• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.259-262
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• 1992

This study was performed to investigate experimental transmission of Cryptosporidium parvum in a calf. A 25-day-old Korean native calf was inoculated per os with $1{\times}10^6$ C. parvum oocysts isolated from a Korean mouse. The calf commenced oocyst discharge in feces on post-inoculation day 4, and continued until the aah 11. The number of discharged oocysts Peaked($4.9{\times}10^5$) on post-inoculation day 6. However, the calf did not show signs of diarrhea. The present results indicate that C. parvum is cross-transmissible between the calf and the mouse.

• Parasites, Hosts and Diseases
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• v.31 no.3
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• pp.193-200
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• 1993

A total of 230 randomly collected formalin-fixed fecal samples (submitted to the Severance Hospital, Yonsei University) were selected for tests for human cryptosporidiosis. The stool specimens were examined for Cwptosporidium oocysts by acid-fast (AF) stain, auramin-rhodamine (AR) stain, and monoclonal antibody (mAb) OW3 fluorescence method specific for oocyst wall. Of the 230 stool specimens, 21% were identified by the AF method, 22% were identified by the AR method, and 10% were Identified by the mob fluorescence method, indicating that human Crvptosporidium infections have been existing in Korea.

• Korean Journal of Veterinary Research
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• v.54 no.4
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• pp.257-260
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• 2014

A calf suffering from diarrhea was admitted to the Animal and Plant Quarantine Agency for diagnostic evaluation. Postmortem examination revealed that the mesenteric lymph node was enlarged and small intestine wall was thin. Microscopically, a large number of small round organisms were attached to the small intestine villi. Villous atrophy and proprial neutrophil infiltration were also observed. Based on modified Ziehl-Neelsen staining, electron microscopy, and ELISA results, the calf was diagnosed with fatal cryptosporidiosis.

• Parasites, Hosts and Diseases
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• v.55 no.2
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• pp.129-135
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• 2017

A total of 60 samples were collected from 35 swimming pools in Beijing, China, and the presence of Cryptosporidium and Giardia were investigated. The results showed that 16.7% and 15.0% of samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively, with a mean concentration of 0.30 oocysts/10 L and 0.27 cysts/10 L. The oocysts and cysts were found to have higher rates of occurrence in August than in May. Genotyping confirmed the presence of Cryptosporidium hominis, C. parvum, and Giardia assemblages A and B, all of which were associated with human infections. The predominant species/assemblages were C. hominis and Giardia assemblage A. Analyses of the relationships between parasite oocysts/cysts, indicator bacteria, and physical-chemical parameters revealed that there was no correlation between 2 parasites and fecal bacterial indicators, whilst there was a significant correlation between protozoa and urea concentration, which indicates that urea concentration rather than fecal bacterial indicators might be an appropriate index for chlorine-resistant protozoa in swimming pools. This study provides useful information to improve the safety of swimming pool water and deduce the risk of protozoan infections.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.494-498
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• 1989

Hybridoma cell lines, which secrete monoclonal antibodies (mAbs) against the surface antigens of Cryptosporidium parvum Sporozoites, were produced by fusing spleen cells of C. parvum Sporozoite-immunized mice with P3-X63-Ag8 myeloma cells. Two cloned antibody-secreting cell lines, Kor1 and Ea2, were established and produced IgG1 and IgG2a antibodies, respectively. Percoll-purified sporozoites were solubilized and separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Western blot assay demonstrates that an antigen of 20-kDa was bound by monoclonals. By indirect immunofluorescence microscopy, mAb exhibited uniform binding to the sporozoite surface.

• Environmental Engineering Research
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• v.14 no.4
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• pp.244-249
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• 2009

Designing an ozone contactor is complicated because the residual ozone, log C. parvum inactivation, and bromate formation should be optimized with fluctuating water quality. OCM software was developed to assist a plant designer or an operator to fulfill the sophisticated optimization required in the design or operation of a new or an existing plant. In this article, numerical simulations were carried out using the OCM software for the design of a new ozone contactor under diverse design factors (i.e., three pHs, three temperatures, low and high dispersion numbers, and four and ten cells with complete mixing) with kinetic parameters obtained from the sand-filter effluent of a water treatment plant treating water from the Paldang impoundment. The results of the simulation suggested that a high residual ozone concentration at low pH and low temperature would be challenging, and PFR-like hydrodynamics could lower the residual ozone concentration. The inactivation of C. parvum oocysts increased at a lower pH. A lower dispersion number and more cell division increased the inactivation efficiency. Bromate was instantaneously formed during the initial ozonation stage. The effluent concentration was much lower than the regulatory levels imposed by the USEPA because of the low bromide level in raw water.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.531-538
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• 2007

The effects of temperature, coagulants and pre-chlorination on the removal of turbidity and pathogenic protozoa by coagulation process were investigated using jar test of lab scale. In room temperature ($25^{\circ}C$), protozoa were removed over 1.0log at the proper concentration range of coagulants, and up to over 2log at the optimal concentration of coagulants. Considering the 1.5log target removal for Giardiain the processes of coagulation, sedimentation, and filtration, this results implies that the target could be satisfied. However, the removal of protozoa and turbidity was reduced, and optimal PAC concentration was narrowed in low turbidity and cold temperature ($5^{\circ}C$). These results suggest that the drop of coagulation efficiency may be occurred in winter if the conditions are not optimized. Despite the effect of water temperature, the relation of turbidity and protozoa removal appeared to be good. The various kinds of coagulants did not significantly affected for removals of turbidity and protozoa when the concentrations of $Al_2O_3$ were considered. Prechlorination did not increase or decrease the removal of turbidity and protozoa in optimum condition at room temperature, pH 7, 15mg/L of PAC concentration.

• Korean Journal of Poultry Science
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• v.17 no.1
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• pp.53-58
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• 1990

Tests to evaluate the efficacy of disinfectant "Lysococ" against the oocfsts of Eimeria tenella were tested. In the sporulation test the sporulation of unsporulated oocysts of E. tenella was nearly suppressed by contact with "Lysococ" in 4% concentration after 30 minutes. In the suspension test with sporulated oocysts, "Lysococ" 4% disinfected sporulated oocysts of 5. tenella completely after a contact tune on 10 minutes. When using the oocyst-carrier test, the 4% solution was able to disinfect sporulated oocysts after a 90 minutes contact time.ter a 90 minutes contact time.

• Korean Journal of Veterinary Research
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• v.50 no.2
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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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• v.49 no.1
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• pp.25-31
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• 2011

Cryptosporidium parvum is known as one of the most highly resistant parasites to gamma irradiation. To morphologically have an insight on the radioresistance of this parasite, ultrastructural changes in C. parvum sporozoites were observed after gamma irradiation using various doses (1, 5, 10, and 25 kGy) following a range of post-irradiation incubation times (10 kGy for 6, 12, 24, 48, 72, and 96 hr). The ultrastructures of C. parvum oocysts changed remarkably after a 10-kGy irradiation. Nuclear membrane changes and degranulation of dense granules were observed with high doses over 10 kGy, and morphological changes in micronemes and rhoptries were observed with very high doses over 25 kGy. Oocyst walls were not affected by irradiation, whereas the internal structures of sporozoites degenerated completely 96 hr post-irradiation using a dose of 10 kGy. From this study, morphological evidence of radioresistance of C. parvum has been supplemented.