Isolation and identification of porcine epidemic diarrhea virus strain LN-2015-1 and its S gene mutation analysis / 中国兽医学报

ABSTRACT

In order to understand the porcine epidemic diarrhea virus (PEDV) origin and variant characteristics in Liaoning province,diagnosed by PCR,separated by Vero cell,and identified by cell pathological observation,RT-PCR and S gene sequence analysis,1 PEDV strains (LN-2015-1) was successfully isolated from a pig farm of Liaoning province.Analysis of S gene sequence showed that compared withCV777 strain,there were the longest 9 bp insertion,6 bp deletion and 13 bp continuous mutation in addition to point mutation.There also were the longest 3 AA insert,2 AA deletion,and 3 AA or more continuous mutation.The epitope analysis showed that there were 16AA mutations in the 5 epitope regions.Homology analysis show that it had the highest sequence similarity of 99.2％ with HB-HA2015 strain,higher sequence similarity of 98.5％-98.8％ with the domestic and foreign representative strains isolated since 2010,and lower sequence similarity of 93.2％-95.6％ with the traditional strain isolated before 2010;the phylogenetic analysis showed that LN-2015-1 was clustered into the same group with home and abroad variation strain in recent years,and formed a small subgroup with HB-HA2015 at the same time.The evolutionary distance was far from the traditional strains.