title: Initial steps of the pathogenesis of the infection caused by Streptococcus suis: fighting against nonspecific defenses.
abstract: Interactions between a bacterial pathogen and its potentially susceptible host are initiated with the colonization step. During respiratory/oral infection, the pathogens must compete with the normal microflora, resist defense mechanisms of the local mucosal immunity, and finally reach, adhere, and breach the mucosal epithelial cell barrier in order to induce invasive disease. This is the case during infection by the swine and zoonotic pathogen Streptococcus suis, which is able to counteract mucosal barriers to induce severe meningitis and sepsis in swine and in humans. The initial steps of the pathogenesis of S. suis infection has been a neglected area of research, overshadowed by studies on the systemic and central nervous phases of the disease. In this Review article, we provide for the first time, an exclusive focus on S. suis colonization and the potential mechanisms involved in S. suis establishment at the mucosa, as well as the mechanisms regulating mucosal barrier breakdown. The role of mucosal immunity is also addressed. Finally, we demystify the extensive list of putative adhesins and virulence factors reported to be involved in the initial steps of pathogenesis by S. suis.
authors.affiliation: Laboratory of Immunology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada.|Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada.
authors.forename: Mariela
authors.initials: M
authors.lastname: Segura
authors.affiliation: Laboratory of Immunology, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada.|Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada.|Laboratory of Streptococcus suis, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Calzas
authors.affiliation: Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada.|Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Quebec City, Quebec, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Grenier
authors.affiliation: Swine and Poultry Infectious Diseases Research Centre (CRIPA), Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada.|Laboratory of Streptococcus suis, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec, Canada.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D000818:Animals; D004847:Epithelial Cells / Q000276:immunology; D054884:Host-Pathogen Interactions; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology*; D016920:Meningitis, Bacterial / Q000382:microbiology* / Q000662:veterinary; D018805:Sepsis / Q000382:microbiology* / Q000662:veterinary; D013290:Streptococcal Infections / Q000382:microbiology / Q000662:veterinary; D017011:Streptococcus suis / Q000472:pathogenicity*; D013552:Swine; D037521:Virulence Factors / Q000378:metabolism*; D015047:Zoonoses / Q000382:microbiology
chemical_list: D018829:Adhesins, Bacterial; D037521:Virulence Factors
keywords: 
  Streptococcus suis
  ; colonization; epithelial cells; mucosal immunity; swine; zoonosis