Division 5

The simultaneous inoculation of a porcine cell line and one of the above-mentioned tissue culture systems (preferably primary bovine thyroid cells) is a useful guide as to whether vesicular samples contain swine vesicular disease virus or foot and mouth disease virus, as the former will only grow in cells of porcine origin. However, foot-and-mouth disease virus isolates with a prolonged history of transmission between pigs may also preferentially grow in porcine cell culture systems.