关键词: 三带喙库蚊, 猪繁殖与呼吸综合征病毒, 分离, 鉴定, 猪场

Abstract: 【Objective】To determine whether the porcine reproductive and respiratory syndrome virus (PRRSV) can survive in mosquitoes in infected pig farms. 【Methods】 The mosquito samples were collected from 3 pig farms infected by the porcine reproductive and respiratory syndrome (PRRS) and determined by RT-PCR method based on the primers of PRRSV N gene, then the PCR-positive mosquitoes were cultured in Marc-145 cells for isolation of PRRSV, which was identified by indirect immuno-fluorescence assay and sequence analysis of Nsp2 gene. 【Results】 At least 4 mosquito species, Culex tritaeniorhychus, Culex modestus, Anopheles sinensis and Armigeres obturbans were identified on 3 pig farms and C. tritaeniorhynchus was found to be the predominant species (86.76%). By RT-PCR, PRRSV was detected in the samples of Culex tritaeniorhychus but none in other 3 mosquito species. The cell pathological effects such as cell fusion and cavitation were observed in Marc-145 cells inoculated by the samples of C. tritaeniorhynchus. The antigen of PRRSV in cultural cells was detected by indirect immunofluorescence assay. The PRRSV NSP2 gene, which was amplified and sequenced from infected moisquito cells, was highly homologous in nucleotide sequence with those from the infected pigs in same farm. 【Conclusion】C. tritaeniorhynchus is the predominant species and PRRSV can survive in this mosquito.

Key words: Culex tritaeniorhynchus, porcine reproductive and respiratory syndrome virus (PRRSV)；isolation； identification, pig farm