Seasonal tracking of histo-blood group antigen expression and norovirus binding in oyster gastrointestinal cells.

Noroviruses (NORs) are the most common cause of viral gastroenteritis outbreaks. Outbreaks are often associated with the consumption of contaminated oysters and generally occur between the months of November and March, when oysters produce the highest levels of glycogen. Oyster glycogen has been proposed as playing a role in NOR accumulation. Recent research indicates that histo-blood group antigens (HBGAs) function as viral receptors on human gastrointestinal cells. In this study, oyster glycogen was tested to determine whether it contains HBGA-like molecules and whether it plays a role in NOR binding. The correlation between the amount of HBGA expression and NOR binding also was measured. We also tested whether seasonal changes affected HBGA expression and binding of recombinant NORs. The results indicate that recombinant NOR binding is highly correlated with HBGA expression in Virginica (Crassostrea virginica), Pacific (Crassostrea gigas), and Kumamato (Crassostrea sikamea) oysters, but the association does not have a seasonal pattern. No obvious trend in either HBGA expression or recombinant NOR binding by month was noted. A significant increase in recombinant NOR binding was observed in Virginica and Pacific oysters in a season not generally associated with NOR gastroenteritis outbreaks. A significant increase in HBGA expression also was observed for Pacific and Virginica oysters in the same season. Paradoxically, HBGA expression and NOR binding both were higher in oysters produced in the non-NOR gastroenteritis season (April through October) than in those produced in the NOR gastroenteritis season (November through March), suggesting that seasonal NOR gastroenteritis outbreaks are not associated with high levels of HBGA expression or NOR binding.