title: IbeB is involved in the invasion and pathogenicity of avian pathogenic Escherichia coli.
abstract: The ibeB gene in neonatal meningitis Escherichia coli (NMEC) contribute to the penetration of human brain microvascular endothelial cells (HBMECs). However, whether IbeB plays a role in avian pathogenic E. coli (APEC) infection remains unclear. Thus, this study was conducted to investigate the distribution of the ibeB gene in Chinese APEC strains and examine whether IbeB is involved in APEC pathogenicity. The ibeB gene was found in all 100 detected E. coli isolates with over 97% sequence homology. These results indicated that ibeB is a conserved E. coli gene irrelevant of pathotypes. To determine the role of ibeB in APEC pathogenicity, an ibeB mutant of strain DE205B was constructed and characterized. The inactivation of ibeB resulted in reduced invasion capacity towards DF-1 cells and defective virulence in animal models as compared to the wild-type strain. Animal infection experiments revealed that loss of ibeB decreased APEC colonization and invasion capacity in brains and lungs. These virulence-related phenotypes were partially recoverable by genetic complementation. Reduced expression levels of invasion- and adhesion-associated genes in ibeB mutant could be major reasons as evidenced by reduced ibeA and ompA expression. These results indicate that IbeB is involved in APEC invasion and pathogenicity.
authors.affiliation: Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing 210095, China. shwang0827@126.com
authors.forename: Shaohui
authors.initials: S
authors.lastname: Wang
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Shi
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Xia
authors.forename: Huiqin
authors.initials: H
authors.lastname: Li
authors.forename: Yahui
authors.initials: Y
authors.lastname: Kou
authors.forename: Yinli
authors.initials: Y
authors.lastname: Bao
authors.forename: Jianjun
authors.initials: J
authors.lastname: Dai
authors.forename: Chengping
authors.initials: C
authors.lastname: Lu
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D002642:Chick Embryo; D004372:Ducks; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000473:pathology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics*; D005347:Fibroblasts / Q000382:microbiology; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D011201:Poultry Diseases / Q000382:microbiology*
chemical_list: C096350:CusC protein, E coli; D029968:Escherichia coli Proteins; D008565:Membrane Proteins