Prevalence of Streptococcus suis type 2 using the polimerase chain reaction in slaughtered pigs in the State of Mato Grosso, Brazil/Prevalencia de Streptococcus suis tipo 2 por meio da tecnica de reacao em cadeia da polimerase em suinos abatidos no Estado do Mato Grosso

Streptococcus suis is a pathogen that affects the industrial production of swine worldwide. It is extremely important, because it is associated with pigs and humans diseases. The aim of this study was to determine the prevalence of Streptococcus suis type 2 in 201 samples of tonsils from clinically healthy animals by the PCR technique. The samples positive for S. suis type 2 were tested for the gene encoding extracellular factors (ef). The results showed that the prevalence (23.38%) was higher than other recent survey in the State, demonstrating that the PCR is a more sensitive method in relation to the bacterial isolation. There was a low occurrence of [ef.sup.*] gene in samples (1.49%) showing great importance to local swine population, because negative strains are potentially less virulent that positive strains. Key words: Streptococcus suis type 2, PCR, ef, pigs. Streptococcus suis e um patogeno que a afeta a producao industrial de suinos em todo o mundo. E de extrema importancia, pois esta associado a doencas em suinos e humanos. O objetivo deste estudo foi determinar a prevalencia do Streptococcus suis tipo 2 em 201 amostras de tonsilas de animais clinicamente sadios a partir da tecnica de PCR. As amostras positivas foram submetidas a pesquisa do gene codificador do fator extracelular (ef). Os resultados demonstraram que a prevalencia (23,38%) foi maior que em outro estudo recentemente realizado no mesmo Estado, indicando que a PCR e um metodo mais sensivel em relacao ao isolamento bacteriano. Houve baixa ocorrencia do gene [ef.sup.*] (1,49%), o que mostra uma grande importancia para populacao analisada, pois cepas negativas sao potencialmente menos virulentas que cepas positivas. Palavras-chave: Streptococcus suis tipo 2, PCR, ef, suinos.