2023-2025年河南地区猪流行性腹泻病毒分子流行病学调查OA

To understand the genotypes and epidemic status of currently circulating PEDV strains in Henan Province,China,a total of 62 clinical intestinal and fecal samples from diarrheic piglets were collected in the period between November 2023 and February 2025.These samples were collected on 23 small to medium-sized pig farms across 18 regions in Henan,including Zhoukou,Nanyang,Zhengzhou,Xuchang,Pingdingshan,Puyang,Hebi and so on.Following nucleic acid extraction,the samples were screened for PEDV using RT-PCR targeting the N gene.The full-length S gene of the PEDV-positive samples was amplified,sequenced,and subjected to phylogenetic tree construction,as well as nucleotide and amino acid homology analyses.The results showed that 38 out of the 62 samples(61.29%)were PEDV-positive.Among these,the full-length S gene was successfully amplified from 19 samples.The homology analysis showed that the nu-cleotide sequence identity of the full-length S gene among the strains ranged from 93.4%to 100%,and the amino acid identity ranged from 80.9%to 87.7%.Compared with the classical GⅠ genotype strain CV777,the nucleotide similarity was 89.7%-93.3%,and the amino acid identity was 73.1%-75.9%.In contrast,the strains showed higher nucleotide identity(94.8%-99.2%)and amino acid identity(83.0%-86.5%)with the recently prevalent GⅡ subtype strain CH-HeN-ZLH-2022.The phylogenetic analysis indicated that the pre-dominant circulating strains in the Henan area belonged to the GⅡ subtype,specifically with 15 strains classified as GIIa and 4 as GⅡc.Furthermore,the temporal analysis of the collected samples exhibited an increasing proportion of the GⅡc subtype in recent collections,sug-gesting a potential trend for GⅡc strains to become the predominant epidemic variant.This study provided an analysis of the current preva-lence and variation of the PEDV S gene in Henan Province,offering valuable insights for future PED prevention,control strategies,and vac-cine development in the region.