title: Lineage and virulence of Streptococcus suis serotype 2 isolates from North America.
abstract: We performed multilocus sequence typing of 64 North American Streptococcus suis serotype 2 porcine isolates. Strains were sequence type (ST) 28 (51%), ST25 (44%), and ST1 (5%). We identified nonrandom associations between STs and expression of the virulence markers suilysin (SLY), muramidase-relased protein (MRP), and extracellular factor (EF). Expression of pili encoded by the srtF and srtG pilus clusters was also nonrandomly associated with STs. ST1 strains were SLY+ EF+ MRP+ srtF pilus+ srtG pilus-. ST25 strains were SLY- EF- MRP- srtF pilus- srtG pilus+, and most ST28 strains were SLY- MRP+ EF- srtF pilus+ srtG pilus+. ST28 isolates proved essentially nonvirulent in a mouse infection model; ST25 strains showed moderate virulence and ST1 isolates were highly virulent. ST1 is responsible for a high proportion of S. suis disease in humans worldwide. Its presence in North America indicates that potential zoonotic S. suis outbreaks in this continent cannot be disregarded.
authors.affiliation: Université de Montréal, St-Hyacinthe, Quebec, Canada.
authors.forename: Nahuel
authors.initials: N
authors.lastname: Fittipaldi
authors.forename: Jiangu
authors.initials: J
authors.lastname: Xu
authors.forename: Sonia
authors.initials: S
authors.lastname: Lacouture
authors.forename: Prasit
authors.initials: P
authors.lastname: Tharavichitkul
authors.forename: Makoto
authors.initials: M
authors.lastname: Osaki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sekizaki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takamatsu
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
mesh_terms: D000818:Animals; D021821:Communicable Diseases, Emerging / Q000635:transmission / Q000662:veterinary / Q000821:virology; D005260:Female; D010861:Fimbriae, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D005838:Genotype; D006801:Humans; D058885:Multilocus Sequence Typing; D009656:North America; D012703:Serotyping; D013290:Streptococcal Infections / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D017011:Streptococcus suis / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D034421:Sus scrofa / Q000382:microbiology*; D013552:Swine; D013553:Swine Diseases / Q000635:transmission / Q000821:virology*; D014774:Virulence / Q000235:genetics; D015047:Zoonoses / Q000635:transmission / Q000821:virology