• Parasites, Hosts and Diseases
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• 제50권2호
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• pp.161-164
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• 2012

To evaluate the efficacy of ronidazole for treatment of Tritrichomonas foetus infection, 6 Tritrichomonas-free kittens were experimentally infected with a Korean isolate of T. foetus. The experimental infection was confirmed by direct microscopy, culture, and single-tube nested PCR, and all cats demonstrated trophozoites of T. foetus by day 20 post-infection in the feces. From day 30 after the experimentally induced infection, 3 cats were treated with ronidazole (50 mg/kg twice a day for 14 days) and 3 other cats received placebo. Feces from each cat were tested for the presence of T. foetus by direct smear and culture of rectal swab samples using modified Diamond's medium once a week for 4 weeks. To confirm the culture results, the presence of T. foetus rRNA gene was determined by single-tube nested PCR assay. All 3 cats in the treatment group receiving ronidazole showed negative results for T. foetus infection during 2 weeks of treatment and 4 weeks follow-up by all detection methods used in this study. In contrast, rectal swab samples from cats in the control group were positive for T. foetus continuously throughout the study. The present study indicates that ronidazole is also effective to treat cats infected experimentally with a Korean isolate of T. foetus at a dose of 50 mg/kg twice a day for 14 days.

• 대한수의학회지
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• 제41권1호
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• pp.89-98
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• 2001

This study was conducted to detect the toxoplasma specific-DNA in circulating blood and organs collected from slaughtered pigs at slaughtering house and experimentally infected pigs with Toxoplasma gondii tachyzoites by polymerase chain reaction(PCR), and also PCR was applied to diagnose for acute phase of swine toxoplasmosis as a newly developed diagnostic test. The sensitivity of oligonucleotide primer, T-1 & T-2, designed from toxoplasma B1 gene amplification method was compared with Tp parasite detection by mouse inoculation(MI). On the other hand, latex agglutination test(LAT) was conducted to detect the serum antibodies comparing with the detection of toxoplasma by PCR and MI. The results obtained were summarized as follows. PCR was able to determine at the lowest level of $10^0/ml$ T. gondii in blood samples which were blended with a serial diluted T gondii in vitro. On the other hand, $10^2/5g$ of T gondii could detect from a variety of tissues including lung, diaphragm, liver, heart, spleen and brain in vitro. The primer was proved to specifically determine T gondii in blood and tissues in vitro but it did not detect Neospora caninum used as a negative control. DNA of T. gondii was effectively extracted by freezing, thawing and grinding twice both tissues mixed with T gondii in vitro and in experimentally infected pig's tissues. PCR detected specific DNA in the blood of experimentally infected pigs at 108 hrs and 120 hrs post-infection, it was the same time that the pigs showed fever and parasitaemia. In case of tissue, specific DNA was, however, detected only lung from experimentally infected pigs. Even though the duration of acute phase was from 3 to 7 days post-infection, but the latex agglutination test (LAT) results appeared from 8 days post-infection. A comparison of sensitivity in determining T gondii in blood samples between PCR and MI, PCR positive rate ranged from 25 to 33.3%, but that of MI covered from 75 to 100%.

• 대한수의학회지
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• 제37권4호
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• pp.831-841
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• 1997

The study was aimed at identifying the globule leukocytes (GL) of tracheal mucosa layer of Korean native cattle showing symptom of pneumonia which have died as enterotoxemia and normal Korean native cattle in Kyungpook local area. In another set of experiment, Isolated Klebsiella pneumoniae from suddenly died cattle specimens was subjected to rat for a determining globule leukocyte appearance by using histochemical and immunohistochemical method. In histochemical study, globule leukocytes generally was existed in all the case of postmortem of Korean native cattle and 3 heads of slaughtered cattle which showing symptoms of pneumonia and it showed significant increase in tracheal mucosa of rats experimentally infected with Klebsiella pneumoniae. These increased number of globule leukocytes was moderately remained on early infection stage and gradually decreased in timedependent manner after infection. The granule patterns were also determined as an acidmucopolysaccharide. In immunohistochemical study, serotonin intensity in the treacheal mucosaepithelial cells of rat experimentally infected observed a strong immunoreactivity during early infection and gradually decreased in dependent of infection stage while no IgE immunoreactivity observed. These data show that globule leukocytes were increased in a pneumonia, therefore it was considered as a valuable cell that was associated with early stage of inflammatory response.

• Asian-Australasian Journal of Animal Sciences
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• 제6권3호
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• pp.331-337
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• 1993

In order to understand the effect of duck hepatitis B virus (DHBV) on the economic performance of ducks, Three groups (DHBV congenitally infected, experimentally infected and DHBV negative) Brown Tsaiya ducks (Anas platyrhyncha) were used for experimental animals. Artificial insemination and pedigree hatching were applied in the propagation of ducklings, and the efficiency of vertical transmission and experimental infection was analyzed through the detection of DHBV DNA in the sera of 8-week-old offspring. The observation of the records of the first year indicated that the persistent infection had no significant effects on the performance of ducks, except the egg number of survival ducks up to 40 week of age. Thus DHBV infection did not appear to give ill effects to the economic performance of ducks in first laying year. A higher infection rate (85.3%) was obtained in congenital transmission than that (75.5%) of experimental infection. Both modes of infection did not reach 100% infectious rate, although some ducks developed transient viraemia in a tracing of DHBV DNA for 24 weeks to 11 challenged ducklings.

• 대한미생물학회지
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• 제21권2호
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• pp.211-226
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• 1986

To understand the pathogenesis of anicteric leptospirosis with severe pulmonary hemorrhage occured in Korea, the microbiological and pathological features were observed in the experimentally induced leptospirosis in guinea pigs infected with a virulent strain of Leptospira interrogans isolated from the patient at Wonju, Korea, and the results are summarized as follows. 1. The main pathological features were widespread hemorrhages, especially affecting lung, skeletal muscles, retroperitoneal and perirenal adipose tissues. The hemorrhages accompanied inflammatory process especially of vasculitic pattern as well as occasional coagulation necrosis in the liver, skeletal muscle, and myocardium. The main inflammatory cells were of plasma cell even in the fairly early stage of the infection. 2. Those pathologic changes were more exaggerated in the inoculation site. 3. Within 144 hours of infection, the longer the infection time, the more antigens were observed in the tissues, and the severer the pathologic changes. 4. Leptospiral antigens were detected at first by indirect immunofluorescent and immunoperoxidase technics. As the infection time extended, the antigens were observed in all of the tissues examined except in the skeletal muscle. The shape of the antigens was spiral or thread-like within 72 hours of infection. As the infection progressed, they became fragmented and granular. 5. Leptospires were detected in the blood within 144 hours of infection by darkfield microscopic examination. Thereafter, none was observed. 6. Antibody to leptospires were detected as early as 72 hours of infection. In summary, the virulent strain of L. interrogans used in this experiment induced widespread hemorrhages with inflammatory reaction especially in lung, skeletal muscles, and retroperitoneal adipose tissue. With these findings, it is suggested that the direct toxic effect of leptospires might playa great role in the pathogenesis of this infection.

• 대한바이러스학회지
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• 제27권2호
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• pp.217-225
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• 1997

PCR amplication using the primers for gag, pol and env genes in BLV (bovine leukemia virus) proviral DNA and syncytium assay were carried out for the Korean native goats experimentally infected with bovine leukemia virus to investigate pathogenesis of BLV in the goats, and to establish a model animal for BLV infection. The oligonucleotide primers used in PCR revealed very high specificity. The minimal amount of FLK-BLV cellular chromosomal DNA to detect the integrated BLV proviral DNA was 10 ng. The peripheral blood lymphocytes from the goat infected with BLV were examined at regular intervals by PCR amplification and syncytium assay. Pol or gag genes were detected in none of three infected goats at the 1st week post-infection (p.i.). At the 4th week p.i., one of three goats showed the amplified gag gene. Thereafter detection rates for the genes were increased, indicating that the BLV proviral genes were integrated in all of the lymphocytes from three goats, at the 16th weeks p.i., when it was evident in syncytium assay that the lymphocytes from all of three goats were infested with infective BLV. Investigating the tissues from the necropsied goats at the 8th month p.i., the amplified BLV proviral genes and infective BLV were detected in all of the peripheral lymphocytes from three infected-goats. Among various tissues examined, the amplified BLV proviral genes were observed in spleen and superficial cervical, mandibular and retropharyngeal lymph nodes, and the infective BLV, in superficial cervical and mandibular lymph nodes. It was assumed that the Korean native goat was quite susceptible to BLV infection, indicating that the goat could be a good model animal for BLV.

• KSBB Journal
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• 제10권3호
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• pp.317-322
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• 1995

유전자 재조합 단백질 생산을 위한 곤충세포- 배쿨로바이러스 시스템에 있어서, 바이러스에 감염시 키는 시기가 늦을수록 재조합 단백질의 발현이 낮게 나타났다. 이것은 높은 세포농도일수록 단위세포당 낮은 발현율을 의미하므로 재조합 단백질 생산을 위 해 감염시기에 대한 최적화의 필요성을 보여주며, 재조합 단백질의 최대 생산생을 위한 최적 감염시기 의 존재를 실험적으로 업증하였다. 또한 배지에 5% 누에 체액을 보강함으로써 발현율이 증가하였고, 이 것은 누에 체액 첨가로 인해 세포내 바이러스 숫자가 증가하고 감염 후 세포의 생존성이 오래 유지되 는 것에 기 인하는 것으로 생각된다. 고농도 세포배 양을 위해 yeastolate를 첨가하고, 재조합 단백질 발 헌을 위해 누에 체액을 첨가함으로써 ${\beta}$-galactosidase의 생산이 10배 정도 증가하였다.

• Parasites, Hosts and Diseases
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• 제25권2호
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• pp.141-148
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• 1987

실험적으로 폐홉춘을 감염시킨 백서의 혈청내 항원을 ELISA 법으로 측정하였다. 시험용 혈청은 폐흡충의 피낭유충을 마리당 25개씩 먹인 총 22마리의 백서에서 감염후 12주가 될 때까지 채혈하여 얻었다. 폐흡충에 대한 특이항체는 폐흡충 감염 고양이의 혈청으로부터 ammonium sulfate 침전과 anionezchange chromatography를 이용, IgG를 분리한 후 affinity chromatography를 이용하여 순수분리하였다. 항원을 찾기 위한 ELISA는 소위 "double antibody sandwich method"를 사용하였다. 대조로서 사용한 감염전 혈청의 O.D.치 평균값은 0.04(표준편차 0.04)이었으며 감염후 O.D.치 (표준편차)의 변화를 보면 0.5주(3일)는 0.03(0.01), 1주는 0.55(0.50), 1.5주는 0.69(0.45), 2주는 0.20(0.19), 2.5주는 0.13(0.10)이었고 감염 3주 이후는 대조 혈청의 값으로 떨어졌다. 대조혈청의 $평균간+3{\times}$ 표준편차, 즉 0.16이하를 이 system에서의 비특이적 수치로 잡았을 때 이 이상의 수치를 나타낸 경우는 감염 후 1주부터 2.5주까지의 혈청에서만 관찰되었다. 한편 감염 12주 후에 총 10마리의 백서를 희생시켜 유충을 회수하여 보았다. 폐와 흉강에서는 평균 2.2마리, 근육에서는 평균 6.2마리의 유충을 회수할 수 있었다. 폐흡충 감염 백서에 있어 충체가 생산하는 항원은 감염 1주 후부터 혈청 내에서 검출되었다. 그러나 감염 3주후부터는 검출되지 않았는데 이것은 항원-항체 복합체 형성에 의한 반응 저해 현상에 의한 것으로 생각되었다.

• Parasites, Hosts and Diseases
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• 제51권5호
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• pp.573-577
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• 2013

A loop-mediated isothermal amplification (LAMP) assay allows rapid diagnosis of Toxoplasma gondii infection. In the present study, the LAMP assay was evaluated using blood from both naturally and experimentally infected pigs. The sensitivity of the LAMP assay was compared with that of Q-PCR. Both assays detected T. gondii in the blood of experimentally infected pigs, with 100% agreement. In infected blood samples, the parasite was detected as early as 2 days post-infection and reached a peak in 3-5 days. In 216 field serum samples, the detection rates of LAMP and Q-PCR assays were 6.9% and 7.8%, respectively. This result indicates that the sensitivity of the LAMP assay was slightly lower than that of the Q-PCR assay. However, the LAMP may be an attractive diagnostic method in conditions where sophisticated and expensive equipment is unavailable. This assay could be a powerful supplement to current diagnostic methods.

• Parasites, Hosts and Diseases
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• 제46권4호
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• pp.279-283
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• 2008

To examine humoral immune responses in the host, we measured serum antibody levels in different strains of mice (ICR, BALB/c, and C3H) experimentally infected with Neodiplostomum seoulense. Specific IgG antibody levels were increased remarkably with little difference among 3 strains of mice infected with N. seoulense from day 7 to 35 post-infection. More target proteins of adult parasites reacted with IgG at the time when the worm recovery decreased compared with other times. More than 20 protein bands, from 14 kDa to 94 kDa in size, were separated from the crude antigen of N. seoulense adults by SDS-PAGE, and among them 26, 30, 35, 43, 54, 67, and 94 kDa proteins were the major antigenic proteins. The results suggest that significant IgG antibody responses occur against N. seoulense in mice and this may be related with expulsion of worms.