title: Identification of the ferric iron utilization gene B739_1208 and its role in the virulence of R. anatipestifer CH-1.
abstract: Riemerella anatipestifer is an important bacterial pathogen in ducks and causes heavy economic losses in the duck industry. However, the pathogensis of this bacterium is poorly understood. In this study, a putative outer membrane hemin receptor gene B739_1208 in R. anatipestifer CH-1 was deleted to determine the relationship between iron uptake and virulence. The R. anatipestifer CH-1ΔB739_1208 mutants grew significantly more slowly than the wild-type bacteria in TSB liquid medium. Further characterization revealed that the R. anatipestifer CH-1ΔB739_1208 mutants were deficient in iron uptake. Animal experiments indicated that the median lethal dose of the wild-type RA-CH-1 in ducklings was 3.89×108, whereas the median lethal dose of the R. anatipestifer CH-1ΔB739_1208 mutant in ducklings was 5.68×109. The median lethal dose of the complementation strain in ducklings was 9.84×108. Additional analysis indicated that bacterial loads in the blood, liver, and brain tissues in the R. anatipestifer CH-1ΔB739_1208-infected ducklings were significantly decreased compared to those in the wild-type R. anatipestifer CH-1 infected ducklings. In a duck co-infection model with R. anatipestifer CH-1 and R. anatipestifer CH-1ΔB739_1208, the R. anatipestifer CH-1B739_1208 mutant was outcompeted by the wild-type R. anatipestifer CH-1 in the blood (P<0.002), livers (P<0.001) and brains (P<0.001) of infected ducks, indicating that B739_1208 gene expression provided a competitive advantage in these organs. Our results demonstrate that the B739_1208 gene is a virulence factor in R. anatipestifer CH-1.
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: MengYi
authors.initials: M
authors.lastname: Wang
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: PengYun
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: DeKang
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: MingShu
authors.initials: M
authors.lastname: Wang
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: RenYong
authors.initials: R
authors.lastname: Jia
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: Shun
authors.initials: S
authors.lastname: Chen
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: KunFeng
authors.initials: K
authors.lastname: Sun
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China.
authors.forename: XiaoYue
authors.initials: X
authors.lastname: Chen
authors.affiliation: Unité des Infections Bactériennes Invasives, Département Infection et Epidémiologie, Institut Pasteur, Paris, France.
authors.forename: Francis
authors.initials: F
authors.lastname: Biville
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China. Electronic address: chenganchun@vip.163.com.
authors.forename: AnChun
authors.initials: A
authors.lastname: Cheng
authors.affiliation: Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Research Center of Avian Disease, College of Veterinary Medicine of Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan 611130, PR China. Electronic address: liumafengra@163.com.
authors.forename: MaFeng
authors.initials: M
authors.lastname: Liu
mesh_terms: D000818:Animals; D016470:Bacteremia; D058491:Bacterial Load; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001692:Biological Transport; D001921:Brain / Q000382:microbiology; D004372:Ducks / Q000382:microbiology*; D045826:Flavobacteriaceae Infections / Q000382:microbiology / Q000662:veterinary*; D007501:Iron / Q000378:metabolism*; D008099:Liver / Q000382:microbiology; D009154:Mutation; D011201:Poultry Diseases / Q000382:microbiology*; D060494:Riemerella / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D014774:Virulence; D037521:Virulence Factors
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors; D007501:Iron
keywords: Iron uptake; R. anatipestifer; Virulence