• Parasites, Hosts and Diseases
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• v.44 no.2 s.138
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• pp.117-125
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• 2006

Genetic diversity of 18 Acanthamoeba isolates from ocean sediments was evaluated by comparing mitochondrial (mt) DNA RFLP, 18S rDNA sequences and by examining their cytopathic effects on human corneal epithelial cells versus reference strains. All isolates belonged to morphologic group II. Total of 16 restriction phenotypes of mtDNA from 18 isolates demonstrated the genetic diversity of Acanthamoeba in ocean sediments. Phylogenetic analysis using 18s rDNA sequences revealed that the 18 isolates were distinct from morphological groups I and III. Fifteen isolates showed close relatedness with 17 clinical isolates and A. castellanii Castellani and formed a lineage equivalent to T4 genotype of Byers' group. Two reference strains from ocean sediment, A. hatchetti BH-2 and A. griffini S-7 clustered unequivocally with these 15 isolates. Diversity among isolates was also evident from their cytopathic effects on human corneal cells. This is the first time describing Acanthamoeba diversity in ocean sediments in Korea.

• Journal of the korean veterinary medical association
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• v.29 no.6
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• pp.360-365
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• 1993

Attempts to isolate porcine epidemic diarrhea virus(PEDV) were made by inoculating feces homogenates into Vero cells cultures with trypsin. Cytopathic effects(CPE), such as vacuolation, formation of syncytia, and fusion of cells, were detected even at fir

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.11a
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• pp.451-454
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• 2006

부산시 상수원수를 대상으로 2001년 8월에서 2005년 12월까지 바이러스 검사를 실시하였다. 총 35개의 상수원수 시료 중 22개 시료에서 cytopathic effect가 확인되어 62.8%의 양성률을 보였다. 검출된 바이러스는 $1.92{\sim}11.90$ MPN/100L의 범위로 여름철과 초겨울에 분포하는 특성을 보였다. 원수에서 검출된 바이러스는 정수과정 중 제거 가능하지만 정기적으로 모니터링을 해야 한다고 생각된다.

• Korean Journal of Veterinary Service
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• v.20 no.2
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• pp.195-203
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• 1997

Fecal samples were collected from 47 calves with diarrhea and 12 clinically normal co-h-abitants, and tested for virus using MDBK cell cultures. Three cytopathic viruses were isolated from 8 fecal samples obtained from diarrheic calves. The isolated viruses were neutralized by bovine coronavirus hyperimmune serum In plaque reduction assay and were detected in the cytoplasm of MDBK cell by bovine coronavirus hyperimmune serum using immunofluorescence staining. The viruses agglutinated mouse erythrocytes only among the various animal erythrocytes tested and new isolates were identified as bovine coronavirus.

• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.387-389
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• 2011

A previous study of ours indicated that Citrus auranifoli oil possesses antifungal activity against Malassezia furfur and Malassezia pachydermatis. In this study, we evaluated the anti-M. furfur and M. pachydermatis activities of limonene, which is a major component of C. aurantifolia oil, using the disk diffusion method. We also examined cytotoxicity against human normal epithelial (Beas-2B) cells using the cytopathic effect reduction (CPE) method. The results revealed that the minimum fungicidal concentration (MFC) value of limonene is lower than the value for itraconazole. The MFC value of limonene was seen to be 7.81 ${\mu}g$/mL against M. furfur and 3.90 ${\mu}g$/mL against M. pachydermatis. MFC values of itraconazole against M. furfur and M. pachydermatis were 62.50 ${\mu}g$/mL and 31.25 ${\mu}g$/mL, respectively. In addition, it was noted that limonene was not toxic to Beas-2B cells with normal morphology at a concentration of 100 ${\mu}g$/mL. However, itraconazole exhibited weak toxicity at the same concentration. Therefore, our results indicate that limonene could potentially be effective at controlling M. furfur and M. pachydermatis infections with no cytotoxicity.

• Journal of fish pathology
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• v.17 no.2
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• pp.75-82
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• 2004

Interferons are kinds of cytokines that play an important role in antiviral defense mechanisms during viral infection by converting cells to synthesize proteins that inhibit viral replication. In the present study, an antiviral response against Spring viremia of carp virus (SVCV) was developed in common carp, Cyprinus carpio following stimulation with the potent interferon inducer, poly inosinic : cytidylic acid (poly I:C). Poly I:C injected fish showed lower cumulative mortalities against SVCV than untreated fish did. Moreover, in vitro study showed that head kidney leucocytes (HKLs) produced an interferon-like cytokine (ILC) after stimulation with poly I:C. According cytopathic effect reduction (CPER) assay to examine antiviral activity of crude ILC, the capacity of HKLs for ILC production was highest at 1×$10^6$cells/ml and significantly enhanced when treated with 20~50$\mu{g}$/ml of poly I:C. The optimal temperature and concentration of FBS to induce the highest ILC production were $20^\circ{C}$ and 5%, respectively.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.125-130
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• 2013

Influenza viruses cause significant morbidity and mortality in humans through epidemics or pandemics. Currently, two classes of anti-influenza virus drugs, M2 ion-channel inhibitors (amantadin and rimantadine) and neuraminidase inhibitors (oseltamivir and zanamivir), have been used for the treatment of the influenza virus infection. Since the resistance to these drugs has been reported, the development of a new antiviral agent is necessary. In this study, we examined the antiviral efficacy of the plant extracts against the influenza A/PR/8/34 infection. In vitro, the antiviral activities of the plant extracts were investigated using the cell-based screening. Three plant extracts, Thuja orientalis, Aster spathulifolius, and Pinus thunbergii, were shown to induce a high cell viability rate after the infection with the influenza A/PR/8/34 virus. The antiviral activity of the plant extracts also increased as a function of the concentration of the extracts and these extracts significantly reduced the visible cytopathic effect caused by virus infections. Furthermore, the treatment with T. orientalis was shown to have a stronger inhibitory effect than that with A. spathulifolius or P. thunbergii. These results may suggest that T. orientalis has anti-influenza A/PR/8/34 activity.

• Korean Journal of Microbiology
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• v.38 no.3
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• pp.186-191
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• 2002

The usefulness of oligonucleotide DNA chip was evaluated for detection and primary level identification of major waterborne viruses in environmental samples. The enteric waterborne viruses included enterovirus, adenovirus, and rotavirus. Total intracellular RNA of 10 BGM cell plates showing virus-specific cytopathic effects was extracted at the third day after inoculation. The intracellular RNA was then subjected to either enterovirus-specific RT-PCR followed by sequencing analysis, or the DNA chip. Seven out of 10 positive samples in cell culture were positive but the other three sample were turned out to be negative by both RT-PCR and DNA chip analyses. Nucleotide sequencing results and the DNA chip hybridization results of the RT-PCR product were in complete agreement in the identification of the 7 positive samples as enteroviruses. Using the DNA chip, it took only 3∼4 hr to complete detection and primary level identification of target viruses and additional procedures such as gel electrophoresis or nucleotide sequencing were not necessary. We believe that the DNA chip system can be employed as a highly effective and new detection methodology for environmental viruses.

• Korean Journal of Veterinary Research
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• v.58 no.4
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• pp.177-182
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• 2018

Canine adenovirus type 2 (CAV-2) infection results in significant respiratory illness in dogs. Isolating and culturing CAV-2 allows for investigations into its pathogenesis and the development of vaccines and diagnostic assays. In this study, we successfully isolated a virus from a naturally infected dog in Gyeonggi-do, Korea. The virus was propagated in Madin-Darby canine kidney (MDCK) and Vero cells and showed a specific cytopathic morphology that appeared similar to a bunch of grapes. The virus was first confirmed as CAV-2 based on these cytopathic effects, an immunofluorescence assay, hemagglutination assay, and electron microscopy. The viral titer of the isolate designated APQA1601 reached $10^{6.5}$ 50% tissue culture infections dose per mL in MDCK cells and exhibited no hemagglutination units with erythrocytes from guinea pig. The virus was also confirmed by polymerase chain reaction and next-generation sequencing. The APQA1601 strain had the highest similarity (~99.9%) with the Toronto A26/61 strain, which was isolated in Canada in 1976 when the nucleotide sequences of the full genome of the APQA1601 strain were compared with those of other CAV strains. Isolating CAV-2 will help elucidate the biological properties of CAV-2 circulating in Korean dogs.

• Archives of Pharmacal Research
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• v.15 no.3
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• pp.242-245
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• 1992

Two triterpenes 1 and 2 with antiviral activity against Herpes simplex virus type 1 in vitro were isolated from Prunella vulgaris. Each compound caused a significant reduction in viral cytopathic effect when vero cells were exposed to them for 72 hours after viral challenge. They were identified as betulinic acid (1) and $2\alpha, 3\alpha$-dihydroxyurs-12-en-28-oic acid(2) on the basis of their spectroscopic properties. The antiviral activity of them was estimated as $EC_{50}=30\;\mu$g/ml(1) and $8\;\mu$g/ml(2), respectively by plaque reduction assay.