2019 Volume 72 Issue 9 Pages 533-538
Stillbirth in sows and neurological symptoms in suckling pigs occurred sporadically on a pig farm in Hiroshima Prefecture. Fibrin deposits in the hearts were observed at the necropsies of two of the pigs. A histopathological examination of the principal organs of the two pigs revealed suppurative meningitis and fibrinous suppurative epicarditis due to gram-positive cocci. From the organs, three Streptococcus suis serotype 14 were isolated. In addition, immunostaining with the antiserum against S. suis serotype 14 was positive in the lesions of the brains, spinal cords and hearts. These S. suis serotype 14 isolates showed the same Pulsed-Field Gel Electrophoresis (PFGE) pattern, and were classified into Sequence Type 1 by Multi-Locus Sequence Typing (MLST). In conclusion, we diagnosed these cases as streptococcal infections due to S. suis serotype 14, probably derived from the same clone. This is the first report on the cases caused by S. suis serotype 14 in Japan to be diagnosed by immunohistochemical examinations.