Molecular analysis of coxsackievirus A16 reveals a new genetic group of enteroviruses.

Coxsackievirus A16 (CAV16) a member of the Enterovirus genus of Picornaviridae, is associated with hand-foot-and-mouth disease, a febrile papulovesicular rash of childhood. We have determined the complete nucleotide sequence of the genome of the prototype strain of CAV16 which consists of 7413 nucleotides plus the poly(A) tail. Alignment of the sequence with the previously studied enteroviruses showed that the genome organization is typical for a member of this virus genus. However, the predicted amino acid sequence of individual CAV16 proteins differed from those of all previously sequenced enteroviruses by 25-62%. The genomic sequence of CAV2 in the capsid and 2A polypeptide regions was also determined. It was found to differ from that of CAV16 by no more than 5-43%. The partial nucleotide sequence of enterovirus 71 in the VP1-2A region suggested that it is also closely related to CAV16. The results indicate that CAV16, CAV2, and enterovirus 71 represent a distinct genetic group of enteroviruses.