title: [Effect of autoinducer 2 on Riemerell antatipestifer adherence and invasion to Vero cells].
abstract: OBJECTIVE
  Autoinducer 2 (AI-2), used to communicate among bacterial species, regulates numerous physiological functions of bacteria. In this study, we studied the effect of AI-2 on adherence and invasion of Riemerella antatipestifer (RA) strain CH3 to Vero cells and transcriptional levels of virulence-related and metabolism-related genes were investigated.
  
  
  METHODS
  To verify whether the adherence and invasion of CH3 was affected by AI-2, we added different concentrations of AI-2 to the cocultures of Vero cells and CH3 and then calculated adherence percentages and invasion percentages of tested groups. We further added AI-2 (184.0 micromol/L) to the tryptone soya broth culture of CH3 and then detected the effect of transcriptional levels of related genes of CH3 using real-time PCR.
  
  
  RESULTS
  The adherence of CH3 to Vero cells was decreased most to 62% with 18.4 micromol/L AI-2 and the invasion of CH3 to Vero cells was increased most to 194% with 184.0 micromol/L AI-2. The result of real-time PCR shows that AI-2 increased transcriptional levels of some virulence-related genes and decreased transcriptional levels of some metabolism-related genes.
  
  
  CONCLUSIONS
  These results suggest that AI-2 affected adherence and invasion of CH3 to Vero cells. Moreover, AI-2 could regulate some genes of CH3 to modulate particular physiological behaviors.
authors.affiliation: Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China. liulei0606@gmail.com
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Xiangan
authors.initials: X
authors.lastname: Han
authors.forename: Rui
authors.initials: R
authors.lastname: Liu
authors.forename: Hao
authors.initials: H
authors.lastname: Bai
authors.forename: Hongliang
authors.initials: H
authors.lastname: Dong
authors.forename: Chan
authors.initials: C
authors.lastname: Ding
authors.forename: Haiwen
authors.initials: H
authors.lastname: Liu
authors.forename: Shengqing
authors.initials: S
authors.lastname: Yu
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects*; D001426:Bacterial Proteins / Q000235:genetics*; D002522:Chlorocebus aethiops; D041965:Flavobacteriaceae / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D045826:Flavobacteriaceae Infections / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D007783:Lactones / Q000378:metabolism* / Q000494:pharmacology; D015533:Transcriptional Activation / Q000187:drug effects; D014709:Vero Cells; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D006714:Homoserine