[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].
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.
Zhang
Chun-Ping
CP
Department of Inspection Technology Research, China Institute of Veterinary Drug Control, Beijing 100081, China.
Ning
Yi-Bao
YB
Zhang
Zhong-Qiu
ZQ
Song
Li
L
Qiu
Hui-Shen
HS
Gao
He-Yi
HY
Fan
Xue-Zheng
XZ
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*