牛呼吸疾病综合征主要病毒的检测、分离与鉴定

Detection, isolation, and identification of the main viruses causing bovine respiratory disease complex

摘要:

【背景】牛呼吸疾病综合征(bovine respiratory disease complex，BRDC)是由病原和环境共同作用所致的以支气管肺炎为主的多病因、多症状性疾病，给国内外肉牛养殖业带来了巨大经济损失。引起BRDC的病毒主要包括牛传染性鼻气管炎病毒(infectious bovine rhinotracheitis virus，IBRV)、牛病毒性腹泻病毒(bovine viral diarrhea virus，BVDV)、牛呼吸道合胞体病毒(bovine respiratory syncytial virus，BRSV)、牛副流感病毒3型(bovine parainfluenza virus type 3，BPIV-3)等，优势病原因地、因时、因畜种而异。【目的】清晰了解我国BRDC的流行现状及流行毒株，是有效防控该病的基础。【方法】自2021年9月到2022年7月间，运用反转录聚合酶链反应(reverse transcription-polymerase chain reaction，RT-PCR)技术对来自湖北、湖南、安徽、河南、广东、广西和贵州等地21个牧场的179头具有呼吸道症状牛的196份样品(167份鼻拭子、13份肺脏组织、1份鼻黏液、5份气管拭子、1份唾液和9份血清)进行BRSV、IBRV、BPIV-3和BVDV这4种病毒的检测。【结果】BRSV、IBRV、BPIV-3、BVDV的样本阳性检出率分别为7.14%(95%CI：3.96，11.69)、0.51%(95%CI：0.01，2.81)、4.08%(95%CI：1.78，7.88)和6.63%(95%CI：3.58，11.07)；179头牛检测该4种病毒的阳性检出率分别为7.82%(14/179)(95%CI：4.34，12.77)、0.56%(1/179)(95%CI：0.01，3.07)、4.47%(8/179)(95%CI：1.95，8.62)和7.26%(13/179)(95%CI：3.92，12.10)。0.56%(1/179)(95%CI：0.01，3.07)的牛为BVDV及BRSV共感染。进一步对阳性样品进行了病毒分离，共获得1株BVDV和6株BPIV-3，分型显示BVDV为1d型、BPIV-3为C型。【结论】本研究确定了我国部分地区牛呼吸疾病综合征的优势病毒为BRSV、BVDV及BPIV-3，BVDV及BPIV-3的优势血清型为BVDV-1d、BPIV-3C。研究结果为相关疫苗的研制提供了基础，为牛呼吸疾病综合征的防控提供了参考依据

Abstract:

[Background] Bovine respiratory disease complex (BRDC) is a multi-causal and polysymptomatic disease caused by the joint action of pathogens and environments, which brings serious economic losses to the beef cattle industry. The viral pathogens of BRDC include bovine respiratory syncytial virus (BRSV), infectious bovine rhinotracheitis virus (IBRV), bovine parainfluenza virus 3 (BPIV-3), and bovine viral diarrhea virus (BVDV). The pathogen spectrum of BRDC varies regarding different places, time, and breeds. [Objective] To evaluate the epidemic status and dominant pathogens for the prevention and control of BRDC. [Methods] We obtained and tested 196 samples (including 167 nasal swabs, 13 lung tissue samples, 1 nasal mucus sample, 5 tracheal swabs, 1 saliva sample, and 9 serum samples) of 179 cattle with respiratory symptoms from 21 farms in Hubei, Hunan, Anhui, Henan, Guangdong, Guangxi, and Guizhou from September 2021 to July 2022 for BRSV, IBRV, BPIV-3, and BVDV by using reverse transcription-polymerase chain reaction (RT-PCR). [Results] The positive rates of BRSV, IBRV, BPIV-3, and BVDV in the samples were 7.14% (95% CI: 3.96, 11.69), 0.51% (95% CI: 0.01, 2.81), 4.08% (95% CI: 1.78, 7.88), and 6.63% (95% CI: 3.58, 11.07), respectively. The positive rates of the four viruses in the cattle were 7.82% (14/179) (95% CI: 4.34, 12.77), 0.56% (1/179) (95% CI: 0.01, 3.07), 4.47% (8/179) (95% CI: 1.95, 8.62), and 7.26% (13/179) (95% CI: 3.92, 12.10), respectively. The co-infection with BVDV and BRSV occurred in 0.56% (1/179) (95% CI: 0.01, 3.07) of the cattle. One strain of BVDV and 6 strains of BPIV-3 were then isolated from the positive samples. RT-PCR results showed that the BVDV strain was of type 1d and all the 6 BPIV-3 strains were of type C. [Conclusion] This study revealed that the dominant viruses of BRDC were BRSV, BVDV, and BPIV-3 in some regions in China. BVDV-1d and BPIV-3C were the dominant subtypes of BVDV and BPIV-3, respectively. This study provides a basis for the development of related vaccines and further the prevention and control of BRDC.