Molecular epidemiological survey of porcine reproductive and respiratory syndrome virus in East China from 2021 to 2022
In order to preliminarily study the epidemic characteristics of porcine reproductive and respiratory syndrome virus(PRRSV)in East China,480 clinically suspected PRRSV-positive samples were collected in East China from 2021 to 2022 for PRRSV detection by RT-PCR.Of these samples,175 were PRRSV-positive with a positive rate of 38.89%.The ORF5 genes of 24 positive samples from different pig farms were sequenced and shown to be the American type 2,divided into 4 subtypes.Among them,11 strains belonged to the HP-PRRSV(Sublineage 8.7),6 strains belonged to the PRRSV NADC30-like strain(Sublineage 1.8),and 4 strains belonged to the PRRSV NADC34-like strain(Sublineage 1.5).The PRRSV GP5 sequencing results showed that mutations occurred in the two hypervariable regions aa3-39 and aa185-200 of the epidemic strains.This study shows that the circulating PRRSV strains in East China have a high genetic diversity with complex genotypes,which calls for our special attention.
porcine reproductive and respiratory syndrome virus(PRRSV)ORF5NADC34NADC30genetic variation