Genetic characteristics and genetic evolution of porcine epidemicdiarrhea virus strain FJLY1703 in western Fujian province

In order to clarify the recombination and genetic evolution of porcine epidemic diarrhea virus (PEDV) isolates inwestern Fujian, a PEDV strain (FILY1703) was isolated from PEDV infected piglet samples in western Fujian, and its N, E, M and Sgenes were amplified by PCR and further sequenced and analyzed by bioinformatics software in this study The homology andevolutionary analysis results showed that FJLY1703 had low homology and distant relationship with classical strains such as CV777, but high homology and close evolutionary relationship with the prevalent variants isolated in domestic after 2010 The amino acidsequence analysis showed the COE of FJLY1703 strain S protein had 8 mutations that were similar to prevalent variants in Chinaafter 2010 in comparison with the vaccine strain CV777 Further more, the amino acid sequence of FJLY1703 strain E, M and N genes had 1, 3 and 12 mutation sites respectively, which were the same as the prevalent variants in China Recombination analysis ofS gene showed that FJLY1703 was a recombination strain of classical strain CV777 and mutant strain that prevalent variants after2010, and suggested the need to develop a vaccine against PEDV epidemic strains to control the infection of PEDV This studyprovided data support for the epidemiological study of PEDV in China