title: Contribution of fibronectin-binding protein to pathogenesis of Streptococcus equi ssp. zooepidemicus.
abstract: Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) is responsible for a wide variety of infections in many species. Fibronectin-binding protein is a bacterial cell surface protein, which specifically binds fibronectin (FN). Considering the specific role of FN-binding protein in host-pathogen interactions, we investigated the function of a novel FN-binding domain in the FN-binding protein (FNZ) of S. zooepidemicus. Five recombinant FNZ gene fragments [N1 (amino acids, 38-197), N2 (amino acids, 38-603), N3 (amino acids, 41-315), N4 (amino acids, 192-370), and N5 (amino acids, 38-225)] were expressed in Escherichia coli, and their FN-binding activities were tested. The results showed that amino acids 192-225 in the NH2 -terminal region of FNZ could be responsible for binding fibronectin. The FNZ knockout mutant was constructed in S. zooepidemicus, which results in the reduced capacity to adhere to HEp-2 cell, defective virulence in vivo, decreased biofilm formation, and decreased colonization capacity in blood, liver, lung, and spleen tissues of mice as compared to the wild type. These results suggest that FNZ participates in biofilm formation, FN binding, cell adhesion, and pathogenesis of S. zooepidemicus. Furthermore, this work offers a novel FN-binding domain within FNZ, which will help in further characterization of S. zooepidemicus FN-binding properties.
authors.affiliation: Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Yi
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhe
authors.initials: Z
authors.lastname: Ma
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.forename: Jun-xi
authors.initials: JX
authors.lastname: Zheng
authors.forename: Yong-chun
authors.initials: YC
authors.lastname: Yang
authors.forename: Cheng-ping
authors.initials: CP
authors.lastname: Lu
authors.forename: Hong-jie
authors.initials: HJ
authors.lastname: Fan
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism*; D000825:Animal Structures / Q000382:microbiology; D000818:Animals; D001422:Bacterial Adhesion; D058491:Bacterial Load; D018441:Biofilms / Q000254:growth & development; D002460:Cell Line; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics; D005353:Fibronectins / Q000378:metabolism; D015870:Gene Expression; D055786:Gene Knockout Techniques; D054884:Host-Pathogen Interactions; D006801:Humans; D051379:Mice; D008813:Mice, Inbred ICR; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013290:Streptococcal Infections / Q000382:microbiology / Q000473:pathology; D018502:Streptococcus equi / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D018829:Adhesins, Bacterial; D005353:Fibronectins; D011994:Recombinant Proteins; D037521:Virulence Factors; C078635:fibronectin-binding proteins, bacterial