title: Riemerella anatipestifer lacks luxS, but can uptake exogenous autoinducer-2 to regulate biofilm formation.
abstract: Riemerella anatipestifer (RA) causes major economic losses to the duck industry. Autoinducer-2 (AI-2) is a quorum-sensing signal that regulates bacterial physiology. The luxS and pfs genes are required for AI-2 synthesis in many bacterial species. pfs encodes Pfs, which functions upstream of LuxS in the biosynthesis of AI-2. In this study, we investigated the AI-2 activity of RA using an AI-2 bioassay, which showed that RA does not produce AI-2. Bioinformatic analysis indicated that the RA genome has a pfs, but not a luxS, homologue. To investigate the function of RA pfs, an avian pathogenic Escherichia coli (APEC) pfs mutant was constructed, which was subsequently transformed with a recombinant plasmid carrying RA pfs. An AI-2 bioassay demonstrated that RA pfs restored AI-2 production to the APEC pfs mutant, suggesting that RA pfs functions in AI-2 synthesis. Furthermore, we found that RA utilizes exogenous AI-2 to regulate biofilm formation. RA biofilm formation decreased significantly upon addition of exogenous AI-2. Real-time quantitative PCR results showed that expression of 13 genes related to RA biofilm formation decreased significantly when exogenous AI-2 was added to the RA culture media. These findings will benefit future studies on AI-2 regulation in RA.
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Xiangan
authors.initials: X
authors.lastname: Han
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Guobo
authors.initials: G
authors.lastname: Fan
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Da
authors.initials: D
authors.lastname: Xu
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Jiakun
authors.initials: J
authors.lastname: Zuo
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Shaohui
authors.initials: S
authors.lastname: Wang
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Wang
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Mingxing
authors.initials: M
authors.lastname: Tian
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China.
authors.forename: Chan
authors.initials: C
authors.lastname: Ding
authors.affiliation: Shanghai Veterinary Research Institute, The Chinese Academy of Agricultural Sciences (CAAS), 518 Ziyue Road, Shanghai 200241, PR China. Electronic address: yus@shvri.ac.cn.
authors.forename: Shengqing
authors.initials: S
authors.lastname: Yu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D013437:Carbon-Sulfur Lyases / Q000235:genetics / Q000378:metabolism*; D019295:Computational Biology; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism; D007783:Lactones / Q000378:metabolism*; D009154:Mutation; D060888:Real-Time Polymerase Chain Reaction; D060494:Riemerella / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D006714:Homoserine; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria
keywords: Autoinducer-2; Biofilm formation; Pfs; Riemerella anatipestifer