• 한국가금학회지
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• 제19권3호
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• pp.151-160
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• 1992

현재 콕시듐 병의 방제는 약제 투여, 사육관리, 백신을 이용하거나 혹은 이들 방법을 적당히 혼합하여 실시하고 있다. 약제 투여 방법은 약의 내성이라는 문제점을 내재하고 있지만 아직도 콕시듐 방제에 최우선 방법으로 쓰고 있으며 이러한 약제 내성을 조금이나마 지연시키기 위하여 shuttle, 혹은 rotation program을 쓰고 있다. 따라서 약제 내성 검사는 각 농장에 어떠한 약제가 효과가 있는지를 알아보는데 가장 중요한 방법이 되어 왔던 것이다. 콕시듐 방제에 있어서 사육관리에 의한 방법은 아직은 완전한 효과적인 방법으로 정착되지 않았는데 그 이우는 소독제만으로는 콕시듐의 원충을 죽일 수 없기 때문이다. 백신에 의한 방법은 현재까지 살아있는 콕시듐 원충을 제한적으로 쓰고 있는 단계이다. 새로운 형태의 백신개발이 요즈음 연구가 되고 있는데 이 백신은 순화시킨 콕시듐 원충을 사용하거나 유전공학적 방법 혹은 원충의 일부분에 대한 항원을 추출하여 백신으로 이용하는 것이다.

• 한국가금학회지
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• 제26권2호
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• pp.131-144
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• 1999

Coccidiosis, an intestinal infection caused by intracellular protozoan parasites belonging to several different species of Eimeria seriously impairs the growth and feed utilization of livestock and poultry. Due to complex life cycle of organism and intricate host immune responses to Elmeria, coccidia vaccine development has been difficult. Understanding of basic imunobiology of pertinent host-parasite interactions is necessary for the development of novel control strategy. Although chickens infected with Eimeria spp. produce parasite-specific antibodies in both the circulation and mucosal secretions, antibody mediated responses play a minor role in protection gainst coccidiosis. Rather, increasing evidence show that cell-mediated immunity plays a major role in resistance to coccidiosis. T-lymphocytes appear to respond to coccidiosis both through cytokine production and a direct cytotoxic attack on infected cells. The exact mechanisms by which T-cells eliminate the parasites, however, remain to be investigated. Since it is crucial to understand the intestinal immune system in order to develop an immunological control strategy against any intestinal immune system in order to develop an immunological control strategy against any intestinal diseases, this presentation will summarize our current understanding of the avian intestinal immune system and mucosal immune responses to Eimeria, to provide a conceptual overview of the complex molecular and cellular events involved in intestinal immune responses to enteric pathogens.

• 한국가금학회지
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• 제17권1호
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• pp.53-58
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• 1990

닭콕시듐 원충에 대한 Lysococ소독제의 약제농도 및 접촉시간에 따른 소독효과를 측정코자 국내 분리 Eimeria nella 충의 미포자충란에 대한 포자형성 억제시험 및 포자충란에 대한 살충 효과시험을 실시하였다. 미포자충란에 대한 Lysococ소독제의 포자형성 억제효과는 4％농도로 30분 접촉시 매우 우수하였으며 5％농도에서는 10분 접촉시 완전한 억제효과를 나타내었다. 부유시험에 의한 Lysococ소독제의 포자충란에 대한 살충효과는 4％농도 10분이상 접촉시 완전하였으며, 충란 운반체시험에서는 4％농도 90분 및 5％농도 60분 접촉 시 완전한 살충효과를 나타내었다.

• 대한수의학회지
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• 제31권4호
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• pp.509-513
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• 1991

Preliminary survey on the prevalence of swine internal parasites was carried out at 91 pens of 4 piggeries being operated by the sawdust fermentation floor system in Kyunggi province. To investigate the effects of viability of eggs., larva and cysts, temperatures at the underlayer of the sawdust floor and rooms of pens were taken three times a day for 8 days. In a pig farm which has been operated by the sawdust fermentation floor system for G years, eggs and larva of Ascaris suum, Trichuris suis, Oesophagostomum sp., Hyostrongylus sp. and Strongyloides ransomi were detected from 42(70.0%) among 60 pens. Cysts and oocysts of coccidia, Balantidium coli, Entamoeba sp. were also detected from 50(83.3%) among 60 pens. In three pig farms which have been operated by the sawdust fermentation floor system for one year, eggs and larva of nematoda were not detected at all, and the contamination rates of protozoan cysts and oocysts was relatively low situation. The change of the temperature in the pig room was variable according to outside condition, whereas that in underfloor was consistently stable between $28^{\circ}C$ to $30^{\circ}C$ which was strictly suitable for the development of eggs, larva and cysts.

• 대한수의학회지
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• 제50권2호
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• pp.151-154
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• 2010

A thirty-five week old elk was referred for Chronic Wasting Disease (CWD) confirmation from Chungnam province in Korea. Necropsy revealed much bloody contents in the lumen of small and large intestines, and reddening of its mucosa. Microscopically, few coccidia showing various developmental stages were infiltrated in lamina propria of small intestine with granulomatous inflammation and congestion. They were identified as Eimeria spp. according to their location and morphological characteristics. Because fecal examination and oocyst culture were not available, the species of the Eimeria could not be confirmed. There were no detection of pathogenic bacteria such as clostridia and virus in intestinal contents. CWD was shown to be negative in immunohistochemistry test. In conclusion, it was the first Eimeria case detected in small intestine of Korean domestic elk as far as we know although Eimeria spp. were not the main cause of death.

• Parasites, Hosts and Diseases
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• 제49권3호
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• pp.299-302
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• 2011

During experimental Eimeria infections in chickens, facilities are often contaminated by fecal oocysts known to be highly resistant to both chemical and enzymatic treatments. Thus, studies using experimental Eimeria infections have been limited due to the difficulty of complete elimination of residual oocysts from both cages and facilities. To overcome this limitation, simple, inexpensive, and disposable cages were constructed from cardboard boxes and tested during experimental Eimeria maxima infections. The cages were used in animal rooms with only a 1.7% evidence of coccidia contamination between adjacent cages. No significant differences in fecal oocyst output and body weight gain were noted between animals housed in disposable cages and animals housed in wire control cages. This cage design is a useful means for preventing oocyst contamination during experimental conditions, suggesting that this disposable cage design could be used for other avian infectious disease studies.

• Animal Bioscience
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• 제37권1호
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• pp.1-15
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• 2024

Poultry coccidiosis is an intestinal infection caused by an intracellular parasitic protozoan of the genus Eimeria. Coccidia-induced gastrointestinal inflammation results in large economic losses, hence finding methods to decrease its prevalence is critical for industry participants and academic researchers. It has been demonstrated that coccidiosis can be effectively controlled and managed by employing anticoccidial chemical compounds. However, as a result of their extensive use, anticoccidial drug resistance in Eimeria species has raised concerns. Phytochemical/herbal medicines (Artemisia annua, Bidens pilosa, and garlic) seem to be a promising strategy for preventing coccidiosis, in accordance with the "anticoccidial chemical-free" standards. The impact of herbal supplements on poultry coccidiosis is based on the reduction of oocyst output by preventing the proliferation and growth of Eimeria species in chicken gastrointestinal tissues and lowering intestinal permeability via increased epithelial turnover. This review provides a thorough up-to-date assessment of the state of the art and technologies in the prevention and treatment of coccidiosis in chickens, including the most used phytochemical medications, their mode of action, and the applicable legal framework in the European Union.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1515-1521
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• 2016

Anethole and garlic have an immune modulatory effects on avian coccidiosis, and these effects are correlated with gene expression changes in intestinal epithelial lymphocytes (IELs). In this study, we integrated gene expression datasets from two independent experiments and investigated gene expression profile changes by anethole and garlic respectively, and identified gene expression signatures, which are common targets of these herbs as they might be used for the evaluation of the effect of plant herbs on immunity toward avian coccidiosis. We identified 4,382 and 371 genes, which were differentially expressed in IELs of chickens supplemented with garlic and anethole respectively. The gene ontology (GO) term of differentially expressed genes (DEGs) from garlic treatment resulted in the biological processes (BPs) related to proteolysis, e.g., "modification-dependent protein catabolic process", "proteolysis involved in cellular protein catabolic process", "cellular protein catabolic process", "protein catabolic process", and "ubiquitin-dependent protein catabolic process". In GO analysis, one BP term, "Proteolysis", was obtained. Among DEGs, 300 genes were differentially regulated in response to both garlic and anethole, and 234 and 59 genes were either up- or down-regulated in supplementation with both herbs. Pathway analysis resulted in enrichment of the pathways related to digestion such as "Starch and sucrose metabolism" and "Insulin signaling pathway". Taken together, the results obtained in the present study could contribute to the effective development of evaluation system of plant herbs based on molecular signatures related with their immunological functions in chicken IELs.

• 한국가금학회지
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• 제26권3호
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• pp.149-170
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• 1999

Protozoa of the genus Eimeria are the etiologic agents of avian coccidiosis, the most economically important Parasitic disease for the poultry industry. Coccidia multiply in intestinal epithelial cells of a wide range of hosts, including livestock in addition to poultry. Chemotherapy is extensively used to control coccidiosis. However, development of drug resistance by Eimeria parasites, the intensive cost and labor involved in the identification of new anticoccidial compounds and public awareness of drug residues in foods warrant alternative methods to prevent coccidiocic in the fast growing poultry industry. For these reasons, there is a great interest in developing vaccines against avian coccidiosis. Live Eimeria vaccines confer protective immunity, however a significant disadvantage of using these types of vaccines is their pathogenicity. Live parasites with attenuated pathogenicity also usually produce immunity but may revert back to a pathogenic form and may be contaminated with other pathogenic organisms. Killed Eimeria vaccines are safer but, unlike live attenuated vaccines, are not able to generate cytotoxic T lymphocyte responses. Recombinant vaccines are biochemically purified proteins produced by genetic engineering that consist of particular epitopes or metabolites of Eimeria. Unlike live attenuated organisms, recombinant vaccines do not possess as much risk and generally are able to induce both humoral and cell mediated immunity. DNA vaccines consist of genes encoding immunogenic proteins of pathogens that are directly administered into the host in a manner that the gene is expressed and the resulting protein generates a protective immune response. Although all of these different types of vaccines have been applied to coccidiosis, this disease continues to cause substantial morbidity and mortality in the poultry industry. Future development of an effective vaccine against coccidiosis will depend on further investigation of protective immunity to Eimeria infection and identification of important immundgenic parasite molecules.

• Animal Bioscience
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• 제37권6호
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• pp.993-1000
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• 2024

Objective: This study was conducted to investigate the differential expression of the major histocompatibility complex (MHC) gene region in Eimeria-infected broiler. Methods: We profiled gene expression of Eimeria-infected and uninfected ceca of broilers sampled at 4, 7, and 21 days post-infection (dpi) using RNA sequencing. Differentially expressed genes (DEGs) between two sample groups were identified at each time point. DEGs located on chicken chromosome 16 were used for further analysis. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis was conducted for the functional annotation of DEGs. Results: Fourteen significant (false discovery rate <0.1) DEGs were identified at 4 and 7 dpi and categorized into three groups: MHC-Y class I genes, MHC-B region genes, and non-MHC genes. In Eimeria-infected broilers, MHC-Y class I genes were upregulated at 4 dpi but downregulated at 7 dpi. This result implies that MHC-Y class I genes initially activated an immune response, which was then suppressed by Eimeria. Of the MHC-B region genes, the DMB1 gene was upregulated, and TAP-related genes significantly implemented antigen processing for MHC class I at 4 dpi, which was supported by KEGG pathway analysis. Conclusion: This study is the first to investigate MHC gene responses to coccidia infection in chickens using RNA sequencing. MHC-B and MHC-Y genes showed their immune responses in reaction to Eimeria infection. These findings are valuable for understanding chicken MHC gene function.