Dépôt numérique
RECHERCHER

The periplasmic trehalase affects type 1 fimbriae production and virulence of the extraintestinal pathogenic E. coli strain MT78

Pavanelo, Daniel Brisotto; Houle, Sébastien; Matter, Leticia Beatriz; Dozois, Charles M.; Horn, Fabiana (2018). The periplasmic trehalase affects type 1 fimbriae production and virulence of the extraintestinal pathogenic E. coli strain MT78 Infection and Immunity , vol. 86 , nº 8: e00241-18. p. 1-12. DOI: 10.1128/IAI.00241-18.

Ce document n'est pas hébergé sur EspaceINRS.

Résumé

Extraintestinal pathogenic Escherichia coli (ExPEC) is responsible for various infections outside the gastrointestinal tract in humans and other animals. ExPEC strain MT78 is invasive to various nonphagocytic cells and highly virulent in vivo To identify genes required for invasion of nonphagocytic cells by this strain, we applied signature-tagged mutagenesis to generate a library of mutants and tested them for invasion of avian fibroblasts. Mutants showing reduced cellular invasion included those with insertions in the fim operon, encoding type 1 fimbriae. Another attenuated mutant showed a disruption in the treA gene, which encodes a periplasmic trehalase. The substrate of TreA, trehalose, can be metabolized and used as a carbon source or can serve as an osmoprotectant under conditions of osmotic stress in E. coli K-12. We generated and characterized mutant MT78ΔtreA In contrast to the wild type, MT78ΔtreA was able to grow under osmotic stress caused by 0.6 M urea but not in minimal M9 medium with trehalose as the only carbon source. It presented decreased association and invasion of avian fibroblasts, decreased yeast agglutination titer, and impaired type 1 fimbria production. In a murine model of urinary tract infection, MT78ΔtreA was less able to colonize the bladder. All phenotypes were rescued in the complemented mutant. Our results show that the treA gene is needed for optimal production of type 1 fimbriae in ExPEC strain MT78 and that loss of treA significantly reduces its cell invasion capacity and colonization of the bladder in a murine model of urinary tract infection.

Type de document: Article
Mots-clés libres: ExPEC; MT78; TreA; avian fibroblasts; extraintestinal pathogenic E. coli; signature-tagged mutagenesis; trehalase; trehalose; type 1 fimbriae; urinary tract infection
Centre: Centre INRS-Institut Armand Frappier
Date de dépôt: 04 mars 2019 18:34
Dernière modification: 04 mars 2019 18:34
URI: http://espace.inrs.ca/id/eprint/7476

Actions (Identification requise)

Modifier la notice Modifier la notice