2023-2025年福建省三明市猪流行性腹泻病毒S基因遗传进化分析OA

In order to investigate the prevalence and variation of porcine epidemic diarrhea virus(PEDV)in Sanming City,Fujian Province,452 intestinal samples from diarrheic piglets were collected from 25 farms in the city from 2023 to 2025,to detect PEDV using specific RT-PCR.For positive samples,the S gene was sequenced,and a phylogenetic tree was constructed using MEGA 11 software.The homology of the S gene sequences and the amino acid sequences of the translated S protein,including its neutralizing epitopes and genetic changes,were analyzed using MegAlign software.The results showed that 290 PEDV-positive samples were detected from 20 farms,from which 11 PEDV S gene sequences were obtained,with a homology ranging from 94.3％to 100％,including 7 G2a subtype,2 G2b subtype and 2 S-INDEL subtype.Compared to the classical PEDV CV777,amino acid insertions were available in the S protein of 9 samples at 57,59-62,138-139 and 157-158 aa,and amino acid deletion occurred at 159-160 aa;amino acid deletion was found at 131-132 aa of S protein of the 2G2b subtype,at 57,59-62 and 138-139 aa of S protein of the 2 S-INDEL subtype,and amino acid insertion was at 159-160 aa of the latter.No amino acid mutation was found in the relatively conserved regions of the SS2 and 2C10 neutralizing epitopes of the S protein,but a total of 13 amino acid mutations occurred in COE and SS6 regions.In conclusion,PEDV was severely prevalent in the city,characterized by diverse genotypes of prevalent strains and variant S gene,indicating that pig population could not be well protected by vaccines developed based on G1b subtype CV777.It was recommended to improve feeding management and biosecurity control on farms,to establish a routine monitoring mechanism for strain genetic variation,and thereby curb the prevalence of PEDV through a series of comprehensive measures.