title: Iron-regulated gene ireA in avian pathogenic Escherichia coli participates in adhesion and stress-resistance.
abstract: BACKGROUND
  Avian pathogenic Escherichia coli (APEC) causes avian colibacillosis, which results in economic and welfare costs in the poultry industry worldwide. The pathogenesis of avian pathogenic E. coli strains is not well defined. Here, the function of an outer membrane protein encoded by the ireA gene of avian pathogenic E. coli strain DE205B was investigated.
  
  
  RESULTS
  The ireA gene was distributed in 32.9 % (46/140) of tested E. coli strains, with high percentages in the phylogenetic ECOR groups B2 (58.8 %, 10/17) and D (55.9 %, 19/34). The gene expression level of ireA of APEC strain DE205B in high Fe M9 media was 1.8 times higher (P < 0.05) than that in low Fe M9 media. An ireA deletion mutant and complementary strain were constructed. Compared with the wild-type strain DE205B, the expression of most ferric uptake genes in the ireA deletion mutant were significantly upregulated (P < 0.05). The adhesion ability of the ireA deletion mutant to DF-1 cells was significantly decreased. The survival rate of ireA deletion mutant was reduced 21.17 % (P < 0.01), 25.42 (P < 0.05) and 70.0 % (P < 0.01) under alkali, high osmolarity, and low temperature (4 °C) conditions, respectively, compared with the wild-type strain.
  
  
  CONCLUSIONS
  The results suggested that the protein encoded by the iron-regulated gene ireA has roles in adhesion and stress resistance in avian pathogenic E. coli.
authors.affiliation: Key Laboratory Animal Bacteriology, Ministry of Agriculture, College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, 210095, Jiangsu province, People's Republic of China.
authors.forename: Yaxin
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory Animal Bacteriology, Ministry of Agriculture, College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, 210095, Jiangsu province, People's Republic of China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Dai
authors.affiliation: Key Laboratory Animal Bacteriology, Ministry of Agriculture, College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, 210095, Jiangsu province, People's Republic of China.
authors.forename: Xiangkai
authors.initials: X
authors.lastname: Zhuge
authors.affiliation: Key Laboratory Animal Bacteriology, Ministry of Agriculture, College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, 210095, Jiangsu province, People's Republic of China.
authors.forename: Haojin
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory Animal Bacteriology, Ministry of Agriculture, College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, 210095, Jiangsu province, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Hu
authors.affiliation: Key Laboratory Animal Bacteriology, Ministry of Agriculture, College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, 210095, Jiangsu province, People's Republic of China.
authors.forename: Jianluan
authors.initials: J
authors.lastname: Ren
authors.affiliation: Key Laboratory Animal Bacteriology, Ministry of Agriculture, College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, 210095, Jiangsu province, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.affiliation: Key Laboratory Animal Bacteriology, Ministry of Agriculture, College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, 210095, Jiangsu province, People's Republic of China.
authors.forename: Dezhi
authors.initials: D
authors.lastname: Li
authors.affiliation: Key Laboratory Animal Bacteriology, Ministry of Agriculture, College of veterinary medicine, Nanjing Agricultural University, No.1 Weigang, Nanjing, 210095, Jiangsu province, People's Republic of China. tangfang@njau.edu.cn.
authors.forename: Fang
authors.initials: F
authors.lastname: Tang
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics / Q000502:physiology*; D004372:Ducks; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D009154:Mutation; D011201:Poultry Diseases / Q000382:microbiology* / Q000473:pathology; D013312:Stress, Physiological / Q000235:genetics / Q000502:physiology*
chemical_list: D029968:Escherichia coli Proteins; C437328:IreA protein, E coli
keywords: APEC; Adhesion; IreA; Stress resistance; Virulence