Experimental Helicobacter pylori infection induces antral-predominant, chronic active gastritis in hispid cotton rats (Sigmodon hispidus).
BACKGROUND
The hispid cotton rat has proven to be an excellent animal model for a variety of human infectious disease agents. This study was performed to evaluate the use of the cotton rat as a model of Helicobacter pylori infection.


METHODS
Thirty-eight inbred cotton rats were orogastrically inoculated with a human strain of H. pylori. Twenty-eight control cotton rats were dosed with vehicle only. Animals were sacrificed at 2, 4, 12, 26, or 38 weeks after inoculation for bacterial and histologic and immunologic examinations.


RESULTS
Helicobacter pylori was cultured from the glandular stomach of 89% of the infected cotton rats. The level of colonization was consistently high (approximately 10(4-6) colony-forming units/g tissue). Histologically, the spiral bacteria were demonstrated on the epithelial surface and in the foveolae of the gastric mucosa with highest numbers in the antrum. H. pylori infection was associated with antral-predominant, chronic active gastritis which progressively increased in severity over time. By week 26 of infection, moderate antral gastritis had developed with frequent involvement of the submucosa and formation of lymphocytic aggregates. Splenic T cells from infected cotton rats expressed mRNAs for interferon-gamma, interleukin-4, interleukin-6, and interleukin-10 following in vitro stimulation with H. pylori. Serum levels of H. pylori-specific immunoglobulin G were significantly elevated after 12 weeks of infection.


CONCLUSIONS
The H. pylori-infected cotton rat represents a novel animal model that should prove useful for studies of H. pylori-induced chronic active gastritis and factors affecting gastric colonization by this pathogen.
Mähler
Michael
M
Institute for Laboratory Animal Science and Central Animal Facility, Medical School Hannover, Hannover, Germany. biodoc_maehler@web.de
Heidtmann
Wiebke
W
Niewiesk
Stefan
S
Gruber
Achim
A
Fossmark
Reidar
R
Beil
Winfried
W
Hedrich
Hans
H
Wagner
Siegfried
S
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D002908:Chronic Disease; D004195:Disease Models, Animal; D005753:Gastric Mucosa / Q000382:microbiology; D005756:Gastritis / Q000382:microbiology / Q000473:pathology / Q000503:physiopathology*; D016481:Helicobacter Infections / Q000382:microbiology / Q000473:pathology / Q000503:physiopathology*; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D006801:Humans; D011706:Pyloric Antrum / Q000382:microbiology / Q000473:pathology; D016205:Sigmodontinae; D013270:Stomach / Q000382:microbiology / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology
D000907:Antibodies, Bacterial