title: [Distributions of pathogenic capsular types and in vitro antimicrobial susceptibility of different serotypes of Streptococcus suis isolated from clinically healthy sows from 10 provinces in China].
abstract: OBJECTIVE
  To determine the distributions of major pathogenic capsular types and in vitro antimicrobial susceptibility of different serotypes of Streptococcus suis isolated from clinically healthy sows in China.
  
  
  METHODS
  Tonsil specimens of clinically healthy sows from 10 different provinces in China were collected, a total of 421 S. suis were isolated. Capsular types of S. suis were decided using the sera agglutination reaction. Antimicrobial susceptibility testing was performed using a broth microdilution method and the differences between serotypes were decided statistically.
  
  
  RESULTS
  The prevalent capsular types of S. suis isolated from clinically healthy sows were 9 (26.6%), 3 (23.5%) and 7 (15.7%) types, respectively. 7.4% of isolates were confirmed to be S. suis type 2. Overall, differences in antimicrobial susceptibility among serotypes of S. suis were found. By comparison, lower resistance was observed for S. suis type 2 from clinically healthy sows.
  
  
  CONCLUSIONS
  The prevalence of pathogenic S. suis serotypes from clinically healthy sows again indicates S. suis is a conditional pathogenic bacterium. Differential prevention and treatment regimes should be considered according to antimicrobial susceptibility of different serotypes of S. suis.
authors.affiliation: Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing 100081, China.
authors.forename: Chun-Ping
authors.initials: CP
authors.lastname: Zhang
authors.forename: Yi-Bao
authors.initials: YB
authors.lastname: Ning
authors.forename: Zhong-Qiu
authors.initials: ZQ
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Song
authors.forename: Hui-Shen
authors.initials: HS
authors.lastname: Qiu
authors.forename: He-Yi
authors.initials: HY
authors.lastname: Gao
authors.forename: Xue-Zheng
authors.initials: XZ
authors.lastname: Fan
mesh_terms: D000818:Animals; D002681:China / Q000453:epidemiology; D024881:Drug Resistance, Bacterial; D005260:Female; D012703:Serotyping; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D017011:Streptococcus suis / Q000145:classification* / Q000187:drug effects* / Q000302:isolation & purification; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology*