• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.657-664
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• 1993

To reveal the immunogenicity of ${\gamma}-irradiated$ E tenella and its progeny, a series of experiments on the effects of Cobalt-to ${\gamma}-irradiation$ was performed. The SPF chickens inoculated with diffenrt doses of inoculum were challenged with $1{\times}10^5$ oocysts of virulent E tenella. The levels of 100 Gy ${\gamma}-irradiation$ from $^{60}Co$ and of inoculum with $1{\times}10^4$ oocysts were recognized as proper as immunogen by comparison of survival rates, body weight gains, blood in feces and lesion scores in the chickens. In these trials of challenge with virulent E tenella after inoculation with $1{\times}10^4$ oocysts of the ${\gamma}-irradiated$ E tenella and its progeny, the survival rates of the chickens challenged with the virulent E tenella after immunization with the 1st and the 3rd progeny groups of ${\gamma}-irradiated$ E tenella oocysts were higher(l00%) than that(87.0%) of the challenged control group. The signs of blood in feces and the lesion scores were seen markedly lower with the ourput of the smaller number of oocysts, i.e. OPG 103,900 and 25,800 in the groups of the 1st and the 3rd progeny, respectively, than those(OPG 1,658,900) of the challenged control group. The body weight gains of the 1st and the 3rd progeny groups, the 1st week and the 2nd week after challenge, were higher (2.6g and 155.4g, 11.6g and 168.9g respectively) than those(-85.8g and 63.6g, respectively) of the challenged control group, and the feed conversion ratios(FCR 3.28 and 2.96) of the 1st and the 3rd progeny groups were lower than that(FCR 5.60) of the groups challenged control group. The anticoccidial indices(70.5 and 93.9) of the groups challenged with the virulent oocysts of E tenella after immunization with the 1st and the 3rd progeny of the ${\gamma}-irradiated$ E tenella were significantly higher than that (ACI -81.9) of the challenged control group. It was thought that the immunogenicity of ${\gamma}-irradiated$ E tenella would be increase according to increase the number of generation passaged in chicken. That might be because of increasing the pathogenicity of ${\gamma}-irradiated$ E tenella according to increase the number of generation passaged in chicken.

• Parasites, Hosts and Diseases
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• v.33 no.2
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• pp.107-116
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• 1995

Two hybridoma cell lines against Cwptosporinium possum oocysts nFRl-CN911 were produced. The isotype of these 2 monoclonal antibodies (mAbs) was IgG2b (lE7.2) and and IgM (C6). Enzyme immuno-transfer blotting analysis showed that 157.2 reacted specifically to 36 kDa protein and C6 reacted to 67 and 70 kDa proteins. C. pcnlum was bound specifically to the surface region of oocysts by these mobs. No cross-reactivity was observed with tachyzoites of ToxopLosma gonnii and oocysts of Eimeria zuernii,5. bouis and E. canadensis of bovine origin. The indirect immunofluorescence assay (IIF) using mAb C6 was successful with counterstain. With the IIF using mob C6, oocysts appeared as 3 to $5{\mu}m$ spherical objects fluorescing bright apple green against a reddish dark background. The IIF using mAb C6 was agreed in specificity and sensitivity with those of a commercial diagnostic kit. These results demonstrated that the produced mAbs were specific to C. parvum and that the mAb C6 could be used for diagnosis of cryptosporidiosis.

• Korean Journal of Veterinary Service
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• v.28 no.3
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• pp.275-284
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• 2005

The present study was conducted to investigate the prevalence of Eimeria infection according to anti-coccidiosis drugs treatment in 1,300 slaughtered chickens from 130 farms in Gyeongnam, Jeonnam, Jeonbuk, Gyeongbuk and Chungnam during the period from October 2002 to August 2003. The prevalence of Eimeria infection by drug administration for treatment and prevention or non-administration was shown $71.4\%,\;82.6\%\;and\;72.3\%$, respectively, and so infection rate of chicken farms was similar independent on drug administration or not. The prevalence of Oocysts infection level of chicken farms by administrated drug for treatment was shown lower $(25.3\%)$ than for prevention $(35.4\%)$ and non-treatment $(36.2\%)$. The prevalence of Oocysts infection level by drug administration under 2 days for treatment was shown higher infection rate $(32.2\%)$ than over 3 days $(20\%)$ and also under 2 days for prevention has similar tendency of that of treatment and so, it was conclusion that administration of drug over 3 days has the effect for treatment and prevention of Eimeria infection. The prevalence of Oocysts infection level by age for prevention has various level from $48.8\%\;to\;22.9\%$ but on $22\~25$ days was shown the most higher ratio $(48.8\%)$ and on $19\~21$ days was shown the lowest rate $(22.9\%)$ among the all age groups.

• Parasites, Hosts and Diseases
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• v.29 no.4
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• pp.315-324
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• 1991

Each of SPF chicken(Hi-Line strain, 2-day-old males) was inoculated with 2.5 or $5\times10^4$ oocysts by stomach tube. The oocyst was the medium type of Cryptosporidium previously isolated from Korean chicken origin, and passed in 2-day-old SPF chicken. The patterns of oocyst discharge were monitored daily, and in order to observe the ultrastructure of the developmental stages, the bursa of Fabricius of the chicken was examined by transmission electron microscopy (TEM) on the 12th day postinoculation. The prepatent period for 8 chicken was 5.9 days postinoculation on the average, and the patent period was 12.9 days. The number of oocysts discharged per day for the chicken was reached peak on day 12 postinoculation on the average. A large number of oocysts was found in fecal samples obtained from inoculated chicken on days 8~14 postinoculation. The ultrastructural feature of almost every developmental stage of the medium type from chicken was very similar to that of Cryptosporidium previously isolated from mammalia including human and birds except for the attachment site of C. tsuris to the mucus cell from mammalia, but dimension of the oocysts from fecal samples of the medium type was different from those of C. meleagridis and mammalia origin. The above results reveal that the medium type of Cryptosporidium of Korean chicken origin is identified as Cryptosporidium baileyi.

• Parasites, Hosts and Diseases
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• v.60 no.4
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• pp.241-246
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• 2022

Felids are the unique definitive host of Toxoplasma gondii. The intestine of felid is the only site for initiating Toxoplasma gondii sexual reproduction. T. gondii excretes millions of infectious oocysts from the intestine, which are the primary source of infection. There are many difficulties in developing vaccines and drugs to control oocyst excretion due to the lack of an appropriate experimental model. Here, we established an in vitro feline intestinal epithelial cell (IEC) infection system and an efficient animal model of T. gondii Chinese 1 genotype, Wh6 strain (TgCtwh6). The Kunming mice brain tissues containing TgCtwh6 cysts were harvested 42-day post-infection. The bradyzoites were co-cultured with cat IECs in vitro at a ratio of 1:10. Five 3-month-old domestic cats were orally inoculated with 600 cysts each. The oocysts were detected by daily observation of cat feces by microscopy and polymerase chain reaction. We found that the parasite adhered and invaded cat IECs in vitro, transformed into tachyzoites, and then divided to form rose-like structures. These parasites eventually destroyed host cells, escaped, and finished the asexual reproduction process. Schizonts associated with sexual reproduction have not been observed during development in vitro cultured cells. However, schizonts were detected in all infected cat intestinal epithelial cells, and oocysts were presented in all cat feces. Our study provides a feasible cell model and an efficient infection system for the following studies of T. gondii sexual reproduction, and also lays a foundation to develop drugs and vaccines for blocking excretion and transmission of oocysts.

• Korean Journal of Veterinary Research
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• v.28 no.1
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• pp.169-174
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• 1988

To determine the prevalence and the morphological identification of two Eimeria species in fecal examinations, a total of 1092 fecal specimens collected during the period of March to December in 1987 was tested by means of flotation technique. The results obtained were summarized as follow: 1. The prevalence of two species was revealed as 1.83% and 0.92% in E. bukidnonensis and E. wyomingensis, respectively. 2. The oocysts of E. bukidnonensis measured in range of $41.3{\mu}m$ to $49.4{\mu}m(mean\;45.5{\pm}1.7){\times}28.8{\mu}m$ to $35.3{\mu}m(mean\;32.2{\pm}1.2)$, and E. wyomingensis $36.9{\mu}m$ to $44.5{\mu}m(mean\;39.8{\pm}1.7){\times}26.5{\mu}m$ to $29.9{\mu}m(mean\;28.2{\pm}0.9)$. 3. The oocysts of E. bukidnonensis appeared darker and more robust than those of E. wyomingensis. 4. The striations in the oocyst wall of E. bukidnonensis were more peculiar than in E. wyomingensis. 5. Among the morphological characteristic, the widths could be reliably taken as a differential point of view for two Eimeria species.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.4
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• pp.450-454
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• 1998

Four groups each containing 48 seven-day-old broiler chicks were reared for 7 weeks during winter on rice husk litter spread to depths of 20, 30, 40 or 50 mm. Broiler performance was evaluated in terms of weight gain, feed consumption, feed efficiency and production number. Litter dampness was determined and coccidial oocyst populations were counted at different weeks of age. The depth of litter did not significantly affect live weight gain, feed consumption, feed conversion ratio, liveability or production number. Variation in moisture contents of litter was observed but the coccidial oocysts count per gramme of litter was within the safety level and therefore, there was no outbreak of coccidiosis in any group. Use of rice husk litter at different depths (20 to 50 mm) did not cause any breast blisters or leg abnormalities. It was concluded that rice husk can be used as litter at depths of between 20 and 50 mm during winter to raise broilers without affecting performance characteristics and health of birds.

• 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.

• Journal of Veterinary Clinics
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• v.21 no.2
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• pp.161-167
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• 2004

The present study was conducted to investigate the prevalence of Eimeria infection in 1,300 slaughtered chickens from 130 farms in Gyeongnam, Jeonnam, Jeonbuk, Gyeongbuk and Chungnam during the period from October 2002 to August 2003. The results obtained are summarized as follows: 1. The prevalence of Eimeria infection in 130 chicken farms was 76.9% and Eimeria infection rates of Gyeongnam, Jeonbuk, Gyeongbuk, Jeonnam and Chungnam were 80%, 75%, 70%, 42.9%, respectively. That of Tongyoung was the highest infection(94.4%) than others districts in the Gyeongnam. 2. The prevalence of oocysts infection level in 1,300 slaughtered chickens from 5 districts was 33.4% and that of Jeonbuk was the highest rate(42%) and Gyeongbuk has the lowest rate(20%). Prevalence of OPG level of slaughtered chicken in Tongyoung was the highest rate(42.8%) in Gyeongnam. 3, Mixed infection rate of over types 2 was 79% and triple infection was shown the highest infection(33%) among the infection types. 4. Kinds of E. spp. were E. acerulina, E. mivati, E. necatrix, E. maxima, and E. tenella. E. tenella has the highest infection rate(78%) and E. necatrix has the lowest infection rate(36%) among the Eimeria spp. 5. The monthly prevalence of Eimeria infection was shown higher in July(94.4%) compared with other months and Jun was shown lower(57.9%). But, level of OPG was shown higher in summer season(July, August; over 40%) than that of winter season(January, February; 23.1%, 16%).