• Parasites, Hosts and Diseases
• /
• v.50 no.2
• /
• pp.161-164
• /
• 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.

• Korean Journal of Veterinary Research
• /
• v.41 no.1
• /
• pp.89-98
• /
• 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%.

• Korean Journal of Veterinary Research
• /
• v.37 no.4
• /
• pp.831-841
• /
• 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
• /
• v.6 no.3
• /
• pp.331-337
• /
• 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.

• The Journal of the Korean Society for Microbiology
• /
• v.21 no.2
• /
• pp.211-226
• /
• 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.

• The Journal of Korean Society of Virology
• /
• v.27 no.2
• /
• pp.217-225
• /
• 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
• /
• v.10 no.3
• /
• pp.317-322
• /
• 1995

Insect cells were grown and infected with baculovirus for the production of recombinant protein. Later infection gave the lower expression of recombinant protein. This indicates that the expression rate is lower at higher cell concentration. This phenomena provides a well-posed optimization problem with respect to the infection time. The optimal infection time was experimentally shown to exist for the maximum productivity of recombinant protein. Also, the expression increased with the addition of 5% silkworm hemolymph. This is considered to be due to the increase of intracellular viruses and the longevity of viable cells after the infection. The production of ${\beta}$-galaclosidase increased about ten-fold with the addition of yeastolate and silkworm hemolymph for high cell density and high expression, respectively.

• Parasites, Hosts and Diseases
• /
• v.25 no.2
• /
• pp.141-148
• /
• 1987

Circulating antigens in rats experimentally infected with Paragonimus westermani were examined by ELISA. From a total of 22 albino rats, each fed with 25 metacercariae, blood samples were collected until 12 weeks after infection. The specific antibodies against P. westermani in the serum of an infected cat were purified by ammonium sulfate precipitation, DEAE anion-exchange chromatography and affinity chromatography serially. So-called double antibody sandwich ELISA method was used for the detection of circulating antigens. The results were as follows: Mean value of O.D. in control sera was O. 04 (S.D.=0. 04). After infection, mean O.D.(S.D.) values were changed serially: 0.03(0.01) at 0.5 week(3 days), 0.55(0.50) at 1 week, 0.69(0.45) at 1.5 week, O.20 (0.19) at 2 weeks and O.13(0.10) at 2.5 weeks of infection. They returned, thereafter, to the level before infection. When O. 16 (mean+3 S.D.) were considered as cut-off value, those higher than O. 16 were observed only in the sera collected between 1 and 2.5 weeks after infection. Average 8. 4 immature worms (2.2 from the lungs and pleural cavities; 6.2 from muscles) were recovered in a rat at 12 weeks after infection. The fact that circulating antigens were not detected after 3 weeks of infection was considered to the caused by the formation of antigen-antibady complexs.

• Parasites, Hosts and Diseases
• /
• v.51 no.5
• /
• pp.573-577
• /
• 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
• /
• v.46 no.4
• /
• pp.279-283
• /
• 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.