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septamycin, a polyether antibiotic. taxonomy, fermentation, isolation and characterization.septamycin is a metal complexing polyether antibiotic produced by a strain of streptomyces hygroscopicus nrrl 5678. the metabolite, a monocarboxylic acid, was isolated as the sodium salt c48h81nao16. the crystal structure and absolute configuration were established by x-ray analysis of the p-bromophenacyl derivative. septamycin has a thirty-carbon backbone and contains seven heterocyclic rings. supported by direct comparison septamycin proved to be identical with antibiotic a28695 a isolated fro ...1975172482
effect of infectious bursal disease on the severity of eimeria tenella infections in broiler chicks.a study was initiated to determine whether prior exposure to infectious bursal disease virus (ibdv) influenced the susceptibility of young broiler chicks to eimeria tentella infections. when one-day-old chicks infected with ibdv were subsequently challenged with e. tenella at 7 days of age, they suffered significantly higher mortality and lesion scores than their hatchmates which were not exposed to ibdv. initial exposure to ibdv also had an effect on the development of e. tenella induced hemorr ...1977203907
influence of infectious bursal disease on the development of immunity to eimeria tenella.specific-pathogen-free (spf) chicks infected with infectious bursal disease (ibdv) virus at one day of age or midway (7 days) through a two-week immunization program for eimeria tenella showed significantly less (p less than or equal to 0.05) protection against coccidal challenge as measured by lesion scores than chicks given ibdv after 14 days of coccidial immunization. the chicks showed complete protection to later coccidial challenge administered on day 21. bursae were markedly smaller from i ...1977204282
the use of sodium taurodeoxycholate for excystation of eimeria tenella sporozoites.as an in vitro excystor, sodium taurodeoxycholate (tdc) released 80--90% eimeria tenella sporozites, in contrast to 0--15% excystation by six other bile salts or bile extracts, and pooled chicken bile in 90 min at 37 c with continuous agitation. pooled chicken bile required 4 to 4 1/2 hr to excyst similar percentages of sporozoites. prolonged incubation with other bile salts and bile extracts excysted most sporozoites, but killed them. when the incubation temperature was raised to 44 c, tdc excy ...1979512750
comparison of anticoccidial efficacy, resistance and tolerance of narasin, monensin and lasalocid in chicken battery trials.the anticoccidial efficacy, host tolerance, and projected resistance development of the three polyether antibiotics, monensin, narasin, and lasalocid were compared. the efficacy of narasin against different coccidial strains was found to parallel that of monensin in as much as strains which were refractory to monensin were also refractory to narasin. in contrast, lasalocid easily controlled some strains which were not well controlled by either narasin or monensin and failed to control one strain ...1977605098
effects of monensin-feeding regimens on flock immunity to coccidiosis.feed medication with monensin caused delays in development of immunity in two floor-pen experiments which simulated commercial broiler production. development of immunity was retarded with the higher level of monensin (120 p.p.m.) but was progressively less delayed as the monensin level was decreased (100, 60 or 0 p.p.m.). delay was greatest with eimeria tenella, but also occured with intestinal species including e. acervulina, e. brunetti, e. maxima, e. mivati, and e. necatrix. drug withdrawal ...1977605025
tricyclic aryl-substituted anticoccidial azauracils.syntheses of tricyclic aryl-substituted 6-azauracils are described. these compounds showed anticoccidial activity when tested against eimeria tenella and e. necatrix. compound activity was correlated with the chemical shift of the azauracil ring proton. no correlation existed between activity and compound lipophilicity. one of the compounds, 2-(11-oxo-6,11-dihydrodibenzo[b,e]thiepin-3yl)-as-triazine-3,5(2h,4h)-dione (23), was tested extensively against e. tenella and e. brunetti both in vivo and ...1978580939
[role of nucleic acids in intensifying the virulent properties of eimeria tenella (coccidiida)]. 1978673466
eimeria tenella: synergistic interaction of sulfaquinoxaline and t-butylaminoethanol in the chicken. 1979477812
practical immunization of chickens against coccidiosis using an attenuated strain of eimeria tenella.three floor-pen trials were conducted to compare two attenuated strains of eimeria tenella (wis-f-96 and wis-f-125) with the strain of e. tenella used in a commercial planned immunization program (coccivac). broiler cockerels were started in floor pens on new pine shavings litter. immunizing oocysts were administered in the drinking water during the first week with total dose per bird of 175 oocysts of the control strain (coccivac); 175, 350, or 700 oocysts of the wis-f-125; 350 oocysts of wis-f ...1979471895
effects of anaerobic bacteria on eimeria tenella infection in bacteria-free, monofloral, and conventional chickens.bacteria-free, monofloral, and conventional chicks were infected with eimeria tenella. monofloral chicks were established by inoculating birds in several gnotobiotic isolators with a single species of escherichia coli or with one of three bacteroides sp. isolates (no. 157, no. 202, or no. 366). daily weights of individual birds were recorded for six days post-infection (pi). on day 6 pi all birds were sacrificed and cecal lesions were scored. conventional, infected birds lost weight on days 5 an ...1978353773
robenidine resistance in eimeria tenella.robenidine protected chickens against cecal coccidiosis infections initiated by a strain of the parasite that had no previous exposure to drugs. no cross resistance was found with 13 strains resistant to other anticoccidials. a strain of eimeria tenella that was serially propagated in chickens fed mash containing robenidine became resistant to the chemical. no cross resistance was detected when this experimental strain was tested against 12 other anticoccidials.1978722457
the role of secretory iga in anti-coccidial immunity in the chicken.the serological and secretory immune responses of the chicken to infection with eimeria tenella were evaluated in terms of various anti-coccidial activities. serological responses were detected in the forms of precipitating, sporozoite neutralizing, anti-merozoite and anti-schizont antibodies. similarly, anti-schizont and sporozoite neutralizing activities were found in caecal contents (containing mainly iga) from infected birds and these also had the capacity to damage second generation merozoi ...1978350761
[infectivity of eimeria tenella oocysts after heat-decay of coccidia-containing poultry manure]. 1977324743
demonstration of eimeria tenella in bursa of fabricius of chickens.coccidial life-cytle stages were detected in the bursa of fabricius of broiler chickens inoculated with eimeria tenella, whether or not the chickens had previously been infected with infectious bursal disease virus (ibdv). chickens infected only with e. tenella had developing parasites in the lining epithelium, whereas chickens with both infections had gametocytes also in the epithelial cells surrounding numerous degenerating bursal cysts.1976186013
products from furans. 1. sunthesis and anticoccidial and antimicrobial activity of 5-amino-5,6-dihydro-6-methoxy-2-methyl-2-(4'-biphenylyl)-2h-pyran-3(4h)-ones and related compounds.a michael type addition of an amine to 6-methoxy-2-methyl-2-(4'-biphenylyl)-2h-pyran-3(6h)-one (1) dissolved in ether, benzene, or thf gave 5-amino derivatives of 5,6-dihydro-6-methoxy-2-methyl-2-(4'-biphenylyl)-2h-pyran-3(4h)-one (2). these by subsequent reduction with lialh4 were converted to 5-amino derivatives of 6-methoxy-2-methyl-2-(4'-biphenylyl)tetrahydro-2h-pyran-3-ol (3). both isomers a and b of 1 (in regard to the methoxy group at c6) were used for the synthesis of 2 and 3. the in vit ...1976814239
studies on the relationship between intestinal flora and cecal coccidiosis in chicken.the bacteriological and histopathological changes in the ceca of young chickens after being infected with sporulated oocysts of eimeria tenella were investigated. lactobacilli and bifidobacteria showed remarkable decrease in number on the 5th day after infection, when shizont and gametocyate came to appear, and destruction of mucosa along with severe haemorrhaging was noticed. other predominant bacteria like bacteroidaceae, catenabacteria and peptostreptococci showed only moderate and temporal d ...1976181739
methods in coccidiosis research: separation of oocysts from faeces.factors which may be important in the large-scale extraction of coccidial oocysts from faeces ha.ve been investigated with eimeria tenella. age of bird, inoculum, feeding status at the time of inoculation, period of collection, feeding status during collection, collection medium, homogenization and sieving, flotation, washing, sporulation and further purification have all been considered. the aim has been to establish a method to produce the maximum number of oocysts of a required degree of puri ...197613340
eimeria tenella: inhibition of development in cell culture by serum from chickens fed anticoccidial drugs. 1977602371
interactions in vitro between sporozoites of eimeria tenella and host peritoneal exudate cells: electron microscopal observations.the interactions of sporozoites of eimeria tenella with peritoneal cells from normal and from immunized chickens were examined in vitro. although the uptake of sporozoites by cells from immunized birds was greater than by cells from susceptible birds, no differences were apparent in their appearance in electron micrographs. entry into both macrophages and heterophils (comparable to mammalian neutrophils) was by phagocytosis. the findings are discussed.1977602366
effect of irradiation (gamma rays) on the biology of eimeria tenella oocysts.effect of gamma rays on the biology of the progeny of the irradiated eimeria tenella oocysts was investigated. the parent inoculum of sporulated oocysts was exposed to 5 to 60 kr (gamma rays). these oocysts were fed to chicks. the oocysts voided by the chicks were collected and sporulated. the sporulation rate, pathogenicity, immunogenicity and reproduction potential of these oocysts--the progeny of the irradiated oocysts--were compared with those of the unirradiated oocysts. it was observed tha ...1977596797
mutalomycin, a new polyether antibiotic taxonomy, fermentation, isolation and characterization.mutalomycin is a new metal-complexing polyether antibiotic produced by a strain of streptomyces mutabilis nrrl 8088. the metabolite, a monocarboxylic acid, was isolated as the sodium salt c41h69nao12. the structure of this polyether was established by x-ray analysis of its potassium salt c41h69ko12. mutalomycin contains six heterocyclic rings and is structurally related to nigericin. the metabolite is active against gram-positive bacteria and eimeria tenella (chicken coccidiosis).1977591458
[eimeria tenella studies in quails and eimeria kofoidi studies in chickens].studies on two types of coccidiosis e. tenella isolated from diseased chickens and e. kofidi isolated from diseased young quails were carried out. ten 14 day-old quails of the species alektor is graeca cypriatis and thirty 10-, 20-and 30 day-old chickens of the white plymuth breed were used. by cross invasion of sporulated oocysts of both coccidia types the shizogonal development in non-specific host birds was observed. it was established that e. tenella finds suitable conditions for an endogeni ...1979532091
enhancement of the anticoccidial activity of polyether antibiotics in chickens by tiamulin.the anticoccidial activities of monensin and lasalocid have been studied separately and in combination with tiamulin, a new pleuromutilin derivative. combinations of constant tiamulin concentration (.0125%) in drinking water with various levels of polyether anticoccidials (6.3 to 125 ppm) in feed and conversely of constant levels of anticoccidials with various concentrations of tiamulin were used. the prophylactic efficacy of these combined treatments in battery raised broiler chickens infected ...1979530903
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
a mechanism for secretory iga-mediated inhibition of the cell penetration and intracellular development of eimeria tenella.the ability of eimeria tenella sporozoites to develop normally in cultured chick kidney cells was used as an indicator of the anticoccidial effects of sera and extracts of caecal contents or tissue. pre-treatment of sporozoites with normal serum globulin enhanced the frequency of intracellular development but pre-treatment in balanced salt solution, without protein, damaged sporozoites so that most had lost the ability to differentiate, even when they were able to invade host cells. the same inh ...1979437838
eimeria tenella: specific reversal of t-butylaminoethanol toxicity for parasite and host by choline and dimethylaminoethanol. 1979421765
[composition of volatile fatty acids of ascaridia galli (schrank 1788) and their effect on eimeria tenella railliet et lucet 1891]. 19761024139
eimeria tenella: experimental studies on the development of resistance to amprolium, clopidol and methyl benzoquate.the development of resistance by the houghton strain of eimeria tenella to the anticoccidial drugs amprolium, clopidol and methyl benzoquate has been studied. resistance to amprolium and clopidol developed more readily in experiments where a large number of coccidia were exposed to the drug, either by increasing the number of oocysts in the inoculum or by increasing the number of birds in the group. when 45 birds were given 2.0 x 10(6) oocysts, resistance to amprolium and clopidol appeared after ...1978274682
monensin, eimeria tenella infection, and effects on the bacterial populations in the ceca of gnotobiotic chickens.bacteria-free chicks in separate plastic film isolators were inoculated orally with single species of bacteria. within an isolator, half the birds were fed unmedicated feed and half received feed containing 100 ppm monensin. with clostridium perfringens as the established species of monoflora, bacterial counts from the duodenum were 10(4) times lower and counts from the ceca were three times lower in monensin-fed birds compared to unmedicated birds. infection with eimeria tenella stimulated an e ...1978209434
reduction of clostridium perfringens by feed additive antibiotics in the ceca of chickens infected with eimeria tenella.two experiments were performed ot investigate the effect of feed additive antibiotics on clostridium perfringens and enterobacteriaceae in the ceca of chickens infected with eimeria tenella. in the first experiment, chickens were continuously fed rations containing thiopeptin, 2 mg./kg.; bacitracin, 20 mg./kg.; penicillin, 12 mg./kg.; or chlortetracycline, 22 mg./kg. one day after antibiotic feed was given, each bird received an oral inoculation of 30,000 e. tenella oocysts. the growth of c. per ...1975169521
eimeria tenella in chickens: development of resistance to quinolone anticoccidial drugs.the development of drug resistance by the present houghton strain of eimeria tenella to the quinolones, methyl benzoquate and buquinolate, was found to take place after a single experimental passage. the development of resistance was independent of drug selection pressure and showed cross resistance to other quinolones, but not to amprolium and robenidine. when the weybridge, beltsville and elberfeld strains of e. tenella were compared under similar laboratory conditions, the weybridge and elber ...19751058450
[the intensity of c-14-glycine incorporation into the proteins of different organs of chickens with coccidiosis caused by eimeria tenella]. 197546602
fine structural aspects of an embryo-adapted strain of eimeria tanella in the epithelial cells of the chorio-allantoic membrane.the fine structure and development of the endogenous stages of an embryo-adapted strain of eimeria tenella in chicken embryos is described. first-generation merozoites were formed by endodyogeny in uninucleate developmental stages as well as schizogony and the endoplasmic reticulum of merozoites of the second-generation schizonts appeared as a circular structure, often enclosing other organelles. in contrast to the parent strain, development of the second-generation schizonts was restricted to c ...1978652387
[some aspects of nitrogen metabolism in the liver tissue of chicks infected once and 3 times with a large dose of eimeria tenella oocysts].studies of the contents of total, albuminous and residual nitrogen in the liver tissue of chickens at a single and 3-fold infection with 100 000 oocysts of e. tenella were undertaken. it was established that a single infection of 20-, 40- and 60-day old chickens is accompanied by a decrease in the contents of total and albuminous and an increase in the residual nitrogen. their level is restored as a rule by the 20-th day after infection. in 40-day old chickens by the 20-th day after the 2-nd and ...1976940688
studies on the mode of action of beclotiamine on eimeria tenella.the thiamine antagonist beclotiamine showed anticoccidial activity against eimeria tenella, although metabolites and related substances were inactive. oocyst production in experiments employing unilateral caecal ligation suggested that the drug reached parasitized cells by downward movement through the intestinal lumen, rather than by absorption and systemic transport. in chickens given 100 p.p.m. beclotiamine in the feed over a period of 7 days, duodenal drug concentrations of approximately 5.8 ...1978704151
noboritomycins a and b, new polyether antibiotics.noboritomycins a and b, two new polycyclic ionophoric polyethers were isolated from a strain of streptomyces noboritoensis. the crystal structure and absolute configuration of noboritomycin a were established by x-ray analysis of its silver salt c43/63o14ag. noboritomycin a is the first metabolic polyether possessing two carboxylic acid functions on the carbon backbone (c-31), namely a free acid and an additional carboxylic acid ethylester group. an unusual spiroketal system as well as a salicyl ...1978711624
energy and nitrogen metabolism of chickens infected with either eimeria acervulina or eimeria tenella.1. the effects of sublethal infections of e. acervulina and e. tenella on the energy and nitrogen metabolism of groups of five broilers aged 16 d were studied for 16 d in respiration chambers. 2. the metabolisable energy content of the diet for chickens infected with e. acervulina was 0.689 of its gross energy content and n retention was 42.5 g/100 g n intake compared with 0.738 and 47.1 g respectively, in uninfected pair-fed controls. chickens infected with e. tenella were similarly affected. 3 ...1979466523
eimeria tenella: vitamin requirements for development in primary cultures of chicken kidney cells.development of eimeria tenella was studied in primary cultures of chicken kidney cells maintained in medium 199 lacking each of the following: vitamin a, biotin, p-aminobenzoic acid, folic acid, nicotinamide, ca pantothenate, pyridoxine, pyridoxal, riboflavin, thiamin, ascorbic acid, calciferol, alpha-tocopherol, and menadione. data obtained concerning numbers of mature schizonts or total numbers of parasites or both indicated that all of the vitamins are needed for 1st- and 2nd-generation schiz ...1978739415
attempts at transfer of immunity against eimeria tenella in vitro and in vivo.the spleen lymphocytes obtained from chickens immue against e. tenella were not able to prevent development of e. tenella when applied to chicken kideny cell cultures or intraperitoneally to isogenous healthy chickens. only when both, lymphocytes and e. tenella sporozoites were injected simultaneously to peritoneal cavity of healthy chickens, the production of oocysts was negligible. spleen lymphocytes of chickens probably do not play an important role in the immunity against eimeria tenella coc ...1977903031
effect of dietary antibiotics on chickens infected with eimeria tenella.two experiments were performed to study the effect of dietary antibiotics on percent daily weight change, mortality and gross cecal pathology in chickens during the critical phase of eimeria tenella infection. in the first experiment, chickens were continuously fed ration containing thiopeptin, 2 mg/kg.; bacitracin, 20 mg./kg.; penicillin, 12 mg./kg.; or chlortetracycline, 22 mg./kg. one day after antibiotic fed was given, each bird received an oral inoculation of 30,000 sporulated oocyts. in th ...1976935023
scanning electron microscopy of damage to the cecal mucosae of chickens infected with eimeria tenella.a group of chickens were inoculated with 100,000 eimeria tenella oocysts each. the birds were sacrificed on days 4-14 postinoculation. tissue samples from 4 different areas of each cecum examined were obtained and processed by the osmium-thiocarbohydrazide-osmium technique. examination of the prepared tissues with the scanning electron microscope revealed lesions ranging from localized tissue swelling to complete disruption of the mucosal epithelium due to the rupture of large numbers of epithel ...1978646764
development of immunity to coccidiosis in chickens administered anticoccidials in feed.new combinations of techniques were employed for comparing the development of immunity of eimeria tenella in chickens being medicated with 12 different anticoccidials. broiler-type birds in batteries received a daily measured dose of e. tenella oocysts for 15 consecutive days while the drug was administered at the manufacturer's recommended level. two or more tests of each drug gave the following ratings: strong suppression, monensin (121 ppm), salinomycin (80 ppm), lasalocid (75 ppm); moderate ...1978697660
eimeria tenella: experimental studies on the development of resistance to robenidine.the development of resistance by the houghton strain (h) of e. tenella to robenidine has been studied in the laboratory, by serially passaging the strain in chickens fed increasing concentrations of drug. resistance to robenidine developed more readily in experiments using larger numbers of birds with higher numbers of oocysts in the inoculum. both these factors increased the parasite population and increased the chance of selecting parasites resistant to the drug. e. tenella (h) was made resist ...19761012746
further studies on the use of chicken embryo infections for the study of drug resistance in eimeria tenella.infections in the chicken embryo have been used to study the development of drug resistance in an embryo adapted strain of e. tenella. resistance was developed to decoquinate, clopidol and robenidine by serially passaging this strain, but evidence for the development of resistance to amprolium was inconclusive. resistance to decoquinate developed more readily than to the other drugs. attempts to increase resistance to clopidol, robenidine and amprolium by increasing the sporozoite inoculum and b ...19761012747
cecal coccidiosis in poultry as affected by prior exposure to aflatoxin b1.young new hampshire and broiler chickens were given feed containing 2 concentrations of aflatoxin b1 (0.2 or 2.0 ppm). the larger concentration caused severe toxicosis and death in the new hampshire chicks, but did not cause gross signs in the broiler chicks. however, temporary stunting was seen on both new hampshire and broiler chicks during periods of aflatoxin feeding, along with persisting decreased weight gains in the broiler chicks; the latter apparently recovered during the next 21 days o ...19761247200
comparative in vitro development of precocious and normal strains of eimeria tenella (coccidia).eimeria tenella strain wis-f is known to develop in chickens with a significantly shortened prepatent period and its pathogenicity is virtually completely attenuated. in vitro development of this strain paralleled development of the control (wisconsin) strain through the first asexual generation. instead of entering 2nd generation schizogony, however, most of the wis-f merozoites developed into microgamonts or macrogamonts. wall-forming bodies were prominent in developing macrogametes at 80-88 h ...19761003341
[study of the effect of egg white and thiamine on coccidiosis in chickens caused by e. tenella].studied was the effect of tiamin at the rate of 50 mg/kg mixture and white of egg in ratios of 25 and 50 per cent to the feed on the course of coccidiosis in chickens caused by eimeria tenella. it was found that those of the birds that were offered 25 per cent white of egg and tiamin in a dose of 100 mg per kg exhibited more severe signs of coccidiosis had more pronounced morphologic changes with a higher mortality rate and the amount of the oocysts shed was higher than the same indices in birds ...19761030877
development and characterization of monoclonal antibodies to first-generation merozoites of eimeria bovis.merozoites of eimeria bovis were harvested from bovine monocyte cell cultures and used to immunize balb/c mice. spleens from immunized mice were removed and the cells fused with mouse myeloma cells. supernates from resulting hybridoma cell lines were examined for antibodies to first-generation e. bovis merozoites using an indirect immunofluorescent antibody (ifa) assay. three positive cell lines were identified and cloned by limiting dilution. all three cell lines produced immunoglobulins of the ...19921281590
effects of saturated sodium chloride solution on coccidial oocysts.using the ability to sporulate as a measure of viability, the effects of exposure of unsporulated oocysts of 10 species of coccidia of chickens, rabbits and cattle to saturated nacl solution has been studied. although appreciable deformation and collapse of the oocyst occurred after 1-2 days contact, the effect was reversible after washing free from salt and incubating. some reduction in ability to sporulate following several days contact with saturated salt was noted in most species, although n ...1978756524
eimeria tenella in gnotobiotic chickens: hematocrit, weight change, cecal pathology, and mortality.on days 5 to 8 after oral inoculation with 200,000 eimeria tenella oocysts, the mean hematocrits of bacteria-free, bacillus cereus-monoflora and conventional chickens were equally reduced below control values. weight loss was first observed in bacteria-free and monoflora fowl between days 4 and 5 after e. tenella inoculation, whereas conventional fowl initially displayed weight loss between days 3 and 4. gross cecal lesion scores and total mortality of 4 experiments were not significantly differ ...1975805225
[synthesis of nucleic acids and proteins in the appendix of chickens infected with eimeria tenella].a comparative study was carried out of the synthesis of dna, rna and protein in blind appendages of the intestine of healthy and infected with e. tenella chickens. it was established that the inclusion of p32 into dna and c14 - orotic acid into rna increases in 2-10 days after the infection. an intensive inclusion of c14-lysine into protein of blind appendages was observed in 2-6 days after the infection of chickens. under the effect of the parasite an activation of metabolism of dna, rna and pr ...19761035795
drug resistance in coccidia: a robenidine-resistant strain of eimeria tenella.tests for resistance to a recently introduced anticoccidial drug, robenidine, were performed on a strain of eimeria tenella recovered from broiler chickens infected with acute cecal coccidiosis. the strain was identified previously and again confirmed by the timing of mortality of the infected chickens (five to six days postinfection), the appearance of lesions and parasites in ceca only, and the measurements (21.6 +/- 1.9 micron x 19.8 +/- 2.4 micron) of the oocysts. the tests showed that the s ...1977922562
effects of high environmental temperatures on cecal coccidiosis.maintenance of broiler or white leghorn cockerels in a high temperature (32 c.), high humidity (90%) environment for six days following artificial infection with eimeria tenella significantly reduced coccidiosis severity as compared to birds similarly infected and maintained in an ambient environment averaging 24.5 c., and 62% humidity. disease severity was determined by lesion scores, fecal scores, and hematocrit readings. the heavier broiler stock maintained body temperatures of 0.7-1.6 c. hig ...1976951370
drug screening in cell culture for the detection of anticoccidial activity.methods for screening compounds against eimeria tenella in cell culture and in the chicken are described. an analysis for incidence of anticoccidial activity and host cell toxicity has been made of 11550 compounds screened in vitro, and some correlation of activity in vitro and in vivo has been attempted. the results show that screening compounds in tissue (cell) culture is not a satisfactory or reliable alternative to screening in chickens, although in vitro studies undoubtedly have a part to p ...1976980538
lerbek, a synergistic mixture of methyl benzoquate and clopidol for the prevention of chicken coccidiosis.methyl benzoquate at 20 ppm or clopidol at 250 ppm in the diet show true coccidiostatic activity in infections with eimeria tenella in the chick. lerbek, a synergistic mixture yielding 8-35 ppm methyl benzoquate and 100 ppm clopidol, produced a partially coccidiocidal effect; relapses following restricted periods of medication were less severe, and suppression of parasite development following delayed medication was quicker and more effective with either component of the mixture used alone.19751055985
scanning electron microscopy of the cecal mucosa in eimeria-tenella-infected and uninfected chickens.four major types of surface conformation were observed in the ceca of uninoculated control chickens. spatulate villi were found in the cecal neck region, low ridges in the region where the neck expands, protruding collarlike structures in the mid cecal pouch, and flattened collars in the distal portion. in ceca infected with eimeria tenella, there was some erosion and sloughing of the mucosal cells. these lesions were slight in the neck region, more severe in the dilated portion, most severe in ...19751156258
genetic recombination of precociousness and anticoccidial drug resistance in eimeria tenella.two strains of eimeria tenella differing in decoquinate-resistance and developmental rate were crossed. strain wis-f was decoquinate-sensitive (ds) and precocious (p+), while strain 368 was decoquinate-resistant (dr) and had a normal developmental rate (p-). cultures of the parent strains and a culture derived from a mixture of parent strain oocysts were propagated through drug and developmental barriers to select parasites with the respective parental phenotypes (ds/p + and dr/p-) and the recom ...1976997719
preparation and purification of merozoites of eimeria tenella.second-generation merozoites of eimeria tenella were obtained from both infected cecal tissue and infected chorioallantoic membranes of embryonated eggs. the merozoites were harvested from the tissue by incubation with hyaluronidase, yielding approximately 4 times 10(7) merozoites per cecum and 3 times 10(6) merozoites per chorioallantoic membrane. subsequent purification of the merozoites by density centrifugation and glass bead filtration resulted in a 54% overall yield and a final preparation ...19751165553
sequential use of coccidiostats: effect on development by eimeria tenella of resistance to amprolium, nicarbazin, unistat, and zoalene.a strain of the cecal coccidian of chickens, eimeria tenella, was propagated serially in chickens fed mash containing amprolium, nicarbazin, unistat, or zoalene. each group of chickens received a different coccidiostat on a rotating basis. the strain was propagated through 40 groups of chickens; thus, the strain was intermittently exposed 10 times to each coccidiostat. the end product of this simulated shuttle program of prophylactic anticoccidial medication was a strain resistant to three of th ...19751164311
cultivation of eimeria tenella in japanese quail embryos (coturnix coturnix japonica).complete development of eimeria tenella in japanese quail embryos was observed. sporozoites were inoculated into the allantoic cavity of 7-day-old japanese quail embryos (coturnix coturnix japonica), after which the infected embryos were incubated at 41 c. in the chorioallantoic membrane mature first generation schizonts, mature second generation schizonts, and gametes were detected at 48 hr postinoculation of sporozoites (pi), 84 hr pi, and 126 hr pi, respectively. mature gametes and zygotes we ...19921491294
scanning electron microscopy of eimeria tenella infection and subsequent repair in chicken caeca. 19751181349
relative value of oocyst counts in evaluating anticoccidial activity.birds medicated with roxarsone and in another experiment with zoalene in the feed produced higher oocysts counts than unmedicated control birds receiving the same oocyst dose of eimeria tenella or a mixture of six species (e. tenella, e. necatrix, e. brunetti, e. maxima, e. acervulina, and e. mitvati). these experiments confirm the conclusion that oocyst counts constitute an unsatisfactory and unreliable parameter for judging effectiveness of an anticoccidial even though such increases are a rel ...19751200950
interaction of aflatoxin with eimeria tenella infection and monensin in young broiler chickens.young broiler chicks inoculated with eimeria tenella and given a diet containing 2.5 mug aflatoxin/g had significantly higher mortality than birds with aflatoxicosis or coccidiosis alone or uninoculated controls. this effect was seen even when a light coccidial infection alone did not increase mortality or cause weight depression. in addition this higher mortality with the combination began earleir and occurred at a higher rate than did mortality from aflatoxin or cecal coccidiosis alone. dietar ...19751200947
response of chickens with genetically different hemoglobin types to infection with eimeria tenella and mechanical bleeding.the hematological and body-weight responses of chickens with mutant and normal hemoglobin types were compared under conditions of hematopoietic stress from coccidiosis infection as well as blood loss from mechanical bleeding. a dose of 100,000 eimeria tenella oocysts caused a highly significant decrease (about 30%) in the packed cell volume, resulting in a severe anemia in all hemoglobin types. hematological response to the anemia produced by the coccidiosis was similar for all three hemoglobin ...19751200949
penetration of eimeria tenella sporozoites under different oxygen concentrations in vitro.sporozoites of eimeria tenella (wisconsin strain) were inoculated onto monolayers of normal chicken kidney fibroblasts and cultured in rpmi-1640 supplemented with 5% fetal bovine serum, sodium bicarbonate, and gentamicin under either aerobic, 5% co2/95% air, or anaerobic conditions. penetration of fibroblasts by sporozoites under co2 or anaerobic conditions at 2 and 24 hr postinoculation was 3-4 times greater than that in the aerobic atmosphere. effect of reduced oxygen concentrations, i.e., 20. ...19921597804
anticoccidial activities of 7-bromo-n-(2-imidazolidinylidene)-1h-indazol-6-amine and other alpha 2 adrenergic agonists.activity against the coccidial pathogen eimeria tenella in chickens has been discovered among alpha 2 adrenergic agonists. the clonidine analog 7-bromo-n-(2-imidazolidinylidene)-1h-indazol-6-amine was active in feed at 7.5 ppm, a concentration similar to the use levels of potent commercial agents, e.g., maduramicin. additional alpha 2 agonists were also found to have anticoccidial activity, for example, the catecholamine nordefrin, which is chemically unrelated to clonidine. however, alpha 1 ago ...19921351380
further investigation of anticoccidial activity of 7-bromo-n-(2-imidazolidinylidene)-1h-indazol-6-amine.the clonidine analog 7-bromo-n-(2-imidazolidinylidene)-1h-indazol-6-amine exhibits potent activity against eimeria tenella infections in chickens. disease control was abrogated by a selective alpha 2 antagonist, which is consistent with the dependence of such activity upon binding to receptors with characteristics of the vertebrate alpha 2 adrenoceptor. lack of significant activity against the parasite in tissue culture and our inability to detect significant binding of alpha 2 adrenergic ligand ...19921351381
dihydrofolate reductase from eimeria tenella: rationalization of chemotherapeutic efficacy of pyrimethamine.dihydrofolate reductase activity of 0.2 nmole of dihydrofolate reduced/min/mg protein was detected in crude extracts of unsporulated oocysts of eimeria tenella. the enzyme was purified by a combination of affinity and ion-exchange chromatography. its molecular weight was estimated as 240,000 daltons. an anticoccidial drug pyrimethamine is a potent inhibitor of the activity of e. tenella dihydrofolate reductase (ki = 3 nm), but it is less effective an inhibitor of dihydrofolate reductase from chi ...19751059772
effect of feed additive antibiotics on chickens infected with eimeria tenella.six experiments were carried out to study the effect of feed additive antibiotics on body weight, mortality and oocyst production in chickens infected with coccidiostat-susceptible or -resistant strain of e. tenella. levels of antibiotic and coccidiostat in fed (mg./kg.) were: thiopeptin, 2; zinc bacitracin, 20; penicillin, 12; chlortetracycline, 22; amprolium plus ethopabate, 125 plus 8; clopidol, 125. all experiments included 7 groups; 2 of these groups were uninfected and infected controls, a ...19751161694
simultaneous purification of merozoites and schizonts of eimeria tenella (apicomplexa) by percoll flotation and assessment of cell viability with a double fluorescent dye assay.the asynchronous development of eimeria tenella in orally infected chickens makes it possible to purify second generation merozoites (meros) and shizonts from a single mucosal homogenate. after centrifugation in 30% percoll in phosphate-buffered saline (percoll-pbs), debris, villi, and schizonts float, whereas meros and erythrocytes are pelleted. erythrocytes are lysed by a mild hypotonic shock; meros are filtered through a cotton wool plug and collected by centrifugation. the 30% percoll-pbs su ...19911779304
characterization in vitro and in vivo of resistance to ionophores in a strain of eimeria tenella.a field isolate of eimeria tenella (fs139) was propagated several times in chickens medicated with 200 ppm of dietary monensin. in a laboratory test with 2-wk-old-chickens, the strain was resistant to monensin, salinomycin, and lasalocid given at double use level and was resistant to narasin and maduramicin at the normal use level. in comparison, a laboratory strain (wis) was controlled by the normal use level of each product. when free wis sporozoites were treated in vitro with 1.0 microgram/ml ...19921491300
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
[study of immunity in coccidiosis in chickens experimentally infected with marek's disease].the immunity was studied against coccidiosis in birds that had preliminary been infected with marek's disease. results showed that birds infected with marek's disease are unable to build up stable immunity against an oocyst infection of eimeria tenella. the rate of mortality due to marek's disease in birds infected with the virus of marek's disease and additionally infected with oocysts of e. tenella was higher as compared with that in birds that were infected only with the virus of marek's dise ...19751210012
[determination of the purity of eimeria species of chickens].the morphologic criteria length and breadth were used for the examination of the purity from 23 strains of different eimeria species in the fowl (eimeria tenella, e. acervulina, e. maxima, e. necatrix) by three methods: tabulate graphic method, determination of the size of concentration, analysis with counter. the tabulate graphic method by use of peak value as only criterion of valuation has suitable proved for the screening test. a qualification of the degree of purity is reached in the form o ...19911888074
eimeria tenella: host specificity in gallinaceous birds.eight species representing 8 genera of gallinaceous birds were used: alectoris graeca; colinus virginianus; coturnix coturnix; gallus gallus; meleagris gallopavo; numidia meleagris; pavo cristatus; phasianus colchicus. three week-old birds were dosed with sporulated oocysts of eimeria tenella beltsville strain. at 4, 24, 48, 72, 96, 120 and 144, and 168 hr after inoculation, 1-3 infected birds and uninoculated controls of each species were killed by cardiac exsanguination. pieces of intestines w ...19761271306
growth of eimeria tenella in vitro in macrophages from chicken peritoneal exudates. 19761258530
studies of the mitochondria from eimeria tenella and inhibition of the electron transport by quinolone coccidiostats.intact but fragile mitochondria were isolated from unsporulated oocysts of eimeria tenella. the mitochondria respired in response to succinate, malate plus pyruvate, and l-ascorbate at rates of 1.00, 0.40, and 0.25 mu1 o2/min/mg protein, respectively. spectrophotometric analyses of the cytochromes in mitochondria and whole oocysts revealed b-type and o-type cytochromes, at roughly similar levels, but no cytochrome c could be detected. the mitochondrial respiration was inhibited by cyanide, azide ...19751171697
purification and characterization of a protective antigen from eimeria tenella.chickens were partially protected against coccidiosis induced by eimeria tenella by using extracts prepared from sonicated sporulated oocysts or from sonicated sporozoites. following gel filtration of either extract, most of the protective antigens were confined to a single pool of proteins in the molecular mass range between 20 and 30 kda. further purification of proteins from the protective pool of sporulated oocyst extract yielded a protective polypeptide with a molecular mass of 26 kda. an a ...19911997442
immunization of young chickens by trickle infection with eimeria tenella.immunization of chickens was attempted with low levels of eimeria tenella oocysts (50 oocysts per day) over the first 1 or 2 weeks of life--the "trickle infection" (ti) method. when chickens were immunized by ti at 0-13 days of age, no cecal lesions and a reduced number of oocysts in ceca were observed after challenge at 17 days of age. ti at 0-6 days of age conferred better protection against challenge with e. tenella than did ti at 7-13 days. however, cecal lesions were observed in almost all ...19921485853
estimation of relative fecundity in eimeria tenella strains by a mixed infection method.the relative fecundity of populations of eimeria tenella was estimated by means of mixed infection using electrophoretic variation of glucose-phosphate isomerases (gpis) as a genetic marker. a decoquinate-resistant strain with gpi-9 isozyme (dr-niah), a decoquinate-sensitive one with gpi-1 (ds-iwate), and three decoquinate-resistant lines (no. 3, 4, and 5) derived from cross-fertilization between dr-niah and ds-iwate, were used. the gpi phenotypes of the no. 3 and no. 4 lines are gpi-9, and that ...19921535431
potential of a recombinant antigen as a prophylactic vaccine for day-old broiler chickens against eimeria acervulina and eimeria tenella infections.a genetically engineered eimeria tenella antigen (gx3262), produced as a fusion protein with beta-galactosidase and identified with a monoclonal antibody, induced partial but significant protection in young broiler chickens against experimental e. tenella and eimeria acervulina infections. the antigen appears to share a t-helper cell epitope with the parasite as evidenced by (a) booster inoculation with either the recombinant antigen or with a small number of live oocysts enhanced the protective ...19921589958
ultrastructure of cytoplasmic and nuclear changes in eimeria tenella during first-generation schizogony in cell culture.eimeria tenella sporozoites were inoculated into primary cultures of chick kidney cells. cells fixed from 1 1/2 to 54 hr later were examined with the electron microscope. at 1 1/2 and 24 hr, most intracellular sporozoites were fusiform and retained organelles typical of extracellular sporozoites. however, at 35 hr, rounded trophozoites were present without these structures; only a refractile body, nucleus, mitochondria, and endoplasmic reticulum remained. binucleate parasites were also present a ...19751167908
some observations on the sexual differentiation of eimeria tenella using single sporozoite infections in chicken embryos.unsporulated oocysts were recovered from the allantoic cavity of 5 chicken embryos inoculated with a single sporozoite of eimeria tenella; some of these oocysts sporulated. both macrogametes and microgametes are required for the formation of viable oocysts. the results conclusively demonstrate the bisexual nature of the sporozoite, suggest that sexual differentiation is influenced by environmental factors, and show that true clones of eimeria can be established from individual sporozoites.19761012750
differences between the anticoccidial potencies of monensin in maize-based or wheat-based chicken diets.experiments were carried out to investigate why the anticoccidial ionophore monensin is more potent against the coccidium eimeria tenella in chickens fed on a maize-based diet (as in the usa) than in chickens fed on a wheat-based diet (as in the uk). the explanation seems to be that the pathogenicity of e. tenella is lower in maize-fed chickens than in wheat-fed chickens, whether monensin is present in the diet or not. possible reasons for this are suggested. the better survival of maize-fed bir ...19921386703
modelling coccidial infection in chickens: emphasis on vaccination by in-feed delivery of oocysts.trickle immunization of poultry by incorporating wildtype strains of coccidia in the feed has been shown to be an effective and practical means of controlling coccidiosis. here we develop a mathematical model of the life cycle of eimeria tenella and estimate the model parameters from extant experimental studies. numerical solutions of the model compare well with experiment. the model provides quantitative estimates of the required trickle immunization hitherto only available after extensive time ...19921460873
detection of serum antibodies in eimeria tenella-infected chickens by enzyme linked immunosorbent assay (elisa) with merozoite and oocyst antigens.soluble antigens prepared from sporulated oocytes and second generation merozoites of e. tenella were used for enzyme linked immunosorbent assay (elisa) to investigate antibody in sera of two breeds of chickens, i.e. commercial broilers and spf single comb white leghorn layers, which were experimentally infected with e. tenella. in broilers inoculated with oocysts at 15 days of age, elisa values increased rapidly after day 19 post inoculation (pi) and reached the maximum lebel on days 29 and 32 ...19921535000
localization of a low molecular weight antigen of eimeria tenella by use of hybridoma antibodies.three monoclonal antibodies (mabs), found by western blot analysis to recognize 10-kda bands of eimeria tenella sporozoite preparations, were used with immunoelectron (ie) microscopy, immunogold-silver staining (igss), and indirect immunofluorescent antibody (ifa) light microscopy to determine the location and distribution of the antigens in or on extra- and intracellular parasites. all 3 of the mabs (designated c3, e5, and 1231) were found by ie microscopy to label amylopectin granules of extra ...19921597789
possibilities of bacteremia and toxemia in death of chickens infected with eimeria tenella.the possibility that bacteremia and toxemia were the causes of death in cases of cecal coccidiosis was investigated. germ-free and ordinary chickens with microflora were inoculated with sporulated oocysts of eimeria tenella. at 5 days postinoculation, cecal lesions in ordinary chickens were more severe than those in germ-free ones. cardiac blood, spleen, and liver were examined in ordinary chickens for bacteremia and endotoxemia, and small numbers of bacteria were recovered from both infected an ...19902241681
studies on the stage of action of lasalocid against eimeria tenella and eimeria acervulina in the chicken.broiler chickens in battery pens were either fed a diet containing 100 ppm lasalocid or no drug for 24 h prior to inoculation with sporulated oocysts of eimeria tenella or eimeria acervulina. different groups of birds remained on medicated feed for 24, 48, 72, 96, 120 or 144 h after inoculation. conversely, other groups started on an unmedicated diet, were given medicated feed at different times after oocyst inoculation. starting lasalocid medication 24 h (e. tenella) or 48 h (e. acervulina) aft ...19902251751
improved techniques for the in vitro cultivation of eimeria tenella in primary chick kidney cells.primary kidney cells of 1- to 4-week-old chickens (pckc) grown in flexiperm chambers or culture flasks were infected with ultrapure sporozoites of two eimeria tenella strains. for the 24-h parasite-free adaptation phase of the pckc culture, williams e medium plus 10% foetal calf serum (fcs) was used, and for the subsequent parasite-containing 168-h maintenance phase, we used medium 199 plus 2.5% fcs. monolayers established during that time enabled the routine development of all schizont generati ...19902381892
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
evaluation of anticoccidial drugs in chicken embryos.infections of eimeria tenella in chicken embryos were used to compare the anticoccidial activity of ten drugs. the minimal inhibitory concentration (mic) and minimal toxic concentration (mtc) were affected by the time of inoculation into the embryos and by the chemical nature of the compounds. some compounds (nicarbazin, amprolium) had no effect on the development of coccidia when they were injected into embryos after the day of infection. drugs that act early in the life cycle of coccidia (robe ...19911792230
anticoccidial activity of 8-aminoquinolines, pamaquine, primaquine and several molecular complexes and salts of pamaquine, against eimeria tenella, e. necatrix, e. acervulina, e. maxima, and e. brunetti in battery experiments.pamaquine and primaquine, the well known antimalarial 8-aminoquinolines, have not been reported for their anticoccidial activity. a series of battery experiments was conducted to investigate their activity against a laboratory strain of eimeria tenella, e. necatrix, e. acervulina, e. maxima, or e. brunetti and revealed that both drugs were effective against e. tenella and e. necatrix, but not against the other three species. pamaquine suppressed the symptoms of e. tenella induced coccidiosis at ...19911830767
comparative study of prepatent periods of eimeria tenella in the chicken and the chicken embryo. 19911834214
[study of the immunogenic capacity of the oocytes of e. tenella following irradiation with gamma rays].studied was the immunizing capacity of eimeria tenella oocysts, treated with gamma rays at the rate of 6000 r, in 10- and 20-day-old chickens. the oocysts sporulated after treatment. applied at the rate of 50,000 r they showed lower virulence and were capable of inducing resistance to reinfection with nonirradiated oocysts at rates that were three times as much. following reinfection some birds manifested subclinical coccidiosis but survived. this showed that the immunization with oocysts that h ...19751239853
development of protective immunity against eimeria tenella and e. acervulina in white leghorn chickens inoculated repeatedly with high doses of turkey coccidia.repeated inoculation (immunization) of 2-week-old white leghorn chickens with 10(6) oocysts of the turkey coccidia eimeria adenoeides or e. meleagrimitis partially protected chickens against moderate challenge with e. tenella or e. acervulina oocysts, but not with e. necatrix oocysts. after challenge, mean weight gains of the immunized chickens and the unchallenged controls did not differ significantly, but weight gains of unimmunized chickens were significantly lower. the mean feed-conversion r ...19911953577
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
[subclinical coccidiosis in broilers and pullets].in the period from 1985 to 1987, 24 broiler crops (12 houses; one integration and 3 farms) and 9 pullet flocks (9 houses, 4 farms) were examined for parasites. intestinal lesion scores and the number of parasites in the intestinal lumen (semiquantitative estimation) were recorded, and the eimeria species determined when possible (broilers crops: 3rd and 5th week, pullet flocks 4th, 8th, 12th and 18th week). additionally, the quantity of parasites in litter or faecal samples was examined in regul ...19892598804
enhanced h2o2 release from immune chicken leucocytes following infection with eimeria tenella.cell-mediated immunity is thought to be important in the resistance of chickens to infection by coccidia, and it has been demonstrated that sporozoites of eimeria tenella are very sensitive to superoxide ions. therefore an investigation into the cellular responses in naive specific pathogen-free and hyperimmune birds was carried out with particular attention to their ability to produce reactive derivatives of oxygen. leucocytes were isolated from the blood, spleen and caecal mucosa of chickens i ...19921639433
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