Fate of toxoplasma strain nf 21 in cats after oral administration
Hagiwara, T.; Katsube, Y.; Imaizumi, K.
Japanese Journal of Veterinary Science 43(3): 337-344
Toxoplasma organisms ingested orally by cats initially invaded the small intestine and small intestinal lymph nodes. Between days 2-7 the invaded organisms spread gradually and by days 10 or 14 almost all extraintestinal tissues and organs became infected. During this period, the oocysts were recovered from the feces. Apparently, Toxoplasma invaded cats underwent both asexual-sexual (oocyst formation) and asexual cycles right after the initiation in the small intestine. In the latter cycle, multiplied organisms were disseminated into tissues and organs via lymphatics and/or the blood stream. The organisms parasitized in the small intestine were sensitive against digestion by trypsin up to 10 days after ingestion. The sensitivity of Toxoplasma against tryptic digestion attracted attention as a new nature of the organism parasitized in the intestine. The period from 10-14 days post-ingestion of cysts should be a turning point of the course of latent infection since the dye test titer began to increase, the number of oocysts in the feces usually began to decrease and trypsin resistant organisms began to appear to the small intestine. During this period, invaded organisms spread to almost all tissues and organs without any clinical symptoms.