Studies of Yersinia enterocolitica 0:3 experimental infection in pigs

Y. enterocolitica (serotype 0:3, pYV+, biotype 4) infection of 20-day-old pigs challenged per os with a total dose of 5 x 10(10) CFU was studied. Clinical, paraclinical and morphological findings were examined in dynamics from 1st to 25th days post infection (p.i.). Augmentation of body temperature and erythrocyte sedimentation rate during the first days p.i. were established. The number of leucocytes, peritoneal (pMa) and alveolar (aMa) macrophages was increased significantly from 4th to 15th days p.i. Phagocytic activity of pMa and aMa examined in vitro was maximal on days 15 and 25 p.i. The enhanced phagocytic activity of macrophages was in correlation with the observed histological changes--purulent meningoencephalitis, necrotic tonsillitis, peribronchial lymphoid-leucocytic cell infiltration and catarrhal enteritis. Extensive colonization of internal organs was detected at necropsy till the end of trial. Analysis of the results shows that this orally caused infection runs slowly with dissemination and persistency of Y. enterocolitica 0:3 in the macroorganism, like a generalized infection.