[Three cases of hemolytic Streptococcus infection in guinea-pigs (author's transl)]

Three cases of naturally occurring hemolytic streptococcus infection were detected in guinea-pigs which had been delivered from different sources to the Division of Animal Research, Faculty of Medicine, University of Tokyo, Tokyo, during the period from November, 1976, till February, 1977. The clinical manifestations of the infection were differentiated into two types; ie, the acute type with sepsis and pneumonia as main pathologic changes, and the chronic type with abscess formation of submaxillary lymph node. Streptococcus zooepidemicus was isolated from the conjunctiva of about 56% of these guinea-pigs. Healthy guinea-pigs housed with spontaneously infected ones in the same cage suffered from the infection, showing manifestation and pathologic changes similar to the spontaneous cases. Some of them, however, remained apparently healthy for about 2 months harboring the organisms in the conjunctiva or nasal cavity. It is presumed that such carriers become a source of the infection in nature.