title: Characterization of Streptococcus suis isolates recovered between 2008 and 2011 from diseased pigs in Québec, Canada.
abstract: In the present study we report the distribution of different serotypes of Streptococcus suis among strains isolated from diseased pigs in Québec, Canada, recovered between 2008 and 2011. Serotype 2 strains were further studied for the presence of the following virulence markers: suilysin (sly), muramidase-released protein (MRP), extracellular protein factor (epf) and the pilus encoded by the srtF cluster. Of 1004 field strains collected, 986 were confirmed to be S. suis by either the species-specific PCR targeting the gdh gene or by 16S rRNA gene sequencing analysis. Results showed that, although widely used, the species-specific PCR test can sometimes be misleading and fail to correctly identify some S. suis isolates. Serotypes 2, 3, 1/2, 4, 8 and 22 together represented 51% of S. suis strains (64.5% of typable strains). Results confirmed the relatively low prevalence of serotype 2 in North America, when compared to European and Asian countries. The vast majority of serotype 2 field strains (96%) belong to either the MRP(+), srtF pilus(+), epf(-), sly(-) (52%) or the MRP(-), srtF pilus(-), epf(-), sly(-) phenotypes (44%). Most non-typable strains (89%) presented high surface hydrophobicity, suggesting that these are poorly or non-encapsulated. Electron microscopy studies confirmed the lack of capsular polysaccharide in selected non-typable high hydrophobic strains. The role and pathogenesis of the infection caused by these strains remain to be elucidated.
authors.affiliation: Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, St.-Hyacinthe, Québec, J2S 2M2, Canada. Electronic address: marcelo.gottschalk@umontreal.ca.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
authors.affiliation: Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, St.-Hyacinthe, Québec, J2S 2M2, Canada.
authors.forename: Sonia
authors.initials: S
authors.lastname: Lacouture
authors.affiliation: Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Québec City, Québec, G1V 0A6, Canada.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Bonifait
authors.affiliation: Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, St.-Hyacinthe, Québec, J2S 2M2, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Roy
authors.affiliation: Public Health Ontario, 81 Resources Road, Toronto, Ontario, M9P 3T1, Canada.
authors.forename: Nahuel
authors.initials: N
authors.lastname: Fittipaldi
authors.affiliation: Groupe de Recherche en Écologie Buccale (GREB), Faculté de Médecine Dentaire, Université Laval, Québec City, Québec, G1V 0A6, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Grenier
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011792:Quebec / Q000453:epidemiology; D012703:Serotyping; D013290:Streptococcal Infections / Q000453:epidemiology / Q000235:genetics; D017011:Streptococcus suis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology*; D014774:Virulence
chemical_list: D001426:Bacterial Proteins