Publications

TitleAbstractYear
Filter
PMID
Filter
anticoccidial activity of narasin in battery raised broiler chickens.the anticoccidial activity of the ionophorus antibiotic narasin was tested against six species of coccidia (eimeria acervulina, eimeria mivati, eimeria maxima, eimeria necatrix, eimeria brunetti, and eimeria tenella) in battery-raised broilers. feeding ration medicated with 60, 80, or 100 ppm narasin significantly improved weight gains during the periods of d 0 to d7 and d 0 to d 14 (d 0 = day of inoculation with sporulated oocysts), compared with the weight gains in corresponding inoculated gro ...1979530901
studies on site finding and site specificity of eimeria praecox, eimeria maxima and eimeria acervulina in chickens.sporozoites of 3 species of eimeria were introduced into the caecum of young chickens. e. praecox and e. maxima failed to develop in this site, but light infections of e. acervulina were detected. infection of the small intestine with all 3 species occurred when sporozoites were introduced via the caecum. infections were produced when mucosal scrapings of small intestine from birds, inoculated via the caecum 1-4 h previously, were inoculated orally to susceptible chickens. experiments with 51cr- ...19761012749
effects of roxarsone on pigmentation and coccidiosis in broilers.roxarsone (0.005%) medicated chickens inoculated at seven weeks of age with eimeria maxima oocysts had significantly higher pigment levels in blood plasma than did unmedicated controls. unmedicated e. maxima infected birds had significantly lower pigment levels compared to uninoculated controls. uninoculated roxarsone medicated controls showed no increase in pigment levels over uninoculated unmedicated birds. this experimental design demonstrates that the beneficial effect of roxarsone medicatio ...19751187515
influence of coccidiosis on salmonella colonization in broiler chickens under floor-pen conditions.the influence of coccidiosis on colonization of salmonella typhimurium in broiler chickens under floor pen conditions was studied by semiquantitative methods. chickens of two groups, unmedicated and medicated with nicarbazin (125 ppm via the feed), were exposed to three species of eimeria (eimeria tenella, eimeria maxima, and eimeria acervulina) at 2, 3, and 4 wk of age and given s. typhimurium in the feed 2 days later. salmonella typhimurium was isolated most often (100%) from ceca of chickens ...19921539023
distribution of oocysts, sporocysts and sporozoites of eimeria tenella and eimeria maxima in the digestive tract of chicken.the distribution of oocysts, sporocysts and sporozoites of eimeria tenella and eimeria maxima in the digestive tract of chicken and in excreta was investigated. at 1 h after the oral inoculation of e. tenella oocysts, the number of sporocysts in the cecum was 3.4 x 10(6) and decreased gradually thereafter, and the number of sporozoites in the cecum increased and remained at a high level until 12 h after the inoculation. small numbers of sporocysts and sporozoites of e. tenella were found in othe ...19921561759
antigenic variation among strains of eimeria maxima and e. tenella of the chicken.the immunogenicity and cross-protection of eimeria maxima or e. tenella in chickens against their homologous and heterologous strains were evaluated in two experiments. the immunizing strain of e. tenella protected against itself and partially against heterologous strains. the north carolina (nc) strains of e. tenella were more virulent than the delmarva (dmv) strains. growth of the unimmunized groups was depressed 66% and 32% for the nc and dmv strains, respectively. growth of the immunized-cha ...19921567308
electrophoretic and immunologic characterization of proteins of merozoites of eimeria acervulina, e. maxima, e. necatrix, and e. tenella.merozoites of eimeria acervulina, eimeria maxima, eimeria necatrix, and eimeria tenella were compared by gel electrophoresis, western-blotting with chicken antiserum, indirect fluorescent antibody reactions, and antiserum neutralization. merozoites from the 4 species had dissimilar patterns of proteins and antigens in soluble and membrane fractions. coomassie blue staining of sds-page gels revealed 16-22 protein bands depending on the species of merozoite but only 3 bands per species in the memb ...19921738074
eimeria maxima: isolation of gametocytes and their immunogenicity in mice, rabbits, and chickens.eimeria maxima gametocytes were isolated from infected chicken intestinal tissue by treatment with hyaluronidase and subsequent filtration through polymon filters. the isolated gametocytes were analyzed by microscopical and biochemical methods and shown to be highly enriched. the antigenicity of the gametocytes was analyzed in mice, rabbits, and chickens by elisa and indirect immunofluorescence. contrary to published results, we have found gametocytes to be highly immunogenic in all animals test ...19892466688
[analysis of losses due to subclinical small intestinal coccidiosis caused by eimeria acervulina and eimeria maxima under field conditions].subclinical coccidiosis of broiler chickens caused by eimeria (e.) acervulina and e. maxima results in a negative effect on feed conversion and retardation of growth. in the present report investigations in 80 broiler flocks are described in which the relationship between age of infection and economic effects were analysed under field conditions. under these conditions, infections with e. acervulina and e. maxima were found to have a negative effect on growth and feed conversion, that this negat ...19883176009
live attenuated coccidiosis vaccine: selection of a second precocious line of eimeria maxima.an attenuated line (cp) of eimeria maxima was obtained by selection for early development of oocysts. despite a small reproductive potential the cp line was highly immunogenic against its parent but did not completely protect chickens against challenge with virulent heterologous strains. however, in combination with another attenuated line with similar characteristics, good protection was induced.19883375582
effect of eimeria maxima infection upon the invasion of salmonella serovar typhimurium through the intestine of chicken. 19883386107
effect of eimeria maxima infection on development of eimeria tenella in immunized chickens.chickens previously immunized against eimeria tenella were reinfected with this species with and without infection by e. maxima. the present of e. maxima at the time of reinfection appears to decrease the immunity of the animals and enables e. tenella to develop. in this case, the development of e. maxima is not affected by the presence of e. tenella.19863827147
bacterial flora in the alimentary tract of chickens infected with eimeria brunetti and in chickens immunized with eimeria maxima and cross-infected with eimeria brunetti. 19724335852
coccidiosis: rapid depletion of circulating lymphocytes after challenge of immune chickens with parasite antigens.characteristic changes in the numbers of peripheral blood leukocytes occurred after specific challenge of chickens immunized by infection with the intracellular intestinal coccidian parasite eimeria maxima. within minutes of enteric or intravenous challenge with viable parasites or with soluble parasite antigen, the numbers of circulating lymphocytes and, to a lesser extent, of heterophils were reduced. this was followed by a period of leukocytosis, the main cellular constituents of which were h ...19846610638
some physiological effects of coccidiosis caused by eimeria maxima in young chickens. 19676017226
1,3-bis(p-chlorobenzylideneamino)guanidine hydrochloride (robenzidene): new poultry anticoccidial agent.at 66 parts per million in the feed, robenzidene is highly effective in preventing chicken coccidiosis caused by any one of eight eimeria species. three times this dose is safe for broiler chickens. in dogs and rats, the toxicity was relatively low over a period of 90 days. in laboratory trials, the drug completely prevents oocyst production by seven species and greatly reduces oocyst production by eimeria maxima.19705435895
[electron microscopy studies on the developmental stages of eimeria maxima from the domestic chicken. 3. differentiation of microgametes with special reference to nuclear divisions]. 19724630768
the effect of an interferon inducer on eimeria maxima in the chicken. 19714324618
endocrine changes in the fowl during infection with eimeria maxima.plasma concentrations of thyroxine (t4), triiodothyronine (t3), prolactin, growth hormone and corticosterone were measured in immature domestic fowl which were infected with eimeria maxima, uninfected but given the same amount of food as those infected (pair-fed) or fed ad libitum. infection with e maxima caused a decrease in plasma t4 concentration whereas pair feeding caused an increase when food intake was minimal. plasma t3 concentrations were decreased similarly in both infected and pair-fe ...19854012033
eimeria maxima: characteristics of attenuated lines obtained by selection for precocious development in the chicken.both the weybridge strain and a mixture of six laboratory and field strains of eimeria maxima have been attenuated by selection for early maturation of oocysts during serial passage in chickens. the prepatent times of the resultant precocious lines produces after selection were reduced from approximately 120 hr to less than 107 hr, and their reproduction and pathogenicity were less than those of the parent strains. chickens which had been inoculated with a small number of oocysts of the weybridg ...19863956680
effect of mild infections with six species of eimeria on skin pigmentation of broiler chickens.mild infections of eimeria maxima, e. acervulina, e. mivati, e. brunetti, e. necatrix, or e. tenella that did not affect weight gain significantly (p greater than .05) caused significant (p less than .05) shank depigmentation in 6-week-old broilers fed a broiler diet. infections of e. maxima, e. mivati, or e. acervulina caused numerically more depigmentation than did infections by e. tenella, e. brunetti, or e. necatrix. significant depigmentation was first detected at 4 days postinoculation (pi ...19863774752
genetics of resistance to coccidiosis: response of inbred chicken lines to infection by eimeria tenella and eimeria maxima.1. experiments have been carried out to compare weight gain, mortality and oocyst production in 7 inbred and partially inbred lines of chickens after challenge with the coccidial parasites eimeria tenella and e. maxima. 2. there were large differences between lines in the effects of challenge on weight gain and mortality for both species of parasite. however, the lines suffering the greatest mortality were not those showing the greatest effects on weight gain, indicating that mortality alone is ...19873446338
influence of coccidiosis on growth rate and feed conversion in broilers after experimental infections with eimeria acervulina and eimeria maxima.under experimental conditions, the effects of subclinical eimeria (e.) acervulina and e. maxima infections on growth and feed conversion in broilers of different ages were analysed. it was concluded that infection with e. acervulina and e. maxima led to a process which was independent of the age at which the birds were infected. the infection adversely affected growth and feed conversion for 2 to 3 weeks, followed by a recovery period of 2 to 3 weeks when compensatory growth took place. from thi ...19883218068
passive immunization of chickens against eimeria maxima infection with a monoclonal antibody developed against a gametocyte antigen.eimeria maxima gametocytes contain two major antigens with molecular masses of 56 and 82 kilodaltons (kda) which are recognized by convalescent sera from immune chickens. preparations enriched in these two antigens were used to immunize mice, and several monoclonal antibodies which specifically reacted with the 56-kda antigen were produced. one of these monoclonal antibodies of the immunoglobulin m subclass, along with immune chicken sera raised against affinity-purified 56- and 82-kda antigens, ...19902298492
maternal immunization with gametocyte antigens as a means of providing protective immunity against eimeria maxima in chickens.in the present study, we wished to demonstrate the ability of surface gametocyte antigens to induce protective immunity against eimeria maxima infections in chickens. in order to accomplish this goal, we employed maternal immunization as a means of providing large amounts of specific antibodies to offspring chicks. upon challenge with sporulated e. maxima oocysts, chicks from hens immunized with affinity-purified gametocyte antigens showed greatly reduced oocyst production compared with chicks f ...19921563795
rejection of eimeria by foreign hosts.oocysts of eimeria maxima inoculated into guinea fowl do not develop. infection occurs when intestinal mucosa or liver tissue from guinea fowl given e. maxima is transferred to susceptible chickens. by transferring material at different times after inoculation, it was shown that most of the stages are lost between 6 and 12 h and few, if any, survive to 48 h. sporozoites of e. tenella had low infectivity after 48 h contact in vitro with peritoneal macrophages from guinea fowls and turkeys. sporoz ...1979471537
immunological differences in eimeria maxima: effect of a mixed immunizing inoculum on heterologous challenge.the immunological differences known to exist between laboratory strains of eimeria maxima was confirmed. protection against challenge with different strains or field isolates of the species could be achieved by including small numbers (25 oocysts) of each in the immunizing inoculum. similar protection was obtained when 4 distinct populations which were allowed to interbreed were used in the immunizing inoculum. this hybrid mixture of e. maxima was used to immunize chickens against challenge with ...197994429
a comparison of the effects of infection with eimeria maxima and dietary restriction on weight gain, plasma metabolites and liver glycogen in the immature fowl, gallus domesticus.the effects of eimeria maxima or restricted pair-feeding on weight gain, plasma concentrations of protein, glucose, free fatty acids (ffa) and uric acid and liver glycogen were compared in immature fowl. food intake/kg body weight and weight gain decreased during the acute phase of infection (days 5-7) while weight loss was prolonged for an extra day compared with pair-fed birds. during recovery, food intake/kg body weight of infected birds was greater than that of non-infected controls but ther ...19827070839
the antigenicity of eimeria maxima populations obtained from commercial farms. 19816167700
phylogenetic relationships among eight eimeria species infecting domestic fowl inferred using complete small subunit ribosomal dna sequences.complete 18s ribosomal rna gene sequences were determined for 8 eimeria species of chickens and for eimeria bovis of cattle. sequences were aligned with each other and with sequences from 2 sarcocystis spp., toxoplasma gondii, neospora caninum, and 4 cryptosporidium spp. aligned sequences were analyzed by maximum parsimony to infer evolutionary relationships among the avian eimeria species. eimecia bovis was found to be the sister taxon to the 8 eimeria species infecting chickens. within the avi ...19979105308
eimeria maxima: a comparison of two laboratory strains with a fresh isolate.oocysts of the weybridge and houghton strains of eimeria maxima and a fresh field isolate were similar and measured on average 30-9 x 22-4 mum. the weybridge strain and the field isolate produced similar pathogenic effects in 6-week-old chickens, high doses causing 50-80% mortality and severe weight loss. the houghton strain was slightly less pathogenic and few birds died but more oocysts were produced. with each strain, a single dose gave complete immunity to a light challenge with the homologo ...1976967523
eimeria maxima: elisa and western blot analyses of protective sera.infection of chickens with eimeria maxima induces the production of parasite-specific antisera which can be used passively to protect naive chickens against infection. globulin fractions of these antisera can also be used passively to protect chickens. similarly, intramuscular injection of soybean lectin affinity purified gametocyte antigens of e. maxima in freund's complete adjuvant induces production of antibodies which are maternally transferred and thereby protect hatchlings against e. maxim ...19947526322
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, ...19744426710
effect of dietary raw soybeans on coccidiosis in chickens.six battery experiments determined the effect of feeding raw soybeans (rsb) in corn-soybean diets on coccidiosis in broiler chickens. the experimental design represents a 2 x 3 factorial arrangement of treatments with three dietary levels of incorporation of rsb (0, 50, and 100%), and chickens either infected or uninfected. the coccidial species tested singularly were eimeria acervulina, eimeria maxima, eimeria necatrix, eimeria brunetti, and eimeria tenella. with all species of eimeria a signif ...19957603956
column chromatographic characterization of cytoplasmic proteins in eimeria maxima oocysts from chickens.cytoplasmic proteins from unsporulated and sporulated eimeria maxima oocysts were analyzed by gel-filtration column chromatography. unsporulated oocysts were characterized as having 3 major cytoplasmic proteins and sporulated oocysts as having 5 major cytoplasmic proteins. molecular weights ranged from 5 x 10(3) to 1.4 x 10(6). larger molecular weight proteins were detected in sporulated and unsporulated oocysts, but were associated more with sporocysts of sporulated oocysts.19892521990
eimeria acervulina infection in the chicken: a model system for estimating nutrient requirements during coccidiosis.eimeria maxima inoculations of 5 x 10(4) oocysts and e. acervulina inoculations of 2 x 10(5) to 4 x 10(5) oocysts were shown to depress growth by 15 to 20% in young chicks fed crystalline amino acid (caa) diets. the intestinal lesions produced were typical of light to moderate coccidiosis. in one experiment, the performance of chicks fed monensin was increased in the presence, but not in the absence, of e. acervulina. thus, monensin prevented the negative effects of e. acervulina on chick perfor ...19817322984
eimeria maxima gametocyte antigens: potential use in a subunit maternal vaccine against coccidiosis in chickens.affinity-purified gametocyte antigens (apga) from eimeria maxima, emulsified in freund's adjuvant, were injected intramuscularly into breeding hens on two or three occasions. as a result, progeny of the immunized hens were partially immune to infection with e. maxima, eimeria tenella and eimeria acervulina (with a reduction in total oocyst output of 45-63% as compared with progeny of untreated hens). thus, apga in freund's adjuvant appears to have great potential as part of a maternally applied ...19957793129
eimeria maxima (apicomplexa): a comparison of sporozoite transport in naive and immune chickens.this study compared the early stages of infection in naive and immune chickens infected with eimeria maxima. an immunoperoxidase stain was developed and used to detect sporozoites and early schizonts in tissue sections of intestinal epithelium. a significantly higher proportion of sporozoites was present in the crypts of naive chickens, 48 hr postinoculation of oocysts, compared to immune chickens. sporozoites in immune birds tended to remain in the lamina propria rather than migrate to the cryp ...19883282046
antigenic proteins of eimeria maxima gametocytes: cell-free translation and detection with recovered chicken serum.rna was extracted from isolated eimeria maxima gametocytes and translated in a rabbit reticulocyte cell-free protein synthesis system. the major cell-free translation products from e. maxima gametocyte rna ranged from 225 to 50 kda, distinct and different from uninfected chicken intestine cell-free translation products. rabbit antiserum to e. maxima gametocytes as well as recovered chicken sera specifically precipitated some of the major gametocyte cell-free products. a time course of infected i ...19892917629
ultrastructural evaluation of the effects of diclazuril on the endogenous stages of eimeria maxima and e. brunetti in experimentally inoculated chickens.the ultrastructural morphology of the different endogenous stages of eimeria maxima and e. brunetti was evaluated after oral treatment of inoculated chickens with a single dose of 5 mg/kg diclazuril. the drug induced no ultrastructural change in the growth or differentiation of the various schizont stages of both eimeria spp. in e. maxima, the micromorphological appearance of micro- and macrogamonts developing from the blast from to maturation also remained unaffected by drug treatment. however, ...19892771929
comparison of immune responses in inbred lines of chickens to eimeria maxima and eimeria tenella.immune responses of 4 inbred lines of chickens, that differ in resistance to eimeria maxima and e. tenella, were examined. significant differences were found in in vitro proliferation of peripheral blood lymphocytes to e. maxima sporozoite antigen, the more resistant lines c and 7(2) having higher responses than the more susceptible line 15i. these differences existed pre-infection and were enhanced following both primary and a second infection. the proportions of lymphocyte subsets in the perip ...19957675528
[effect of coccidial infection on acetylcholine-induced contraction of the digestive tract in chickens. ii. comparison of infection between eimeria maxima and e. necatrix, and among 4 species of eimeria (author's transl)]. 19751237053
comparison between effects of standard feed and whole wheat supplemented diet on experimental eimeria tenella and eimeria maxima infections in broiler chickens.the effects of experimental infections with eimeria tenella (experiment 1, n = 144) or e. maxima (experiment 2, n = 216) in broiler chickens fed whole wheat, with or without access to grit, as compared to a standard pelleted feed were studied. inclusion of whole wheat was gradually increased up to 30% at 3 weeks of age. grit was given separately. the chickens were kept on litter in a parasite-free environment with free access to water and feed. at 3 weeks of age half the number of chickens were ...19989926460
infections with eimeria maxima and eimeria acervulina in the fowl: effect of previous infection with the heterologous organism on oocyst production.judged by oocyst production, infections with eimeria acervulina in birds immunized with e. maxima were consistently higher than in birds which had not been immunized. oocyst production of e. maxima in birds previously infected with e. acervulina was greater, in three out of four experiments, than in control chickens, but some of the differences were slight. the findings are discussed but no satisfactory explanation can be offered. in general there was little or no difference between the oocys ...19751168890
immunogenicity of a single sporocyst of eimeria maxima.eight out of a total 40 chickens infected with single sporocysts of eimeria maxima produced infective oocysts. these 8 chickens, when challenged with 4 x 10(5) oocysts per bird at 28 days postinfection, showed at least twice the percent average weight gain of the previously unexposed chickens, indicating that partial immunity was probably conferred by these infections. also, these successful single sporocyst infections suggest that like e. tenella, sporozolles of e. maxima are probably sexually ...1978566315
characterization and immunoprotective properties of a monoclonal antibody against the major oocyst wall protein of eimeria tenella.the oocyst wall of eimeria spp. consists of a 10-nm-thick outer lipid layer and a 90-mm-thick inner layer of glycoprotein which has been described previously to be composed of a single major protein. sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions and (125)i labelling of a oocyst wall fragments and of delipidated intact oocysts revealed a molecule of approximately 12 kda as the major protein component of the oocyst wall of eimeria tenella. an immunoglobulin m ...19968606083
efficacy of semduramicin and salinomycin against eimeria maxima in a laboratory test using two levels of oocyst inocula.the anticoccidial efficacies of semduramicin and salinomycin against five field isolates of eimeria maxima in broiler chickens were compared in five trials. uninfected, unmedicated; infected, unmedicated; infected, 25 ppm semduramicin; and infected, 66 ppm salinomycin treatments were assigned to battery cages using a randomized, complete block design. two levels of inocula, 10(3) and 10(4) oocysts per bird, were used in each trial in the infected treatments, creating a total of seven treatments ...19958825584
production of free radical species during eimeria maxima infections in chickens.five experiments were conducted to investigate the production of nitric oxide (no) and superoxide anion (o2-) during infections of chickens with the coccidial parasite, eimeria maxima, in order to assess the importance of these free radical species in the pathogenesis of the infections. nitric oxide production was estimated by analyzing no2(-)+no3-, stable metabolites of no, in the plasma and intestinal mucosa. the potential for o2- production was estimated from activities of beta-nicotinamide a ...19979181613
interaction of dietary flaxseed with coccidia infections in chickens.two experiments were conducted to determine effects of diets containing n-3 fatty acids (n-3fa) from whole as well as ground flaxseed on the performance of broilers during coccidia infections. diets were fed from 1 d of age through 3 wk of age. chickens were infected with coccidia at 2 wk of age and the effects of infection assessed at 6 d postinfection. the first experiment contrasted effects of several high n-3fa-containing diets, including one supplemented with whole flaxseed, on infections w ...19979181614
evaluation of a gel-immunization technique used with two different immucox vaccine formulations in battery and floor-pen trials with broiler chickens.the use of a gel-immunization technique with immucox vaccination was compared and evaluated against other immunization methods in battery and floor-pen immunization trials. gel immunization was found to be superior to immunization by gavage, by spray cabinet, or by the conventional delivery method of immucox in a battery trial. significantly enhanced protection as measured by weight gain, coupled with the establishment of a more uniform primary immunizing infection as evidenced by greater intest ...19979197391
eimeria brunetti and eimeria necatrix in chickens of argentina and confirmation of seven species of eimeria.ten poultry farms (broiler breeder pullets, layer pullets, and broilers) in the provinces of entre rios and buenos aires in argentina were examined for presence of eimeria spp. litter samples obtained from flocks 7-11 wk old were taken to the laboratory for oocyst counting and sporulation, then concentrated for inoculation into coccidia-free chickens. species were identified by prepatent period, oocyst size, location and appearance of lesions in the intestine, microscopic examination of mucosal ...200011007025
lack of correlation between microscopic lesion scores and gross lesion scores in commercially grown broilers examined for small intestinal eimeria spp. coccidiosis.comparisons were made between microscopic lesion scores (mlss) and gross lesion scores (glss) in sections from small intestine of broilers during three routine coccidiosis screenings. the duodenal and jejunal gls were determined and recorded by different evaluators. during each screening, 2-cm sections of duodenum and jejunum were collected, and sections of intestine were then scored using a microscopic lesion scoring system. no correlation between mls and gls was observed in duodenum in two out ...19979201404
assessment of recombinant bovine somatotropin as an immunomodulator during avian coccidiosis: immunization with living oocysts.coccidiosis, a disease of great economic importance to the poultry industry, is generally controlled prophylactically by additions of anticoccidial drugs to the feed. however, increasing development of drug-resistant coccidia species has stimulated searches for alternative control methods, one of which is vaccination. as part of this effort, recombinant bovine growth hormone (rbst) was tested as a possible immune stimulator in combination with live oocyst vaccination. at a dose of 0.045 mg per c ...19979251145
effects of components of artemisia annua on coccidia infections in chickens.four experiments were run to test the anticoccidial activity of dried artemisia annua leaves and several of their chemical constituents for possible use as prophylactic feed additives. when fed over a period of 3 wk at a level of 5%, a dried leaf supplement of a. annua provided significant protection against lesions due to eimeria tenella but not eimeria acervulina or eimeria maxima. when fed over a period of 5 wk at a level of 1% to chicks undergoing immunization with a live vaccine, it provide ...19979251146
maternal transfer of antibodies induced by infection with eimeria maxima partially protects chickens against challenge with eimeria tenella.infection of breeding hens with eimeria maxima induces production of eimeria-specific igg antibodies which are transferred to hatchlings via the egg yolk and confer a high degree of maternal immunity against homologous challenge and partial immunity to infection with another important species, eimeria tenella. as an example, in an experiment using hatchlings from eggs collected between days 28 and 39 after infection of the hens with 20,000 sporulated e. maxima oocysts, control chicks (challenged ...19947831090
maternal transmission of immunity to eimeria maxima: enzyme-linked immunosorbent assay analysis of protective antibodies induced by infection.vaccination of broiler chickens against eimeria infection is problematic because of the need to ensure that birds are protected from the time of hatching. we have therefore investigated the feasibility of protecting hatchling broilers via maternal transfer of protective antibodies from hens to their offspring. oral infection of broiler breeder hens with 20,000 sporulated eimeria maxima oocysts caused production of antibodies which were passed into the egg yolk and subsequently to hatchlings. the ...19948132342
in vitro interleukin-1 and tumor necrosis factor-alpha production by macrophages from chickens infected with either eimeria maxima or eimeria tenella.we measured the in vitro production of interleukin-1 (il-1) and tumor necrosis factor-alpha (tnf- ) by macrophages from chickens during and immediately following an infection with one of two different species of eimeria, e. maxima and e. tenella. quantitatively, the amounts of il-1 produced during each infection were nearly identical regardless of the oocyst dose of each parasite. tnf production followed a biphasic pattern of increased production with the first peak associated with the pathogene ...19938225766
dynamics of cytokine production during coccidial infections in chickens: colony-stimulating factors and interferon.we assayed two classes of immunoregulatory cytokines, colony-stimulating factors (csf) and interferon (ifn), during and immediately after a primary coccidial infection in chickens. coccidial infection induces significant alterations in serum colony-stimulating activity (csa) and these alterations immediately precede the characteristic biphasic leukocytosis. csa rose sharply during the first 24 h post-inoculation (pi), but returned to control levels by 48 h pi. at this time, we detected an increa ...19937682468
nitrocellulose immunoblotting for identification and molecular gene cloning of eimeria maxima antigens that stimulate lymphocyte proliferation.an immunoblotting technique was used to identify lymphostimulatory antigens within sized polypeptide fractions of eimeria maxima sporozoites. six fractions contained polypeptides that specifically stimulated the proliferation of immune lymphocytes in an in vitro assay, and polyclonal antisera were made in rabbits against these fractions. cdna clones, isolated with antisera against a lymphostimulatory fraction of around 70 kda, were found to encode four different antigens including a classical hs ...19958548529
epidemiological aspects of the use of live anticoccidial vaccines for chickens.this review address the epidemiology (epizootiology) of coccidiosis in commercial chickens with emphasis on the effects on the use of live vaccines. surveys suggest that all seven valid species of chicken coccidia (eimeria acervulina, eimeria brunetti, eimeria maxima, eimeria mitis, eimeria necatrix, eimeria praecox and eimeria tenella) are ubiquitous. all species are pathogenic to various extents. new results are presented on the pathogeneicities of e. acervulina, e. mitis and e. praecox. unles ...19989724880
effects of dietary supplementation with n-3 fatty acid ethyl esters on coccidiosis in chickens.the ethyl esters of eicosapentaenoic (epa) and docosahexaenoic (dha) acids were added to a broiler starter diet singly or in combination [as bulk purified ethyl ester concentrate from menhaden oil (n3fac)] in quantities similar to those found in a diet supplemented with 5% menhaden oil (mo). diets were fed to chickens from 1 d of age through 3 wk of age. at 2 wk of age, the chickens were infected with eimeria tenella, eimeria acervulina, or eimeria maxima. at 6 d postinfection (pi), the effects ...19989835336
eimeria maxima: identification of gametocyte protein antigens.the antigenicity of eimeria maxima gametocyte proteins during the course of an infection and when injected into mice and rabbits was demonstrated using the western blotting technique. serum taken from chickens at various times postinfection reacted to a few gametocyte proteins, with the strongest reactivity seen with serum taken 14-days postinfection. two major antigens having molecular weights of 56,000 and 82,000 were consistently detected by these sera. using immune rabbit or mouse sera to wh ...19892537222
kinetic differences in intestinal and systemic interferon-gamma and antigen-specific antibodies in chickens experimentally infected with eimeria maxima.kinetic differences between systemic vs. intestinal and humoral vs. cellular immune responses were elucidated in chickens experimentally infected with eimeria maxima by comparing interferon-gamma (ifn-gamma) and parasite-specific antibody levels in the intestine and serum during the course of infection. the level of serum ifn-gamma correlated significantly with fecal oocyst shedding (r2 = 0.97), thereby establishing the importance of cell-mediated immunity in coccidia infection. moreover, intest ...200010879910
a recombinant eimeria protein inducing interferon-gamma production: comparison of different gene expression systems and immunization strategies for vaccination against coccidiosis.a rabbit antiserum against an 18- to 27-kd native protein fraction (f3) from eimeria acervulina merozoites identified a cdna (3-1e) containing a 1086-base pair insertion with an open reading frame of 170 amino acids (predicted molecular weight, 18,523). the recombinant 3-1e cdna expressed in escherichia coli produced a 60-kd fusion protein and a 23-kd protein after factor xa treatment of the fusion protein. both proteins were reactive with the f3 antiserum by western blot analysis. a rabbit anti ...200010879919
immunity to coccidia in chickens: adoptive transfer with peripheral blood lymphocytes and spleen cells.suspensions of cells prepared from the caecal tonsils and spleen, and the peripheral blood lymphocytes of chickens immune to eimeria maxima, were tested for their ability to transfer resistance to syngeneic recipients. the intravenous injection of approximately 6 x 10(8) spleen cells or peripheral blood lymphocytes caused a significant reduction of oocyst production by the challenged recipients, in comparison with controls which were uninjected or given cells from birds susceptible to e. maxima. ...19827099704
efficacy of diclazuril in comparison with chemical and ionophorous anticoccidials against eimeria spp. in broiler chickens in floor pens.two 42-d floor pen studies were conducted with commercial broiler chickens to measure the efficacy of 1 ppm diclazuril in the starter or grower diet in shuttle programs with 66 ppm salinomycin. study 1 compared a salinomycin to diclazuril (starter to grower diet) shuttle treatment with salinomycin to salinomycin, salinomycin to 100 ppm monensin, salinomycin to 99.8 ppm lasalocid, and unmedicated treatments. study 2 compared a diclazuril to salinomycin (starter to grower) shuttle treatment with 1 ...200111297280
quantification of the crowding effect during infections with the seven eimeria species of the domesticated fowl: its importance for experimental designs and the production of oocyst stocks.the 'crowding effect' in avian coccidia, following administration of graded numbers of sporulated oocysts to naïve hosts, is recognisable by two characteristics. first, increasing doses of oocysts give rise to progressively higher oocyst yields, until a level of infection is reached (the 'maximally producing dose') above which further dose increases result in progressive decreases in oocyst yields. second, the number of oocysts produced per oocyst administered (the 'reproductive potential') tend ...200111429169
protection against coccidiosis in outbred chickens elicited by gamma-irradiated eimeria maxima.in an effort to develop an attenuated coccidiosis vaccine against coccidiosis, we exposed eimeria maxima oocysts to an optimum dose of gamma irradiation (17 krad) that does not affect sporozoite invasion of the intestinal mucosa but does prevent asexual parasite development. irradiated e. maxima oocysts were suspended in gelatin slabs and placed in battery cages for ingestion by 1-day-old chickens. separate groups of chickens were given gelatin slabs containing nonirradiated e. maxima oocysts or ...19979356719
the importance of transmission-blocking immunity in the control of infections by apicomplexan parasites.transmission-blocking immunity may have great potential for use in the control of diseases caused by apicomplexan parasites. in this review i will describe our work on the application of transmission-blocking immunity to the control of the eimeria parasite and compare our results to those working on transmission-blocking immunity against cryptosporidium and plasmodium. eimeria causes the disease known as coccidiosis in domestic animals. coccidiosis is particularly problematic in the chicken indu ...19979394186
modelling host cell availability and the crowding effect in eimeria infections.within-host mathematical models of eimeria maxima and eimeria praecox infections of the chicken are presented and used to investigate the role of host cell availability as a possible determinant of the so-called 'crowding effect'; whereby the fecundity of the parasites decreases as infectious dose increases. assumptions about the number of available host cells, the average lifespan of these cells and the age structure within the host-cell population were made and mathematical models were constru ...200111429170
evaluation of the efficacy of eimeria maxima oocyst immunization with different strains of day-old broiler and roaster chickens.the performances of three different strains of male and female broiler or roaster chickens immunized at 1 day of age with a drug-resistant field isolate of eimeria maxima were evaluated in battery and floorpen immunization trials. no difference in immunization potential was seen between these strains or sexes of day-old chickens immunized with 2500 oocysts/bird of e. maxima and challenged at 10 days of age with 25,000 oocysts/bird of the same isolate in two separate battery trials. all immunized ...19979454911
maternal transmission of immunity to eimeria maxima: western blot analysis of protective antibodies induced by infection.infection of breeding hens with eimeria maxima induces production of parasite-specific antibodies which are transferred, via the egg yolk, to hatchling chicks. these antibodies (immunoglobulin g) are highly protective, mediating up to a 97% reduction in oocyst excretion in challenged hatchlings. however, the degree of maternally derived immunity transferred by the hens to their offspring declines with increasing time after infection of the hens. this decline in immunity is directly related to de ...19947927759
quantifying risk factors of coccidiosis in broilers using on-farm data based on a veterinary practice.a study was done to find and quantify risk factors for coccidiosis. the study population consisted of 4774 broiler flocks kept on 177 farms. flocks were considered a case when at least one bird in the flock showed microscopic presence of oocysts in intestinal scrapings in a grow-out cycle. other flocks were defined as controls. this was done for three types of eimeria: eimeria acervulina, eimeria tenella and eimeria maxima. logistic regression was used to assess variables that influence the occu ...19989500183
biochemical characterisation of the 56 and 82 kda immunodominant gametocyte antigens from eimeria maxima.two immunodominant gametocyte antigens from eimeria maxima with m(r) 56 kda and m(r) 82 kda have been identified previously as potential candidates for inclusion in a recombinant subunit vaccine against coccidiosis in poultry. here, these proteins have been biochemically characterised, immunolocalised within the parasite, and sequences for their amino termini determined. these antigens co-purify by affinity chromatography suggesting an interaction with each other. however, separation of the prot ...200212062551
effects of dietary vitamin e on chickens infected with eimeria maxima: observations over time of primary infection.two trrials were conducted to define temporal changes in plasma d-alpha-tocopherol (at) caused by infection with eimeria maxima in chickens that consumed either low (25 ppm) or high (225 ppm) levels of dietary dl-alpha-tocopheryl acetate (ve-ac) from 1 day of age. in both trials, rates of weight gain were depressed between days 5 and 7 post-inoculation (pi) and were not influenced by the level of dietary ve-ac. plasma at was consistently depressed at 5 and 7 days pi in chickens consuming either ...200212495044
sporulation of eimeria maxima oocysts in litter with different moisture contents.the aim of this study was to determine if the sporulation of eimeria maxima oocysts was affected by the moisture content of the litter. fresh feces were collected from chickens experimentally infected with e. maxima. the feces were mixed with dried wood shavings and different amounts of water to obtain final moisture contents of 16, 42, and 62% and a final oocyst concentration of 5,000 per g of mixture. the samples were kept at 23 c and 75% relative humidity and were thoroughly aerated every 12 ...200111599698
interaction of dietary vitamin e with eimeria maxima infections in chickens.in two trials, broiler chickens, processed similarly to those placed in commercial operation, were fed, from 1 d of age, a range (13 to 200 ppm) of dl-alpha-tocopheryl acetate (ve-ac) levels, and the effects on the pathology of eimeria maxima infections were assessed at 6 d postinoculation (pi). in trial 1, dietary levels of ve-ac had little significant effect on variables characterizing pathology except for the number of oocysts shed, which was significantly increased in chicks treated with hig ...200211885898
the use of diclazuril in extended withdrawal anticoccidial programs: 1. efficacy against eimeria spp. in broiler chickens in floor pens.a 49-d floor pen study was conducted with broiler chickens to compare the effects of different anticoccidial withdrawal times on the efficacy of 1 ppm diclazuril. the starter diet in three treatments contained 66 ppm salinomycin + 50 ppm roxarsone (3-nitro-4-hydroxyphenylarsonic acid), followed by 1 ppm diclazuril in the grower diet commencing on day 17. diclazuril was withdrawn from these treatments on day 28, 35, or 42 (finisher diet), respectively. two other treatments in the study were given ...200211902410
rna-dependent rna polymerase activity associated with virus-like dsrna in eimeria maxima and e. necatrix of the domestic fowl.rna-dependent rna polymerase (rdrp) activity was identified in lysates of eimeria maxima sporozoites and e. necatrix sporozoites and merozoites. pretreatment of cell lysates with dnase i, rnase a, proteinase k and actinomycin d prior to rdrp assay was employed to characterize rdrp activity. dnase i and actinomycin d had little effect, while proteinase k abolished rdrp activity in both species. rnase a at a concentration of 1 mg/ml also reduced the polymerase activity in e. maxima and e. necatrix ...19999950224
protective immunity against coccidiosis elicited by radiation-attenuated eimeria maxima sporozoites that are incapable of asexual development.eimeria maxima oocysts were exposed to various doses of gamma radiation that did not affect sporozoite invasion of intestinal epithelium but did prevent subsequent merogonic development therein. although merogony and oocyst formation were inhibited, parasites exposed to 12 krad radiation induced a level of immunity against e. maxima challenge equivalent to that induced by non-irradiated oocysts. chickens immunized per os with 20 krad-treated e. maxima oocysts were not protected against coccidial ...19938452512
anticoccidial efficacy of semduramicin. 1. evaluation against field isolates by dose titration in battery tests.semduramicin (aviax), a novel polyether ionophore, was titrated in a series of five battery tests at 20, 25, and 30 ppm in feed to determine the optimum level for use. twelve-day-old broiler chicks were medicated for 48 h prior to inoculation in each 9-day test. the inocula included monospecific field isolates of eimeria tenella, eimeria brunetti, eimeria necatrix, and eimeria maxima, and a mixture of these species with eimeria acervulina and eimeria mitis. the numbers of oocysts inoculated were ...19938265494
avian coccidiosis: changes in intestinal lymphocyte populations associated with the development of immunity to eimeria maxima.the effect of infection and subsequent challenge with eimeria maxima on the populations of lymphocytes in the small intestine of light sussex chickens was assessed by immunohistochemistry. t cells were characterized for cd3, cd4, cd8, tcr1 (gamma delta heterodimer) or tcr2 (alpha beta 1 heterodimer) markers, and b cells for the expression of igm, iga and igg. after a primary inoculum there were, in both the epithelium and the lamina propria, two distinct increases in the numbers of t lymphocytes ...19958587790
mapping quantitative trait loci associated with resistance to coccidiosis and growth.to map qtl associated with disease resistance to avian coccidiosis and growth, two commercial broiler lines with different degrees of resistance to the disease were crossed to generate an f1 generation that was intercrossed to produce 314 f2 generation offspring. the f2 offspring were inoculated with sporulated oocysts of eimeria maxima. five disease-associated phenotypes were measured after the infection. intertrait comparisons revealed that oocyst shedding was a good parameter for evaluating d ...200312580238
a comparison of sporozoite transport after homologous and heterologous challenge in chickens immunized with the guelph strain or the florida strain of eimeria maxima.the two strains of eimeria maxima, guelph and florida, used in this study were previously shown to only partially cross-protect immunologically with respect to lesion scores, weight gains and feed conversions after heterologous challenge. in this paper, we provide evidence that this partial lack of cross-protection is manifested at the level of sporozoite transport. in birds immunized and challenged with the homologous strain, sporozoites accumulated in the lamina propria and were blocked from f ...200111206107
analysis of chicken mucosal immune response to eimeria tenella and eimeria maxima infection by quantitative reverse transcription-pcr.the recent cloning of chicken genes coding for interleukins, chemokines, and other proteins involved in immune regulation and inflammation allowed us to analyze their expression during infection with eimeria. the expression levels of different genes in jejunal and cecal rna extracts isolated from uninfected chickens and chickens infected with eimeria maxima or e. tenella were measured using a precise quantitative reverse transcription-pcr technique. seven days after e. tenella infection, express ...200111254616
effects of daily oral doses of l-arginine on coccidiosis infections in chickens.l-arginine is an essential amino acid for chickens, as well as the substrate for biosynthesis of nitric oxide (no), a bioregulatory free radical molecule known to have antimicrobial activity. biosynthesis of no by induced nitric oxide synthase (inos) can be stimulated during immunological response to infection. therefore, in chickens, production of no as a response to an infection should be influenced by dietary levels of l-arginine. two experiments were carried out to determine whether oral dos ...199910560821
characterisation of the antigenic and immunogenic properties of bacterially expressed, sexual stage antigens of the coccidian parasite, eimeria maxima.coccidiosis in poultry is caused by the intestinal parasite eimeria; it causes significant financial losses to the commercial poultry industry worldwide. coxabic is the first commercially available subunit vaccine against coccidiosis. the vaccine consists of affinity purified sexual stage (gametocyte) antigens (apga) isolated from eimeria maxima. production of this vaccine is time-consuming and laborious and, therefore, a recombinant subunit vaccine substitute for coxabic is desirable. the genes ...200415474724
profiling local gene expression changes associated with eimeria maxima and eimeria acervulina using cdna microarray.eimeria parasites show preferential sites of invasion in the avian intestine and produce a species-specific host immune response. two economically important species, eimeria acervulina and eimeria maxima, preferentially invade and develop in the avian duodenum and jejunum/ileum, respectively. to investigate local host immune responses induced by parasite infection, global transcriptional changes in intestinal intraepithelial lymphocytes (iels) induced by oral inoculation of chickens with e. acer ...200312712262
a study of eimeria maxima tyzzer, 1929, a coccidium of the fowl (gallus gallus). 195914418119
comparative testing of anticoccidials in broiler chickens: the role of coccidial lesion scores.the relationship between oocyst dose and lesion score was evaluated in trials involving five field isolates each of eimeria acervulina, eimeria maxima, and eimeria tenella. each trial included an uninfected, unmedicated treatment, and at least three treatments of unmedicated birds given different doses of oocysts from a single isolate. in four trials each with e. acervulina and e. tenella, and all five trials with e. maxima, infected, salinomycin-medicated (60 ppm) treatments were included. each ...199910230905
antigenic diversity in eimeria maxima and the influence of host genetics and immunization schedule on cross-protective immunity.eimeria spp. are a group of highly successful intracellular protozoan parasites that develop within enterocytes. eimeria maxima from the chicken is characterized by high immunogenicity (a small priming infection gives complete immunity to subsequent homologous challenge) and naturally occurring antigenically variant populations that do not completely cross-protect. in this study we examined the expression of antigenic diversity in e. maxima, as manifested by cross-strain protection in a series o ...200211953384
anticoccidial vaccination: the absence or reduction of numbers of endogenous parasites from gross lesions in immune chickens after virulent coccidial challenge.male and female floor-reared chickens were immunized with a live, attenuated anticoccidial vaccine (paracox) and then, 28 days after vaccination, were challenged with virulent strains of eimeria acervulina, eimeria brunetti, eimeria maxima, eimeria necatrix or eimeria tenella. the relationship between the post-challenge growth rate and specific gross lesion grades, matched in individual birds, was examined. the numbers of endogenous parasites associated with graded lesions of each species were c ...200314522710
cross protection studies with eimeria maxima strains.the purpose of this study was to determine whether differences in fecundity of eimeria maxima isolates were related to their abilities to elicit cross-protective immunity. immunizations were initiated by low-dose gavages of sporulated oocysts to day-old broiler chicks under conditions that allowed parasite recycling, and chickens were challenged with homologous and heterologous strains. immunization efficacies were measured using a protective index calculated from weight gain, gross lesion score ...200515991044
acquisition of immunity to eimeria maxima in newly hatched chickens given 100 oocysts.the acquisition of immunity to eimeria maxima by chicks infected 18 hr after hatch with a single dose of 100 oocysts was investigated. in the first experiment, birds were moved each day to clean cages in order to prevent the possibility of secondary infection resulting from ingestion of oocysts passed in their feces. immunity was measured at 4 wk of age by calculation of oocyst production following challenge with 500 oocysts or weight gain following challenge with 100,000 oocysts. large numbers ...200516252500
chicken ifn-gamma monoclonal antibodies and their application in enzyme-linked immunosorbent assay.twelve mabs against native or recombinant chicken ifn-gamma were produced and characterized by virus neutralization, elisa, and western blot assays. no data were obtained to suggest that the form of the immunogen (native versus recombinant) influenced the antigenic specificity of the mabs produced. while only two antibodies inhibited the in vitro virus neutralizing activity of ifn-gamma, other evidence indicated that the specificity of these mabs was indeed directed against ifn-gamma. by western ...200010713342
analysis of disease resistance-associated parameters in broiler chickens challenged with eimeria maxima.to determine an optimal dose for coccidial inoculation and to evaluate genetic resistance or susceptibility in individual chickens, broilers were inoculated with four different doses of eimeria maxima oocysts. body weight gain, fecal oocyst shedding, concentrations of plasma no2- + no3-, carotenoid, and interferon-gamma were measured at two different time periods postinfection. the results showed significant dose and sex effects on most parameters and interaction between dose and sex in some par ...200010824947
effect of ibuprofen on coccidiosis in broiler chickens.ibuprofen (ibu)-a nonsteroidal anti-inflammatory drug-inhibits the biosynthesis of prostaglandins with pro-inflammatory and immunosuppressive properties and is therefore proposed as a candidate molecule for the treatment of coccidiosis in broiler chickens. in all experiments, ibu was administered via drinking water. in a first experiment, chickens were infected at 10 or 21 days of age with oocysts of eimeria acervulina (5 x 10(4)), eimeria maxima (3 x 10(4)), and eimeria tenella (7.5 x 10(3)) an ...200415077799
eimeria maxima trap family protein emtfp250: subcellular localisation and induction of immune responses by immunisation with a recombinant c-terminal derivative.emtfp250 is a high molecular mass, asexual stage antigen from eimeria maxima strongly associated with maternally derived immunity to this protozoan parasite in hatchling chickens. cloning and sequence analysis has predicted the antigen to be a novel member of the thrombospondin-related anonymous protein (trap) family of apicomplexan parasites. members of the trap family are microneme proteins and are associated with host cell invasion and apicomplexan gliding motility. in order to assess the imm ...200415157769
cloning and characterization of chicken il-10 and its role in the immune response to eimeria maxima.we isolated the full-length chicken il-10 (chil-10) cdna from an expressed sequence tag library derived from rna from cecal tonsils of eimeria tenella-infected chickens. it encodes a 178-aa polypeptide, with a predicted 162-aa mature peptide. chicken il-10 has 45 and 42% aa identity with human and murine il-10, respectively. the structures of the chil-10 gene and its promoter were determined by direct sequencing of a bacterial artificial chromosome containing chil-10. the chil-10 gene structure ...200415294985
genetic characterization of three unique operational taxonomic units of eimeria from chickens in australia based on nuclear spacer ribosomal dna.coccidiosis of chickens is one of the commonest and economically most important parasitic diseases of poultry worldwide. given the limitations of traditional approaches, molecular tools have been developed for the specific diagnosis of coccidiosis. recently, a polymerase chain reaction (pcr)-based capillary electrophoresis (ce) method, employing genetic markers in the second internal transcribed spacer (its-2) of nuclear ribosomal dna, was established for both analytical and diagnostic purposes. ...200818243560
Displaying items 1 - 100 of 243