Author
Tian, Peng | |
ENGELBREKTSON, ANNA | |
MANDRELL, ROBERT |
Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/29/2008 Publication Date: 5/12/2008 Citation: Tian, P., Engelbrektson, A.L., Mandrell, R.E. 2008. Seasonal Tracking of Histo-blood Group Antigen Expression and Norovirus Binding in Oyster Gastrointestinal Cells. Journal of Food Protection. 71:1696-1700. Interpretive Summary: Noroviruses (NORs) are the most common cause of viral gastroenteritis outbreaks and the illnesses are sometimes described as “highly seasonal syndrome” or "winter vomiting disease”. Outbreaks are often associated with the consumption of contaminated oysters or other bivalves and generally occur between the months of November and March, when oysters produce the highest levels of oyster glycogen. It has been proposed that oyster glycogen might play a role in NOR accumulation via ionic bonding of viral particles to the mucopolysaccharide moiety of the gastrointestinal tract during feeding. Recent research indicates that histo-blood group antigens (HBGAs) function as viral receptors on human GI cells. In this study, oyster glycogen was tested to determine if it contains HBGA-like molecules and if it plays a role in NOR binding and accumulation. The correlation between the amount of HBGA expression and NOR binding was also measured. In addition, we tested if seasonal changes affected HBGA expression and binding of recombinant NORs (rNORs). The results indicate that rNOR binding is correlated highly with HBGA expression in the three oyster species tested (Crassostrea virginica, Crassostrea gigas, and Crassostrea sikamea), but is not associated by any particular seasonal pattern. No obvious trend in either HBGA presence or rNOR binding by month was noted. A significant difference in rNOR binding was observed only in Virginica and Pacific oysters between typical NOR outbreak months (November – March) and months not generally associated with NOR outbreaks (April – October). A significant difference in HBGA expression measured immunochemically was also observed for Pacific and Virginica oysters. Paradoxically, HGBA expression and NOR binding both were higher with oysters produced in “non-NOR outbreak months” compared to “NOR outbreak months”, suggesting that seasonal NOR outbreaks are not associated with high amounts of HBGA expression and NOR binding. We speculate that the survival rate of NORs, correlating with potentially infectious NORs, may be influenced by UV exposure or an unknown factor such as increased production and consumption of oysters during the cold water months. It is also possible that the NOR carrier rate is higher during the winter season as people spend more time inside together. Technical Abstract: Noroviruses (NORs) are the most common cause of viral gastroenteritis outbreaks and the illnesses are sometimes described as “highly seasonal syndrome” or "winter vomiting disease”. Outbreaks are often associated with the consumption of contaminated oysters or other bivalves and generally occur between the months of November and March, when oysters produce the highest levels of oyster glycogen. It has been proposed that oyster glycogen might play a role in NOR accumulation via ionic bonding of viral particles to the mucopolysaccharide moiety of the gastrointestinal tract during feeding. Recent research indicates that histo-blood group antigens (HBGAs) function as viral receptors on human GI cells. In this study, oyster glycogen was tested to determine if it contains HBGA-like molecules and if it plays a role in NOR binding and accumulation. The correlation between the amount of HBGA expression and NOR binding was also measured. In addition, we tested if seasonal changes affected HBGA expression and binding of recombinant NORs (rNORs). The results indicate that rNOR binding is correlated highly with HBGA expression in the three oyster species tested (Crassostrea virginica, Crassostrea gigas, and Crassostrea sikamea), but is not associated by any particular seasonal pattern. No obvious trend in either HBGA presence or rNOR binding by month was noted. A significant difference in rNOR binding was observed only in Virginica and Pacific oysters between typical NOR outbreak months (November – March) and months not generally associated with NOR outbreaks (April – October). A significant difference in HBGA expression measured immunochemically was also observed for Pacific and Virginica oysters. Paradoxically, HGBA expression and NOR binding both were higher with oysters produced in “non-NOR outbreak months” compared to “NOR outbreak months”, suggesting that seasonal NOR outbreaks are not associated with high amounts of HBGA expression and NOR binding. We speculate that the survival rate of NORs, correlating with potentially infectious NORs, may be influenced by UV exposure or an unknown factor such as increased production and consumption of oysters during the cold water months. It is also possible that the NOR carrier rate is higher during the winter season as people spend more time inside together. |