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PubMed1980

Monensin sensitivity of recent field isolates of turkey coccidia.

The efficacy of monensin at concentrations of 60 and 100 ppm was evaluated against 22 isolates not exposed to monensin and 16 monensin-exposed field isolates of coccidia obtained from US and Canadian turkey flocks, respectively. Isolates not previously exposed to monensin were effectively controlled by monensin. However, 7 monensin-resistant isolates (predominantly Eimeria meleagrimitis) were independently isolated from turkey flocks in Ontario, Canada where monensin was being used as an anticoccidial. Subsequent sensitivity evaluations of two of these isolates revealed cross-resistance to lasolocid, narasin, and salinomycin. Evaluation of the stability of monensin resistance in one isolate suggested that monensin sensitivity was not restored after 10 generations of relaxed selection. Although the extent of monensin resistance among field isolates of turkey coccidia is unknown, these results provide the first unequivocal characterization of monensin resistance in field isolates of coccidia. Contrarily, after more than eight years of intensive use of monensin as an anticoccidial in US broiler production facilities, this type of resistance to the polyether antibiotic anticoccidials has not been encountered in chicken coccidia.

Animals↗
PubMed1983

Specificity and crossreactivity of immune serum and hybridoma antibodies to various species of avian coccidia.

The species-specificity and crossreactivity of serum antibodies (Ab) from birds immunized specifically with six different species of coccidia and of 24 hybridoma antibodies (Ab) developed against four species of chicken and two species of turkey coccidia were determined by use of the indirect immunofluorescent antibody (IFA) test on air-dried sporozoites. With few exceptions, the immune chicken sera were found to crossreact with all species of coccidia tested. Seven of the hybridoma Ab were species-specific, while the other 17 Ab demonstrated varying degrees of crossreactivity. Similar types of IFA patterns were seen with both the species-specific and crossreactive hybridoma Ab. Some of the crossreactive hybridoma Ab produced one type of IFA pattern with the sporozoites against which they were originally raised and different patterns with other species of sporozoites. The development of the hybridoma Ab has made it possible to identify the species of coccidia found in mixed infections and check the purity of laboratory strains.

Animals↗
PubMed1981

Lasalocid for improved weight gains and control of Coccidia in lambs.

Lasalocid at 25 mg/kg of feed was highly effective in reducing numbers of oocysts in feces of naturally infected ewes and lambs. Treated ewes were fed lasalocid-medicated feed before and after parturition, and the 17 lambs from these ewes also were fed medicated feed gained 5.26 kg more (P less than 0.05) than did the 17 nontreated lambs from nontreated ewes. Naturally infected lambs maintained in semiconfinement acquired coccidia infections between 23 and 64 (mean of 38) days after birth. A coccidiostat given before and during the time coccidia-naive lambs were first exposed to coccidia was necessary to achieve the greatest production response to treatment. When naturally infected feeder lambs (30.9 kg) maintained in semiconfinement were fed lasalocid-medicated feed at 25 mg/kg of feed or unmedicated feed for 91 days, no significant difference (P greater than 0.05) in rate or efficiency of gain was detected, even though lasalocid was highly effective against coccidia.

Administration, Oral↗
PubMed2006

Quantitative trait loci (QTL) mapping of resistance to strongyles and coccidia in the free-living Soay sheep (Ovis aries).

A genome-wide scan was performed to detect quantitative trait loci (QTL) for resistance to gastrointestinal parasites and ectoparasitic keds segregating in the free-living Soay sheep population on St. Kilda (UK). The mapping panel consisted of a single pedigree of 882 individuals of which 588 were genotyped. The Soay linkage map used for the scans comprised 251 markers covering the whole genome at average spacing of 15cM. The traits here investigated were the strongyle faecal egg count (FEC), the coccidia faecal oocyst count (FOC) and a count of keds (Melophagus ovinus). QTL mapping was performed by means of variance component analysis so that the genetic parameters of the study traits were also estimated and compared with previous studies in Soay and domestic sheep. Strongyle FEC and coccidia FOC showed moderate heritability (h(2)=0.26 and 0.22, respectively) in lambs but low heritability in adults (h(2)<0.10). Ked count appeared to have very low h(2) in both lambs and adults. Genome scans were performed for the traits with moderate heritability and two genomic regions reached the level of suggestive linkage for coccidia FOC in lambs (logarithm of the odds=2.68 and 2.21 on chromosomes 3 and X, respectively). We believe this is the first study to report a QTL search for parasite resistance in a free-living animal population and therefore may represent a useful reference for similar studies aimed at understanding the genetics of host-parasite co-evolution in the wild.

Animals↗
PubMed1976

Some problems of host and parasite interactions in the coccidia.

The current status of some concepts of host and parasite interactions in the coccidia are discussed and evaluated. It is suggested that winter coccidiosis of cattle caused by Eimeria zuernii results from activation of arrested endogenous stages in the tissues of the host. A second aspect of clinical coccidiosis is that infections are seldom monospecific, but little work has been done on infections in animals with multiple species of coccidia. Information in the literature indicates that there are interactions between species of Eimeria in concurrent infections, and it is hoped that investigators will undertake studies to define more clearly what interactions there may be. Finally, the finding that there is a genetic basis for successful transmission of Eimeria separata from rats to mice provides a tool for studying the basis of host-specificity in the coccidia.

Animals↗
PubMedDate not supplied

Phylogenetic analysis of coccidia based on 18S rDNA sequence comparison indicates that Isospora is most closely related to Toxoplasma and Neospora.

The phylogenetic relationships and taxonomic affinities of coccidia with isosporan-type oocysts have been unclear as overlapping characters, recently discovered life cycle features, and even recently discovered taxa, continue to be incorporated into biological classifications of the group. We determined the full or partial 18S ribosomal RNA gene sequences of three mammalian Isospora spp., Isospora felis, Isospora ohioensis and Isospora suis, and a Sarcocystis sp. of a rattlesnake, and used these sequences for a phylogenetic analysis of the genus Isospora and the cyst-forming coccidia. Various alveolate 18S rDNA sequences were aligned and analyzed using maximum parsimony to obtain a phylogenetic hypothesis for the group. The three Isospora spp. were found to be most closely related to Toxoplasma gondii and Neospora caninum. This clade in turn formed the sister group to the Sarcocystis spp. included in the analysis. The results confirm that the genus Isospora does not belong to the family Eimeriidae, but should be classified together with the cyst-forming coccidia in the family Sarcocystidae. Furthermore, there appear to be two lineages within the Sarcocystidae. One lineage comprises Isospora and the Toxoplasma/Neospora clade which share the characters of having a proliferative phase of development preceding gamogony in the definitive host and an exogenous phase of sporogony. The other lineage comprises the Sarcocystis spp. which have no proliferative phase in the definitive host and an endogenous phase of sporogony.

Animals↗
PubMedDate not supplied

Survival of coccidia in poultry litter and reservoirs of infection.

The survival of coccidia was studied in poultry litter, dust, soil, and invertebrate animals. The populations of coccidia in litter were recorded during broiler growout in 16 broiler houses and in floor-pen trials involving anticoccidial drugs. The viability of oocysts declined rapidly in poultry litter regardless of the species; it was retained best in 40% moisture at 4 C. Sporocysts from broken oocytes did not survive even short exposure to poultry litter. Survival of oocysts was poorest at temperatures higher than 4 C, regardless of the carrier. In four floor-pen experiments designed to study the efficacy of anticoccidial drugs, the oocyst counts correlated in a general way with lesion scores and performance, indicating the oocyst counts might be useful along with other parameters to judge the effectiveness of drugs. Coccidia were transmitted to susceptible chicks by feeding them darkling beetles, flies, or house dust from poultry houses. More carrier samples were positive during the warmer months. Oocyst counts in litter of commercial poultry houses were very low during the first or last weeks of broiler growout but were high during the normal 3-to-6-week stress period. These results confirm the poor survival of oocysts in poultry litter and suggest that carryover from one flock to the next depends on the survival of a few oocysts in dust or arthropod vectors.

Animals↗
PubMedDate not supplied

[Amino acid makeup of the oocyst proteins of some species of coccidia of hens].

The composition of amino acids of sporocysts, membranes of oocysts and oocysts of four species of Coccidia from hens is reported. A considerable figgerence was found to exist in the quantitative composition of amino acids in oocysts of different Coccidia species and in different structures of oocysts. It is necessary to carry out a search of preparations breaking the inclusions of some amino acids into the protein molecule of oocysts of Coccidia from hens.

Amino Acids↗
PubMed1976

[Coccidia and coccidiosis in the rock partridge, Alectoris graeca cypriates. I. Coccidian species, systematics and morphological characteristics and the seasonal and age-related dynamics].

A total of 6,375 samples were taken from rock partridges of the Alektoris graeca cypriates species. Coccidia were found in 1,437 of them. In forty-three per cent of the cases the parasites belonged to Eimeria kofoidi, in 29.2 per cent--to E. procera, in 12 per cent--to E. cotornicis, in 6.9 per cent--to E. phasiani, and in 9.7 per cent--to E. tenella. Most often a mixed infection of several species was established. Most pathogenic and most widely occurring proved the E. kofoidi species. Highest per cent of infection and greatest parasite burden were found in the young birds up to two months of age, chiefly in the spring and summer seasons, (May-June). Most susceptible to the infection were those aged 14 days to 2 months. The carriers of coccidia among the adult specimens constituted 4 to 6 per cent, and during the spring these became more numerous--up to 35 per cent. This makes it reasonable to believe that improper hygiene in rock partridge breeding could bring about mass coccidia infection and thus interfere with the reproduction process.

Age Factors↗
PubMed2006

Three new species of coccidia (Apicomplexa: Eimeriorina) from the Marble-throated skink, Marmorosphax tricolor Bavay, 1869 (Reptilia: Scincidae), endemic to New Caledonia with a taxonomic revision of Eimeria spp. from scincid hosts.

Three new species of coccidia are described from Marble-throated skink Marmorosphax tricolor from New Caledonia, namely, Isospora bocagei sp. n., Acroeimeria rouxi sp. n., and Choleoeimeria sadlieri sp.n. All species differ markedly from other eimerian coccidia described from scincid hosts. Isospora marmorosphaxi develops extra-nuclearly in small intestine. A. rouxi develops epicitoplasmatically in small intestine. C. sadlieri affects the gall bladder mucosa. Generic affiliation of Eimeria-like coccidia from reptiles is discussed and all taxa (with adequate information on endogenous development available) from scincid hosts are revised and placed into genera Acroeimeria and Choleoeimeria.

Animals↗
PubMed2005

Tracing the emergence of drug-resistance in coccidia (Eimeria spp.) of commercial broiler flocks medicated with decoquinate for the first time in the United Kingdom.

Decoquinate is a quinolone coccidiostat introduced during 1967 as an in-feed prophylactic for broiler chickens. Despite early drug-resistance problems and its age, the drug is still used commercially worldwide. Decoquinate here serves as a valuable model in a field study that addresses the dynamics and economic impact of the development of coccidial resistance to potent synthetic anticoccidial drugs. The results of this unique, hitherto unpublished, study on the initial emergence of resistance of avian coccidia (Eimeria spp.) to a new drug in the field may be of strategic value in the continued use of decoquinate or the introduction of new drugs. The commercial performance of the first 3-5 crops of broilers to be medicated with decoquinate on each of six farms was monitored during 14 months in 1968-1969, supplemented by assessments of the species, population dynamics and decoquinate-resistance of coccidia isolated from each farm. During the rearing of each flock in a single shed on each farm, oocysts were counted in fresh faecal samples collected on three occasions, and the species were identified by their morphology if possible, supported if necessary by the biological characteristics of infections in chickens. E. acervulina was the most common species, followed by E. mitis, E. maxima, E. tenella and E. praecox. E. brunetti occurred rarely, and E. necatrix was not found. Decoquinate-resistance was evident in several species during the rearing of the first decoquinate-medicated crop on each farm, although clinical coccidiosis did not occur. It was concluded that inherently resistant mutants of E. acervulina, E. brunetti, E. maxima, E. tenella, and probably also E. mitis and E. praecox, were selected from field populations by 6 weeks during their first exposure to decoquinate. During up to four more subsequent crops, cycling of resistant parasites stimulated host immunity, which had no obvious adverse impact on commercial performance. There was no apparent seasonal effect. A hypothesis is proposed to explain the sudden and rapid emergence of quinolone-resistance in the coccidia, and why bird health was not thereby compromised in these circumstances.

Animals↗
PubMed1974

Immune responses in infections with coccidia: macrophage activity.

Peritoneal exudate cells from chickens immunized with two species of coccidia, Eimeria tenella or Eimeria maxima, were examined for their capacity to phagocytose stages of the parasite in vitro. True phagocytosis of the sporozoite stage is difficult to estimate because of its ability to invade cells, but may be evaluated by comparison with control suspensions. Peak activity (compared with cells from coccidia-free chickens) was found 3 to 5 weeks after the first inoulum of oocysts of E. tenella, and 1 week after the first inoculum of E. maxima- times which correspond to the onset of complete immunity to infection. Cells from coccidia-free chickens, in the presence of serum from birds immunized with E. tenella, phagocytosed sporozoites of E. tenella in a similar manner to cells from immunized birds. The immune serum had both cytophilic and opsonic adherence properties and the latter was species specific (for the two species tested).

Animals↗
PubMed1989

Interaction between coccidia and Nematodirus battus in lambs on pasture.

Five thousand oocysts of each of two species of coccidia, Eimeria crandallis and E ovinoidalis or 30,000 infective larvae of Nematodirus battus, given as single infections to three- to five-week-old lambs, caused only transient diarrhoea and had no effect on growth. Lambs infected first with coccidia and two weeks later with N battus suffered severe diarrhoea, weight loss and some deaths. Simultaneous administration of the coccidia and the nematodes increased the clinical severity of the syndrome and increased the numbers of nematode eggs produced.

Animals↗
PubMed2005

Molecular characterization of isosporoid coccidia (Isospora and Atoxoplasma spp.) in passerine birds.

Prevalence and disease caused by isosporoid coccidia in passerine birds are well recognized, but confusion about the life cycles of the parasites has led to taxonomic inconsistencies. In this study, we characterized segments of the chromosomal small and large-subunit ribosomal RNA (rRNA) genes of coccidial parasites from 23 species of passerine birds, as well as heat shock protein 70, apicoplast rRNA, and chromosomal 5.8s rRNA genes from a subgroup of these animals, and we correlated genetic data with morphologic findings for different parasite developmental stages, host phylogeny, and overall taxonomic relations within the phylum Apicomplexa. Our findings indicate that isosporoid coccidia of passerine birds are monophyletic but exhibit substantial diversity, with most avian species having one or several unique parasite lineages that underwent synchronous speciation with their hosts, interrupted by sporadic episodes of lateral transmission across species and families. Molecular analyses support a homoxenous life cycle, with sexual forms occurring chiefly in the intestines and asexual merozoites present systemically. Rarely, extraintestinal sexual stages can occur. The passerine coccidia are genetically most closely related to species of Eimeria rather than Isospora. We suggest that these parasites, whether identified from blood merozoite stages or fecal oocysts, be provisionally grouped as a homogeneous clade of individual species in a single taxon and formally named when reliable criteria allowing reclassification of related genera in the suborder Eimeriina are clarified.

Animals↗
PubMed1993

Differentiation of Toxoplasma gondii from closely related coccidia by riboprint analysis and a surface antigen gene polymerase chain reaction.

The tachyzoite of the human pathogen Toxoplasma gondii is morphologically indistinguishable from the proliferative stages of some other zoonotic coccidia, including Sarcocystis. To determine the identity of such coccidia obtained from human tissues and other sources, we compared riboprints (through restriction enzyme analysis of the polymerase chain reaction [PCR]-amplified small subunit rRNA gene) of the following protozoa: the RH and ts-4 strains of T. gondii, lines OH3 and S11, which are two recently isolated T. gondii-like parasites from Brazil, Neospora caninum, Sarcocystis species, and the malarial parasite Plasmodium berghei. In addition, the protozoan genomes were examined by PCR for homologs of surface antigen genes of T. gondii, and by Southern hybridization to the heterologous rRNA gene probe pSM 389. Strains OH3, S11, ts-4, and RH shared identical riboprints, and OH3, S11, and ts-4 have p22 and p30 surface antigen gene structures similar to RH. In contrast, riboprints for N. caninum and T. gondii differ with respect to Dde 1 sites, and moreover, their genomes vary significantly from one another at both the p22 and p30 gene loci. The riboprints of Sarcocystis and P. berghei differ markedly from T. gondii and N. caninum and from each other. Bam HI pSM 389 restriction fragment length polymorphisms differentiate ts-4 from RH, OH3, and S11. Our results confirm that OH3 and S11 are indeed T. gondii, but that N. caninum and T. gondii are likely to be separate species, thereby resolving previous uncertainties concerning the identity of these parasites. Together, the variation in riboprints and surface antigen gene structure reflects the phylogenetic diversity among these coccidia, and in addition, confirms the value of riboprinting in the identification of apicomplexan parasites such as T. gondii.

Animals↗
PubMed1997

Protozoan parasites of the intestinal tract: a review of Coccidia and Microsporida.

Ubiquitous in nature, members of the Coccidia and Microsporida are being reported with increasing frequency in the immunocompromised as well as the immunocompetent population. These protozoans are primarily waterborne, but foodborne disease has also been reported. These organisms are responsible for acute, as well as protracted, cases of watery diarrhea with various other related sequelae. The Coccidia includes three genera--Cryptospridium, Isospora, and Cyclospora. The latter two are of lesser importance in terms of morbidity and mortality. The Microsporida includes genera (Enterocytozoon, Encephalitozoon) only recently recognized as important agents of disease. Unlike the Coccidia, these organisms are more restricted to the immunocompromised population. Increased incidence and numbers of patients with prolonged diarrhea due to these forms indicate the need for increased clinical vigilance with regard to prevention, diagnosis, and treatment.

Animals↗
PubMed1992

[The survival ability of salmonella, coccidia oocysts and ascarid eggs in laying hen feces from different housing systems].

The time of survival of Salmonella typhimurium, coccidia oocysts and ascaris eggs in manure of layer was determined in 5 different housing systems and 2 storing places for litter. The experiments were carried out in a stable of experimental station Frankenforst of the university of Bonn with a flock of 2200 hens. The effects of the environment conditions temperature, dry matter content, pH-value and intestinal microflora of the manure have also been studied. The time of survival was different depending on the housing system. A recovery of viable coccidia oocysts was possible after 13-370 days, ascaris eggs 53-347 days and Salmonella typhimurium 2-175 days. The tenacity of the investigated test organism mainly depend on the dry matter content of the manure. The longest period of survival of salmonellas was found in dry environment conditions, were as coccidia oocysts and ascaris eggs have been observed with the shortest period of survival. The possibility of the examined resistant parasite stages to develop was disturbed. Only few of them were able to develop and with a longer development time than those examined in the control suspension. The results of this study indicate that chicken manure, before using it in plant production, should be stored long enough to prevent men or animals from possible infections.

Animals↗
PubMed1992

Development of a model ribosomal RNA hybridization assay for the detection of Sarcocystis and other coccidia.

Two regions of the primary structure of the small subunit rRNA of Sarcocystis muris bradyzoites were compared with nucleotide sequences of S. gigantea, Toxoplasma gondii, Plasmodium berghei and Mus musculus and used to design genus- and species-specific probes for the detection and identification of coccidia. Total cellular RNA of purified S. muris, S. cruzi, T. gondii and Eimeria nieschulzi and coccidia-infected tissues of mouse, ox, sheep and pig, were assayed using twenty-base oligomers labelled with 32P. Hybridization occurred at temperatures ranging from 21 degrees C to 41 degrees C or 51 degrees C. One probe detected only S. muris and another successfully hybridized to several members of coccidia, including S. muris, S. cruzi, T. gondii and E. nieschulzi. One ng of total cellular RNA was sufficient to yield detectable hybrids in slot blot assays. The excellent sensitivity suggests that rRNA-based probes are capable of detecting individual parasites, and can assay low levels of coccidial infections not detectable by other methods. The results of this study show that it is possible to customize the specificity of rRNA-based probes for diagnostic, epidemiological or taxonomic purposes.

Animals↗