REPRODUCTION OF PROLIFERATIVE ENTERITIS IN HAMSTERS WITH A PURE CULTURE OF PORCINE ILEAL SYMBIONT INTRACELLULARIS

Hamsters, three weeks old, were inoculated orally with suspensions of intracellular bacteria, grown in tissue culture cells, IEC-18, rat ent erocytes. Cells had been infected with suspensions of intracellular ba cteria derived from the lesions of proliferative haemorrhagic enteropa thy occurring naturally in two pigs 916/91 and 1482/89. Infected cell lines containing each separate strain, 916/91 and 1482/89, were passag ed one, two or five times and pure cultures of intracellular bacteria, identified as ileal symbiont intracellularis by immunological means, were collected from the cells and used as inocula. Ten of sixteen hams ters dosed with 916/91 passaged one or five times, developed lesions o f proliferative enteritis evident at necropsy three weeks after inocul ation. Hamsters inoculated with 1482/ 89 passaged twice and stored fro zen, or IEC-18 cells alone or those left uninoculated, failed to devel op lesions of proliferative enteritis. Campylobacter jejuni infection occurred throughout, in all groups. Marked hyperplasia of ileal entero cytes, associated with numerous intracellular curved bacteria was inva riably detected in experimentally affected hamsters. Immunofluorescenc e reactions with specific antibodies indicated that these intracellula r bacteria were also ileal symbiont intracellularis. The results sugge sted that proliferative enteritis could be reproduced in hamsters with a pure culture of an agent derived from pigs. We concluded that the r eproduction of the disease with our inocula containing a single agent clarifies the aetiology of proliferative enteritis in both hamsters an d pigs.