Pathogenesis of the attenuated foot-and-mouth disease virus O/JPN/2000 in experimentally infected pigs

• Published in: Journal of Veterinary Medical Science Vol. 80; no. 11; pp. 1669 - 1675
• Main Authors: YAMADA, Manabu, FUKAI, Katsuhiko, MORIOKA, Kazuki, NISHI, Tatsuya, YAMAZOE, Reiko, KITANO, Rie, SHIMADA, Nobuaki, YOSHIDA, Kazuo, KANNO, Toru, SAKAMOTO, Kenichi, YAMAKAWA, Makoto
• Format: Journal Article
• Language: English
• Published: Japan JAPANESE SOCIETY OF VETERINARY SCIENCE 2018; Japan Science and Technology Agency; The Japanese Society of Veterinary Science
• Subjects: Administration, Oral; Animals; Cell culture; Degeneration; DNA nucleotidylexotransferase; Fever; Foot & mouth disease; Foot-and-Mouth Disease - immunology; Foot-and-Mouth Disease - pathology; Foot-and-Mouth Disease - virology; foot-and-mouth disease virus; Foot-and-Mouth Disease Virus - classification; Foot-and-Mouth Disease Virus - isolation & purification; Foot-and-Mouth Disease Virus - pathogenicity; histopathology; immunohistochemistry; Inoculation; Kidneys; Pathogenesis; Pathogenicity; Pathology; Phenotypes; pig; Plaque assay; Real-Time Polymerase Chain Reaction - veterinary; Saliva; Serial Passage; Serogroup; Swine; Swine Diseases - pathology; Swine Diseases - virology; Tissue culture; Vaccines, Attenuated; Virus Shedding; histopathology; foot-and-mouth disease virus; immunohistochemistry; pig
• ISSN: 0916-7250; 1347-7439; 1347-7439
• DOI: 10.1292/jvms.18-0377

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 106 50% tissue culture infectious dose (TCID50)/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.