• Korean Journal of Veterinary Research
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• v.39 no.1
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• pp.204-212
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• 1999

The visceral dissemination of Borrelia burgdorferi in New Zealand White rabbits was evaluated following intradermal inoculation of $1{\times}10^8$ spirochetes. We inoculated Borrelia burgdorferi B31, B garinii KW1 and B afzehlii S13, respectively, and monitored the dissemination in the experimentally infected rabbits for 28 days. In the B burgdorferi B31-challenged group, the spirochetes were completely cleared in rabbits at day 1 and visceral dissemination was not demonstrated. However, B garinii KW1 and B afzelii S13 were found to successfully disseminate in visceral organs of rabbits during the experiment period of 28 days. And experimentally infection-derived immunological responses in rabbits were identified with enzyme-linked immunosorbent assay and immunoblot analysis. Based on these results, the differences in the virulence of Lyme borrelial strains were proved in rabbit model.

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.301-308
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• 1993

Three or 7day old piglets were infected experimentally with different encephalomyocarditis virus isolates to detect the viral antigen by the immunoperoxidase technique and to observe strain difference in their pathogenecity in newborn pigs by comparing clinical signs and pathologic lesions. Clinical signs of the infected pigs were different depending on the virus strain, pig age and infection route. Encephalomyocarditis virus(EMCV) NVSL-PR isolate was more pathogenic than MN-25 and MN-30 isolate. Three day old piglets showed more severe illness than 7 day old piglets. Predominant clinical signs were sudden death without noticeable clinical signs and dyspnea manifested as heavy abdominal breathing. Contact-infection from infected piglets to controls was observed in the oro-nasally infected group but not the intramuscular group. Common necropsy findings of dead piglets in both age groups infected with MN-25 and NVSL-PR were accumulation of excessive fluid in the body cavities and mild to diffuse necrotic areas observed in the hearts and occasionally in the livers. Microscopically, myocarditis with inflammatory cell infiltration, necrosis of the myocardial muscle fibers and occasional mineralization were observed along with interstitial pneumonia and centrolobular necrosis in the liver. Using an immunoperoxidase technique, viral antigen was detected in myocardial muscle fibers of piglets infected with EMCV.

• Biomedical Science Letters
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• v.5 no.2
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• pp.147-153
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• 1999

The changes of antibody titer were observed in rats which were experimentally infected with Echinostoma hortense metacercaria. Serum levels of IgG and IgM were measured by enzyme-linked immunosorbent assay (ELISA). The mean absorbance values obtained for specific-IgG were from 0.130$\pm$0.014 (mean$\pm$S.D.) to 0.480$\pm$0.073. The peak appeared in the 4th week after infection, then declined slowly during the 5th and 6th week, although mild elevation apperared in the 8th week. The mean absorbance values of specific-IgM were detected from 0.160$\pm$0.034 to 0.409$\pm$0.084. The peak value (0.409$\pm$0.084) was on the 14th day after infection, then declined on the 8th week. Results showed that the assay could be used for detection of E. hortense infection in experimentally infected rats or laboratory experiments where evidence of infection is required.

• Korean Journal of Veterinary Research
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• v.31 no.1
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• pp.99-108
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• 1991

To observe the changes of serum proteins according to the process of Babesia gibsoni(B gibsoni) infection, the babesia protozoa($10^8/kg$) were inoculated into the cephalic vein of healthy dogs. The serum proteins of experimentally infected dogs were separated by using cellulose acetate electrophoresis. The results obtained were as follows; 1. Cellulose acetate electrophoresis was fractionated to total 6 of bands such as, albumin, ${\alpha}_1$, ${\alpha}_2$, ${\beta}_1$, ${\beta}_2$ and $\gamma$-globulin. 2. The concentration of total protein was shown a decreasing tendency after B gibsoni infection. Albumin and A/G ratio were lowered through all periods of the infection, but they were not significant changes. 3. The level of ${\alpha}_1$-globulin was significantly(p<0.05) incresed in early stage of the infection. 4. The levels of ${\alpha}_2$ and total $\alpha$-globulin were shown highly significant decreases (p<0.01) through all periods of the infection. 5. The levels of ${\beta}_1$ and total $\beta$-globulin had highly significant changes (p<0.01) that was increased in early stage of infection and decreased later. 6. The level of $\gamma$-globulin was seen to be constantly increased through all periods of infection. It was a highly significant change (p<0.01). 7. Plasma protein: fibrinogen (PP:F) ratio was shown a temporally significant increase (p<0.05) following the decrease in early infection.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.575-585
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• 2000

This study was performed to observe the influence of host immune response on the chemotherapy of mice experimentally infected with Fasciola hepatica. Following immunosuppression with prednisolone or immunoenhancement with Freund's complete adjuvant(FCA), mice were experimentally infected with 3 Fasciola hepatica metacercariae and treated with closantel at 1 week post infection. In the group of mice infected with metacercariae alone, 2 mice of 10 were dead at 10 weeks post infection(20% mortality), and adult flukes were recovered from the liver and the peritoneal cavity of the remaining 8 mice(100% infectivity). In the group of mice treated with prednisolone and infected with metacercariae, 8 of 10 mice died before euthanasia with a mean time of death earlier than the control group (p<0.05). In the group of immunosuppressed mice infected with metacercariae and treated with closantel 20mg/kg, 4 of 10 mice died before sacrifice. In the group of mice infected and treated with closantel 20mg/kg, mortality and infectivity was 10% and 30%, respectively. Similar results were observed in mice infected and treated with closantel 5mg/kg which resulted in 10% and 50% mortality and infectivity, respectively. These results indicated that the efficacy of closantel treatment was decreased in immunosuppressed mice, while the pathogenicity was increased. In immunoenhanced mice infected with metacercariae, on the other hand, the efficacy of chemotherapy with both 5mg/kg or 20mg/kg closantel resulted in only 10% infectivity. The results shown in this study strongly suggest that a close interaction between chemotherapy against F hepatica with closantel and the host immune system exists. Considering that fascioliasis is a zoonosis, treatment regimen against the infection to immunosuppressed patients may require a concurrent prescription of an appro-priate immuno-enhancing adjuvant.

• Parasites, Hosts and Diseases
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• v.53 no.1
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• pp.51-58
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• 2015

Toxocariasis is a soil-transmitted helminthozoonosis due to infection of humans by larvae of Toxocara canis. The disease could produce cognitive and behavioral disturbances especially in children. Meanwhile, in our modern era, the incidence of immunosuppression has been progressively increasing due to increased incidence of malignancy as well as increased use of immunosuppressive agents. The present study aimed at comparing some of the pathological and immunological alterations in the brain of normal and immunosuppressed mice experimentally infected with T. canis. Therefore, 180 Swiss albino mice were divided into 4 groups including normal (control) group, immunocompetent T. canis-infected group, immunosuppressed group (control), and immunosuppressed infected group. Infected mice were subjected to larval counts in the brain, and the brains from all mice were assessed for histopathological changes, astrogliosis, and IL-5 mRNA expression levels in brain tissues. The results showed that under immunosuppression, there were significant increase in brain larval counts, significant enhancement of reactive gliosis, and significant reduction in IL-5 mRNA expression. All these changes were maximal in the chronic stage of infection. In conclusion, the immunopathological alterations in the brains of infected animals were progressive over time, and were exaggerated under the effect of immunosuppression as did the intensity of cerebral infection.

• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.150-154
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• 1977

In the diagnosis of parasitic helminthic diseases, the value of examining and identifying the parasitic eggs and/or adult parasites from patient's urine or stool are well appreciated. However, these methods have a limited value in the diagnosis of tissue or intracellular parasitism, and we have to rely on supplementary methods such as immune-serological test. The author tested the value of gel precipitation reactions as a diagnostic method of clonorchiasis by observing the appearance of bands in rats experimentally infected with Clonorchis sinensis, And the therapeutic effect of CIBA 35'058-Ba was evaluated by this serological method. The antigen was prepared from the adult worms infected in rabbits by Tsuji method. Rats infected with 40 metacercariae each were bled on 7,14,21,26,28,39,42(43),49(53) days after infection to observe the appearance of precipitin bands by both Oucterlony method and immunoelectrophoresis. Fifteen rats were separately infected and treated with CIBA 35'058-Ba in dose of 15mg/kg of body weight. The following results were obtained: 1. It was observed that there exist individual variations in the appearance of the first precipitin band with the range of 2-4 weeks after infection. 2. The number of precipitin bands was increased until 6-7 weeks after infection. In all cases, 3 precipitin bands were appeared by Oucterlony method and 6-7 bands were appeared by immunoelectrophoresis after 6-7 weeks of infecion. 3. It was hardly possible to notice any change in the number of bands after the administration of CIBA 35'058-Ba. This result suggested that the drug has no effect on clonorchiasis which was confirmed by the autopsy of the experimental rats.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1151-1160
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• 1999

This study was conducted to detect the toxoplasma-specific DNA in peripheral blood collected from cats experimentally infected with Toxoplasma gondii (RH strain) and from domiciled cats by B1 gene-base polymerise chain reaction(PCR). The sensitivity of oligonucleotide primer, T-1 & T-2, designed from toxoplasma B1 gene amplification method was compared with parasite detection by mouse inoculation(MI). And also, latex agglutination test(LAT) and indirect fluorescent antibody test(IFAT) were conducted to detect the fluctuation of serum antibodies compared with the detection of toxoplasma by PCR and MI. Toxoplasma B1 gene PCR was shown consistently high sensitivity and the results obtained by PCR agreed completely with those from MI. All blood samples collected before infection with T gondii gave negative results by PCR and MI. Also, toxoplasma Bl gene PCR was not cross reaction with Neospora caninum DNA and normal cat leucocyte as controls. The toxoplasma-specific DNA was detected by PCR in blood of 5 cats experimentally infected with T gondii 6 days after infection and the detection of this specific-DNA was long lasted in blood for 64 days after infection. The detection of toxoplasma-specific DNA by PCR could be identified as few as 10 tachyzoites and the isolation of T gondii by MI could be isolated as few as 1 tachyzoite from tenfold serial dilution of T gondii with normal cat blood, respectively. In healthy domiciled cats, the toxoplasma-specific DNA and the parasite were detected and isolated in blood from 3 of 56(5.3%) cats by both PCR and MI, respectively. In the results of antibody test from the total 56 heads of healthy domiciled cats, the positive rates are 15(26.7%) by LAT and 19(33.9%) by IFAT. These results suggest that PCR detection of toxoplasma can be applied as a sensitive and specific diagnostic and research tool.

• Korean Journal of Veterinary Research
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• v.13 no.2
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• pp.119-129
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• 1973

A hypothesis that is a stress condition in animal may cause either enhancement or reduction of the host resistance against microbial infection was experimentally studied. Among of many processes for stress formation an experimental electrization in mice was devised, on the bases of blood picture analysis, and studied the effect of experimental electrization of mice on E. coll infection. The results obtained were as follows. 1. Electrization with ordinary current, A. C. 60 cps., on the path of symmetrical line of both posterior limbs at 20 to 100 volts (less than 10 mA) for 15 to 30 seconds was able to induce a stress reaction in blood pattern without showing any dangers of electrocution, electric burns and other residual signs, and no correlation between blood pattern of the reaction and an amount of current between 20 to 100 volts was observed. As the electrodes, two of 21 gauge hypodermic needles were used, when the electrization each of them were inserted into the center of toe tissue of the both legs. 2. Serum protein fractions following the experimental electrization showed a tendency of a low A/G ratio and a high value of ${\alpha}$-globulin. 3. In the studies on the effect of electrical stress on the pathogenesis of E. coli in mice, a group in which a simultaneous electrization and infection, and a group infected two hours after electrization showed 80 per cent mortality. On the other hand, infection after 20 hours electrization and control groups showed their mortality of 40 and 60 per cent respectively.

• Parasites, Hosts and Diseases
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• v.55 no.6
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• pp.623-630
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• 2017

Plasmodium lactate dehydrogenase (pLDH) is a strong target antigen for the determination of infection with Plasmodium species specifically. However, a more effective antibody is needed because of the low sensitivity of the current antibody in many immunological diagnostic assays. In this study, recombinant Plasmodium vivax LDH (PvLDH) was experimentally constructed and expressed as a native antigen to develop an effective P. vivax-specific monoclonal antibody (mAb). Two mAbs (2CF5 and 1G10) were tested using ELISA and immunofluorescence assays (IFA), as both demonstrated reactivity against pLDH antigen. Of the 2 antibodies, 2CF5 was not able to detect P. falciparum, suggesting that it might possess P. vivax-specificity. The detection limit for a pair of 2 mAbs-linked sandwich ELISA was 31.3 ng/ml of the recombinant antigen. The P. vivax-specific performance of mAbs-linked ELISA was confirmed by in vitro-cultured P. falciparum and P. vivax-infected patient blood samples. In conclusion, the 2 new antibodies possessed the potential to detect P. vivax and will be useful in immunoassay.