• Journal of Microbiology and Biotechnology
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• 제31권12호
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• pp.1709-1715
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• 2021

Outbreaks of food poisoning due to the consumption of norovirus-contaminated shellfish continue to occur. Male-specific (F+) coliphage has been suggested as an indicator of viral species due to the association with animal and human wastes. Here, we compared two methods, the double agar overlay and the quantitative real-time PCR (RT-PCR)-based method, for evaluating the applicability of F+ coliphage-based detection technique in microbial contamination tracking of shellfish samples. The RT-PCR-based method showed 1.6-39 times higher coliphage PFU values from spiked shellfish samples, in relation to the double agar overlay method. These differences indicated that the RT-PCR-based technique can detect both intact viruses and non-particle-protected viral DNA/RNA, suggesting that the RT-PCR based method could be a more efficient tool for tracking microbial contamination in shellfish. However, the virome information on F+ coliphage-contaminated oyster samples revealed that the high specificity of the RT-PCR- based method has a limitation in microbial contamination tracking due to the genomic diversity of F+ coliphages. Further research on the development of appropriate primer sets for microbial contamination tracking is therefore necessary. This study provides preliminary insight that should be examined in the search for suitable microbial contamination tracking methods to control the sanitation of shellfish and related seawater.

• 한국수산과학회지
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• 제48권6호
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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.

• 한국수산과학회지
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• 제49권4호
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• pp.454-459
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• 2016

Pre- or post-harvest processing is required to mitigate the risk of norovirus infection mediated by shellfish or seafood. We investigated the environmental resistance of human norovirus (HuNoV) under various conditions of temperature, salinity, and pH in seawater. Male-specific coliphage (MSC) was as the reference virus for all tests. At 4℃, HuNoV GII4 spiked into seawater was continually detected by RT-PCR for 35 days, regardless of salinity or pH level. It maintained nearly stable concentrations, meaning HuNoV can sustain a viral population in seawater long enough to be accumulated by shellfish and other filter feeders during winter. MSC was also stable at 4℃ although viral infectivity dropped sharply after 28 days. The effects of salinity and pH on MSC were indistinct. At 25℃ the detectable period of HuNoV GII4 by RT-PCR in seawater decreased to about one-third or half of the period at 4℃. High salinity (32 psu) and alkaline pH (8.5) were also unfavorable for sustaining HuNoV abundance at 25℃ in seawater. The resistance patterns of MSC to high temperature, high salinity, and alkaline pH were more dramatic and viral infectivity decreased over time, almost in direct proportion to experimental days. MSC was undetectable after 12 days under all salinities and pH levels at 25℃.

• 한국식품과학회지
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• 제49권2호
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• pp.123-131
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• 2017

노로바이러스는 국내에서도 지속적으로 유행성 바이러스성 위장염을 일으키고 있다. 노로바이러스 저감화사업단(NOROTECL)의 1중 2세부과제에서는 농산물의 노로바이러스 오염 원인을 추적조사하여 노로바이러스 전파를 예방하고 저감화하기 위한 과제를 수행하였다. 2015년 1월부터 11월 사이에 노로바이러스와 관련이 있을 것으로 추정되는 80개 농산물, 80개 토양, 78개 인체분변, 3개 가축분변, 80개 농업용수, 80개 하천수 시료를 대상으로 노로바이러스, Male specific coliphage (MSC), 위생지표세균(Coliform, E. coli) 세 가지 검사를 통해 오염현황을 조사하였다. Semi-nested PCR과 DNA sequencing을 통해 18개의 Genogroup I과 3개의 Genogroup II 노로바이러스가 총 18개의 시료에서 발견되었다. Genogroup이 확정된 노로바이러스에 대하여 RT-PCR을 진행하였다. 대장균군과 대장균은 농산물에서 68%와 1%, 토양에서 88%와 7.5%, 인체분변에서 44%와 12.8%, 가축 분변에서 67%와 67%, 농업용수에서 74%와 30%, 하천수에서 96%와 51%의 검출율을 각각 나타냈다. MSC 결과에서는 14개의 시료가 양성으로 나타났다.

• 한국수산과학회지
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• 제56권6호
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• pp.798-809
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• 2023

In this study, we evaluated the impacts of land-based pollution sources on seawater and shellfish in the Jindongman area after 20.5 mm and 90.6 mm rainfall events. We analyzed sanitary indicator microorganisms used in survey management, such as total coliform, fecal coliform, Escherichia coli, and male-specific coliphage in Waste water treatment plant (WWTP), major inland pollution source,s seawater, and shellfish for 4 days after rainfall events. Our results showed that the range of coliform group and fecal coliform was 1.8-49 and <1.8-4.5 MPN (most probable number)/100 mL, respectively, after rainfall events in WWTP discharge water. Furthermore, the radius of the calculated impacted area of major inland pollution sources ranged from 5 to 798 m after 20.5 mm of rainfall and 30 to 1,031 m after 90.6 mm of rainfall. The fecal coliform of seawater at 30 stations in the shellfish growing area and areas adjacent to four stations was <1.8-130 and from <1.8-79 MPN/100 mL, respectively. The E. coli level of shellfish at 7 stations in the shellfish growing area was <18-220 MPN/100 g.