Catalase (KatA) and KatA-associated protein (KapA) are essential to persistent colonization in the Helicobacter pylori SS1 mouse model

Harris, Andrew G. and Wilson, John E. and Danon, Stephen J. and Dixon, Michael F. and Donegan, Kevin and Hazell, Stuart L. (2003) Catalase (KatA) and KatA-associated protein (KapA) are essential to persistent colonization in the Helicobacter pylori SS1 mouse model. Microbiology, 149 (3). pp. 665-672. ISSN 1350-0872


Helicobacter pylori infects the human gastric mucosa and elicits an aggressive inflammatory response. Despite the severity of the inflammatory response, the bacterium is able to persist and cause a chronic infection. It is believed that antioxidant defence mechanisms enable this organism to persist. Wild-type H. pylori strain SS1, and KatA- and KapA-deficient mutants, were used to infect C57/BL6 mice to test this hypothesis. Neither KatA nor KapA was essential for the initial colonization of H. pylori SS1 in the murine model of infection. The wild-type SS1 colonized the gastric mucosa at significantly higher levels than both mutants throughout the 24-week experiment. Neither KatA- nor KapA-deficient mutants were able to maintain consistent ongoing colonization for the 24-week period, indicating the necessity of both KapA and KatA in sustaining a long-term infection. At 24 weeks, 5/10 mice inoculated with the KatA mutant and 2/10 mice inoculated with the KapA mutant were colonized, compared with 10/10 of the mice inoculated with the wild-type SS1. An increase in the severity of inflammation in the wild-type-inoculated mice appeared to correlate with the decline in colonization of animals inoculated with the mutants, suggesting that increased oxidative stress militated against continued infection by the mutants. These data indicate that KapA may be of equal or greater importance than KatA in terms of sustained infection on inflamed gastric mucosae.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to paper due to publisher's copyright restrictions.
Faculty / Department / School: Historic - Faculty of Sciences - Department of Biological and Physical Sciences
Date Deposited: 02 May 2010 12:40
Last Modified: 02 Jul 2013 23:51
Uncontrolled Keywords: animal model; animal tissue; article; bacterial colonization; bacterial strain; bacterium mutant; controlled study; disease severity; Helicobacter infection; Helicobacter pylori; hypothesis; inflammation; inoculation; mouse strain; nonhuman; oxidative stress; protein deficiency; stomach mucosa
Fields of Research : 06 Biological Sciences > 0605 Microbiology > 060501 Bacteriology
06 Biological Sciences > 0605 Microbiology > 060502 Infectious Agents
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970106 Expanding Knowledge in the Biological Sciences
Identification Number or DOI: 10.1099/mic.0.26012-0

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