Serological relationship between cattle exposed to Brucella abortus, Yersinia enterocolitica O:9 and Escherichia coli O157:H7

Abstract

Sera from cattle naturally infected with Brucella abortus ( n=160), vaccinated with B. abortus S19 ( n=88) or immunized with Yersinia enterocolitica O:9 ( n=25) or Escherichia coli O157:H7 ( n=80) were collected. The sera were compared for antibody content to the same bacteria by indirect enzyme immunoassay (IELISA), fluorescence polarization assay (FPA) and competitive enzyme immunoassay (CELISA). Cattle sera ( n=523) collected randomly from across Canada were tested in the same tests. Sera from the B. abortus infected group reacted positively in the brucellosis IELISA (IELISA Br), CELISA and FPA (FPA Br) and the Y. enterocolitica IELISA (IELISA Ye) while the Y. enterocolitica FPA (FPA Ye) detected antibody in 93.8% and the E. coli IELISA (IELISA Ec) 86.9% and the E. coli FPA (FPA Ec) 48.1%. About 70% of the sera from B. abortus S19 vaccinated animals reacted in the three IELISAs, 45% in the CELISA, and 37.7% in the FPA Ec, 21.6% in the FPA Br and 5.7% in the FPA Ye. Sera from E. coli O:157 exposed cattle reacted mainly in the IELISA Ec and FPA Ec although surprisingly 87.5% reacted in the IELISA Ye and only 3.8% in the IELISA Br. No reactions were observed with these sera in the FPA Br and FPA Ye but one serum gave a low positive reaction in the CELISA. All sera from Y. enterocolitica O:9 exposed cattle reacted in the IELISA Br and IELISA Ye and 80% in the IELISA Ec. In the CELISA, 44% gave a positive reaction and 64% were positive in the FPA Br, 28% in the FPA Ye and 12% in the FPA Ec. Of the 523 Canadian sera, about 50% reacted in the E. coli tests with only minor reactions in the Y. enterocolitica O:9 and B. abortus assays. From the data, the cross reaction between E. coli O157:H7, Y. enterocilitica O:9 and B. abortus is dependent on the test used. Thus, extensive cross reaction was observed with the IELISA with much less reactivity in the FPA and the CELISA.