title: Phagocytosis and killing of Streptococcus suis by porcine neutrophils.
abstract: Streptococcus suis serotype 2 is an important swine pathogen responsible for diverse infections, mainly meningitis. Virulence factors and the pathogenesis of infection are not well understood. Neutrophils may play an important role in the pathogenesis of infection given that infiltration by neutrophils and mononuclear cells are frequently observed in lesions caused by S. suis. The objective of this work was to study the interactions between S. suis serotype 2 and porcine neutrophils. Results showed that suilysin is toxic to neutrophils and this could help S. suis evade innate immunity. Moreover, suilysin appears to affect complement-dependent killing by decreasing the opsonization of S. suis and the bactericidal capacity of neutrophils. Our results confirm that capsule polysaccharide protects S. suis against killing and phagocytosis by neutrophils. We also showed that the presence of specific IgG against S. suis serotype 2 promoted killing by neutrophils, indicating that the induction of a strong humoral response is beneficial for clearance of this pathogen.
authors.affiliation: Groupe de recherche sur les maladies infectieuses du porc (GREMIP), Faculté de médecine vétérinaire, Université de Montréal, 3200 Sicotte, St-Hyacinthe, Qué., Canada J2S 2M2.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Chabot-Roy
authors.forename: Philip
authors.initials: P
authors.lastname: Willson
authors.forename: Mariela
authors.initials: M
authors.lastname: Segura
authors.forename: Sonia
authors.initials: S
authors.lastname: Lacouture
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
mesh_terms: D000818:Animals; D003602:Cytotoxicity, Immunologic; D006460:Hemolysin Proteins; D009504:Neutrophils / Q000276:immunology*; D009930:Organic Chemicals / Q000378:metabolism; D010587:Phagocytosis; D017011:Streptococcus suis / Q000276:immunology* / Q000378:metabolism; D013552:Swine
chemical_list: D006460:Hemolysin Proteins; D009930:Organic Chemicals; C104760:suilysin