Yamada Manabu, Fukai Katsuhiko, Morioka Kazuki, Nishi Tatsuya, Yamazoe Reiko, Kitano Rie, Shimada Nobuaki, Yoshida Kazuo, Kanno Toru, Sakamoto Kenichi, Yamakawa Makoto
Exotic Disease Research Station, National Institute of Animal Health, National Agriculture and Food Research Organization, Kodaira, Tokyo 187-0022, Japan.
Hokkaido Research Station, National Institute of Animal Health, National Agriculture and Food Research Organization, Sapporo, Hokkaido 062-0045, Japan.
J Vet Med Sci. 2018 Nov 9;80(11):1669-1675. doi: 10.1292/jvms.18-0377. Epub 2018 Sep 14.
We examined the pathogenesis of the attenuated foot-and-mouth disease virus (FMDV) O/JPN/2000 in pigs. The virus used in this study was passaged three times in primary bovine kidney (BK) cells and once in baby hamster kidney-21 (BHK-21) cells after isolation. A plaque assay demonstrated that this virus exhibited the small plaque (SP) phenotype. There was no clinical or histological evidence of vesicular lesions in pigs intraorally inoculated with 10 50% tissue culture infectious dose (TCID)/ml of the SP virus (SPV) of FMDV O/JPN/2000. Although fever was detected from 2 or 3 days post inoculation (dpi), there was no other prominent clinical sign up to 6 dpi. Virus shedding from saliva and nasal swab samples was not observed in any pigs inoculated with the SPV of FMDV O/JPN/2000. In the foot, mild lamellar degeneration of prickle cells in the upper layer of the stratum spinosum was histologically observed without development into vesicular or necrotic lesions. Immunohistochemical virus antigen- and terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL)-positive reactions observed in the foot at 1 dpi seemed to disappear after 3 and 6 dpi. Our findings suggest that the SPV of FMDV O/JPN/2000 had low pathogenicity against pigs by intraoral inoculation.
我们研究了口蹄疫病毒（FMDV）O/JPN/2000弱毒株在猪体内的致病机制。本研究中使用的病毒在分离后，先在原代牛肾（BK）细胞中传代3次，再在幼仓鼠肾-21（BHK-21）细胞中传代1次。空斑试验表明，该病毒呈现小空斑（SP）表型。用1050%组织培养感染剂量（TCID）/ml的FMDV O/JPN/2000的SP病毒（SPV）经口接种猪后，没有出现水疱性病变的临床或组织学证据。虽然在接种后2或3天（dpi）检测到发热，但直到6 dpi都没有其他明显的临床症状。在任何接种FMDV O/JPN/2000的SPV的猪中，均未观察到唾液和鼻拭子样本中有病毒排出。在足部，组织学观察到棘层上层的棘细胞有轻度板层变性，但未发展成水疱或坏死性病变。在1 dpi时足部观察到的免疫组化病毒抗原和末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）阳性反应在3和6 dpi后似乎消失。我们的研究结果表明，FMDV O/JPN/2000的SPV经口接种对猪的致病性较低。
