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1.
为建立牛病毒性腹泻病毒(BVDV)、牛轮状病毒(BRV)和牛冠状病毒(BCoV)的快速检测方法,根据GenBank中登录的BVDV 5'-UTR、BRV NSP5和BCoV N基因序列设计特异性引物和探针,通过优化反应体系和条件,建立了同时检测上述3种病毒的TaqMan三重RT-qPCR方法。该方法仅对BVDV 5'-UTR、BRV NSP5和BCoV N基因扩增呈阳性,而对牛传染性鼻气管炎病毒、牛副流感病毒、魏氏梭菌(A型、B型和D型)、多杀性巴氏杆菌(A型和B型)等犊牛腹泻相关病原扩增均呈阴性;最低检出限为10拷贝/μL;组内和组间变异系数均小于2%。利用本研究建立的TaqMan三重RT-qPCR方法对29份临床样品进行检测,获得BVDV、BRV、BCoV的4种混合感染型,其中BVDV与BCoV的混合感染率最高(27.6%);与已有单重RT-qPCR方法比较,发现两种方法检测BVDV、BRV和BCoV的符合率分别为100%、96.5%、100%。结果表明,本研究建立的TaqMan三重RT-qPCR方法具有特异性强、敏感性高、重复性好、可行性高等优点,可为今后BVDV、BRV和BCoV共感染引起的牛腹泻性疾病的鉴别诊断和流行病学调查提供新技术手段。  相似文献   

2.
辽宁省某奶牛养殖场10~30日龄犊牛发生腹泻,为查明病因,我们对送检的18份犊牛腹泻样本分别进行牛轮状病毒(BRV)、牛冠状病毒(BCoV)、牛病毒性腹泻病毒(BVDV)、产肠毒素大肠杆菌(ETEC)、沙门氏菌(Salmonella)和安氏隐孢子虫(C. andersoni)的PCR检测。结果显示:18份犊牛腹泻样本中,BRV、BCoV、BVDV的检出率分别为83.3%(15/18)、88.9%(16/18)、61.1%(11/18),这3种病原的混合感染率较高,其他病原均未检出,说明该奶牛场的犊牛腹泻主要由BRV、BCoV、BVDV混合感染引起。  相似文献   

3.
孙吉  岳华  汤承 《畜牧兽医学报》2022,53(1):209-218
牛A群轮状病毒(BRVA)、牛冠状病毒(BCoV)、牛病毒性腹泻病毒(BVDV)、牛诺瓦病毒(BNoV)和牛纽布病毒(BNeV)是引起犊牛腹泻的常见病毒,且临床上多存在混合感染的情况.本试验的目的 是建立可以同时检测上述5种病毒的多重PCR方法.通过设计引物,优化反应体系和条件,成功建立了可同时检测BRVA、BCoV、...  相似文献   

4.
【目的】 调查新疆喀什地区安格斯犊牛腹泻主要病毒性病原流行情况及牛诺如病毒(Bovine norovirus,BNoV)全基因组遗传关系。【方法】 采用RT-PCR技术分别对2021年不同季节在喀什4个牛场采集的363份犊牛腹泻粪便样品进行牛轮状病毒(Bovine rotavirus,BRV)、牛冠状病毒(Bovine coronavirus,BCoV)、牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV)和BNoV 4种病毒性病原检测,并对扩增获得的BNoV全基因序列进行分析。【结果】 BCoV和BNoV检出率较高,分别为36.09%(131/363)和25.07%(91/363),混合感染中BCoV+BNoV检出数量最多,阳性率为44.00%(22/50)。对喀什地区4个场区进行检测,其中A场主要检测出BCoV和BNoV,检出率分别为43.52%(47/108)和32.41%(35/108);B场主要检测到BCoV,检出率为52.21%(71/136);C、D场病原检出率普遍较低。秋、冬季检出量最多的病毒分别为BNoV和BCoV,检出率分别为66.67%(50/75)和77.59%(90/116)。对BNoV全基因序列分析显示,本试验检测到的新疆喀什地区BNoV Bo/XJ-KS/01/CHN株(登录号:ON076888)属于GⅢ.2型BNoV,与中国CN/HB-SJZ和CH/HB/BD/2019毒株在进化树中处于同一分支,且与CN/HB-SJZ-2毒株核苷酸相似性最高,为93.70%;与英国分离到的Jena/1999/UK毒株核苷酸相似性最低,为72.49%。进一步对3个开放阅读框(ORF)比对分析发现,测得的BNoV全基因组序列与国内参考株CN/HB-SJZ-2的核苷酸和氨基酸相似性主要是在ORF1区域最高,分别为94.24%和98.69%;与国外参考株Jena/1999/UK的核苷酸和氨基酸相似性主要是在ORF3区域最低,分别为63.59%和64.57%。与国内外毒株比对结果显示,未出现基因重组现象。【结论】 南疆地区犊牛腹泻流行情况因季节、场区不同有一定的差异。病毒性病原主要在秋、冬季感染率较高,以单一BCoV、BRV和BNoV感染为主。本研究测定分析的BNoV GⅢ.2型Bo/XJ-KS/01/CHN全基因序列与中国CN/HB-SJZ-2参考株亲缘关系最近,与国内外全基因组参考序列比对未出现基因重组现象。  相似文献   

5.
为了明确新疆石河子某规模化奶牛场犊牛腹泻病死率较高的原因。本研究对腹泻犊牛的粪样及病死犊牛肠道内容物进行病原检测,并对分离菌株进行毒力基因检测、耐药基因检测、动物致病性试验及药敏试验。最终明确病因主要由牛冠状病毒(BCoV)和牛轮状病毒(BRV)和大肠杆菌混合感染引起。药敏试验表明,分离到的大肠杆菌对28种抗生素产生了严重的耐药,仅对多粘菌素和呋喃妥因敏感,并且发现该菌同时携带2种毒力基因和10种耐药基因。本研究分离的一株大肠杆菌携带有丰富的耐药基因,具有多重耐药性,为该奶牛场上临床治疗加大了难度。而本试验结果为该养殖场提供科学的临床药物指导,为该牛场治疗此次犊牛腹泻提供了依据,同时为新疆犊牛腹泻混合感染的防控提供了病例参考和技术资料。  相似文献   

6.
利用多重荧光定量RT-PCR (real-time RT-PCR)方法,提高对多病原检测的速度和灵敏度,促进对犊牛腹泻的快速诊断和及时治疗。分别在牛星状病毒(BAstV)ORF2基因,牛病毒性腹泻病毒1型(BVDV-1)5'端非编码区,牛冠状病毒(BCV)N pro基因和牛轮状病毒(BRV)VP6基因的保守基因序列设计、合成并试验筛选了四对有效的特异性引物和探针。进一步利用含4种病毒目的片段的重组质粒,对引物和探针的浓度以及反应条件进行了优化,建立了Real-time RT-PCR标准曲线,并对四重Real-time PCR方法的特异性、敏感性、重复性和各种临床样本的适用性进行了评价。结果显示:Real-time RT-PCR最适退火温度和时间分别为50.0℃和45 s,BAstV、BVDV-1、BCV和BRV的引物浓度分别为300、300、400和500 nmol·L-1,探针浓度分别为250、150、100和300 nmol·L-1。对BVDV-1、BCV和BRV的最低检测限均为102copies·μL-1,对BAstV的最低检测限为103 copies·μL-1,具有良好的特异性和重复性。该方法对临床采集的粪样的阳性检出率高于PCR方法。上述结果表明,建立的四重Real-time RT-PCR方法可以用于犊牛腹泻常见病原BAstV、BVDV-1、BCV和BRV的快速鉴别诊断。  相似文献   

7.
试验旨在掌握河北省唐山市13个县(市、区)奶牛场奶犊牛病毒性腹泻病原的流行状况,有效防控奶犊牛腹泻。采集唐山市不同地区38个奶牛场腹泻犊牛粪便样品788份,提取腹泻粪便样品中的基因组RNA。根据GenBank公布的牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV)E2基因、牛轮状病毒(Bovine rotavirus,BRV)VP6基因、牛冠状病毒(Bovine coronavirus,BCV)N基因序列,利用Primer Premier 5.0软件分别设计特异性引物,采用PCR方法检测粪便样品中这3种基因,利用Excel 2007对不同地区、不同季节和混合感染病原检测结果进行汇总分析。在采样范围内的788份犊牛腹泻粪便样品中,BVDV、BRV和BCV阳性检出率分别为29.82%(235/788)、29.44%(232/788)和18.02%(142/788);在所有被检地区,滦南县BVDV感染率最高,阳性检出率为45.38%(59/130),汉沽区BRV和BCV感染率最高,阳性检出率分别为55.00%(22/40)和37.50%(15/40);从采样季节来看,春季、夏季和秋季BRV感染率最高,阳性检出率分别为27.71%(46/166)、39.58%(114/288)和19.89%(39/196),冬季则以BVDV感染为主,阳性检出率为52.17%(72/138);从混合感染情况来看,以BRV+BCV二重混合感染为主,感染率为8.37%(66/788)。河北省唐山市各地区腹泻犊牛群中均存在BVDV、BRV和BCV感染,以BVDV、BRV单一感染为主。  相似文献   

8.
陕西省某规模化奶牛场发生一起新生犊牛腹泻病例,为了确定发病原因,通过临床剖检,无菌采集病料进行细菌分离鉴定、PCR检测病毒等技术,最终确诊这起疫病为牛冠状病毒(BCoV)、牛轮状病毒(BRV)和大肠埃希氏菌混合感染所致的犊牛腹泻。对分离到的大肠埃希氏菌进行药敏试验,结果显示分离菌对左氟沙星和诺氟沙星敏感,对四环素、复方新诺明、多黏菌素B、卡那霉素、庆大霉素、多西环素、氨苄西林、大观霉素均耐药。  相似文献   

9.
为了解青海省部分牛群中牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)、牛轮状病毒(bovine rotavirus,BRV)和牛冠状病毒(bovine coronavirus,BCV)3种牛病毒性腹泻病原的感染现状,本研究采用RT-PCR方法首次对2012~2013年青海省部分地区的32份具有腹泻症状的临床病料及152份健康牛粪便样品进行了BVDV、BRV、BCV的核酸检测与分析。结果显示,32份腹泻牛病料样品中BVDV、BRV、BCV的阳性率分别为65.63%(21/32)、18.75%(6/32)、34.38%(11/32),且存在2种或3种病原的混合感染;152份健康牛粪便样品中BVDV、BRV、BCV的阳性率分别为3.95%(6/152)、1.97%(3/152)、0(0/152)。该结果表明青海省部分牛群中普遍存在BVDV、BRV、BCV的感染,且混合感染现象严重,需进一步加强青海省地区牛病毒性腹泻病原的综合防控。  相似文献   

10.
【目的】 试验旨在对新疆某规模牛场患腹泻疾病的犊牛进行病原学鉴定及基因型分析。【方法】 采用抗原诊断试剂盒方法对在新疆某牛场随机采集的15份腹泻犊牛粪便样品进行检测,对抗原检测结果为阳性的样品进行反复冻融和过滤处理,然后将样品接种于Marc-145细胞进行病毒的分离和传代。对分离毒株进行间接免疫荧光试验(IFA)和负染电镜观察进一步确定病原。对分离株的VP6和VP7基因进行PCR扩增测序,并对其进行基因相似性比对和进化树分析。【结果】 抗原诊断试剂盒结果显示,3份粪便样品呈牛轮状病毒(Bovine rotavirus,BRV)抗原阳性。将阳性粪便样品分别接种于Marc-145细胞,仅有1份样品连续盲传至第9代出现明显的细胞病变效应(CPE)。IFA结果显示,接种该分离株的Marc-145细胞有亮绿色荧光,对照组未见荧光。电镜观察可见约65 nm的圆形病毒粒子,并命名为XJ-2022株。经PCR扩增获得VP6和VP7基因的目的条带,长度分别为1 356和342 bp。基因相似性比对和遗传进化分析表明,VP6基因与人源A群轮状病毒参考株DB2015-066(LC367318.1)相似性最高且遗传进化亲缘关系最近;VP7基因与牛源G10轮状病毒参考株XJX2(MN937506.1)相似性最高,遗传进化亲缘关系最近,确定该分离株为A群G10型轮状病毒。【结论】 试验成功分离到基因型为A群G10型BRV XJ-2022株,该毒株为新疆地区首次发现的多宿主来源的基因重配病毒。  相似文献   

11.
为确定甘肃省临夏州某奶牛场犊牛腹泻的病因,并提供合适的治疗方案和防控措施,试验采集该牛场13头腹泻犊牛的粪便和血清,通过胶体金技术、ELISA方法、细菌分离鉴定、Kirby-Bauer法分别进行病毒病原学检测、病毒血清学抗体检测、病原菌鉴定和药物敏感性试验。病毒学检测结果显示,13份粪样中未检测出牛轮状病毒(BRV)、牛冠状病毒(BCV)的抗原,牛病毒性腹泻病毒(BVDV)抗原阳性率为23.08%(3/13);未检出BRV和BCV的抗体,BVDV血清学抗体阳性率为38.46%(5/13)。病原菌检测结果显示,13份粪便样品中,分离出13株大肠杆菌和7株奇异变形杆菌。药敏试验表明,分离的大肠杆菌和奇异变形杆菌对20种常规药物均产生了不同程度的耐药,且无对两种细菌均有效的药物。此次犊牛腹泻是由BVDV、大肠杆菌、奇异变形杆菌混合感染引起的,且大肠杆菌和奇异变形杆菌的耐药现象严重,本试验结果为该牛场进一步治疗此次的犊牛腹泻病提供了合理有效的依据。  相似文献   

12.
The correlation between maternal serum antibodies in beef calves at 2 days old and protection against diarrhea induced by natural bovine rotavirus (BRV) infection was examined. Virus neutralizing (VN) antibody titers against BRV in sera from calves that developed diarrhea by BRV infection within 14 days of age (BRV-diarrheal calves) were significantly lower than those from calves that had no diarrhea. In the BRV-diarrheal calves, a positive correlation was found between the VN antibody titers and age of the onset of diarrhea. There were negative correlations between the VN antibody titers and duration of the diarrhea, VN antibody titers and cumulative diarrhea scores, and the VN antibody titers and duration of virus shedding. These results suggest that the VN antibody titers against BRV in newborn calf serum could be an indicator of protection against BRV-induced diarrhea.  相似文献   

13.
Bovine coronavirus (BCoV) is an important cause of diarrhoea in calves, winter dysentery in adult cattle and respiratory tract disease in feedlot cattle. Serum, faecal and nasal swab samples were collected from a total of 96 cattle with clinical signs in 29 barns of 23 villages in Northwestern Turkey. The cattle were subdivided into 3 distinct age groups (0-30 days old, 4-12 months old and 2-7 years old). An indirect antigen-capture ELISA and an antibody-detection ELISA as well as geometric mean BCoV antibody titres were used to detect BoCV shed in the faeces and in the nasal secretions, respectively. Relationships between BCoV shedding and age group, seroconversion and clinical signs in cattle were also analysed. The rate of faecal shedding of BoCV was 37.1% (13/35) in 0-30 days old calves, 25.6% (10/39) in 4-12 months old feedlot cattle and 18.2% (4/22) in 2-7 years old cows. The overall rate of BCoV faecal shedding was 28.1% (27/96) in the cattle examined. Only one animal in the 4-12 months old age group was found to shed BoCV nasally. The analysis showed that there was a significant difference (P < 0.0001) with respect to faecal shedding between the clinical signs and the age groups. BCoV antibody titre in 50% of all cattle was < or =100 as detected by ELISA while 27.1% of the cattle had high titres ranging between 1,600 and 25,600. The seroconversion rate was 7.3% (7/96) in animals shedding BoCV in the faeces and 42.7% (41/96) in cattle negative for faecal shedding as detected by ELISA, and 20.8% of cattle with no seroconversion shed BCoV in the faeces. There was no statistically significant association between seroconversion and nasal or faecal BCoV shedding. These findings confirm the presence of BCoV infections in Turkey. Further studies are needed to isolate BCoV strains in Turkey and to investigate their antigenic and genetic properties.  相似文献   

14.
Three pregnant cows were inoculated intramuscularly with inactivated vaccine to bovine rotavirus (BRV) serotype 1 (BRV-1) and serotype 2 (BRV-2). Serum neutralizing antibody (NA) titers against both serotypes increased significantly after immunization. NA titers of colostrum obtained from immunized cows against BRV-1 and BRV-2 were 29286 and 38109, respectively, which were significantly higher than those from non-immunized control cows. Nine and 6 colostrum deprived calves were orally challenged with BRV-1 and BRV-2, respectively, and monitored for clinical manifestation and viral shedding. Five calves of them, 3 with BRV-1 and 2 with BRV-2, received 2 l of milk replacer supplemented with 10% immune colostrum 2 hr before challenge and twice daily for the first 5 days after challenge. Other 10 calves, 6 with BRV-1 and 4 with BRV-2, were fed only milk replacer as controls. All control calves developed severe diarrhea and shed a large amount of BRV in feces, beginning from 24 to 48 hr after challenge inoculation. On the contrary, all calves but one fed colostrum supplement remained clinically healthy after challenge, and BRV was not detected in their feces during feeding immune colostrum. The possibility that continuous feeding of immune colostrum is capable of preventing newborn calves from diarrhea associated with BRV and viral shedding was suggested.  相似文献   

15.
Serum antibody analyses for bovine herpesvirus type 1 (BHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCV), and bovine rotavirus (BRV) were performed on 527 randomly selected cows, before calving, and on 407 three-week-old calves. In cows and calves, BCV and BRV were the most seroprevalent viruses (80% to 100% according to virus and vaccination status). Bovine respiratory syncytial virus was the least seroprevalent in the cows, independent of the vaccination status. In nonvaccinated cows the seroprevalence to BRSV was 36.7%, and 53.5% in cows vaccinated less than two weeks prior to collecting blood, and 67.6% in cows vaccinated two weeks or more prior to blood collection. In their calves, BHV-1 was the least seroprevalent, independent of the vaccination status. The serological status and antibody titers in calves were generally associated with those of the dam. The occurrence of respiratory diseases in the calves was associated with cow and calf serological profiles (BHV-1, BRSV and BCV in the nonvaccinated group, BHV-1, BVDV and BCV in the vaccinated group). The occurrence of diarrhea was not associated with cow and calf serological profiles but was negatively associated with high level calf serum IgG in the nonvaccinated group (odds ratio = 0.73). Bovine coronavirus and BRV were shed by 1.4% and 4.9% of calves in the nonvaccinated group, and by 0% and 9.9% of calves in the vaccinated group, respectively. Bovine rotavirus shedding was associated with fecal diarrheic consistency at the moment of fecal sampling but not with previous occurrence of diarrhea.  相似文献   

16.
为了解重庆市肉牛病毒性腹泻的病原流行情况,本研究对重庆市8个肉牛养殖场的81份腹泻粪便样本中牛病毒性腹泻-黏膜病病毒(bovine viral diarrhea virus,BVDV)、牛冠状病毒(bovine coronavirus,BCV)、牛轮状病毒(bovine rotavirus,BRV)和牛星状病毒(bovine astrovirus,BAstV)4种致腹泻病毒进行了RT-PCR检测,对PCR产物进行测序,用Mega 6.0软件进行系统发育分析。结果显示,BRV、BAstV和BVDV检出率分别为66.7%、8.6%和7.4%,BCV未检出。遗传进化分析结果表明,测序的5个BRV单独聚为一小支,与GenBank中其他VP6序列有明显的遗传距离;BVDV与中国株和丹麦株聚为一支,遗传关系最近;5个BAstV单独聚为一支,与中国香港株遗传关系最近,但仍有明显的遗传距离。本试验结果表明,重庆地区肉牛腹泻主要发生在6月龄以下犊牛,BRV是该地区肉牛腹泻的重要原因,BRV、BAstV和BVDV 3种病毒的遗传多样性值得进一步关注。  相似文献   

17.
Group A bovine rotavirus (BRV) is one of the main causes of neonatal calf diarrhea. The present study reports the incidence of rotavirus diarrhea and the genotypes of BRV strains circulating in beef and dairy herds from Argentina, during a 10-year period (1994-2003). Group A BRV was detected in 62.5% (250/400) of the total studied cases of diarrhea. Positive cases were analyzed by heminested multiplex RT-PCR for P and G genotypes identification. Sixty percent of them were typed as P[5]G6, 4.4% P[11]G10, 4.4% P[11]G6 and 2.4% P[5]G10. Additionally, 9.2% of the cases were initially typed as G8 combined with P[5] or P[11], but sequence analysis revealed they belonged to genotype G6, lineage Hun4-like. Partial typing was assessed in 12.0% of the cases. One of the partially typed samples was closely related to genotype G15. BRV was detected in 71% and 58% of the outbreaks registered in beef and dairy farms, respectively. A clear differential distribution of G/P types was found according to the herd type. P[5]G6 was the prevalent strain in beef herds, while P[11] was the prevalent P-type in dairy herds (71%), associated in similar proportions with G6 and G10, These findings indicate that BRV genotypes included in the current commercially available rotavirus vaccines (G6, G10, P[5] and P[11]) should protect calves from most Argentinean field strains. Nevertheless, continuous surveillance is necessary to detect the emergence of new variants.  相似文献   

18.
In order to investigate the pathogen prevalence of bovine viral diarrhea in Chongqing, this study carried out an investigation of bovine viral diarrhea virus (BVDV), bovine coronavirus (BCV), bovine rotavirus (BRV) and bovine astrovirus (BAstV) on a total of 81 diarrhea samples of beef cattle which were collected from Chongqing by RT-PCR. After the PCR products were sequenced, phylogenetic analysis was performed with Mega 6.0 software. From 81 samples, the positive rate of BRV,BAstV and BVDV were 66.7%,8.6% and 7.4%, respectively,BCV was not detected.Phylogenetic analysis showed that 5 strains of BRV sequences were clustered into a small branch, which had significant genetic distance with other VP6 sequences in GenBank; 5 strains of BVDV, Chinese and Denmark strains were clustered into one branch,genetic relationship were close; 5 strains of BAstV clustered into a branch with Hongkong strain, but there was still an obvious genetic distance. The result showed that calves under the age of half year were the main group of beef cattle with diarrhea in Chongqing. BRV was an important cause of diarrhea in Chongqing, the genetic diversity of BRV,BAstV and BVDV could be reference to further concern.  相似文献   

19.
Canine respiratory coronavirus (CRCoV), which is more closely related to the bovine coronavirus (BCoV), has recently been detected in dogs. In this study, we examined whether BCoV was capable of infecting and exhibiting pathogenicity in dogs. Three 1-month-old pups were oronasally given field isolates of BCoV, and were kept together with 2 control animals. As a result, increases in BCoV-neutralizing antibody titers were confirmed in all pups in the challenged and control groups. Moreover, the virus gene was also detected in oral and rectal swabs by RT-PCR. These results indicate that BCoV infects dogs, and easily infects other dogs that are kept together. However, no clinical symptoms such as respiratory symptoms and diarrhea were observed.  相似文献   

20.
旨在全面了解牛冠状病毒(BCoV)在吉林省肉牛群的流行情况,选择吉林省东中西部地区的12个县市的规模化、养殖合作社、家庭型养殖户等牛场在不同季节采集血液、鼻拭子、粪拭子及临床病死牛组织脏器,采用血清学及分子生物学诊断检测技术,对BCoV进行流行病学调查,了解BCoV在该吉林省部分地区的流行情况。共采集临床血清样品1 298份,粪便样品、肝、肺、脾、气管等组织样品462份,应用商品化BCoV抗体检测试剂盒检测血清抗体和纳米PCR新型检测技术对临床样品进行PCR检测,并对核酸检测出的阳性结果测序分析。结果显示BCoV抗体血清阳性率为1.08%,粪便、肝等临床样品阳性率21.10%。经测序分析调查地区BCoV流行株与我国四川流行株相似性达99%以上。本研究对吉林省中部地区BCoV流行情况进行了全面调查,丰富了牛冠状病毒的流行病学调查数据,为指导牛冠状病毒的防控工作奠定了基础。  相似文献   

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