Isolation And Identification Of Porcine Astrovirus And Development Of A SYBR Green I Real Time Quantitative PCR Method

Astrovirus are zoonotic pathogen, and has been demonstrated to infect human, porcine and caine. Astrovirus infection was later reported worldwide. The aim of this study is to make investigation on the pathogenic prevalence and to establish a rapid method of detection of porcine astrovirus.By way of isolation and purification in fecal samples of suspected porcine astrovirus infected cases from Shanghai pig farm, we detected a porcine astrovirus. Cell culture of the virus particle shows cell swelling, and there appears small particles in the cytoplasm.The virus particles are approximately 28～30nm in diameter and share a unique 5 or 6 surface star at the electron microscope. Animal experiments show that the test group pigs suffered from clinical symptoms of porcine astrovirus infection.In this study, the fragments of porcine astrovirus ORF2 genes amplified by RT-PCR were used as a standard template to establish the standard curve and melting curve. And the sensitivity, specificity and reproducibility were tested later. The CT value of the standard curve and the template concentration showed a good linear relationship.The sensitivity up to 10 copies, it is 100 times than general PCR.The sensitivity and specificity of this method are good enough for the detection of porcine astrovirus. Of course it has important practical value to prevent and control of porcine astrovirus infection.