Isolation And Characterization Of Poricine Rotavirus From The Liaoning Province And Development Of Loop-mediated Isothermal Amplification

Porcine rotaviruses belong to the genus Rotavirus in the family Reoviridae, Rotaviruses are important causes of diarrheal disease in neonates and the young of many species and a common cause of gastrenteritis in nursing and postweaning pigs. PEDV,TGEV and PoRV are the main diarrhea viruses which bring huge economic losses to many countries.In this study, 362 samples from diarrheic pigs on several provinces were analyzed by RT-PCR. 223(61.6%),2(0.55%),8(2.2%),66(18.23)pigswere tested positive for PEDV,TGEV,PoRV,PKV respectively.A porcine rotavirus was isolated from a fecal sample from a diarrheic piglet in Jiangsu Province, China. Rotavirus-specific cytopathic effects were observed after 8 blind passages on MA-104 cells, yielding a virus titer of 10-6.875 TCID50/mL. By applying an 80 % nucleotide cutoff value and the RotaC2.0 automated genotyping tool, the VP4 genotype of the new isolate was identified as P[7]. The VP7 genotype was identified as G[9], lineage VI, and sublineage c. According to the recent classification of group A rotavirus, the JS strain belonged to P[7]G[9] gene.The usefulness of RT-LAMP for rapid preclinical detection of porcine rotavirus infection was evaluated. The RT-LAMP reaction could be accomplished in 60 miniutes under certain condition at 63℃by using a series of four primers aiming at the VP4 gene of porcine rotavirus. The RT-LAMP results of Rotavirus showed higher sensitivities than that of RT-PCR. No cross-reactivities were observed from the specimens of other diarrhea viruses including PEDV,PCV2,TGEV,PKV. Furthermore, It was showed that the sensitivity was 100 times higher than that of RT- PCR. The results indicated thatrotavirus RT-LAMP is a valuable tool for its rapid, economical detection and has potential prospectfor rapid pre-clinical test and surveillance of porcine rotavirus in developing countries.