Langohr Ingeborg M, Stevenson Gregory W, Nelson Eric A, Lenz Stephen D, Wei Huiling, Pogranichniy Roman M
Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA.
J Vet Diagn Invest. 2012 Jan;24(1):51-64. doi: 10.1177/1040638711417142. Epub 2011 Oct 12.
The role of Bovine viral diarrhea virus (BVDV) in the development of Porcine circovirus-2 (PCV-2)-associated disease (PCVAD) was investigated in 2 experimental studies. In the first, separate groups of germ-free pigs were inoculated with filtered tissue homogenate (from diseased pigs) containing PCV-2b + BVDV-1-like virus (group 1), PCV-2a + BVDV-1-like virus (group 4), BVDV-1-like virus only (group 3), or PCV-2b + BVDV-1-like virus following a BVDV vaccination protocol (group 2). This last group was used to test if BVDV vaccination would prevent clinical PCVAD in this model. Many of the inoculated pigs had mild multisystemic inflammation consistent with classic PCVAD. One vaccinated, dually inoculated pig had acute respiratory distress followed by death at 21 days postinfection. Lesions in this pig resembled the severe form of PCVAD observed in the field since the fall of 2004, suggesting a role of ruminant pestiviruses and/or vaccination in the development of this disease. In the second study, cesarean-derived, colostrum-deprived pigs were inoculated with PCV-2b and a cytopathic strain of BVDV-1 (cpBVDV-NADL) either alone or in combination. Clinical signs of PCVAD were seen in a single animal inoculated only with PCV-2b. This pig had growth retardation followed by acute respiratory distress leading to death 30 days postinfection. Pulmonary lesions in this animal were similar to those seen in the pig that died in the first study. Infection with cpBVDV-NADL did not enhance PCV-2b replication or lesion formation.
在两项实验研究中，对牛病毒性腹泻病毒（BVDV）在猪圆环病毒2型（PCV - 2）相关疾病（PCVAD）发展中的作用进行了研究。在第一项研究中，将无菌猪分成不同组，分别接种含有PCV - 2b + BVDV - 1样病毒的过滤组织匀浆（来自患病猪）（第1组）、PCV - 2a + BVDV - 1样病毒（第4组）、仅BVDV - 1样病毒（第3组），或按照BVDV疫苗接种方案接种PCV - 2b + BVDV - 1样病毒（第2组）。最后一组用于测试BVDV疫苗接种是否能预防该模型中的临床PCVAD。许多接种的猪出现了与经典PCVAD一致的轻度多系统炎症。一头接种疫苗后又双重接种的猪在感染后21天出现急性呼吸窘迫，随后死亡。这头猪的病变类似于自2004年秋季以来在田间观察到的严重形式的PCVAD，表明反刍动物瘟病毒和/或疫苗接种在该疾病发展中起作用。在第二项研究中，对剖腹产、未初乳喂养的猪单独或联合接种PCV - 2b和BVDV - 1的细胞病变毒株（cpBVDV - NADL）。仅接种PCV - 2b的一只动物出现了PCVAD的临床症状。这头猪生长发育迟缓，随后出现急性呼吸窘迫，在感染后30天死亡。这只动物的肺部病变与第一项研究中死亡的猪相似。感染cpBVDV - NADL并未增强PCV - 2b的复制或病变形成。
