Isolation and partial characterization of a novel porcine astrovirus

Astroviral infection has been described as one of the causes of porcine diarrhoeal disease. Here we describe the detection of astrovirus-like particles by electron microscopy in a diarrhoeal specimen. Furthermore, a cytopathic virus was isolated and propagated in an established porcine kidney cell line, PK-15. Reverse transcription and PCR performed with astrovirus-specific primers amplified a product with the expected size. Sequencing of the PCR product revealed that the virus observed by electron microscopy and propagated in the porcine cell line is an astrovirus, showing 86% identity at the nucleotide level with the only known porcine astrovirus, PAstV. Phylogenetic analysis clustered the novel isolate, Sb4685, together with PAstV in a broad clade comprising mammalian astroviruses.