Open AccessNovel roles for autotransporter adhesin AatA of avian pathogenic E scherichia coli : colonization during infection and cell aggregation
Author(s) -
Wang Shaohui,
Xia Yongjie,
Dai Jianjun,
Shi Zhenyu,
Kou Yahui,
Li Huiqin,
Bao Yinli,
Lu Chengping
Publication year - 2011
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2011.00862.x
Subject(s) - bacterial adhesin , virulence , biology , microbiology and biotechnology , pathogenic escherichia coli , fimbria , pilus , escherichia coli , complementation , mutant , in vivo , colonization , gene , genetics
Systemic infections in avian species caused by avian pathogenic E scherichia coli ( APEC ) are economically devastating to poultry industries worldwide. To unravel factors possibly involved in APEC pathogenicity, suppression subtractive hybridization was applied, leading to the identification of a putative APEC autotransporter adhesin gene aatA in our previous study. In this study, pathogenic mechanism of AatA was further determined. A deletion mutant of aatA was constructed in the APEC DE 205 B , which results in the reduced capacity to adhere to DF ‐1 cells, defective virulence in vivo , and decreased colonization capacity in lung during the systemic infection compared with the wild‐type strain. Furthermore, these capacities were restored in the complementation strains. These results indicated that AatA makes a significant contribution to APEC virulence through bacterial adherence to host tissues in vivo and in vitro . In addition, aggregation assays for strain AAEC 189 expressing aatA indicated that AatA mediates cell aggregation and settling of cells. However, this cell aggregation is blocked by Type I fimbriae. This study illustrates the first examination of the role of AatA in aggregation and systemic infection.