Abstract
There piglets of the same litter, 45 days old, died suddenly without showing symptoms on a farm in Yamaguchi Prefecture in May, 1984. Autopsy revealed much fibrin adherent to the pleura. Alphahaemolytic streptococci were isolated almost pure from the brain, lung, liver, kidney and hydrothorax.
Judging from their biochemical characteristics and serological typing, they were identified as those of “Streptococcus suis” type I/II (Group R·S).
