Cultivation and characterization of Lawsonia intracellularis isolated from rabbit and pig.

Lawsonia intracellularis is an obligate intracellular pathogenic bacterium that causes proliferative enteropathy in domestic and experimental animals. In this study, we improved the in vitro cultivation method of L. intracellularis to increase the passage efficiency and showed that L. intracellularis isolated from a rabbit and a pig have different antigenic properties. Bacteria should be recovered from infected cells before cell death due to infection to obtain higher bacterial passage efficiency, and measurement of LDH activity in the cell culture medium was useful for determining the timing of bacterial passage. L. intracellularis isolated from the rabbit and pig showed different band patterns in immunoblotting. Our results should be helpful in the development of serological diagnosis and epidemiological investigation methods.