• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.123-130
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• 1995

Artemisinin, a sesquiterpene lactone, is isolated from the leafy portion of the Artemisia annua and has been known to be effective against Plasmodium species. Since the genera of Plasmodium and Eimeria(E) tenella are included the same order, Eucoccidiidae, it is presumed that artemisinin may also be effective against E tenella. In order to study the anticoccididal effects of artemisinin, the chickens inoculated with E tenella were treated with artemisinin at different concentrations as feed additive and the results were compared to those of non-medicated, infected control(NIC) and non-medicated, non-infected control(NNC) group. Artemisinin demonstrated anticoccidial effects by showing, compared to NIC group, improved results in all parameters, such as bloody diarrhea, lesion scores, the numbers of excreted oocystis in feces, body weight gain and feed conversion rate. Anticoccidial index(ACI) of artemisinin treated group (5ppm~50ppm) was higher than that of NIC group. Improvements were greatest in the group treated with artemisinin 50ppm with an ACI of 147.6. These results indicate that artemisinin has anticoccidial effects on the Eimeria tenella.

• Korean Journal of Veterinary Service
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• v.30 no.1
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• pp.175-181
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• 2007

Parasites cause great economic loss in livestock in Korea, and can be categorized as either or indirect losses. In order to monitor the parasites from October 2005 to January 2006, 401 samples were randomly collected from cattle farms and examined the prevalence of gastro-intestinal (GI) parasites by using the sucrose flotation method and formalin-ether centrifugation method. The overall infection rate of GI parasites was about 43.4%. Of these parasites, nematodes were identified as Capillaria bovis (5.5%), Strongyloides papillosus (2.5%), Trichuris discolor (1.2%). Cestoda was observed only one species, Moniezia benedeni (2.2%). The rate of Eimeria spp was 39.2%. A total of five species of Eimeria was identified; among the species identified as above E bovis and E zuernii appeared with relatively higher infection rates. The combined infection of parasites was 35.2% in single species, 29.0% in double and 2.0% in triple infections. No cases of clinical symptoms were observed in this survey. The EPG levels of each species of parasites were very low in all infected cases.

• Parasites, Hosts and Diseases
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• v.52 no.4
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• pp.435-438
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• 2014

The disinfectant effects (DEs) of 10 types of chemicals, defined by their ability to destroy or inhibit oocysts and consequently prevent sporulation of Eimeria tenella field isolate, were evaluated in vitro. Correct species assignments and sample purities were confirmed by the singular internal transcribed spacer (ITS)-PCR analysis. A total of 18 treatments were performed, and the disinfection suppression levels were 75.9% for 39% benzene + 22% xylene (1:10 dilution), 85.5% for 30% cresol soup (1:1 dilution), and 91.7% for 99.9% acetic acid (1:2 dilution) group. The results indicate that acetic acid, cresol soup, and benzene+xylene are good candidates for suppression of E. tenella oocyst sporulation.

• Korean Journal of Poultry Science
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• v.26 no.2
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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.

• Korean Journal of Veterinary Service
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• v.35 no.2
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• pp.105-109
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• 2012

Apoptosis is a host defense mechanism that the cell uses to limit production of infectious pathogens. Although many bacteria, viruses and parasites can induce apoptosis in infected cells, some pathogens usually exhibit the ability to suppress the induction of apoptosis in the infected cells. Sophisticated evasion strategies of obligate intracellular parasites, in particular prevention of host cell apoptosis, are necessary to ensure successful replication. To study the ability of Eimeria tenella in this regard, in vitro experiments were performed applying Madin-Darby bovine kidney (MDBK) cells as host cell. We have demonstrated that productive infection of adherent cell lines by E. tenella resulted in an anti-apototic effect. This phenomenon was confirmed using in situ terminal deoxynucleotidyl transferase-mediated (TdT) deoxyuridine triphosphates (dUTP)-fluorescein nick end labeling (TUNEL) assay to detect apoptosis. Therefore, E. tenella could complete its cycle of productive infection while inducing anti-apoptosis in the infected cells. This finding might have implications for the pathobiology of E. tenella and other Eimeria species.

• Korean Journal of Veterinary Pathology
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• v.3 no.2
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• pp.69-71
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• 1999

A case of chronic cholangiohepatitis associated with Eimeria spp. is reported in a 6-month-old, male, native Korean goat. The goat died after having a 1-week history of diarrhea, anorexia and weight loss. At necropsy, numerous multifocal to coalescing, pale and mottled red foci were present throughout the liver. Histologically, numerous coccidian parasites in both sexual and asexual stages were found in the intrahepatic biliary epithelia and bile duct lumens. Based on the light microscopic and ultrastrastructural features, the parasites present in the liver were compatible with the genus Eimeria ; however, the species was not speciated.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.297-318
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• 2021

Coccidiosis is a major parasitic disease in the poultry industry, with great economic implications worldwide. It is a ubiquitous protozoan infection caused by several species of the genus Eimeria (host-specific) that colonize and reproduce in the intestine of birds, ultimately altering the health and performance of the flock. At present, several methods are used to diagnose coccidiosis in poultry, including field and laboratory techniques (intestinal lesion scoring, oocyst counting in feces, and biochemical and molecular diagnosis). Traditionally, diagnosed flocks have been treated either by vaccination to improve the active immunity of the birds against coccidiosis or supplementation of prophylactic anticoccidials to ameliorate the deleterious effects of coccidiosis. However, these methods has certain drawbacks such as vaccine-induced coccidiosis, drug resistance, and residual drug accumulation in the host. Consequently, alternative safe anti-coccidial agents, including the use of phytogenic compounds, have been explored for preventing coccidiosis. Here, we provide a simple overview of the literature on poultry coccidiosis by focusing on the etiology, diagnostic practices, and preventive measures.

• Journal of Animal Science and Technology
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• v.63 no.4
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• pp.864-871
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• 2021

Infectious calf diarrhea is one of the most significant diseases of neonatal calves. This study is conducted to identify the prevalence of pathogens in calf diarrhea for 2 years. A total of 544 feces samples from Korean native beef calves were obtained to investigate selected seven pathogens causing calf diarrhea: bovine rotavirus, bovine coronavirus, Cryptosporidium parvum, bovine viral diarrhea virus, Eimeria species, Escherichia coli K99, and Salmonella species. The presence of diarrhea, the number and species of detected pathogens, and the calves' ages were analyzed using various statistical methods depending on the case. Of the 544 calves, 340 calves (62.5%) had normal feces and 204 calves (37.5%) had diarrhea. The presence of pathogens was significantly associated with diarrhea (p < 0.01) and fecal scores and the number of detected pathogens showed a significant linear trend (p < 0.001). Of the 7 target pathogens, 6 were detected in samples, but only C. parvum (p = 0.001) and bovine rotavirus (p < 0.001) were found at significantly higher rates in diarrheic calves than in non-diarrheic calves. Only Eimeria spp. showed a significant linear trend between the detection rate of the pathogen and the age groups (p < 0.05).

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.109-115
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• 1987

Fecal samples collected from 1,424 cattle were examined for the presence of Coccidia species. A total of eleven species of Eimeria was identified; among the species identified as above E. bovis and E. zuernii appeared with relatively higher infection rates. The infection rate was most prevalent in Korean native cattle (29.07%), followed by the imported beef cattle (18.41%) and the dairy cattle (11. 99%). The number of species within positive samples ranged from one to four.

• Korean Journal of Veterinary Service
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• v.20 no.4
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• pp.349-358
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• 1997

From December 1995 to July 1997, a total of 546 Korean indigenous goats were examined for the presence of internal parasites by parenchymal organs and fecal examinations. Four hundreds seventy eight(87.5%) of the goats were infected with 4 classes and 12 parasitic species. The nematodes were Haemonchus contortus(57.5%), Oesophagostomun venulosum (52.6%), Strongyloides papillosus(48.4%), Ostertagia sp(28.4%), Trichostrongylus colubriformis(17.0%), and Trichuris ovis(13.2%). The trematodes were Paramphistomum sp(17.6%), Fasciola hepatica(15.4%), and Eurytrema Pancreaticum (8.8%). The cestode was Moniezia expansa(16.7%), and the protozoa were Eimeria sp(74.9%) and Toxoplasma gondii(8.6%). The incidence of single or mixed infections among 12 parasitic species were one species infection (6.2%), 2 species(11.5%), 3 species(19.6%), 4 species(24.9%), 5 species(17.8%), 6 species(5.9 %), and 7 species(1.6), respectively. The level of infection according to the age was considerably higher under one year(97.2%) than between one and two years(89.7%), and over two years(69.3%) Among 12 parasites, seasonal pattern was remarkably observed. Most paracites were detected at the highest level in the Winter, whereas Strongyloides papillosus and Paramphistomum sp were in the Spring, and Ostertagia sp and Fasciola hepatica were in the Autumn. Infection rates of Anaplasma sp were 8.6% of 210 goats by blood smear method, and 51.0% by complement fixation test.