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The effects of transplacental porcine circovirus type 2 (PCV2) infection on porcine epidemic diarrhoea virus (PEDV)-induced enteritis were examined in neonatal piglets. Six pregnant sows were randomly allocated to an infected (n=3) or control group (n=3). Three pregnant sows were inoculated intranasally with 6 mL of tissue culture fluid containing 1.2 x 10(5) tissue culture infective doses 50% (TCID(50))/mL of PCV2 strain SNUVR000470 three weeks before the expected farrowing date. Three control pregnant sows were similarly exposed to uninfected cell culture supernatants. Thirty piglets from PCV2-infected sows were randomly assigned to two groups (A and B) of 15 piglets each. Another 30 piglets from noninfected sows were randomly assigned to two groups (C and D) of 15 piglets each. The piglets in groups A and C were dosed orally at three days of age with 2mL of virus stock (1 x 10(6.5) TCID(50)/mL) of the PEDV strain, SNUVR971496, at the third passage. The mean villous height and crypt depth (VH:CD) ratio in PEDV-infected piglets from PCV2-infected sows (group A) were significantly different from those of the PEDV-infected piglets from PCV2 negative sows (group C) at 36, 48, and 72 h post-inoculation (hpi) (P<0.05). In PEDV-infected piglets from PCV2-infected sows (group A), significantly more PEDV nucleic acid was detected in the jejunal tissues (P<0.05) at 24 hpi than in the same tissues of the PEDV-infected piglets from PCV2 negative sows (group C). Thereafter, at 36, 48, 60, and 70 hpi significantly more PEDV nucleic acid (P<0.05) was detected in the jejunal tissues of the PEDV-infected piglets from PCV2 negative sows (group C) than those of the PEDV-infected piglets from the PCV2-infected sows (group A). It is concluded that the clinical course of PEDV disease was markedly affected by transplacental infection of PCV2. 相似文献
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为探明2011年我国猪群仔猪腹泻的病因,采用巢式RT-PCR方法对河南和辽宁省2个规模猪场采集43份出现腹泻的粪便进行猪流行性腹泻病毒（PEDV）、猪传染性胃肠炎病毒（TGEV）和轮状病毒（PRoV）的检测,结果表明：43份腹泻样品均为PEDV,没有检测出TGEV和PRoV。对扩增的PEDV进行测序和分析显示,这些PEDV流行毒株均属于基因G2.3亚型,彼此之间的同源性高达99.2%～100%,与2011年韩国和2008年泰国流行的PEDV毒株同属于一个进化分支。将其中3份病料在Vero细胞传代后接种2日龄仔猪,结果发现接种后13～57h内仔猪全部死亡,接种仔猪呈现典型的腹泻症状和病理变化特征,提示了这些PEDV流行毒株具有较强的致病性。 相似文献
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本研究建立了可同时检测猪流行性腹泻病毒（Porcineepidemicdiarrheavirus,PEDV）、传染性胃肠炎病毒（TransmissiblegastroenteritisVirus,TGEV）、A群轮状病毒（GroupArotavirus,GARV）和猪嵴病毒（Porcinekobu—virus）的多重RT—PCR方法。检测中,建立的多重RT—PCR方法能够检测到500Pg的TGEV、PEDV、GARV和猪嵴病毒等量混合RNA模板,与常规的单一RT—PCR检测结果基本相同（检测TGEV、PEDV、GARV和猪嵴病毒的灵敏性分别为1000A、1000／6、93．33％和96．67％,特异性均为i00％）。结果表明,建立的多重RTPCR方法敏感性和特异性良好,可作为临床上猪病毒性腹泻病因快速、高效的诊断工具。应用该方法对2010—2012年华中地区190份腹泻仔猪样本进行检测,PEDV、TGEV、GARV和猪嵴病毒的阳性率分别为62．11％、0．53％、7．37％和82．11％。混合感染方面,PEDV和猪嵴病毒混合感染率为47．89％,PEDV和GARV混合感染率为4．74％,GARV和猪嵴病毒混合感染率为7．37％,PEDV、GARV和猪嵴病毒混合感染率为4．74％,未发现TGEV与其它3种病毒的混合感染情况。另外,有27份样本中仅检出PEDV（14．21％）,57份样本只检出猪嵴病毒（30％）。分析表明,我国自2010年底大面积暴发的病毒性腹泻是多病原混合感染造成的,主要病原为PEDV,猪嵴病毒在其中所起作用尚待进一步验证和研究。 相似文献
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Brush border membrane-bound digestive enzymes such as disaccharidases (lactase, sucrase, and maltase), leucine aminopeptidase N, and alkaline phosphatase were measured in jejunum from pigs experimentally infected with porcine epidemic diarrhea virus (PEDV). Three piglets from the infected and control groups were euthanized by electrocution and subjected to necropsy at 24, 36, 48, 60, and 72 hours post-inoculation (hpi). The infection of PEDV to jejunum resulted in significant decreases in brush border membrane-bound digestive enzymes such as disaccharidases (lactase, sucrase, and maltase), leucine aminopeptidase N, and alkaline phosphatase. PEDV replication results in massive destruction of villous enterocytes leading to a marked reduction of intestinal epithelial surface and brush border membrane-bound digestive enzyme activity. Reduced enzymatic activity and villous atrophy in the small intestine is thought to result in a maldigestive and malabsorptive diarrhea. 相似文献
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为快速鉴别诊断猪流行性腹泻病毒(PEDV)、猪传染性胃肠炎病毒(TGEV)、猪轮状病毒(PoRV)和猪嵴病毒(PKV),根据PEDV的M基因、TGEV的N基因、PoRV的VP6基因和PKV的3D基因序列设计4对特异性引物,通过PCR扩增目的片段并构建重组质粒,建立了一种可同时检测4种病毒的RT-PCR诊断方法,该方法可特异性扩增这4种病毒的相应片段,而对猪瘟病毒(CSFV)、猪圆环病毒2型(PCV-2)、猪繁殖与呼吸综合征病毒(PRRSV)、猪伪狂犬病病毒(PRV)均无扩增,最低检出量分别为1.33×10^4、1.33×10^3、1.33×10^4、1.33×10^5copies/μL。应用该方法对临床55份猪腹泻样品进行检测,结果检测出14份PEDV、1份PoRV和27份PKV,未检出TGEV,其中PEDV和PKV混合感染9份。上述结果表明,建立的多重RT-PCR检测方法快速、特异、敏感,可用于以上4种腹泻病毒的临床检测和流行病学调查。 相似文献
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Jung K Kang BK Kim JY Shin KS Lee CS Song DS 《Veterinary journal (London, England : 1997)》2008,177(2):231-235
Epidermal growth factor (EGF) promotes gastrointestinal mucosal recovery by stimulating the mitogenic activity of intestinal crypt epithelial cells. The aim of this study was to determine the effects of EGF on atrophic enteritis induced in piglets by experimental infection with porcine epidemic diarrhoea virus (PEDV) strain Dr13. Two groups of 12 conventional, colostrum-deprived, 1-day-old, large White-Duroc cross breed piglets were inoculated orally with PEDV (3 x 10(5) 50% tissue culture infective doses), with or without EGF (10 microg/kg/day, intraperitoneally once daily for 4 days after infection) and compared to 12 uninfected, untreated control piglets. PEDV+EGF piglets had less severe clinical signs than PEDV only piglets at 48 and 60 h post-infection (hpi). Histologically, the ratio of villous height:crypt depth of PEDV+EGF piglets was significantly higher than PEDV only piglets at 36 and 48 hpi. Immunohistochemistry for Ki67 demonstrated increased proliferation in intestinal crypt epithelial cells of PEDV+EGF piglets compared to PEDV only piglets at 36, 48 and 60 hpi. EGF stimulates proliferation of intestinal crypt epithelial cells and promotes recovery from atrophic enteritis in PEDV-infected piglets. 相似文献
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Song DS Oh JS Kang BK Yang JS Moon HJ Yoo HS Jang YS Park BK 《Research in veterinary science》2007,82(1):134-140
A Vero cell attenuated porcine epidemic diarrhea virus (PEDV) strain, DR13, was distinguished from wild-type PEDV using restriction enzyme fragment length polymorphism (RFLP). Cell attenuated DR13 was orally or intramuscularly (IM) administered to late-term pregnant sows, and mortality resulting from the highly virulent PEDV challenge was investigated in passively immunized suckling piglets of the two different groups. The mortality rate of the oral group (13%) was lower than that of the IM group (60%). In particular, the concentration of IgA against PEDV was higher in piglets of sows in the oral group, compared to the IM group. The attenuated DR13 virus remained safe, even after three backpassages in piglets. The findings of this study support the theory that the Vero cell attenuated DR13 virus may be applied as an oral vaccine for inducing specific immunity in late-term pregnant sows with a high margin of protection against PEDV infection. 相似文献
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青海地区猪流行性腹泻的病原诊断 总被引：1，自引：1，他引：0
对青海地区疑似猪流行性腹泻病料进行了细菌学和轮状病毒核酸电泳的诊断。试验结果:排除了致病菌和轮状病毒的病原感染;乳猪回归试验,复制出与自然病例相同的临床症状;病料经处理后与猪流行性腹泻病毒免疫血清发生特异性凝集;与猪传染性胃肠炎病毒荧光抗体染色呈阴性反应;与猪流行性腹泻病毒免疫血清进行间接荧光染色时,在细胞浆内见到了特异性荧光;电镜观察到冠状病毒科的病毒颗粒。从而确诊青海地区猪流行性腹泻病原为猪流行性腹泻病毒,代号为PEDV—青毒1株。 相似文献
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An immunohistochemistry technique was developed for the diagnosis of porcine epidemic diarrhea virus (PEDV). The technique was tested on formalin-fixed, paraffin-embedded intestinal tissues from piglets naturally infected with PEDV. Five different monoclonal antibodies (MAbs) were tested in this study. PEDV antigen was consistently detected in the PLP (4% paraformaldehyde, 100 mM L-lysine dihydrochloride, 10 mM sodium m-periodate in phosphate-buffered saline)-fixed PEDV-infected Vero cells or formalin-fixed, paraffin-embedded intestinal tissues from piglets naturally infected with PEDV. The C9-2-2 MAb gave the strongest reactivity and least background staining, detecting 10 of 10 infected pigs. The positive reaction was cytoplasmic. Positive enterocytes were distributed over the tip and along the sides of atrophied or fused villi in the jejunum and ileum. Positive-staining cells were not detected in the crypts. No staining was observed in cecum and colon. No positive cells were observed when the C9-2-2 MAb was reacted with the tissue sections from noninfected piglets or from transmissible gastroenteritus virus (TGEV)- and rotavirus-infected piglets. The selected anti-PEDV MAbs tested on formalin-fixed, paraffin-embedded tissue sections are useful for diagnosis when virus isolation is not available. This method would be of particular value in countries where both PEDV and TGEV are epizootic and would aid in differentiating between PEDV and TGEV infection. 相似文献
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NAN Wen-jin HU Hong-hui WU Jing-bo HUANG Jian-qiang PENG Guo-liang XIAO Zheng-zhong 《中国畜牧兽医》2017,44(6):1769-1777
In order to understand the main pathogen of newborn piglets diarrhea in North Guangdong region, 31 diarrhea samples were collected from six pig farms in North Guangdong, the pathogen of porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV) and porcine rotavirus (PoRV) were detected by Real-time RT-PCR, meanwhile, ORF3 gene of PEDV amplified from positive samples were sequenced and analyzed. Pathogen detection results showed that 83.87%(26/31) samples were positive for PEDV, all herds and samples were negative for TGEV and PoRV. The sequence analysis revealed that the ORF3 gene of 5 epidemic strains of PEDV were all 675 bp, homologies of nucleotides were 98.7% to 100.0%, and homologies with reference sequences of nucleotides were 94.5% to 100.0%, and some gene mutation in common nucleotides site. The results of gene phylogenetic trees showed that PEDV could be divided into two groups, PEDV genetic relationship between field strains in North Guangdong and some regions in China, Southeast Asia, North America, Europe from 2013 to 2015 was closer, classed as a gene subgroup, from 2011 to 2012 main epidemic strains in our country and vaccine strains classed as other two gene subgroups. These results indicated that PEDV infection was the main pathogen of newborn piglets diarrhea in North Guangdong region, as time passed, the PEDV epidemic strains gene presented a tendency of evolution and variation. 相似文献
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猪场新生仔猪流行性腹泻防控措施 总被引：1，自引：1，他引：0
猪流行性腹泻主要侵害仔猪,尤其是7日龄以内的仔猪,发病率和病死率极高,严重影响养猪业的发展。文章分析了猪流行性腹泻的流行特点、防控难点及针对性防控措施。 相似文献
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猪流行性腹泻病毒分离鉴定及其灭活疫苗免疫保护效果研究 总被引：5，自引：0，他引：5
为筛选能用于猪流行性腹泻病毒(PEDV)疫苗研发的流行毒株,收集PEDV阳性病料,以Vero细胞进行病毒分离试验,并对分离毒株进行外源病毒检测、病毒培养特性研究、仔猪毒力试验及免疫效力试验等。9份PEDV阳性病料共分离到3株病毒,分别命名为PEDV-SC12、PEDV-JS12、PEDV-JX12。其中PEDV-SC12株存在支原体污染;PEDV-JS12株与PEDV-JX12株均能被PEDV特异性阳性血清中和;PEDV-JS12株能在Vero细胞上增殖并产生细胞病变,但适应细胞45代以后病毒培养效价仍然偏低;PEDV-JX12滴度能维持在106.0 TCID50/mL以上。PEDV-JX12株毒力试验显示,该分离株能够通过人工感染复制出腹泻病例,并能从发病动物体内检测到感染的病毒。免疫攻毒保护试验显示,以PEDV-JX12株制备的灭活疫苗免疫母猪,对所产仔猪攻毒后免疫组6.25%(1/16)发病,对照组100%(8/8)发病。说明PEDV-JX12株能够适应细胞培养,免疫接种母猪能给仔猪提供有效保护,可以用于PEDV流行毒株的疫苗研发。 相似文献
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猪流行性腹泻病毒(PEDV)和猪丁型冠状病毒(PDCov)都属于冠状病毒科,它们会引起仔猪腹泻、脱水的临床症状,在某些情况下还会导致死亡。本研究旨在评估PEDV和PDCov对仔猪感染后42 d的生长性能和组织增生的影响。将断奶后14 d、平均体重为(10.82±0.78)kg的225头仔猪随机分为3组,每组5个重复,每个重复15头,对照组不做任何处理,PEDV和PDCov组分别接种PEDV和PDCov病毒。结果:对照组RT-PCT结果均显示阴性,而接种后3 d PEDV和PDCoV组猪的感染率最高。对照组和PDCov组较PEDV组末重显著提高了18.33%和22.60%(P<0.05)。对照组和PDCov组感染后0~7 d平均日增重较PEDV组分别提高了345.45%和300%(P<0.05),PDCov组0~7 d平均日采食量较PEDV组显著提高了47.92%(P<0.05),8~14 d平均日采食量较对照组和PEDV组分别提高了36.23%和42.42%(P<0.05)。对照组和PDCov组0~7 d饲料报酬较PEDV组显著提高了446.15%和423.08%(P<0.05),而对照组和PEDV组感染后15~21 d饲料报酬分别较PDCov组提高了59.52%和59.52%(P<0.05)。对照组和PDCov组较PEDV组显著提高了期末脂肪、瘦肉、蛋白质、体重、骨矿物质和骨密度(P<0.05),但PEDV组瘦肉:脂肪值较PDCov组显著提高了12.92%(P<0.05)。结论:在本研究条件下,只有感染PEDV的猪在42 d出现组织增生和采食量降低情况。 相似文献
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猪流行性腹泻病毒检测方法研究进展 总被引：1，自引：0，他引：1
介绍了猪流行性腹泻病毒实验室检测方法的研究进展,在细胞生物学方面,主依靠病毒分离培养、病毒电镜形态检查、病毒特异性抗原及其抗体的检查等检测方法;在分子生物学方面,主依靠核酸杂交技术、RT—PCR法和实时荧光定量RT—PCR法等检测方法。介绍和比较了各种方法的优缺点和实用性,为临床兽医科技工作者提供参考。 相似文献
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本研究旨在分离猪流行性腹泻病毒（porcine epidemic diarrhea virus,PEDV）变异株,通过悬浮培养工艺制备成高效价的PEDV灭活疫苗。2017年从中国多个规模化猪场采集腹泻病死仔猪的小肠及其内容物200份,通过RT-PCR方法进行PEDV检测并测序,筛选一株PEDV变异株,将其在2 L反应器里悬浮培养的Vero细胞上进行病毒分离与传代培养,收获的病毒液鉴定后测定TCID50,经甲醛灭活后加入氢氧化铝胶佐剂配制成PEDV灭活疫苗,对其物理性状、稳定性、黏度、无菌等进行检验,检验合格后免疫妊娠母猪及所产仔猪,对其安全性和免疫效力进行研究。结果显示,200份病料中有86份为PEDV阳性,将筛选的PEDV变异株病料在Vero细胞上传至第5代时出现细胞病变,传至第10代收获病毒液,经鉴定后确定为PEDV变异毒株,并命名为PEDV-GF10株。收获的病毒液浓缩后测得病毒滴度可达1×108.0 TCID50/mL。疫苗检验合格后在母猪产前40和25 d时试验组后海穴肌内注射4 mL疫苗,空白组不免疫,结果显示试验组与空白组母猪的生产情况无明显差异,所产3日龄仔猪分别免疫不同剂量后体温无显著差异,表明该疫苗对母猪和仔猪均安全性良好。随机挑选试验组与空白组母猪所产3日龄仔猪各20头,分别口服4 mL PEDV-F10病毒培养物,空白组母猪所产仔猪在攻毒24 h后PEDV发病率为100%,抗体均为阴性;试验组母猪所产仔猪只有10%出现了轻微的腹泻症状,仔猪获得了高达90%保护率,且仔猪被动免疫后抗体能持续至35 d以上。以上结果表明,PEDV-GF10变异株通过悬浮细胞培养后病毒滴度显著提高,研制的PEDV-GF10株灭活疫苗安全有效,能够对中国的PEDV变异株达到有效防控,为国内PED防控提供了理论依据。 相似文献
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为了研究仔猪所吮乳汁中IgA抗体水平与乳汁中PEDV感染情况,探讨母猪免疫猪流行性腹泻疫苗后乳汁与血清中IgA、IgG抗体水平的相关性,临床采集多家规模化猪场母猪群乳汁、血清样品以及发病仔猪所吮母猪乳汁样品。采用实验室已经建立的IgA、IgG抗体ELISA方法,检测临床上猪流行性腹泻疫苗免疫后IgA抗体与IgG抗体的相关性,同时采用RT-PCR方法检测发病仔猪所吮乳汁中PEDV感染情况。结果表明,免疫猪流行性腹泻活疫苗后母猪乳汁中IgA抗体水平与血清中IgA、IgG抗体水平呈现很好的正相关性;当发病仔猪所吮母猪乳汁IgA抗体检测结果为阴性时,其PEDV抗原检测结果为阳性;乳汁IgA抗体检测结果趋于阳性样品临界值时,其PEDV抗原检测结果亦为阳性。结论:乳汁中低水平的IgA抗体很难有效地保护仔猪抵御PEDV感染;乳汁中IgA抗体与血清IgA、IgG抗体呈现很好的相关性,且乳汁中IgA抗体水平远远高于血清;通过IgG抗体水平可以间接反映乳汁中的IgA抗体水平,在初乳样品采集难度较大的情况下,可用于间接评估猪流行性腹泻免疫保护水平。 相似文献