PRESENCE OF YERSINIA-ENTEROCOLITICA 0 9 IN FECAL SAMPLES OF BRUCELLA-ABORTUS RUMINANTS REVEALING ATYPICAL SEROLOGIC REACTIONS AGAINST ANTIGENS/

During a campaign of prophylaxis occuring in 1990-1991 positive serolo gic reactions against Brucella abortus antigens were noticed in brucel losis free cattle breeding areas of Puy-de-Dome. 2.5 % of bovine live stock were concerned and 0.2 % of animals were sero-positive. However no symptoms of brucellosis and no Brucella strains isolation were foun d in these animals. Thus, at the time of the 1991-1992 campaign of pro phylaxis we searched for Yersinia enterocolitica 0 : 9 which have comm on antigenic determinants with Brucella abortus. We found Y. enterocol itica in fecal samples of 10 animals (9 bovines cattle and 1 goat) amo ng 16 animals with positive serologic reactions against Brucella antig ens which lived in 10 different cattle breedings. It seems important t o systemically look for the presence of Y. enterocolitica 0 : 9 in bov ines with atypical serologic reactions against Brucella antigens.