Isolation,identification and genetic analysis of a three-lineage NADC30 PRRSV recombinant strain
10.16303/j.cnki.1005-4545.2025.03.04
- VernacularTitle:1株类NADC30 PRRSV三谱系重组株的分离鉴定及遗传分析
- Author:
Bingyan CAI
1
;
Yangyang QIAO
;
Tianxin LIU
;
Weiyong ZUO
;
Yongjuan WANG
;
Kai ZHANG
;
Hui LU
;
Haiming WANG
Author Information
1. 江苏农牧科技职业学院,江苏泰州 225300
- Publication Type:Journal Article
- Keywords:
porcine reproductive and respiratory syndrome virus;
NADC30-like PRRSV;
HLJ38;
re-combination analysis
- From:
Chinese Journal of Veterinary Science
2025;45(3):420-426
- CountryChina
- Language:Chinese
-
Abstract:
In June 2018,sows at a pig farm in Jiamusi,Heilongjiang Province,suffered a large num-ber of miscarriages,and subsequently weaned piglets at the farm began to show persistent high fe-ver symptoms at around 35 days of age,with some pigs having a fever of more than 41.5 ℃.In or-der to determine the cause of this outbreak,63 clinical samples from this farm were tested.The re-sults showed that 60 out of 63 samples were positive for the porcine reproductive and respiratory syndrome virus(PRRSV)antigen.Subsequently,PRRSV antigen-positive plasmid was transfected into African green monkey embryonic kidney cells(Marc-145),and after three generations of blind transmission,indirect immunofluorescence assay(IFA)was performed.The results showed that one PRRSV strain,named HLJ38,was successfully isolated.Then the whole genome of HLJ38 strain was sequenced and then analyzed in detail by bioinformatics software.Sequence analysis showed that there were three deletions of 131 amino acids(323-433 aa,483 aa and 504-522 aa)in the derived sequence of Nsp2 gene of HLJ38 strain,which was consistent with the molecular ge-netic marker of NADC30 PRRSV.The phylogenetic tree analysis showed that HLJ38 and NADC30 PRRSV in GenBank belong to lineage 1 subgroup,and the nucleotide homology of HLJ38 and NADC30 PRRSV in GenBank was only 85.2％and 84.6％.Recombinant analysis showed that HLJ38 was a recombinant NADC30-like PRRSV,and the recombinant gene fragments were de-rived from multiple strains,among which the fragment of 1-201 nt was provided by VR2332 strain and fragment of 6 641-8 061 nt derived from the HP-PRRSV strain.In summary,the re-sults showed that the outbreak in this pig farm may be caused by the recombination of PRRSV strains among different lineages,and the recombinant circulating strains not only have certain pathogenicity but also suggest that the existing commercial vaccines provide limited cross-protec-tion against them.Recombination between different lineages increases the genetic diversity of PRRSV and aggravates the difficulty of prevention and control of PRRS in pig farms.Therefore,it is necessary to continuously monitor the epidemic dynamics of PRRSV in pig farms and take effec-tive measures in time to curb the spread of PRRS.
