• 대한수의학회지
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• 제33권4호
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• pp.623-632
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• 1993

This study was conducted to develop a sensitized latex-antigen for serodiagnosis of toxoplasmosis in animals. Tachyzoites of T gondii(RH-strain) harvested from mouse peritoneal cavity were purified through the filtraton of polycarbonate membrane(pore size, $3.0{{\mu}m}$, Costar Co.) and disrupted by ultrasonicator. The tachyzoite suspension was ultracentrifuged for 30 min at $60,000{\times}g(4{^{\circ}C})$ and the supernatant was used as a water-lysate antigen. Polystyrene latex particles of $0.8{{\mu}m}$ in diameter(Sigma) were used for the preparation of sensitized latex-antigen suspension. The several parameters including the preparation conditions, incubation buffer. serum dilution buffer and stability of agglutination reactions were evaluated and the results obtained were summarized as follows : 1. The antigen consisting of a water-lysate of T gondii tachyzoites was adsorbed onto polystyrene latex particles of $0.8{{\mu}m}$ in diameter by adding a latex suspension to an equal volume of diluted antigen solution and by incubating the mixture at $37{^{\circ}C}$ under different conditions. 2. The optimum incubation buffer used for the antigen sensitization was 0.1M Tris-HCl buffer(pH 8.0). 3. The optimum serum dilution buffer used for the latex agglutination test was 0.1M Tris-HCl-NaCl buffer(pH 7.4) containing 300 mM NaCl. But 0.1M Tris-HCl-NaCl buffer(pH 7.4) containing 300-600 mM NaCl, 0.5% BSA and 0.01% Tween-20 improved the agglutination pattems and cleared the background of microplate well without the effects on L.A titer. 4. The time required for antigen sensitization was 40 and 60 min in incubation buffer(pH 8.0) at $37{^{\circ}C}$. But the optimun time for antigen sensitization was min at $37{^{\circ}C}$. 5. The optimun quantity of antigen absorbed on latex particles for proper agglutination was the range of 20 to $32{\mu}g$ of latex particles. 6. The optimun concentration of the latex-antigen suspension for the proper agglutination reaction was determined as 0.2%(w/v). 7. The specificity, rapidity and simplicity of the latex-particle agglutination test suggested that it might be adaptable to large scale serum screening.

• 한국동물위생학회지
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• 제42권2호
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• pp.93-112
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• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.

• 한국동물위생학회지
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• 제44권2호
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• pp.85-91
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• 2021

This study was performed to identify the prevalence of cryptosporidiosis and giardiasis in diarrhea feces of Korean native calves raised in Gimje, Jeollabuk-do, with a rapid diagnostic kit. The prevalence of both diseases were classified according to the age of calf, season of sampling period, and sampled farm where diarrheic calf is commonly observed. In diarrhea feces of 431 calves, cryptosporidiosis had a high incidence rate between 1 and 3 weeks of age, whereas giardiasis showed a high incidence between 4 and 6 weeks of age. It is thought that the incidence of protozoan diseases is markedly influenced by the calf's postnatal age. Regarding with the sampling season, the prevalence of cryptosporidiosis and giardiasis in calves was significantly higher in spring and summer than in autumn and winter (P<0.05). Among the sampled farms where both diseases are commonly observed, cryptosporidiosis was more frequently detected than giardiasis in calves. Particularly, in farms where cryptosporidiosis is common, it tends to be a disease that is difficult to eradicate as it occurs continuously throughout the year. Hygiene management such as regular cleaning and disinfection of the livestock and the surrounding environments is considered necessary to reduce and prevent damage from these protozoal diseases.

• 한국임상수의학회지
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• 제27권6호
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• pp.640-646
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• 2010

네오스포라 감염증은 세포내성 원충성 기생충인 Neospora caninum에 의해 발생하는 질병으로 전세계적으로 발생하고 있으며, 소에서는 번식장해로 인한 막대한 경제적 손실을 유발한다. 본 연구는 4 곳의 각기 다른 목장으로부터 N. caninum에 자연 감염된 양성우와 음성우를 포함한 26두의 임신우를 선정하여 2주 내지 4주 간격으로 혈액을 채취하여 호르몬, 항체가, IFN${\gamma}$ 수준과 유산 혹은 분만과의 상관관계를 조사하였다. 유산하지 않은 Neospora 양성우14두의 S/P 평균값은 분만 전 15주에 최고치를 보였고, 이후 분만 때까지 감소하였다. 유산한 양성우 3두의 유산 시기는 각각 인공 수정 후 20주 (142일), 26주 (185일), 28주 (199일)였으며, 이들의 S/P값은 유산 전 13주부터 유산 때까지 높은 수준을 유지하였다. 유산하지 않은 양성우에서 IFN${\gamma}$ 수준은 개체에 따라 그리고 동일한 개체라도 임신기간이 경과함에 따라 다양하게 나타났으며, 유산한 양성우에서 IFN${\gamma}$ 수준은 계속 높은 상태를 유지하거나 또는 유산시점에 근접하여 급상승하였다. Neospora 음성우 9두의 IFN${\gamma}$ 수준은 양성우보다 낮았지만, 그 양상은 유산하지 않은 양성우와 유사하였다. 유산하지 않은 양성우와 음성우에서 평균적인 progesterone수준은 분만 전 7주부터 뚜렷하게 감소하였다. 유산한 양성우에서는 유산 전 5주와 7주의 평균적인 progesterone 수준은 정상 분만한 음성우나 양성우의 분만전 5주와 7주에 측정된 평균 progesterone 수준보다 낮았다. 유산한 양성우에서 17${\beta}$-estradiol의 평균 수준은 유산 시점에 근접할수록 증가하였지만, 혈청내 총양은 유산하지 않은 양성우와 음성우에서 분만시점에 근접하여 측정한 평균 17${\beta}$-estradiol 수준보다 더 낮았다. 이상의 결과로 미루어 보아 Neospora에 감염된 소에서 17${\beta}$-estradiol과 progesterone 수준의 저하는 IFN${\gamma}$ 산생을 증가시켜, 결국에는 유산을 초래할 수 있다고 생각된다.