摘要
Abstract
In order to investigate the status of infection and genetic variation of porcine reproductive and respiratory syndrome virus(PRRSV)in Liaocheng City,588 samples of serum,tissue and semen from sick pigs suspected of PRRSV were collected from 52 farms in 4 counties/cities from October to December 2023 to detect nucleic acids of PRRSV by RT-qPCR.ORF5 gene sequences of some positive PRRSV samples were amplified by RT-PCR to analyze their genotypes and genetic variation.The results showed that 101 positive samples were detected from 23 farms,and the positive detection rates of farms and samples were 44.23%(23/52)and 17.18%(101/588),respectively;the detection rates of positive PRRSV nucleic acids of samples from different regions and in different seasons were 12.38%-20.45%and 2.64%-20.33%,respectively;high pathogenic,classical,NADC30-like and NADC34-like strains were 10.89%,28.71%,54.46%and 5.94%,respectively.9 PRRSV ORF5 gene sequences were obtained through amplification,including 5 highest similar to those of NADC30-like stains,3 to those of pathogenic strains and 1 to that of classical strain;amino acid site mutation was observed in GP5 proteins of the samples under different genotypes,especially NADC30-like strains with highest mutation rate.In conclusion,PRRSV infection was available in 4 regions of Liaocheng,likely all year round;for the complex epidemiological genotypes,NADC30-like and highly pathogenic strains were dominant,with a risk of pathogen mutation.Thus,it was recommended to continuously monitor the prevalence and genotypic characteristics of PRRSV on swine farms,analyze the genetic sequence variation of virulent strains,so as to avoid potential loss that might be caused by PRRSV to local farms.关键词
猪繁殖与呼吸综合征病毒/分子流行病学/ORF5基因/遗传变异分析Key words
PRRSV/molecular epidemiology/ORF5 gene/genetic variation analysis分类
农业科技
