Isolation of an adenovirus antigenically distinct from equine adenovirus type 1 from diarrheic foal feces.

Adenovirus was isolated in equine fetal kidney cell cultures from the feces of 2 foals with diarrhea that also had large numbers (greater than 10(6)/g) of rotavirus particles in their feces. Unlike equine adenovirus type 1 (EAdV1), the fecal EAdV did not hemagglutinate human O, rhesus macaque, or equine RBC. By serum neutralization, the fecal viruses were identical with each other, but showed no relationship to EAdV1. Antiserum prepared against the fecal viruses did not contain hemagglutination-inhibiting antibody to EAdV1. It is proposed that the fecal viruses be considered prototypic of EAdV2. The frequency of neutralizing antibody to EAdV2 in 339 equine serum samples was 77%. Neither EAdV1 nor EAdV2 is related by serum neutralization to any of 30 human adenovirus serotypes.