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A study was conducted to determine the susceptibility of swine to Korean foot-and-mouth disease virus (FMDV; subtype O, isolated from Chungju province) in April, 2000. One holstein cow was inoculated intradermolingually with suspension of homogenized tissue from a Korean native cow naturally infected with Korean FMDV. Infected cow was housed with one susceptible cow and one susceptible pig (contact sentinels). Four additional susceptible pigs were housed in the same room but caged separately (noncontacted sentinels). The contacted pig and cow as well as non-contact pigs developed typical clinical signs after 2, 3, and 7 days post exposure, respectively. We compared neutralizing antibody from the animals to FMDV O₁ Lombardy, O Taiwan, O₁ Campos, and O₁ Manisa after 0, 4, 7, 10, 14, 21, 28 days post challenge and post-exposure. The highest viral neutralization titer could be interpreted that serotype O Korea (Chungju isolate) is antigenically more related to O₁ Manisa. In addition, immunohistochemistry was used to further characterize Korean FMDV from tissues of infected pigs. Korean FMDV antigen was observed in the tongue, hoof, esophagus, and tonsil tissues of sentinel pigs. These findings suggest that Korean FMD virus isolated from cattle can be rapidly transmitted to pigs both directly and indirectly contrast field observation in which only cattle were clinically ill.
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