and 54.2% (13/24), respectively, and the rate in the other 4 groups were all 0. The H. pyloricolony density in mice with vaccination was significantly lower than that of other 4 groups (P<0.05). The total protection rate and H. pylori colony density differed significantly between the two-valence vaccination group and the single-valence vaccination groups (P<0.05).</p><p><b>CONCLUSION</b>The two-valence vaccine consisting of catalase, UreB and adjuvant has better immunoprotective effects than the single-valence vaccines.</p>