title: Current Taxonomical Situation of Streptococcus suis.
abstract: Streptococcus suis, a major porcine pathogen and an important zoonotic agent, is considered to be composed of phenotypically and genetically diverse strains. However, recent studies reported several "S. suis-like strains" that were identified as S. suis by commonly used methods for the identification of this bacterium, but were regarded as distinct species from S. suis according to the standards of several taxonomic analyses. Furthermore, it has been suggested that some S. suis-like strains can be assigned to several novel species. In this review, we discuss the current taxonomical situation of S. suis with a focus on (1) the classification history of the taxon of S. suis; (2) S. suis-like strains revealed by taxonomic analyses; (3) methods for detecting and identifying this species, including a novel method that can distinguish S. suis isolates from S. suis-like strains; and (4) current topics on the reclassification of S. suis-like strains.
authors.affiliation: Division of Bacterial and Parasitic Diseases, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan. mokura@affrc.go.jp.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Okura
authors.affiliation: Division of Bacterial and Parasitic Diseases, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan. osaki@affrc.go.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Osaki
authors.affiliation: Department of Infectious Diseases, Kobe Institute of Health, 4-6-5 Minatojima-Nakamachi, Chuo-ku, Kobe, Hyogo 650-0045, Japan. ryohei_nomoto@office.city.kobe.lg.jp.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Nomoto
authors.affiliation: Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. sakurairo1218@yahoo.co.jp.
authors.forename: Sakura
authors.initials: S
authors.lastname: Arai
authors.affiliation: Organization for Advanced Science and Technology, Kobe University, 1-1 Rokko-dai, Nada-ku, Kobe, Hyogo 657-8501, Japan. tamie@opal.kobe-u.ac.jp.
authors.forename: Ro
authors.initials: R
authors.lastname: Osawa
authors.affiliation: Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. asekizak@mail.ecc.u-tokyo.ac.jp.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sekizaki
authors.affiliation: Division of Bacterial and Parasitic Diseases, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan. p1013dt@affrc.go.jp.|The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, Gifu 501-1193, Japan. p1013dt@affrc.go.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takamatsu
keywords: S. suis-like strains; Streptococcus suis; species demarcation; taxonomic analyses