INTRATRACHEAL INFECTION OF CmCKHNS WITH SPORULATED OOCYSTS OF EIMERIA TENELLA

Sanda A., Salman Al Said: Intratracheal Infection of Chickens with Sporulated Oocysts of Eimeria tenella. Acta vet. Bmo, 47, 1978: 185-187. Experiment involving 16 treated and 10 control chickens, aged 3 weeks, was conducted to study the intratracheal route of infection by sporulated oocysts of Eimeria tenella. In the experimental birds a surgical procedure was conducted to prevent ingestion of the expectorated oocysts. The birds were then intratracheally inoculated with 80 000 sporulated oocysts of E. tenella. The same amount of oocysts was given to the control birds per os. Five days post infection the chickens were killed and their intestines dissected. Occurrence of pathological changes in caecal mucosa was observed along with microscopical determination of schizonts in swabs from the mucosa and histological examination of the caecal wall. On the basis of our results it can be concluded that after the intratracheal infection with sporulated oocysts of E. tenella coccidiosis occurred in 40.3 per cent of the experimental birds. Coccidiosis, parenteral infection, histological changes, caecum, trachea. Under natural conditions coccidiosis occurs after swallowing of sporulated oocysts with food. Along with this classical route of infection also the parenteral one has been successfully employed (Sharma and Reid 1962; Davies and Joyner 1962; Sharma 1964; Long and Rose 1965). Intravenous, intramuscular, intraperitoneal and subcutaneous infections were reported. Via the blood stream the sporozoites reach their respective final destination in the intestinal segments and cause pathological changes typical of the parasite species. According to data in literature the success of parenteral invasion depends upon the number of inoculated oocysts which should be the doubled peroral dose to cause the same changes in the intestinal mucosa. Although successful cultivation of Eimeria tenella on tissue cultures from bovine tracheal cells was reported (Hammond and Fayer 1968; Matsuoka, Callender and Shumard 1969), no data on intratracheal or transpulmonary infection with .Eimeria spp. in chickens were found. The aim of our work is to investigate the transpulmonary route of infection with sporulated oocysts of E. tenella in chickens by means of aerosol. This way of infection could prove helpful in immunization of chickens against coccidiosis. The present experiment was designed to follow the occurrence of coccidiosis in chickens given the sporulated E. tenella oocysts via the trachea into the lungs. Materials and Methods In the experiment 16 Shaver cockerels aged 3 weeks were employed. In the preliminary experiment 0.3 ml of water solution of methylene blue was administered into the trachea of chicks by a polyethylene tube. Mter one hour the chickens were killed and necropsied. The methylene