• Journal of Environmental Science International
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• v.23 no.2
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• pp.219-229
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• 2014

The occurrence trends and moleculargenetic characteristics of noroviruses detected from gastroenteritis patients in Jeju from 2008 to 2010 were investigated. In addition, the norovirus contamination and its characteristics of groundwaters in Jeju were examined. The incidence caused by norovirus in viral gastroenteritis patients has increased every year and was higher in male than in female. The patients caused by norovirus occurred throughout all months. The incidences started to increase from November, were very high from December to February, started to decrease from March, and were very low from June to September. The patients caused by norovirus occurred throughout all ages, however, the infants below 5 years were the most susceptible to norovirus infection and the age group from teens to forties were the most insensitive to norovirus infection. The sequencing analysis showed that 18 genotypes (8 genogroup I (GI) and 10 genogroup II (GII)) were detected, the incidences caused by GI and GII were 11.5% and 88.5%, respectively, and predominant genotype was GII-4 (70.5%), which was the major genotype giving rise to norovirus incidences in Jeju, together with GII-3 (6.1%) and GI-4 (4.1%). Among 20 groundwaters sampled at 9 wells (4 non-drinking water wells and 5 drinking water wells), noroviruses were detected from 2 groundwaters sampled at one non-drinking water well and their genotypes were GI-5 and GI-8.

• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.71-76
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• 2018

Norovirus is a leading cause of sporadic pathogenic non-bacterial gastroenteritis worldwide. For the detection of norovirus, reverse transcription real-time PCR (RT qPCR) has quickly become a major tool due to its sensitivity and specificity. However, accurate viral RNA extraction methods are essential for RT qPCR analysis. TRIzol reagents are used to extract RNA from biological materials and are therefore widely used for norovirus RNA extraction. In this study, the yield of viral RNA extraction using TRIzol from genogroup II (GII) among the human norovirus genogroup I (GI) and GII, and murine norovirus (GV) depended on the pH of the virus sample solution. The yield of RNA extraction was higher at the alkaline pH than in the acidic region compared with the Ct (threshold cycle) value of the real-time PCR. From the results of this study, it was found that the pH condition is very important for the quantitative analysis of norovirus by extracting GII RNA using TRIzol.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.501-507
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• 2014

Norovirus (NoV) is a major cause of food poisoning outbreaks in Korea. Most NoV outbreaks originate from environmental contamination, but bivalves such as oysters are also important vectors. Oyster Crassostrea gigas contamination by NoV has been reported in Korea, but no quantitative analyses of NoV have been performed. We investigated the NoV concentration in 21 oyster samples from a Korean commercial oyster-growing area with confirmed fecal contamination from January to December 2012, using real-time reverse transcription-polymerase chain reaction. Additionally, we assessed the NoV concentration after heating to investigate the effects of heat treatment on NoV-infected oysters. In NoV-positive samples, the cycle threshold (Ct) values were 37.43-39.41 and 36.77-39.30, while viral concentrations were $8.97{\times}10^2-2.24{\times}10^2$ and $3.05{\times}10^2-7.47{\times}10^1$ copies/g for genogroups I and II, respectively. After heat treatment, NoV genogroup I decreased by 83.4%, 88.0%, 89.4% and 100% at $60^{\circ}C$, $68^{\circ}C$, $70^{\circ}C$, and $100^{\circ}C$, respectively, for 15 min, while genogroup II respectively decreased by 67.3%, 76.3%, 80.1%, and 89.8% under the same conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.898-903
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• 2015

Noroviruses (NoV) are known to cause acute epidemic gastroenteritis worldwide. Outbreak strains are predominantly genogroup I (GI) and genogroup II (GII) in oysters Crassostrea gigas. We investigated the changes in concentration of male specific coliphage (MSC) and NoV under heat treatment of the naturally contaminated oyster, Crassostrea gigas. After heat treatment for 5 min in $85^{\circ}C$, no viable MSC was detected. The concentrations of GI and GII NoV decreased by 1.65 log and 2.25 log, respectively, following heat treatment for 5 min at $100^{\circ}C$. Moreover, both GI and GII NoV were completely deactivated by heat treatment for 10 min at $100^{\circ}C$. Therefore, in order to reduce the risk of norovirus infection from contaminated oysters, immersion in boiling water for at least 10 min is recommended.

• Journal of fish pathology
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• v.22 no.3
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• pp.211-218
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• 2009

In this study, we have compared the genome of marine birnavirus (MABV) detected from starry flounder Platichthys stellatus and olive flounder Paralichthys olivaceus. A molecular analysis based on the nucleotide sequence (433 bases) of VP2-NS-VP3 region revealed that MABV (08-KU) from starry flounder showed 98% similarity with MABV Y6 isolated from Yellowtail Seriola quinqueradita in Japan (Accession no: AY283781) and with other aquabirnaviruses identify more than 76%. Comparison with MABV strains (06-KP, 08-KC) from olive flounder and MABV Y6 strain showed 97-98% sequence identities. Phylogenetic analysis was performed in order to examine the relationship among previously determined aquatic birnaviruses isolates showed that MABV and IPNV strains were classified into seven clusters. Three isolates from starry flounder and olive flounder in this study, belong to the genogroup VII including MABV Y6 strain and other aquabirnaviruses isolated from marine fish and molluscan shellfish in Japan. This report is the first description of a MABV from starry flounder in Korea.

• Journal of Microbiology
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• v.44 no.4
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• pp.403-408
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• 2006

The purpose of this study was to determine the efficacy of a nucleic acid sequence-based amplification (NASBA) method of detecting noroviruses in artificially and naturally contaminated shellfish. We used 58 fecal samples that tested positive for noroviruses with electron microscopy (EM) to develop an NASBA assay for these viruses. Oligonucleotide primers targeting the polymerase coding region were used to amplify the viral RNA in an isothermal process that resulted in the accumulation of RNA amplicons. These amplicons were detected by hybridization with digoxigenin-labeled oligonucleotide probes that were highly specific for genogroup I (GI) and genogroup II (GII) of noroviruses. The expected band of 327bp appeared in denaturing agarose gel without any nonspecific band. The specific signal for each amplicon was obtained through Northern blotting in many repeats. All fecal samples of which 46(79.3%) belonged to GII and 12(20.6%) belonged to GI were positive for noroviruses by EM and by NASBA. Target RNA concentrations as low as 5pg/ml were detected in fecal specimens using NASBA. When the assay was applied to artificially contaminated shellfish, the sensitivity to nucleic acid was 100pg/1.5g shellfish tissue. The potential use of this assay was also confirmed in naturally contaminated shellfish collected from different ponds in Guangzhou city of China, of which 24 (18.76%) out of 128 samples were positive for noroviruses; of these, 19 (79.6%) belonged to GII and 5 (20.4%) belonged to GI. The NASBA assay provided a more rapid and efficient way of detecting noroviruses in fecal samples and demonstrated its potential for detecting noroviruses in food and environmental samples with high specificity and sensitivity.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.556-562
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• 2014

The occurrence of human norovirus (NoV) genogroup I (GI) and genogroup II (GII) strains was investigated in Korea. Between 2007 and 2010, 265 samples were collected from 89 Korean water source locations. NoV GI was detected in 4.5% and NoV GII in 1.5%. Samples collected in winter had the highest occurrence; 9.4% for NoV GI and 6.3% for NoV GII. NoV GI detection was highest in groundwater, with the next highest in river water and the lowest in lake water (5.9%, 5.4%, and 1.6%, respectively), and NoV GII was found only in river water. When three representative Korean basin systems (Han (H)-, Geum/Seom (G/S)-, and Nakdong (N)-river basins) were compared, both NoV genogroups were high in the G/S-, but absent in the H- river basin. The most prevalent genotypes within the GI and GII groups were GI.5 and GII.4, respectively. The NoVs found in surface water were identical to those found in patients and those found in groundwater. The NoVs appeared to be transmitted from the patient to the surface water, and then to the groundwater, suggesting a fecal-oral route of transmission. This is the first nationwide surveillance of NoV in major Korean water sources.

• Journal of fish pathology
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• v.17 no.1
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• pp.1-10
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• 2004

In order to analyse the detection of viral hemorrhagic septicemia virus (VHSV) in marine environment surrounding coastal region of Eastern and Southern sea of Korea, the pools of each organ sample of three fish were taken for virus assay from February to May in 2003. The samples comprised 42, taken from 9 species of marine fishes. The VHSV was detected from chub mackerel Scomber japonicus and striped mullet Mugil cephalus in epithelioma papulosum cyprini (EPC) cells. The identity of the virus was confirmed a reverse transcriptase-polymerase chain reaction (RT-PCR). VHSV has previously been reported from chub mackerel, but not from striped mullet. The new isolates was classified as a member of genogroup I (American type) of VHSV and was closely related to the VHSV KVHS'01-l based on comparisons of the partial nucleotide sequence of the glycoprotein (G) gene.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.407-412
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• 2009

In this study, a rapid and efficient concentrating procedure that can be used for detecting viruses in vegetables was developed. The Sabin strain of poliovirus type 1 was used to evaluate the efficiency of virus recovery. The procedure included: (a) elution with 0.25 M threonine-0.3 M NaCl pH 9.5; (b) polyethylene glycol (PEG) 8000 precipitation; (c) chloroform extraction; (d) 2$^{nd}$ PEG precipitation; (f) RNA extraction; (g) reverse transcription-polymerase chain reaction (RT-PCR) combined with semi-nested PCR. The overall recoveries by elution/concentration were 29.0% from cabbage and 13.7% from lettuce. The whole procedure usually takes 18 hr. The overall detection sensitivity was 100 RT-PCR units of genogroup II norovirus (GII NoV)/25 g cabbage and 100 RT-PCR units of GII NoV/10 g lettuce. The virus detecting method developed in this study should facilitate the detection of low levels of NoV in cabbage and lettuce.

• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.235-241
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• 2023

Noroviruses are a major cause of gastroenteritis in humans and animals worldwide. In 2021, canine norovirus (CNoV) infection was detected at an animal clinic in Gwangju area, South Korea. A semi-nested polymerase chain reaction was developed to amplify a 478 bp fragment of the RdRp gene of CNoV. The phylogenetic analysis of this fragment confirmed the strain to be genogroup IV.2 (Dog/GIV.2/gw/s377/2021/KOR), which exhibited the highest similarity to the feline NoV strain GIV.2/CU081210E/USA/2010 (accession no. NC_045762) with 95.1% nucleotide (nt) identity and 98.7% amino acid (aa) identity. These research findings indicate that the detected norovirus in dogs is genetically similar to a feline-origin norovirus, suggesting easy cross-species transmission among animals.