Viruses and virus-like particles identified in ostrich gut contents.

Samples of either gut content from ostriches showing symptoms of enteritis, or allantoic fluid of eggs inoculated with ostrich isolates, were examined for the presence of viral agents by direct negative-contrast electron microscopy. Only a few virus types could be identified with certainty, namely a circovirus (1 sample), a coronavirus (1 sample), a member of either the toga- or bunyaviridae (1 sample), enterovirus (16 samples) and paramyxovirus (26 samples). A large number of samples contained structures resembling myxovirus particles that were interpreted as fringed membranous particles of non-viral origin. An unusual observation of probable single-strand nucleocapsid helices, possibly originating from digested plant material and which were identified in a number of small intestine samples, is reported. This is the 1st report of a spectrum of viruses and virus-like particles occurring in enteric samples from ostriches in South Africa. The low incidence and variety of viruses reported here contribute to the multifactorial origin and complexity of enteric disease in ostriches as well as in other birds and mammalian species.