title: Serotypes of Streptococcus suis isolated from healthy pigs in Phayao Province, Thailand.
abstract: BACKGROUND
  Streptococcus suis (S. suis) is an important swine and human pathogen. There are 33 serotypes that have been described. Zoonotic cases are very common the Northern part of Thailand, especially in Phayao Province. However, the prevalence of S. suis and, more particularly the different serotypes, in pigs in this region is poorly known and needed to be addressed.
  Distribution of S. suis serotypes varies depending on the geographical area. Knowledge of the serotype distribution is important for epidemiological studies. Consequently, 180 tonsil samples from slaughterhouse pigs in Phayao Province had been collected for surveillance, from which 196 S. suis isolates were recovered. Each isolate was subcultured and its serotype identified using multiplex PCR. Slide agglutination combined with precipitation tests were used following multiplex PCR to differentiate the isolates showing similar sizes of amplified products specific to either serotype 1 or 14 and 2 or 1/2. Non-typable isolates by multiplex PCR were serotyped by the coagglutination test.
  
  
  RESULTS
  Of the 196 isolates, 123 (62.8%) were typable and 73 (37.2%) were non-typable. This study revealed the presence of serotypes 1, 1/2, 2, 3, 4, 5, 7, 9, 11, 12, 13, 14, 21, 22, 23, 24, 25, 29, and 30. Serotype 23 was the most prevalent (20/196, 10.2%), followed by serotype 9 (16/196, 8.2%), serotype 7 (16/196, 8.2%), and serotype 2 (11/196, 5.6%). The latter is the serotype responsible for most human cases.
  
  
  CONCLUSIONS
  Almost all serotypes previously described are present in Northern Thailand. Therefore, this report provides useful data for future bacteriological studies.
authors.affiliation: Veterinary Research and Development Center (Upper Northern Region), 221 M.6, Wiengtarn, Hangchat, Lampang, 52190, Thailand. thongkamkoon@msn.com.
authors.forename: P
authors.initials: P
authors.lastname: Thongkamkoon
authors.affiliation: Department of Livestock Development, National Institute of Animal Health, Chatuchak, Bangkok, 10900, Thailand.
authors.forename: T
authors.initials: T
authors.lastname: Kiatyingangsulee
authors.affiliation: Faculty of Veterinary Medicine, University of Montreal, 3200 Sicotte, Saint-Hyacinthe, QC, J2S 2M2, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Gottschalk
mesh_terms: D000003:Abattoirs; D000818:Animals; D001777:Blood Coagulation; D004269:DNA, Bacterial / Q000032:analysis; D060885:Multiplex Polymerase Chain Reaction; D014066:Palatine Tonsil / Q000382:microbiology*; D015995:Prevalence; D065288:Serogroup; D012703:Serotyping; D013290:Streptococcal Infections / Q000453:epidemiology / Q000662:veterinary; D017011:Streptococcus suis / Q000145:classification / Q000235:genetics*; D013552:Swine / Q000382:microbiology*; D013553:Swine Diseases / Q000453:epidemiology; D013785:Thailand
chemical_list: D004269:DNA, Bacterial
keywords: Phayao Province; Pigs; Serotypes; Streptococcus suis; Tonsil