Serological response in rabbits to Listeria monocytogenes after oral or intragastric inoculation.

The serological response in rabbits against Listeria monocytogenes after oral or intragastric inoculation was investigated. Both the number of sero-positive animals and the average serum titres were higher in animals inoculated by the oral route. This difference was especially marked in rabbits inoculated with the lower dose (1 x 10(3) colony-forming units (cfu)), which developed a strong serological response (average serum titre of 1280 after 4 inoculations) in most of the inoculated animals (80%), without any clinical signs. The implication of these results in the epidemiology of listeriosis is discussed.