Isolation and phylogenetic characterization of bat astroviruses in southern China.

Astroviruses are associated with acute gastroenteritis of human and many animal species. Recently, two studies have reported that novel astroviruses were found in bats. In order to extensively understand the genetic and phylogenetic characterization of bat astroviruses, we tested fecal samples of nine bat species that were collected at four natural habitats in three areas of southern China. The geographic distributions of the bats involved differed from previous reports. Three out of nine species of bats were observed to harbor astroviruses. These included Miniopterus schreibersii, Scotophilus kuhlii, and Rousettus leschenaultia. Phylogenetic analysis based on amino acid sequences of partial ORFs of astroviruses revealed that the bat astroviruses are not only divergent from previously described human and other animal astroviruses but also show remarkable diversity among themselves. However, five bat astroviruses were phylogenetically related to mink astrovirus, ovine astrovirus, and the recently discovered human astroviruses VA1, VA2, and VA3. The results indicate that astroviruses may have adapted to the Chiroptera, and bats may transmit astroviruses to humans and other animals, or vice versa.