[Pathogenicity in mice infected with three different strains H. pylori].
OBJECTIVE
To observe the differences of colonization and histopathology between CagA+ strains and lacking CagA by three different strains infecting C57BL/C mice.


METHODS
CYP3401 wild type strain (CagA+), CYP3401(the isogenic CagA) knockout mutant CagA-, Sydney strain (CagA+) were used. The mice were administered orally with 0.5 ml, 10(9) CFU/ml of the above bacterial suspensions, respectively. Serum IgG antibodies were measured by ELISA. All the mice were sacrificed at 8 weeks after inoculation and their stomaches were removed for histopathologic study.


RESULTS
The colonization of the bacteria was evident in Sydney strain and mild type strain, but characterized by wild to moderate infiltration by nutrophils and momocytes histologically. Only a small number of organisms were observed in the CagA- strains group. The levels of serum IgG antibodies were the highest in Sydney and wild strains group as compared with the control group (P < 0.01). There was no significant difference between the CagA-group and the control group.


CONCLUSIONS
A strong correlation was observed between CagA+, bacterial colonization, gastric mucosa inflammation, and serum IgG antibodies. The study of C57BL/C mice helps understand the pathogenicity with CagA+ strains in human body and study H. pylori infection and associated diseases.
Gong
G
G
Department of Nanlou Gastroenterlology, General Hospital of PLA, Beijing 100853.
Toshio
F
F
Akira
N
N
D000818:Animals; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000096:biosynthesis; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D015870:Gene Expression; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D051379:Mice; D008810:Mice, Inbred C57BL; D011897:Random Allocation
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C080866:cagA protein, Helicobacter pylori