title: Biofilm formation, host-cell adherence, and virulence genes regulation of Streptococcus suis in response to autoinducer-2 signaling.
abstract: Autoinducer-2 (AI-2) is a universal signal molecule mediating intra- and interspecies communication among bacteria. AI-2 is a byproduct of the LuxS enzyme during the catabolism of S-adenosylhomocysteine and plays critical roles in regulating various behaviors of bacteria. In our previous study, the function of LuxS in AI-2 production was verified in Streptococcus suis (SS). Decreased levels of SS biofilm formation and host-cell adherence as well as the inability to produce AI-2 were observed in SS having a luxS mutant gene. In this study, exogenous addition of a low concentration of AI-2 synthesized in vitro was found to promote biofilm formation and host-cell adherence. However, higher concentrations of AI-2 inhibited SS biofilm formation and host-cell adherence. Real-time PCR results showed that the mRNA level of virulence factors of SS biofilm, gdh, cps2, sly, and mrp increased and ef, fbps, and gapdh decreased with increasing AI-2 concentrations. These findings demonstrated that AI-2 supplemented exogenously acted as a concentration-dependent signaling molecule to regulate SS biofilm formation, host-cell adherence, and transcription levels of many virulence genes.
authors.affiliation: College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471003, China, wangyocean@163.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Yi
authors.forename: Zhicheng
authors.initials: Z
authors.lastname: Zhang
authors.forename: Hongjie
authors.initials: H
authors.lastname: Fan
authors.forename: Xiangchao
authors.initials: X
authors.lastname: Cheng
authors.forename: Chengping
authors.initials: C
authors.lastname: Lu
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D020869:Gene Expression Profiling; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism; D007783:Lactones / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D017011:Streptococcus suis / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D037521:Virulence Factors / Q000096:biosynthesis*
chemical_list: D007783:Lactones; C091088:N-octanoylhomoserine lactone; D037521:Virulence Factors; D006714:Homoserine