[Localization of endogenous developmental stages of Cryptosporidium meleagridis Slavin, 1955 (Apicomplexa: Cryptosporidiidae) in birds]. / Lokalizace endogenních vývojových stadií Cryptosporidium meleagridis Slavin, 1955 (Apicomplexa: Cryptosporidiidae) u ptáku.

Localization of endogenous developmental stages of C. meleagridis was studied on the basis of observation of 4734 preparations from individual parts (in the distance of approx. 5 cm) of the small intestine, caeca (collum caeci, corpus, apex caeci), colon, cloaca, bursa of Fabricius, respiratory organs (sinus infraorbitalis, larynx, trachea, bronchi, air sacs) using the method of scraping mucous epithelium stained according to Giemsa after fixation with methanol (as well as histologically) from 155 naturally infected 9-66 day turkeys (Meleagris gallopavo f. dom.) in four large flocks in Central Bohemia, ten 46 and 47 day chicks (Gallus gallus f. dom.) and 1-3 day chicks infected experimentally. The protozoon was detected in various stages of its development in the microvilli of the small intestine of chicks 23-39 days old in the portion of 40-80 cm from the end of the duodenum. On day 5 after infection, asexual stages were found in experimentally infected chickens as near as in 8-12 cm. All forms of endogenous developmental stages including oocysts occurred usually massively in approx. 10 cm from the site of bifurcation of the caeca (plica ileocaecalis) in the ileum and in the collum caeci. The infection was prominently less intensive in the case of mucous epithelium of the colon, in the cloaca only meronts occurred very sporadically showing various developmental stages. The findings in the bursa of Fabricius and in the organs of respiratory tract were negative. In a total of 129 turkeys examined post mortem on three farms C. meleagridis were observed, endogenous developmental stages of the protozoon were found in 55 (42.6%) cases. Asexual stages (meronts in different stages of development) were observed sporadically for the first time in 23 days old birds. Maximum of infected turkeys in which all developmental stages of C. meleagridis were localized above all in the ileum and collum caeci were 30-39 days old (out of the total number of 60 dead birds examined the infection occurred in 30, i.e. in 63.3%). C. meleagridis was found in nine out of 10 dead 46- and 47-day chicks on two farms and in five out of 98 dead 14-49 day chicks, in four out of 10 pullets 7-9 months old and in one out of 22 dead parrots (Cacatua molucensis) sent for routine examination to the State Veterinary Institute in Prague from different parts of Central Bohemia.(ABSTRACT TRUNCATED AT 400 WORDS)