Attempted Cross-Transmission of Coccidia Between Sheep and Goats and Description of Eimeria ovinoidalis sp. n.

SYNOPSIS.
Attempted infection of 2 young lambs with oocysts of Eimeria christenseni from a goat was unsuccessful. Negative results were obtained also when young kids were fed oocysts of Eimeria ninakohlyakimovae from sheep. There was no difficulty in infecting lambs with the sheep coccidium resembling E. ninakohlyakimovae nor goats with the goat coccidium E. christenseni. Oocysts from the goat measured 38.4 × 26.7 m, but were easily distinguished from Eimeria ahsata from the sheep by sporocyst size and shape, and from Eimeria ovina by oocyst size. Eimeria ninakohlyakimovae -like oocysts from sheep averaged 23.0 ×18.2 m and were morphologically indistinguishable from previously reported goat coccidia.
Since no cross infections of sheep and goats could be accomplished with oocysts of Eimeria sp. characteristic of one or the other host, I concluded that sheep coccidia previously known as E. ninakohlyakimovae are distinct from morphologically similar goat coccidia and therefore constitute a separate species. Since the name E. ninakohlyakimovae was first used for coccidia from the goat, the sheep coccidium is renamed Eimeria ovinoidalis with oocyst structure and endogenous stages similar to those previously described from the sheep.     

Attempted cross-transmission of coccidia between sheep and goats and description of Eimeria ovinoidalis sp. n.

Attempted infection of 2 young lambs with oocysts of Eimeria christenseni from a goat was unsuccessful. Negative results were obtained also when young kids were fed oocysts of Eimeria ninakohlyakimovae from sheep. There was no difficulty in infecting lambs with the sheep coccidium resembling E. ninakohlyakimovae nor goats with the goat coccidium E. christenseni. Oocysts from the goat measured 38.4 X 26.7 microns, but were easily distinguished from Eimeria ahsata from the sheep by sporocyst size and shape, and from Eimeria ovina by oocyst size. Eimeria ninakohlyakimovae-like oocysts from sheep averaged 23.0 X 18.2 microns and were morphologically indistinguishable from previously reported goat coccidia. Since no cross infections of sheep and goats could be accomplished with oocysts of Eimeria sp. characteristic of one or the other host, I concluded that sheep coccidia previously known as E. ninakohlykimovae are distinct from morphologically similar goat coccidia and therefore constitute a separate species. Since the name E. ninakohlyakimovae was first used for coccidia from the goat, the sheep coccidium is renamed Eimeria ovinoidalis with oocyst structure and endogenous stages similar to those previously described from the sheep.     

The effect of 'Alcide' on 4 strains of rodent coccidial oocysts

The effect of 'Alcide' on oocysts of 2 species of Eimeria from rats and 2 from mice was investigated. E. pragensis oocysts survived 24 h contact with the chemical, but those of the other species were inactivated. Periods of exposure of less than 2 1/2 h did not inactivate oocysts of any Eimeria species.     

Five new species of Coccidia (Apicomplexa: Eimeriidae) from colubrid snakes of Ecuador.

Fecal samples from 11 colubrid snakes, representing 10 species, collected in Ecuador during October 1994 were examined for coccidian parasites. Feces of 4 individuals, representing 4 host species, contained coccidian oocysts. Three species of Eimeria and 2 species of Isospora were observed and are described here as new. Oocysts of both Eimeria and Isospora were found in the feces of a slug-eating snake, Dipsas vermiculata. Sporulated oocysts of the Eimeria sp. are spheroid to subspheroid, 16.7 by 16.6 microm (14-18 by 14-18 microm) and those of the Isospora sp. are spheroid and 15.0 microm (13-18 microm) in diameter. Imantodes cenchoa, the common bluntheaded treesnake, was infected with a species of Eimeria. These sporulated oocysts are ellipsoid, 23.3 by 16.2 microm (25-21 by 15-17 microm). Sporulated eimerian oocysts from Leptodeira annulata, the southern cat-eyed snake, are subspheroid, 22.5 by 18.8 microm (19-26 by 17-21 microm). Feces of a juvenile Imantodes lentiferus, the bluntheaded vine snake, contained ovoid to ellipsoid isosporan oocysts, which measured 21.6 by 15.0 microm (20-23 by 14-16 microm) when sporulated.     

Peripartal Excretion of Eimeria Oocyst by Cows on Swedish Dairy Farms and the Age of Calves at First Excretion

Faecal samples were collected 3 times a week for 6 weeks from 22 peripartal cows and for up to 15 weeks after birth from 27 calves in 3 herds, to determine the numbers of Eimeria oocysts excreted and the age at which the calves first excreted oocysts. Only low numbers of oocysts were excreted by the cows and no oocysts were detected in 93% of the samples. However, half the cows excreted oocysts at least once. The age at which the calves first excreted oocysts ranged from 2.5 to at least 15 weeks, and there was a significant difference between the herds in their mean age at first excretion. Oocysts of Eimeria alabamensis, E. auburnensis, E. bovis and E. ellipsoidalis were found in numbers ranging from 7 to 8450 oocysts per gram faeces. About 50% of the calves excreted oocysts before they were transferred to group pens. The primary source of infection of the calves was probably their penmates or the previous occupants of the pens, and the cows probably played a subsidiary role.     

Variation in Eimeria oocyst count and species composition in weanling beef heifers

Rectal fecal samples were collected daily on 10 consecutive days in November 2004 from 11 weaned beef heifers to assess daily variation in fecal oocyst count and species composition. Subsequent samples were collected from the same animals on 15 April 2005 and 9 June 2005. Oocyst numbers were determined by the modified McMaster's test, and species were identified by examination of oocysts recovered with the Wisconsin sugar flotation technique. Soil samples were collected from the heifer pasture on 8 June 2005, and oocysts were quantified and identified to species. Mean fecal oocyst counts varied little at all sampling dates ranging from 134-377 oocysts/g. Ten Eimeria spp. were identified in fecal samples collected in November and April and 11 in June. Eimeria bovis was the most common species identified at all samplings. Mean species composition showed little variation during the 10-day sampling period in November, remained similar in April, and varied slightly in June. Twelve Eimeria spp. were identified in soil samples in proportions similar to those seen in fecal samples. The results indicate that clinically normal weanling beef heifers are likely to be infected with a diverse, but relatively stable, community of Eimeria spp.     

Effect of Eimeria falciformis infection on the development of toxoplasmosis in mice

White mice previously infected with 10(2), 10(3) or 10(4) Eimeria falciformis oocysts on days 0, 5, 10 or 30 were inoculated per os with 10(1), 10(2), 10(3) or 10(4) Toxoplasma oocysts. While the results obtained for mice with higher Toxoplasma inocula were consistent, animals with 10(1) and 10(2) oocysts previous inoculation with Eimeria showed important differences related with those infected only with Toxoplasma. For example, survival time was higher in animals infected with both parasites, especially if inoculated with Eimeria 30 days before Toxoplasma infection. Furthermore the number of T. gondii cysts found in the animals previously infected with Eimeria was lower compared with mice inoculated with Toxoplasma only. Body weight of mice infected with Toxoplasma previous infection with Eimeria was almost normal in relation to those infected only with Toxoplasma, indicating a probable pathological effect due to the parasite, more evident in "non immunized" mice.     

Eimeria and Klossia spp. (Protozoa: Sporozoa) from Wild Mammals in Borneo*

SYNOPSIS. During a survey of parasites of Sabah mammals, coccidia oocysts were found in 9 of 22 host species examined. Sporulated oocysts of Klossia sp. from Rattus whiteheadi are described. New geographic records are reported for Eimeria callosciuri, Eimeria sabani, and Eimeria tupaiae. New host and geographic records are reported for Eimeria separata from Rattus cremoriventer, for E. tupaiae and Eimeria ferruginea from Tupaia tana, for Eimeria nieschulzi from Rattus muelleri, and for E. sabani and Klossia sp. from R. whiteheadi.