PERSISTENT YERSINIA-ENTEROCOLITICA INFECTION IN 3 RAT STRAINS

Yersinia enterocolitica may persist for prolonged periods of time in h umans sometimes resulting in the development of reactive arthritis. To elucidate factors predisposing for persistence we developed animal mo dels. In Lewis and Fischer rats, viable bacteria could be demonstrated for prolonged time and abscesses could be found in the liver, spleen and lungs. Splenic abscesses were observed for more than 20 weeks. Yer sinia enterocolitica persisted in Lewis and Fischer rats, but only Lew is rats developed reactive arthritis. In Brown Norway rats abscesses d eveloped early during infection but in contrast to the other strains d isappeared after 3 weeks. Culture of homogenized abscess-containing ti ssue of all three rat strains yielded Yersiniae. Immunofluorescence st udies of the abscesses showed diffuse staining inside the abscesses on ly, indicating the presence of Yersinia enterocolitica antigen. Brown Norway rats, in contrast to Lewis and Fischer rats, developed a differ ent serological reaction pattern against Yersinia enterocolitica antig ens and this correlated with the disappearance of the abscesses. (C) 1 995 Academic Press Limited