<I>Actinomyces pyogenes</I>が分離された乳用牛の流産

Abstract

Four cases of abortion occurred consecutively on a dairy farm in Hiroshima Prefecture from January to May, 1988. An aborted fetus and dam's fresh lochia of the last case were examined bacteriologically and serologically as a diagnostic service. Actinomyces pyogenes was isolated purely from the lungs, brain, spinal cord, thoracic fluid, contents of digestive organs, and lochia, and it was presumed to be the causative agent in this abortion. However, the aborted fetus could not be examined histopathologically due to severe autolysis. A serological survey on A. pyogenes infection was carried out on four aborted dams and raising cows at this farm, using the agargel diffusion test for protease antibodies against A. pyogenes. The antibody was demonstrated in high titer as 1: 64 in the serum of he dam that was aborted in May, and it was increased to 1: 128 after one month. Twenty-two out of 30 cows on the same farm were revealed to be positive reacters by this test, and nine cows including the three other aborted dam had levels of A. pyogenes protease antibody titers of >8 in ser