• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.155-157
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• 1996

We have successfully maintained Cyptospori, diam mons by cryopreservation. Oocysts were suspended in distilled water, stored at $-20^{\circ}C$ for 24 hrs, and then cryopreserved at $-70^{\circ}C$. Cryopreserved specimens were slowly thawed at $5^{\circ}C$. Oocysts, which had been cryopreserved for 1% months without cryoprotective agents. retained their infectivity by the mouse titration method. Oocysts stored at $5^{\circ}C$ in 2.5% potassium dichromate failed to retain their infectivity beyond 6.5 months.

• The Journal of the Korean Society for Microbiology
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• v.16 no.1
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• pp.83-89
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• 1981

Japanese encephalitis has been prevalent for long time in the Far East and many patients have been reported in both South East and Mid-West Asia recently. Recently, vaccine was used in prevention of this viral disease of man which was derived from formalin inactivated virus inoculated into mouse brain, but live attenuated active vaccine for human is not developed yet. Author inoculated Japanese encephalitis virus into several cell culture strains for development of live attenuated encephalitis virus strain and the results were as follows: 1. Japanese encephalitis virus was inactivated rapidly in cell free medium at $36^{\circ}C$ and totally inactivated by 72 hours. 2. In growth curve of Japanese encephalitis virus in HeLa cell cultures, maximal multiplication of the virus was occured at 4th day and virus multiplication was continued for at least 12 days. 3. After succeeding passage of the virus in HeLa cell cultures and human esophagus epithelial cell cultures, infectivity of virus for mice was disappeared from 2nd passage in HeLa cell cultures and 3rd passage in esophagus epithelial cell cultures. 4. In inoculation to monkey kidney epithelial cells and chick embryo cell cultures, infectivity of the virus for mice was continued after 10th passages.

• Journal of Life Science
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• v.16 no.5
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• pp.729-733
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• 2006

Cryptosporidium is a waterborne pathogenic parasite which causes diarrhea. Immunomagnetic separation-immunofluorescent assay (IMS-IFA) has been a widely adopted for Cryptosporidium detection as standard method. However, this method does not provide information about viability or infectivity of Cryptosporidium. Therefore, many researchers have studied viability or infectivity analyses of Cryptosporidium with various methods such as vital staining, in vitro excystation, RT-PCR, cell culture, and mouse infection assay. In this study, two direct RT-PCR methods, cell culture RT-PCR and cell culture IFA were compared for sensitivity and other characteristics. The results showed that direct RT-PCR method with HSP70 genes had the highest sensitivity with detection up to 1 viable cell of Cryptosporidium. The infectious Cryptosporidium were detected up to 10 to 25 cells by cell culture methods in combination with RT-PCR and IFA. The infectious Cryptosporidium were apt to be quantified by cell culture IFA.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.6-6
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• 2003

Listeria monocytogenes is a facultative bacterium that cause severe clinical disease including meningoencephalitis, septicaemia, and abortion in pregnant women, newborn infants, the debilitated elderly or immunocompromised people. In preliminary experiments on murine listeriosis we noticed suppurative gastritis in mice infected with L. monocytogenes by the intragastric route. The aims of the present study were ⅰ) to describe the histopathology of the experimentally listeria-induced gastroenteritis ⅱ) to investigate the influence of bacterial strain and laboratory mouse strain on infectivity and on the severity of the infection; [3] to examine possible effects of preliminary intragastric administration of sodium bicarbonate. (omitted)

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.581-588
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• 1998

Eight monoclonal antibodies(MAbs) against bovine coronavirus(BCV) were produced and characterized. Three MAbs(1G9, 4H12, 5C1) specific to the S glycoprotein and two HE glycoprotein-specific MAbs(2A5, 5G4) were found to neutralize the BCV in fluorescence focus neutralization(FFN) test. Two HE-specific MAbs from the neutralizing MAbs inhibited the hemagglutinating activity of the BCV. None of the N protein-specific MAbs(1C1, 5A12, 6H1) neutralized the virus infectivity. Bovine coronavirus and mouse hepatitis virus, which belong to group II coronaviruses, were differentiated from other groups of coronaviruses(porcine transmissible gastroenteritis virus, porcine epidemic diarrhea virus, canine coronavirus) by all MAbs in fluorescence antibody test(FA), but not in FFN test.

• Biomedical Science Letters
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• v.12 no.2
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• pp.99-104
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• 2006

Present study was performed to investigate the host-parasite relationship of the Korean Trichinella isolate (KTI). In the experiment to observe the infectivity of KTI to several kinds of animals, the reproductive capacity index (RCT) was highest in cats, and that in mice, hamsters and rats was followe4 in descending order. However, birds, i.e. wild goose and chicken, did not infect with KTI. The number of larvae per a gram of muscle (LPG: 377) was highest in the tongue of cats experimentally infected with KTI larvae. LPG in the diaphragm, anterior leg, back, posterior leg and abdominal muscles were 313, 246, 234, 225 and 170 respectively. Muscle larvae recovered at 55 days after infection were revealed the highest infectivity (RCI: 137.2) in mice. RCI was comparatively low in the mice infected with less than 25 day-old and more than 300 day-old larvae. In the experiment to observe the susceptibility of KTI by the mouse strain, ICR (RCI: 137.2), C57BL/6 (RCI: 108.8), DBA/2 (RCI: 107.1), C3H (RCI: 98.7), BALB/c (RCI: 96.9), FVB (RCI: 96.1) and B6C3F1 (RCI: 85.3) were very susceptible. However, BDF1 (RCI: 57.7) and CBA (RCI. 57.1) were revealed the moderate susceptibility, and B6CBAF1 (RCI: 23.1) was shown the lowest. The infection sites of adults were posteriorly transferred in the small intestine of experimental mice according to the infection periods of muscle larvae. The infection characteristics of KTI observed in this study may be useful as the basic data in the advanced studies, furthermore in the study of other Trichinella isolates.

• The Journal of the Korean Society for Microbiology
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• v.22 no.1
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• pp.1-8
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• 1987

Hantaan virus(HV) 76-118 strain was inoculated into suckling ICR mice by intra-nasal route with an inoculum of $10LD_{50}$. Mortality was 65% at the 3rd week after inoculation, but declined to 35% at the 4th week. Infectivity was determined by the measuring immuno-fluorescent antibody in sera. The peak of infectivity was 80% at the 4'th week after inoculation. Viremia was reached peak level of $1.7{\times}10^4\;PFU/ml$ by day 10. Immunofluorescent antibody and neutralizing antibody appeared by 2 weeks and 15-17 days respectively, but achieved similar titer by 35 days. By using a monoclonal antibody to HV 76-118, viral antigens were initially detected in inguinal and axillary lymph node by 2 days. Viral antigens in bone marrow and lung were delayed much more than in those of lymph node. These were similar with those of intra-peritoneal and intra-muscular route. Immune complex against IgG, IgM and C3 appeared by 16 days, 14 days, and 18 days respectively. The pattern of immunofluorescence in the basement membrane of glomeruli was diffuse membranous. Spotted pattern was also observed in the tissue stained with anti-mouse C3 antibody. By 20 days, control tissue was also shown immune complex in the glomeruli.

• Parasites, Hosts and Diseases
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• v.42 no.2
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• pp.85-89
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• 2004

Cryptosporidium parvum oocysts were isolated from a child suffering from acute gastroenteritis and successfully passaged in a calf and mice (designated hereafter SNU-H1) in the Republic of Korea; its molecular genotype has been analyzed. The GAG microsatellite region was amplified by a polymerase chain reaction (PCR), with a 238 base pair product, which is commonly displayed in C. parvum. The isolate was shown to be a mixture of the genotypes 1 (anthroponotic) and 2 (zoonotic). To study its infectivity in animals, 2 calves and 3 strains of mice were infected with the SNU-H1; in these animals, the propagation of both genotypes was successful. In immunosup-pressed (ImSP) BALB/c and C57BU6 mice the number of oocysts decreased after day 10 post-infection (PI); but in ImSP ICR mice, they remained constant until day 27 PI. The results show that both the C. parvum genotypes 1 and 2 can be propagated in calves and ImSP mice.

• Parasites, Hosts and Diseases
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• v.49 no.4
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• pp.423-426
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• 2011

In the genus Cryptosporidium, there are more than 14 species with different sizes and habitats, as well as different hosts. Among these, C. parvum and C. hominis are known to be human pathogens. As C. parvum can survive exposure to harsh environmental conditions, including various disinfectants or high doses of radiation, it is considered to be an important environmental pathogen that may be a threat to human health. However, the resistance of other Cryptosporidium species to various environmental conditions is unknown. In this study, resistance against ${\gamma}$-irradiation was compared between C. parvum and C. muris using in vivo infection in mice. The capability of C. muris to infect mice could be eliminated with 1,000 Gy of ${\gamma}$-irradiation, while C. parvum remained infective in mice after up to 1,000 Gy of ${\gamma}$-irradiation, although the peak number of oocysts per gram of feces decreased to 16% that of non-irradiated oocysts. The difference in radioresistance between these 2 Cryptosporidium species should be investigated by further studies.

• Parasites, Hosts and Diseases
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• v.31 no.2
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• pp.135-140
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• 1993

An experimental study was performed to observe the infectivlty of sparganum (plerocercold of Spirometra erinncel) treated by prazlquantel, gamma-irradiation and mechanical cutting. The spargana were obtained from the naturally Infected European grass snake, Rhabdophis tigrina, or from the expenmentally infected mice. A total of 83 mice (ICR straine were divided Into 3 experimental groups by the source of the damage, fed each UH 5 spargana, and sacnaced 1 month later for worm recovery. In the praziquantel group, the worms were incubated In the concentration of 10㎍/ml (control: Tyrode for 4 hours) for 0.5. 1.2 and 4 hours at 36℃. and fed to mice. The recovery rate from mice in prazlquantel group was not different from that (80%) of control poop and in the range of 76-100%. In the gamma-Irradiation group, the worms were irradiated by 10-1000 Gy with Csl37. The average recovery rates of 69-100% were not different from that of control up to 100 Gy. The rate was 56% under 150 Gy, and 5% by 1000 Gy. In the mechanical cutting group, the worms were cut at 0.5, 1, 2 and 3 m from the anterior end of the scolex. The average recovery rates In each group were 70-90% and that of control was 90%. The present folding suggests that the sparganum be highly resistant to prazlquantel, gamma- irradiation and mechanical cutting. The vitality center of the sparganum must be at the anterior end of Its scolex.