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Dechka, Jennifer

University of British Columbia

Campylobacter jejuni is a widespread enteric pathogen that causes mild to severe gastroenteritis in humans. Despite the prevalence of C. jejuni, its virulence mechanisms are poorly understood. It had long been postulated that C. jejuni’s characteristic helical shape was important for pathogenesis, which our group has now shown to be the case. Peptidoglycan remodelling enzymes play a key role in maintaining cell shape. The LytM domain-containing protein 1291 was identified while searching the C. jejuni genome for peptidoglycan peptidases. As 1291 was predicted to lack proteolytic activity, it was subsequently predicted to activate the C. jejuni amidase, AmiA. Deletion of 1291 caused distinct phenotypic changes compared to wild type C. jejuni. The 1291 deletion mutant demonstrated a long chain-like cellular morphology similar to an amiA deletion strain and contributed to key pathogenesis phenotypes. In comparison to wild type, ∆1291 displayed severe motility and autoagglutination defects, as well as an increase in biofilm formation. Both 1291 and the E. coli LytM domain-containing amidase activator EnvC showed cross-species complementation. Specifically, 1291 was able to complement the severe chaining phenotype of an E. coli amidase activator deletion strain, and EnvC was able to complement the chain-like phenotype of ∆1291. This work provides evidence that 1291 acts as a pathogenesis factor in C. jejuni and is involved in cellular morphological changes, likely through the activation of C. jejuni’s sole amidase, AmiA.

Text

2022-12-22

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/83482

Microbiology and Immunology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/