title: Genetic organization and preferential distribution of putative pilus gene clusters in Streptococcus suis.
abstract: Recent analyses of Streptococcus suis isolates using multilocus sequence typing (MLST) suggested the importance of sequence type (ST) 1 and ST27 complexes for animal hygiene and public health. In this study, to investigate whether pilus-associated genes in S. suis can be used as novel genetic markers for important clonal groups, we examined the correlation between STs and putative pilus-associated gene profiles in S. suis. Genomic searches using sequenced genomes and sequence data determined in several isolates revealed the presence of at least four distinct putative pilus gene clusters in S. suis (srtBCD, srtE, srtF, and srtG clusters). On the basis of the presence or absence of genes in the four clusters, 108 S. suis isolates from various origins were classified into 12 genotypes (genotypes A-L). Genotypes A and B, which possessed srtBCD plus srtF clusters and srtF plus srtG clusters, respectively, were the most common in isolates from diseased pigs and humans, and 29.9% and 59.8% of the isolates belonged to genotypes A and B, respectively. In contrast, only 4.8% and 28.6% of isolates from healthy carriers were genotypes A and B, respectively. MLST analysis showed the associations of genotypes A and B with ST1 and ST27 complexes, respectively. In addition, srtBCD and srtG clusters were preferentially distributed to ST1 and ST27 complex members, respectively. These results suggest that profiling of selected pilus-associated genes could be used as an easy screening method to monitor isolates important for S. suis infection.
authors.affiliation: Research Team for Bacterial/Parasitic Diseases, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan. p1013dt@affrc.go.jp
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takamatsu
authors.forename: Hiroto
authors.initials: H
authors.lastname: Nishino
authors.forename: Tomono
authors.initials: T
authors.lastname: Ishiji
authors.forename: Jun
authors.initials: J
authors.lastname: Ishii
authors.forename: Makoto
authors.initials: M
authors.lastname: Osaki
authors.forename: Nahuel
authors.initials: N
authors.lastname: Fittipaldi
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gottschalk
authors.forename: Prasit
authors.initials: P
authors.lastname: Tharavichitkul
authors.forename: Shinji
authors.initials: S
authors.lastname: Takai
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sekizaki
mesh_terms: D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D017931:DNA Primers; D010861:Fimbriae, Bacterial / Q000235:genetics; D020869:Gene Expression Profiling; D016680:Genome, Bacterial; D006801:Humans; D005810:Multigene Family; D016133:Polymerase Chain Reaction; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000662:veterinary; D017011:Streptococcus suis / Q000235:genetics* / Q000302:isolation & purification; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*
chemical_list: D017931:DNA Primers