• Journal of Environmental Health Sciences
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• v.38 no.1
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• pp.57-65
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• 2012

Objectives: For our survey of the incidence of norovirus infections and the genogroup distribution of norovirus in Seoul, Republic of Korea, we evaluated through regular surveillance the prevalence of norovirus infections in patients with acute gastroenteritis occurring in Seoul from January 2007 to July 2011. Methods: For norovirus detection, we conducted epidemiological analyses on the basis of the junction of ORF1 and ORF2 (approximately 314 bp). 11,202 fecal specimens were collected from patients in Seoul with acute gastroenteritis between January 2007 and July 2011 and then tested for the presence of NoV via reverse transcription (RT) - polymerase chain reaction (PCR). Results: 16.6% (1,861/11,202) of the fecal specimens were determined to be positive for noroviruses. The incidences of norovirus infection in Seoul in the case of acute gastroenteritis with regular surveillance were 28.0% in 2007, 14.6% in 2008, 9.1% in 2009, 14.1% in 2010, and 12.9% in 2011, which shows that noroviruses constituted a major causative agent of acute gastroenteritis. Also, the incidence of noroviral infection in patients with acute gastroenteritis increased after the large-scale new influenza in 2009. Conclusions: The genetic characteristics of norovirus and the epidemiologic patterns of a viral pathogen in acute gastroenteritis patients may provide potentially effective data for epidemiological studies in Seoul, Korea.

• Journal of fish pathology
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• v.16 no.1
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• pp.1-12
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• 2003

RT-PCR method was applied to detect and clone the nucleocapsid protein (N) gene and glycoprotein (G) gene for sequencing 5 Korean VHSV isolates from cultured olive flounder, Paralichthys olivaceus. Phylogenetic analysis was performed to investigate their relationship with the VHSV strains described previously and isolated from different geographical area. Generally, VHSV strains were separated phylogenetically according to the major geographical area of isolation: Genogroup I (American type), Genogroup Il (British Isles) and Genogroup ill (European type). This study revealed that all 5 Korean VHSV isolates were belonged to Genogroup I and closely related to Japanese Obama25 type.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.670-676
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• 2017

Recently, mass mortality of the young abalone Haliotis discus hannai has occurred in commercial seed production farms in Korea. The mortality rate was above 50% of the total cultured organisms in the farm, and the shell length of the moribund organisms was about 3cm. The mortal phenomenon was that the young abalones were weakly scattered on the bottom of the pond from the attachment matrix, or that they could not be moved back to their normal positions. The diseased farmed Pacific abalone had abdominal edema. From the edema in the moribund individuals, three bacterial strains were isolated and all the strains were identified as Vibrio harveyi. These strains were compared with thirty six strains isolated from the fish. The results was that the Vibrio harveyi from the fish were sorted into genogroup A or B; however, the three strains of the diseased farmed Pacific abalone were sorted into genogroup A and the new genogroup C. The identical mortality and pathological symptoms of the naturally infected organisms were reproduced by artificial infection with WA AG-1 and WA CS-5 strains. The $LD_{50}$ of WA AG-1 and WA CS-5 were each $1.0{\times}10^3cfu\;animal^{-1}$ and $1.7{\times}10^4cfu\;animal^{-1}$.

• Korean Journal of Veterinary Research
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• v.48 no.3
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• pp.287-293
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• 2008

The cDNA of the aquabirnavirus, GC-1 isolated from rockfish Sebastes schlegeli in Korea, was synthesized using the reverse transcriptase-polymerase chain reaction. The nucleotide and deduced amino acid sequences were determined from cDNA of the VP2-NS-VP3 coding region of genome segment A. The nucleotide sequences of the segment A were 3,086 base pairs (bp) in length and contained large open reading frame (ORF) and terminal sequences. The large ORF was comprised of 2,916 bp nucleotides and composed of 972 deduced amino acid sequences. Pairwise comparisons were made with other aquabirnavirus sequences published previously. The study of genetic relationships between GC-1 and aquabirnaviruses in the large ORF and VP2 coding regions demonstrated that the GC-1 has the nearest genetic relationship with the marine birnaviruses (MABV strains), and the GC-1 and MABV strains can be clustered as the same genogroup. GC-1 can be included in MABV, which is the 7th genogroup of family Aquabirnaviridae.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.123-131
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• 2017

Norovirus causes frequent epidemic viral gastroenteritis in Korea. The team for the control of noroviral foodborne outbreaks (NOROTECL) executed a project to trace the cause of norovirus contamination in agricultural products and environmental samples to reduce norovirus outbreaks in Korea. Between January and November in 2015, the contaminations by norovirus and indicator microorganisms such as coliforms, Escherichia coil and male specific coliphage (MSC) were examined in 80 agricultural products, 80 soil samples, 78 human feces samples, 3 animal feces samples, 80 agricultural water samples and 80 river water samples. Semi-nested PCR and DNA sequencing revealed 18 genogroup I and 3 genogroup II noroviruses in a total of 18 samples. These noroviruses were validated by real-time (RT)-PCR analysis. For indicator microorganisms, coliform and E. coli were respectively detected in agricultural products (68, 1%), soils (88, 7%), human feces (44, 12.8%), animal feces (67, 67%), agricultural waters (74, 30%) and river waters (96, 51%). The MSC results revealed 14 positive samples.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.32.1-32.8
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• 2021

Feline calicivirus (FCV) is a highly infectious pathogen in cats and widely distributed worldwide with high genetic variation. Full-length open reading frame 2 of 5 from recently isolated Korean FCV isolates were sequenced and compared with those of global isolates. The results of phylogenetic analysis supported dividing global FCV isolates into two genogroups (type I and II) and demonstrated the presence of genogroup II in Korea, indicating their geographic spread in East Asia. High sequence variations in region E of the FCV isolates emphasizes that a novel vaccine needs to be developed to induce protective immunity against various FCV strains.

• The Journal of Korean Society of Virology
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• v.28 no.1
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• pp.11-20
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• 1998

Twenty isolates of Hantavirus were isolated from patients and reserovirs from 1988 to 1994 in Korea. Isolation rate was 1.9% (10/538) in patients, 6.2% (5/81) in Apodemus sp., 2.6% (1/38) in Rattus sp. and 0.6% (4/677) in bats. Reciprocal mean IFA titers ranged from 27.5 to 1,024 at the specimen collection. According to the growth rate and reaching peak titier of infectivity, the isolates were grouped as rapid, intermediate, and slow growing groups. All isolates were confirmed as Hantaan type by the nested RT-PCR on the G1 region of the M segment. Comparison of nucleotide sequence (Nt: 2101 - Nt: 2280) of the G2 region revealed that the sequence homology bewteen Hantaan 76/118 virus and the isolates was more than 90%. Several nucleotide positions of the isolates showed high variation. The variation rate of patientisolates was about one-half when compared with that of rodentisolates. On the basis of phylogenetic analysis Hantaan viruses isolated were divided into two genogroups. These results indicate that Hantaan virus is highly dominant serotype in Korea and the virologic property and genogroup are not correlated.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1150-1154
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• 2009

Low levels of virus contamination and naturally occurring reverse transcription-polymerase chain reaction (RT-PCR) inhibitors restrain virus detection in oysters. A rapid and efficient oyster-processing procedure that can be used for sensitive virus detection in oysters was developed. Poliovirus type 1 Sabin strain was used to evaluate the efficacy of virus recovery. The procedure included (a) acid-adsorption and elution with buffers (0.25M glycine-0.14 M NaCl, pH 7.5; 0.25M threonine-0.14M NaCl, pH 7.5); (b) polyethylene glycol (PEG) precipitation; (c) resuspension in Tween 80/Tris solution and chloroform extraction; (d) the second PEG precipitation; (e) viral RNA extraction with TRIzol and isopropanol precipitation; and (f) RT-PCR combined with semi-nested PCR. The overall recovery of elution/concentration was 19.5% with poliovirus. The whole procedure usually takes 19 hr. The overall detection sensitivity was 4 RT-PCR units of genogroup I norovirus (NoV) and 6.4 RT-PCR units of genogroup II Nov/25 g of oysters initially seeded. The virus-detecting method developed in this study should facilitate the detection of low levels of NoV in oysters.

• Journal of fish pathology
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• v.25 no.3
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• pp.143-150
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• 2012

Infectious haematopoietic necrosis virus (IHNV) is an important fish pathogen that infects both wild and cultured salmonids. Since the first isolation of IHNV from rainbow trout and masu salmon in 1991, a series of IHN disease outbreak has been reported in Korea. In 2011, we isolated two IHNV isolates from rainbow trout cultured in Korea. The full open-reading frame (ORF) encoding the glycoprotein (G) of them were sequenced and the amino acid sequences were phylogenetically analyzed. Phylogenetic analysis of the G revealed that both IHNV isolates were grouped into an Asian genogroup containing Korean IHNV isolates and Japanese IHNV isolates. However, based on their sequence variation, they were divided into different subgroup. While one isolate was similar to other Korean isolates, the other isolate showed a high level of similarity with Japanese isolates, suggesting the possibility of influx of new IHNV strain into Korea.

• Journal of fish pathology
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• v.24 no.3
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• pp.255-268
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• 2011

For detection of noroviruses (NVs), we compared various PCR primer sets based on reverse transcription nested PCR (RT-nested PCR) in the water samples from Dong brook in Busan, South Korea. We designed various new primer sets based on the most conserved sequences of the capsid protein gene that react with diverse NVs found in Korea. Designed primer sets (KG1F/KG1R and KG2F/KG2R, named as PNK) for the respective genogroups of NVs, genogroup I and II (GI and GII), were applied to detect NVs in the water samples from Dong brook concentrated with ultracentrifugation. In the application to the water samples, proportion of GI (76.47%) and GII (70.59%) in water samples of Dong brook in RT-nested PCR with the primer sets of this study. However, no significant differences of the proportion of the positive samples were not found between RT-nested PCRs with reported and newly designed primer sets. From the nucleotide sequencing, GI and GII of NVs present in Dong brook were appeared to be the members of 1/2/4/5/9/10 genotypes, and 3/4/5/11/13 genotypes respectively. Appeared genotype 4 of GII known as an one of main genotype found in patients of many Asian countries warned us to consider the risks of norovirus in aquatic environments in southern part of Korea.