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PubMed1978

Ovine coccidiosis: effect of the antibiotic monensin against Eimeria ninakohlyakimovae and other naturally occurring coccidia of sheep.

Sixteen female and 16 male lambs were used in 4 groups to determine the effect of monensin on naturally occurring and experimentally induced coccidiosis. Determinations of numbers of oocysts discharged, quantities of feces discharged, feed consumption, and weight gain were made for female and male lambs in each group. The effect of experimentally induced and naturally occurring coccidiosis on the performance of each group was compared. Nonmedicated lambs, experimentally inoculated with Eimeria ninakohlyakimovae, gained the least weight. Lambs naturally infected with coccidia gained next best and inoculated lambs, in 2 groups medicated with 10 or 20 ppm of monensin in the feed, gained best. The average net gain for the 4 groups was 7.8, 9.7, 13.7, and 13.7 kg. The medicated lambs required less feed/kilogram of weight gain than did the nonmedicated lambs. In general, female lambs were more severely affected by the coccidia, consumed more feed, produced more fecal material, and gained less weight than did male lambs.

Animal Feed↗
PubMed1984

[Incidence of coccidia in dogs in Brno and the surrounding area].

In the course of two years, 663 dogs from Brno and its vicinity were subjected to clinical and parasitological examination with a special reference to the occurrence of coccidia. A saturated sugar solution with the specific weight of 1150 was used as the flotation medium. Coccidia were found in 2.17% of the dogs examined. The oocysts of the groups Isospora ohioensis, I. burowsi and I. neorivolta were identified most frequently (2.11% of the dogs). Four dogs (0.60%), all alike, eliminated the oocysts of Hammondia heydorni and sporocysts of Sarcocystis species, and two dogs oocysts of Hammondia heydorni and sporocysts of Sarcocystis species, and two dogs (0.30%) excreted oocysts of I. canis. Out of the animals infected, 58% were younger than six months. Clinical signs were observed only at a medium to strong invasion with oocysts of the species I. ohioensis, I. burowsi and I. neorivolta. The digestive tract was affected most severely--the animals suffered from bloodless diarrhoeas lasting two to twelve days, from occasional vomiting and systemic dehydration. Invasion by I. canis, Hammondia heydorni and Sarcoystis sp. did not cause any clinical changes.

Animals↗
PubMed1994

New host and geographic records for coccidia (Apicomplexa: Eimeriidae) from North American turtles.

Two-hundred-fifty-three turtles, representing 26 species within 5 families (Chelydridae, Emydidae, Kinosternidae, Testudinidae, Trionychidae) were examined for coccidia. Of these, 127 (50%) were found to harbor 1 or more of 28 species of eimerians, or isosporan, or both. One-hundred-thirteen (89%) of the infected turtles were aquatic species, whereas only 14 (11%) of the infected turtles were terrestrial species. Two-fold more aquatic turtles were infected with coccidia (113 of 200, 57%) compared to only 26% (14 of 53) of the terrestrial species. This report documents 14 new host and 8 new geographic records for eimerians from turtles in Arkansas and Texas.

Animals↗
PubMedDate not supplied

[One more biological characteristic of coccidia in the genus Cryptosporidium (Sporozoa: Apicocomplexa)].

Suckling rats were used as a model host for our previous EM studies of the endogenous development of Cryptosporidium parvum isolated from spontaneously infected calves (Beĭer e. a., 1990; Beĭer, Sidorenko, 1990). In the course of repeated infections it was noticed that the oocysts discharged by the recipient host (rat) were obviously larger than those in the donor's (calf's) isolates. Keeping in mind the presumable taxonomic significance of coccidian oocysts as a constant and rather reliable tool for species discrimination we made a comparative quantitative and statistical analysis of the mean values of oocysts of C. parvum, originating from several sources (table 2): a random human isolate (N 1), several random isolates from spontaneously infected calves (N 2-5), isolates from calves (N 6-8) used as the infecting material for suckling rats, and fecal samples from the experimentally infected rats (N 9-15). The results obtained have shown that the oocysts discharged by rats (N 9-15) were larger that those of calf origin (N 6-8), with the differences being statistically significant with 95% confidence. Besides, within the same host (rat) at least two oocyst groups were distinguished (N 9-11 and 12-15, resp.) whose differences in mean values also appeared statistically significant. The larger oocysts displayed differences in morphology bearing distinct walls which were never observed either in the donor isolates or in the smaller population of the recipient oocysts. The established differences in oocyst dimensions lay presumably within the frames of the normal reaction of C. parvum and other Cryptosporidium species, due to biological peculiarities of unusual life cycles of these unique coccidia: their homoxenous (i.e. confined to one host body only) development is combined with polyxeny (i.e. a wide host specificity that involves the number of host species representing different environmental conditions). The parasite's ability to change its functional morphology and size may appear some kind of preadaption to the number of varying conditions met by these polyxenous coccidia. This and other relevant assumptions are discussed in the paper.

Animals↗
PubMedDate not supplied

[Life cycle and nucleic acid distribution in the endogenous development stages of coccidia (Coccidiida, Eimeriidae) of the Vinogradov gerbil].

Studies were undertaken of the life cycles of three intestinal coccidia: Eimeria arabiana, E. bistratum and E. poljanski, parasites of meriones vinogradovi. The number of the asexual generations, the period of appearance of the endogenous stages and the first oocysts, localization were determined. The successive phases of the growth and development of schizonts of different generations, macrogametes and microgametocytes were described. The distribution of DNA and RNA in different endogenous stages of three kinds of coccidia were studied by methods of cytochemistry.

Animals↗
PubMedDate not supplied

A survey of Coccidia on 43 poultry farms in Argentina.

Fecal samples from 43 broiler and breeder farms in the Entre Rios and Buenos Aires districts of Argentina were examined for Coccidia. Thirty-eight samples were positive by microscopic examination after salt flotation, with counts of 138 to 415,800 oocysts per gram of feces. Samples were aerated for 2 days and inoculated into 21-day-old chicks for determination of prepatent period. Eimeria praecox was conclusively identified in 56% of the samples by producing typical oocysts (17 x 21 microns) in the feces by 83-90 hr postinoculation (PI). Eimeria mitis was present in 67% of the samples, producing typical oocysts (14 x 15.5 microns) before 95 hr PI. Typical oocysts of Eimeria maxima (20 x 30 microns) and/or typical lesions in the midgut upon necropsy 5-6 days PI were present in 42% of the samples. Eimeria tenella was suspected in 24 of 43 samples on the basis of oocyst size but was confirmed in six samples (14%) at necropsy of infected birds with typical lesions in the ceca (hemorrhage, coagulated blood in the lumen, and thickened cecal mucosa). Characteristic lesions of Eimeria acervulina and ovoid oocysts (14 x 18 microns) were present in all 40 positive samples (93%). Lesions in the lower small intestine of birds inoculated with two of the samples (5%) were typical of Eimeria brunetti. These results confirmed the presence of six species of Coccidia in Argentine poultry (all except Eimeria necatrix, which is known from previous reports) and demonstrated a prevalence and intensity for E. praecox and E. mitis that were previously unreported.

Animals↗
PubMed2006

Genetical identification of coccidia in red-crowned crane, Grus japonensis.

We genetically analyzed eimerian oocysts isolated from the red-crowned crane (Grus japonensis) in Hokkaido, a northern island of Japan. Two types of oocysts of which shapes were similar to Eimeria gruis and E. reichenowi were found. Nearly the total length of the 18S ribosomal RNA gene (about 1.7 kbp in length) was amplified from single oocyst of each type and was sequenced. The respective sequences showed high similarity to those of published partial sequences (349 bp) of E. gruis type oocyst and E. reichenowi type oocyst isolated from the hooded crane (G. monacha) and the white-naped crane (G. vipio) in Izumi, in the southern island of Japan. Phylogenetic analysis indicated that E. gruis type and E. reichenowi type are different species, and suggested that these crane coccidia have evolved independently from the intestinal parasitizing Eimeria species.

Animals↗
PubMedDate not supplied

Research on avian coccidia: an update.

Despite the availability of many anticoccidial drugs, infections caused by species of Eimeria continue to be a source of significant economic loss to the poultry industry. After two decades in which the use world wide of ionophorous antibiotics gave unparalleled control of coccidiosis, drug resistance is once again tipping the balance in favour of the parasites. The realization that even the most spectacularly successful drugs might, after all, have a finite life if not used conservatively, has focused attention on ways in which the life span of drugs can be prolonged. Many drugs with different (if unknown) modes of action are available, and a variety of shuttle and rotation programmes can be considered. In view of the limitations of chemotherapy, particularly for the rearing of replacement flocks, there is considerable interest in the development of vaccines. Prospects for the introduction of live vaccines based on attenuated parasites are now very good, but the availability in the future of genetically engineered vaccines is more uncertain as little is known about the parasite molecules that stimulate protective immunity and, even if isolated, how they can be administered to the host so that it responds in the immunologically correct manner. Current research on Eimeria spp. in the chicken is broadly representative of that being done on other coccidia. Many lines of investigation are not connected with the development of new drugs or vaccination per se (and therefore have no obvious practical applications), but they are providing new insights into the biological complexity of the organisms and the ways in which they interact with their hosts. It remains possible, however, that a more detailed understanding and analysis of the molecules that are essential in the maintenance of the parasitic life style can be exploited in the future to provide alternative targets for chemical or immunological attack. The research topics considered in this review are arbitrarily grouped as studies on: (1) the basic biology of parasites, including aspects of the life cycle, and structure and function of the apical organelles; (2) the molecular biology of the parasites, including analyses of the number and structure of chromosomes, characterization of DNA sequences, and an account of the viral RNA that has been found in some species of Eimeria; and (3) control of coccidiosis, encompassing first immunity and the development of vaccines, and secondly, chemotherapy.

Animals↗
PubMed2002

Redescription of Neospora caninum and its differentiation from related coccidia.

Neospora caninum is a protozoan parasite of animals, which before 1984 was misidentified as Toxoplasma gondii. Infection by this parasite is a major cause of abortion in cattle and causes paralysis in dogs. Since the original description of N. caninum in 1988, considerable progress has been made in the understanding of its life cycle, biology, genetics and diagnosis. In this article, the authors redescribe the parasite, distinguish it from related coccidia, and provide accession numbers to its type specimens deposited in museums.

Animals↗
PubMed1999

Gut intraepithelial lymphocytes and immunity to Coccidia.

Little is known about the physiological functions of the intra-epithelial lymphocytes (IELs) of mucosal tissues, including their role in immunity to infection. Most IELs are T cells, but their surface phenotype and activation characteristics are different from those of peripheral T cells. Here, Vincent McDonald outlines the distinctive features of IELs and presents evidence, particularly from studies of Coccidia, that these cells have an important role in the control of intracellular infection at the mucosal surface.

Animals↗
PubMed2001

Dietary betaine accumulates in the liver and intestinal tissue and stabilizes the intestinal epithelial structure in healthy and coccidia-infected broiler chicks.

The aim of this experiment was to study the patterns of betaine accumulation into intestinal tissue, liver and plasma of broiler chicks with or without coccidial infection. The chicks were raised on a corn-based, low-betaine diet with or without 1000 ppm betaine supplementation and with or without intestinal microparasite (Eimeria maxima) challenge to the age of 21 days. Plasma, liver, intestinal tissue and digesta of non-challenged (NC) birds and plasma and intestinal tissue of coccidiosis challenged (CC) birds were analysed for betaine content. NC birds were also analyzed for homocysteine in plasma and S-adenosylmethionine (S-AM) in liver. The jejunal epithelium was histologically examined for the presence of coccidia and the crypt-villus ratio was measured. Dietary betaine supplementation decreased the plasma homocysteine concentration but had no effect on liver S-AM of NC birds. The data suggest that chicks on a low-betaine diet accumulate betaine into the intestinal tissue. When the diet was supplemented with betaine, betaine accumulated heavily into liver and to a lesser degree into intestinal tissue. The concentration of betaine in jejunal and ileal digesta was low suggesting that dietary betaine was mainly absorbed from the proximal small intestine. The coccidial challenge decreased the concentration of betaine in the liver, but greatly increased that in the intestinal tissue. The crypt-villus ratio was decreased by the dietary betaine supplementation in healthy and challenged chicks, suggesting that dietary betaine both protects the jejunal villi against coccidial infection and also stabilizes the mucosal structure in healthy broiler chicks. These results support our earlier findings suggesting that betaine is likely to act as an important intestinal osmolyte in broiler chicks.

Animals↗
PubMed2001

Chasing coccidia--new tools enter the race.

The 8th International Coccidiosis Conference, held on 9--13 July 2001 in Palm Cove, Australia, was a showcase of the latest studies on widely known coccidia, including Eimeria and Toxoplasma in addition to the emerging or re-emerging parasites such as Neospora, Cryptosporidium and Cyclospora. This meeting was staged in conjunction with the Annual Scientific Meeting of the Australian Society for Parasitology.

Animals↗
PubMed1999

Some coccidia from the gall-bladder and intestine of the teiid lizard Ameiva ameiva ameiva and the gecko Hemidactylus mabouia in north Brazil.

A study has been made of the endogenous development of two eimeriid Coccidia in the teiid lizard Ameiva ameiva, which were previously considered by Carini (1932) to be conspecific with Eimeria rochalimai and Eimeria boveroi Carini & Pinto, 1926, described in the gecko Hemidactylus mabouia. It has been shown that this is not so, and the two parasites of A. ameiva have been named Choleoeimeria carinii n. sp. and Acroeimeria pintoi n. sp. A description is also given of the endogenous stages of the two eimeriid coccidians previously described in Hemidactylus mabouia. The one from the gall-bladder is renamed Choleoeimeria rochalimai (Carini & Pinto, 1926) nov. comb., and a redescription is made of Eimeria boveroi. The shortcomings of diagnosis based solely on morphology of the oocysts are discussed, particularly with regards the eimeriids of reptiles.

Animals↗
PubMed1987

The number of species of rodent coccidia and of other protozoa.

About 447 species of coccidia have been named from the 1687 living, known species of rodents; 207 host species, 92 host genera, and 15 host families are represented; this is about 12% of the known species of rodents. About 4600 species of apicomplexan protozoa have been named. Assuming that the same proportion of the total number of apicomplexan species has been named as of the coccidian species, there must actually be about 38,333 species of apicomplexan protozoa. There are 5.4 times as many protozoan genera as of apicomplexan genera. Assuming that the number of species in each genus is the same for all the protozoa as it is for the Apicomplexa, there may actually be 206,998 species of protozoa. This may be too conservative an estimate. Based on other criteria, an estimate of over 20 million species could be made.

Animals↗
PubMed1987

Corrections in the names of rodent coccidia (Apicomplexa, Coccidiasina).

The following new taxonomic combinations are introduced for coccidia whose names were previously given erroneously: Dorisa bengalensis (Bandyopadhyay & Ray, 1982) n. comb. from the Indian palm squirrel Funambulus pennanti in India; Eimeria sicistae from the intestine of the birch mouse Sicista tianschanica in the USSR; E. hydrochaeri Carini, 1937 emend. from the capybara Hydrochaerus hydrochaerus in South America; Frenkelia sp. (Doby, Jeannes & Rault 1965) from the brain of the water vole Arvicola sapidus in Europe; Frenkelia sp. (Karstad, 1963) from the brain of the muskrat Ondatra zibethica in North America; Frenkelia sp. (Enemar, 1965) from the brain of the lemming Lemmus lemmus in Europe; Frenkelia sp. (Sebek, 1975) from the brain of the field mouse Apodemus flavicollis in Europe; and Sarcocystis sp. (Ryan, Wyand & Nielsen, 1982) from the skeletal muscles of the muskrat Ondatra zibethica in North America.

Animals↗
PubMed1978

Effects of pelleting and sterilization of diet on 2 strains of rabbit coccidia.

Both autoclaving and irradiation at levels currently used for other laboratory animal diets appear to be satisfactory for the elimination of 2 of the most robust and pathogenic species of rabbit coccidia. Pelleting by the usual methods, even at 68 degrees C, was found to be unsatisfactory in eliminating all oocysts from heavily infected diet.

Animal Feed↗
PubMed1990

Prevalence and distribution of bovine coccidia in Japan.

A field survey was carried out on prevalence of bovine coccidia in 9 prefectures of Japan in the autumn of 1985. A total of 1,015 fecal samples was obtained from dairy and beef cattle more than 2 weeks old. Coccidial oocysts were found in 59.0% of all the samples examined. There were no significant differences in the prevalence between dairy and beef cattle of the same age group. The prevalence was the highest in the animals between 6 and 11 months old and decreased to 25% in those more than 24 months old. In the majority of the samples positive for oocysts, OPG (the number of oocysts per gram of feces) was less than 200. No clinical coccidiosis was found except in a few cases. Eleven Eimeria and one Isospora species were identified. Of these species, E. bovis and E. ellipsoidalis were the most prevalent, followed by E. aubrunensis, E. brasiliensis, and E. cylindrica in all the prefectures. The other species identified were E. canadensis, E. alabamensis, E. zuernii, E. wyomingensis, E. bukidnonesis, E. subspherica, and Isospora sp. in the order of frequency. Isospora sp. will be a pseudoparasite caused by the contamination with feces of passerine birds.

Age Factors↗
PubMed1993

Pathologic changes in the small bowel in nine patients with diarrhea associated with a coccidia-like body.

OBJECTIVE: To confirm a suspected small-bowel injury in patients with a syndrome of protracted diarrhea associated with a coccidia-like body (CLB). DESIGN: Investigation of an epidemic including a case-control study. SETTING: Outpatient clinic in Kathmandu serving primarily the tourist and expatriate community in Nepal. PATIENTS: Nine patients with diarrhea with at least one stool specimen that was positive for the presence of a CLB and seven noninfected volunteer controls. MEASUREMENTS: Clinical data, microscopic examination of stool, bacteriologic and viral studies on submitted stool specimens, upper gastrointestinal endoscopy including duodenal aspiration and microscopy, small-bowel biopsy with subsequent light and electron microscopy. RESULTS: Endoscopic evidence of inflammation of the distal duodenum was present in five of nine patients with CLB and in none of the seven controls. All nine patients with CLB were noted to have histologic evidence of small-bowel injury, which included acute and chronic inflammation, surface epithelial disarray, and varying degrees of villous atrophy and crypt hyperplasia. One of the seven controls had similar pathologic findings and developed CLB-related diarrhea 5 days later. The other controls had normal distal duodenal histologic results. The organism was found in two of nine duodenal aspirates but was not present in the preserved biopsy specimens as determined by light or electron microscopy. CONCLUSIONS: The pathologic basis of CLB-associated diarrhea appears to be small-bowel injury whose cause remains to be elucidated.

Adult↗