Opriessnig Tanja, Xiao Chao-Ting, Gerber Priscilla F, Zhang Jianqiang, Halbur Patrick G
The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, United Kingdom; Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America.
PLoS One. 2014 Aug 12;9(8):e104766. doi: 10.1371/journal.pone.0104766. eCollection 2014.
Porcine epidemic diarrhea virus emerged in North America in April 2013 and has since been identified in 30 U.S. States, Canada and Mexico. The rapid spread of PEDV has raised concerns about the role of feed and particularly pork-by-product components such as spray-dried porcine plasma (SDPP) in PEDV transmission. The aim of this study was to determine the infectivity of PEDV RNA present in commercial SDPP. Specifically, 40 3-week-old PEDV naïve pigs were randomly assigned to one of five treatment groups. At day post inoculation (dpi) 0, NEG-CONTROL pigs were sham-inoculated, PEDV-CONTROL pigs received cell culture propagated PEDV, and SDPP-CONTROL pigs were switched to a diet with 5% SDPP containing 5.1±0.1 log10 PEDV RNA copies/g. To evaluate a potential positive effect of anti-PEDV antibodies in SDPP on PEDV challenge, four days prior to PEDV challenge the pigs in the SDPP-PEDV group were switched to and remained on a 5% SDPP diet through dpi 28. Another group, EGG-PEDV, was orally administered a commercial egg-derived liquid PEDV globulin product from dpi -4 through 6. All PEDV-CONTROL pigs began shedding PEDV in feces by dpi 3 and seroconverted between dpi 7 and 14, whereas pigs in NEG-CONTROL and SDPP-CONTROL groups remained PEDV RNA negative and did not seroconvert to PEDV for the study duration. This indicates no evidence of infectivity of the PEDV RNA in the SDPP lot utilized. Furthermore, under the study conditions SDPP or egg-derived liquid PEDV globulin addition did not significantly alter PEDV-shedding or overall disease course after experimental challenge.
猪流行性腹泻病毒于2013年4月在北美出现,此后在美国30个州、加拿大和墨西哥被发现。PEDV的迅速传播引发了人们对饲料尤其是猪肉副产品成分(如喷雾干燥猪血浆,SDPP)在PEDV传播中作用的担忧。本研究的目的是确定商业SDPP中存在的PEDV RNA的传染性。具体而言,将40头3周龄未接触过PEDV的仔猪随机分为五个处理组之一。在接种后第0天(dpi 0),阴性对照组仔猪进行假接种,PEDV对照组仔猪接种细胞培养增殖的PEDV,SDPP对照组仔猪改用含5% SDPP(每克含5.1±0.1 log10 PEDV RNA拷贝)的日粮。为了评估SDPP中抗PEDV抗体对PEDV攻击的潜在积极作用,在PEDV攻击前四天,将SDPP-PEDV组的仔猪改用5% SDPP日粮,并在dpi 28前一直维持该日粮。另一组,即鸡蛋-PEDV组,从dpi -4至6口服一种商业鸡蛋来源的液体PEDV球蛋白产品。所有PEDV对照组仔猪在dpi 3时开始粪便中排出PEDV,并在dpi 7至14之间血清转化,而阴性对照组和SDPP对照组的仔猪在研究期间PEDV RNA均为阴性,且未血清转化为PEDV。这表明在所使用的SDPP批次中,没有证据表明PEDV RNA具有传染性。此外,在研究条件下,添加SDPP或鸡蛋来源的液体PEDV球蛋白在实验攻击后并未显著改变PEDV的排出或总体病程。