title: Novel roles for autotransporter adhesin AatA of avian pathogenic Escherichia coli: colonization during infection and cell aggregation.
abstract: Systemic infections in avian species caused by avian pathogenic Escherichia 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 DE205B, 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 AAEC189 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.
authors.affiliation: Key Laboratory of Animal Disease Diagnostics and Immunology, Ministry of Agriculture, Nanjing Agricultural University, China.
authors.forename: Shaohui
authors.initials: S
authors.lastname: Wang
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Xia
authors.forename: Jianjun
authors.initials: J
authors.lastname: Dai
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Shi
authors.forename: Yahui
authors.initials: Y
authors.lastname: Kou
authors.forename: Huiqin
authors.initials: H
authors.lastname: Li
authors.forename: Yinli
authors.initials: Y
authors.lastname: Bao
authors.forename: Chengping
authors.initials: C
authors.lastname: Lu
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D016470:Bacteremia / Q000382:microbiology / Q000473:pathology; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002645:Chickens; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004372:Ducks; D004926:Escherichia coli / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000473:pathology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D005816:Genetic Complementation Test; D008168:Lung / Q000382:microbiology; D008969:Molecular Sequence Data; D011201:Poultry Diseases / Q000382:microbiology / Q000473:pathology; D017422:Sequence Analysis, DNA; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C512825:AatA protein, E coli; D018830:Adhesins, Escherichia coli; D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D037521:Virulence Factors