title: IbeR facilitates stress-resistance, invasion and pathogenicity of avian pathogenic Escherichia coli.
abstract: Systemic infections by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide. IbeR, located on genomic island GimA, was shown to serve as an RpoS-like regulator in rpoS gene mutation neonatal meningitis E. coli (NMEC) RS218. However, the role of IbeR in pathogenicity of APEC carrying active RpoS has not yet been investigated. We showed that the APEC IbeR could elicit antibodies in infected ducks, suggesting that IbeR might be involved in APEC pathogenicity. To investigate the function of IbeR in APEC pathogenesis, mutant and complementation strains were constructed and characterized. Inactivation of ibeR led to attenuated virulence and reduced invasion capacity towards DF-1 cells, brains and cerebrospinal fluid (CSF) in vitro and in vivo. Bactericidal assays demonstrated that the mutant strain had impaired resistance to environmental stress and specific pathogen-free (SPF) chicken serum. These virulence-related phenotypes were restored by genetic complementation. Quantitative real-time reverse transcription PCR revealed that IbeR controlled expression of stress-resistance genes and virulence genes, which might led to the associated virulence phenotype.
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Shaohui
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yinli
authors.initials: Y
authors.lastname: Bao
authors.affiliation: Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Qingmei
authors.initials: Q
authors.lastname: Meng
authors.affiliation: Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China; School of Public Health, Fudan University, Shanghai, 200032, China.
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
authors.forename: Yichao
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Tang
authors.affiliation: Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Xiangkai
authors.initials: X
authors.lastname: ZhuGe
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
authors.forename: Shengqing
authors.initials: S
authors.lastname: Yu
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
authors.forename: Xiangan
authors.initials: X
authors.lastname: Han
authors.affiliation: Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Dai
authors.affiliation: Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Chengping
authors.initials: C
authors.lastname: Lu
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000917:Antibody Formation; D002460:Cell Line; D002642:Chick Embryo; D002645:Chickens / Q000382:microbiology; D004372:Ducks / Q000276:immunology / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008581:Meningitis / Q000382:microbiology; D051381:Rats; D017384:Sequence Deletion; D013312:Stress, Physiological / Q000235:genetics; D014774:Virulence / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins