[Complicated forms of superinvasion opisthorchiasis: pathogenetic aspects]

Superinvasion opisthorchiasis is characterized by host growth retardation and weight reduction, which are due to the cleptoeffect of Opisthorchis felineus; metabolic disturbances, proliferative processes, accelerated collagen biosynthesis and biodegradation in the organs reflect parasite-host interactions as components of the system. The productive reactions of visceral pathology are initiated by the parasite's metabolites located in the liver, lung, heart, and testes.

High susceptibility of Djungarian hamsters (Phodopus sungorus) to the infection with Babesia microti supported by hemodynamics

As the comparative study was carried out on the susceptibility by the pursuit of parasitemia among the Djungarian, Syrian, and Chinese hamsters as well as BALB/c mice infected with the Syrian hamster-adapted Babesia microti strain, and Djungarian hamsters showed the highest parasitemia among them. Then, the other hematological parameters were pursued in the Djungarian hamsters infected with the hamster-adapted B. microti strain. Remarkable symptoms observed were hemoglobinuria clinically, anemia hematologically, and splenomegaly macroscopically during all over the observation period for 24 weeks post infection (PI). Parasitemia began to rise at 2 weeks and peaked at 4 weeks PI. After that, parasitemia decreased gradually but was maintained with a level of about 10% on average until 24 weeks PI at the end of the experiment. A decrease in the RBC count, Hb, and PCV, and an increase in the reticulocyte and WBC counts due to the development of immature neutrophils, lymphocytes and monocytes were recognized together with a rise of parasitemia. The hamsters had macrocytic hypochromic anemia due to the increase of MCV and the decrease of MCHC in the growth phase of the parasite. It was considered that the Djungarian hamsters will be useful for the infection examination, isolation, maintenance, and passage of B. microti in laboratory.

[The first finding of a spontaneous gastric cryptosporidiosis infection in hamsters (Phodopus roborovskii Satunin, 1903)]

The desert hamster (Phodopus roborovskii Satunin, 1903) represents a new host of Cryptosporidium muris Tyzzer (1907), 1910. This very first finding was made in the laboratories of the National Veterinary Institute, Prague, Czech Republic. In September 1994 three 11-month and one 3-month desert hamsters were sent for laboratory examination. Parasitological examination post mortem of a 3-month desert hamster revealed "large" Cryptosporidium oocysts in excrements as well as in the contents of intestines. In all animals in which autopsy was carried out congestion of lungs, spleen and liver, acute catarrhal inflammation and flatulences in portions of gut were observed. Presence of morphologically identical oocysts of cryptosporidia was confirmed in the same group of desert hamsters also during parasitological reexamination carried out in October 1994. Applying the methods according to Breza (1957) and Pavlásek (1991) oocysts of the protozoon under study were detected in pooled samples of excrements of 3, 4, 5, 10 and 11-month animals. Two out of four live 2-3-month desert hamsters were infected naturally, both parents (10-11 months old), sent by the owner to our laboratory to be used for further observation. Both adult animals showed slight tremor, somnolence, rough hair and recumbent position, the male showed paresis of pelvic limbs. For four days in the laboratory conditions excrements of all six live desert hamsters, the interval being 2-12 hours, were examined and in four of them the finding of oocysts of the protozoon was repeatedly positive. Adult animals were euthanasied.(ABSTRACT TRUNCATED AT 250 WORDS)