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Localization and persistence of hepatitis A virus in artificially contaminated oysters
Park, Hyunkyung,Jung, Soontag,Shin, Hansaem,Ha, Sang-Do,Park, Tae Jung,Park, Jong Pil,Seo, Dong Joo,Choi, Changsun Elsevier 2019 International journal of food microbiology Vol.299 No.-
<P><B>Abstract</B></P> <P>Bivalve molluscan shellfish, such as oysters, clams, and cockles, are well-recognized as vectors that concentrate foodborne pathogens by filter feeding. The objective of this study was to investigate the distribution and persistence of hepatitis A virus (HAV) in experimentally contaminated oysters that were either fed or not fed with algae. Oysters were experimentally contaminated with HAV and maintained in depuration conditions. qRT-PCR, immunohistochemistry (IHC), and <I>in situ</I> hybridization (ISH) were performed on oyster samples collected at 0, 1, 3, 5, and 7 days post-inoculation. When HAV-contaminated oysters were depurated for 7 days, HAV was detected in 91.1–97.8% of the digestive glands and gills. While the high viral load in the digestive glands in oysters did not change significantly regardless of algae-feeding, the viral load of the gills gradually decreased in both groups during the depuration. HAV antigen and RNA were detected in the digestive diverticula and connective tissues by both IHC and ISH. HAV was detected in the stomach, intestine, and gills by only ISH. The distribution of HAV in various oyster tissues may explain the persistence of contamination in oysters during the depuration process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High titer of HAV was accumulated in the digestive gland and gills of oysters. </LI> <LI> HAV capsid was localized in the hemocyte and digestive gland by immunohistochemistry. </LI> <LI> HAV RNA was visualized in the hemocytes and digestive gland by <I>in situ</I> hybridization. </LI> <LI> HAV was persistently detected in oysters for 7 days under depuration condition. </LI> </UL> </P>
Shin, Hansaem,Park, Hyunkyung,Seo, Dong Joo,Jung, Soontag,Yeo, Daseul,Wang, Zhaoqi,Park, Ki Hwan,Choi, Changsun Mary Ann Liebert, Inc. Publishers 2019 Foodborne Pathogens and Disease Vol.16 No.6
<P> Contamination of fresh vegetables and berries with human enteric viruses is a major cause of food poisoning. The aim of this study was to investigate the prevalence of norovirus GI, norovirus GII, hepatitis A virus (HAV), adenovirus, astrovirus, rotavirus, and male-specific coliphage systematically in fresh fruit and vegetables and associated agricultural environmental samples, including irrigation water, soil, and worker's gloves. Enteric viruses were detected by international standard methods (ISO/TS 15216), and male-specific coliphages were isolated using US EPA Method 1601. For the study, 773 samples were collected from June 2016 to April 2017, including Chinese cabbage (n=244), cucumber (n=98), lettuce (n=73), strawberry (n=120), soil (n=191), irrigation water (n=14), and gloves (n=27). Two cucumber and two irrigation water samples were positive for norovirus GI, and one cucumber and two irrigation water samples were positive for norovirus GII. HAV was detected in one strawberry sample and one glove sample. The other tested foodborne viruses were not detected in any of the samples. Sixteen male-specific coliphages were isolated from Chinese cabbage, cucumber, lettuce, cherry tomato, soil, and irrigation water. The isolation of male-specific coliphage would be more practical to investigate the fecal contamination in produce rather than pathogenic viruses. </P>