[Study on the molecular epidemiology of Streptococcus suis type 2 from healthy pigs in Guangxi].
OBJECTIVE
In order to investigate the positive rate of streptococcus suis type 2 and the genes of their suilysin (sly), extracellular protein (epf) and muramidasa-released protein ( mrp) and to understand the antibiotic susceptibility of S. suis type 2.


METHODS
S. suis type 2, isolated from slaughtered healthy pig's tonsil in 10 county area of Guangxi, were identified by Multiplex PCR, and the genes of their sly, epf, mrp and the antimicrobial sensitivity analysis were performed.


RESULTS
1105 strains of Streptococcus including 667 strains of S. suis and 33 strains of S. suis type 2 were detected from 1179 samples. In these S. suis type 2 strains, there were 22 strains of sly + mrp + epf+ type,1 strain of sly + mrp + epf - type, 2 strains of sly - mrp + epf + type, 7 strains of sly - mrp + epf - type and 1 strain of sly - mrp - epf- type. When these strains were subjected to be tested with penicillin, eritrocina, vacocin, gentamycin, specti-nomysin, enraxacin, ciprofloxaxin, cephalothin VI, sulfadiazine sodium, cyantin, mycifradin, amikacin and achromcin, some were found to be resistant to but most strains were susceptible to cephalothin VI, penicillin and enraxacin. There were 31, 29 and 27 strains over medium sensitivity, respectively, but 28 and 27 resistant strains to amikacin and achromcin were found.


CONCLUSIONS
The positive rate of S. suis type 2 in clinical healthy pigs was low (2.8%) and did not show obvious difference between the counties with or without a history of S. suis infection. All the isolated strains were susceptible to cephalothin VI, but most strains were virulent.
Xiong
Yi
Y
Guangxi General Veterinary Prevention and Quarantine Services, Nanning 530001, China.
Liu
Qi
Q
Qin
Fang-yun
FY
Bai
Yun
Y
Zhu
Wei
W
Li
Hua-ming
HM
Guo
Jian-gang
JG
Qin
Lun
L
Pan
Jie
J
Long
Jian-ming
JM
Chen
Lei
L
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D006460:Hemolysin Proteins / Q000235:genetics; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology / Q000379:methods*; D016133:Polymerase Chain Reaction; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000235:genetics / Q000382:microbiology*; D017011:Streptococcus suis / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology* / Q000235:genetics / Q000382:microbiology*
D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C082316:Epf protein, Streptococcus suis; D006460:Hemolysin Proteins; C421489:MRP protein, Streptococcus suis; C104760:suilysin