Virus-like particles with T = 19 icosahedral symmetry in a human gastroenteritis stool

Virus-like particles not previously described were observed in a human gastroenteritis stool using negative-stain TEM. The stool was among a number of acute-phase illness stools which had been collected in Egypt during 1980. The particles measured 65–70 nm in diameter, and it was possible to detect individual capsomeres on many of these particles. The capsomeric pattern identified on the particles corresponded to an icosahedrally symmetric T = 19 capsid. Distinctive five-fold vertices, usually appearing as darker spots on the capsid, were an additional feature of these particles. The capsid structure, which is skew, could readily be distinguished from the T = 25 capsid of adenovirus and the holey capsids of rotavirus and reovirus. Antibody to the particles was detected in both the shedding individual's acute- and convalescent-phase serum specimens using IEM, although an antibody increase was not demonstrated.