Clinico-hematologic and serological comparison of Japanese and Russian strains of Theileria sergenti.

The Japanese and Russian strains of Theileria sergenti were compared clinico-hematologically and serologically. They were subjected to passage in splenectomized calves 4 approximately 8 months old by the infectation of infected ticks or the inoculation of infected blood. As a result, the average of incubation of the Japanese strain was proved to be 23 days by the tick infection and 21 days by the inoculation of infected blood stored in a frozen state. The rate of detection and the average size of various forms of Theileria in the proliferative stage of the Japanese strain were as follows: Comma-shaped and bacilli forms, 86.8%; bacilli from 2.15 x 0.73 micron; oval and spherical forms, 11.3% and 1.97 x 1.22 and 1.46 micron, respectively; tetracoccal form and anaplasma-like form, 0.9 and 1.0%, respectively, and 0.54 micron in diameter. The highest parasitic rate of the Japanese strain was 11.9% on the average, and the rate of decrease in erythrocyte count 70.6% on the average. Rods were seen in protozoa particularly rich in cytoplasm. Such symptoms as pyrexia, depression, and anorexia appeared as Theileria propagated. No hemoglobinuria occurred or no schizonts were detected. Essentially the same results were obtained from the Russian strain as from the Japanese. Besides, Haemaphysalis longicornis produced in Japan acted also as a vector for the Russian strain. There was a good serological agreement between the Japanese and the russian strain in the results of the cross complement fixation test and the cross indirect fluorescent antibody test. There was no difference in the results of the complement fixation with the eight strains of the Japanese strain.