RESUMEN
Serum samples from healthy dairy and beef cattle, living in tick-infested areas of Connecticut, USA, were analyzed by polyvalent enzyme-linked immunosorbent assays (ELISA), indirect fluorescent antibody (IFA) staining methods, or Western blot procedures to detect antibodies to tick-borne agents. Of the 80 sera tested by ELISA with whole-cell or 10 separate recombinant antigens (fusion proteins) of Borrelia burgdorferi sensu stricto, 57 (71%) were positive to 1 or more antigens, while 36 (45%) reacted to whole-cell antigens by IFA staining methods. Three (4%) of 80 samples had antibodies to Anaplasma phagocytophilum. There were antibodies to outer surface protein (Osp) A, OspB, OspC, OspE, OspF, protein (p) 41-G, p35, p37, and VlsE antigens of B. burgdorferi, but there was no reactivity to the p39 antigen by ELISA. Western immunoblots of a subset of 9 sera verified antibody presence in all samples and showed distinct reactivities to multiple proteins having molecular masses of about 31 kilodaltons (kDa), 34 kDa, 35 kDa, 41 kDa, and 83/93 kDa. High specificity (97%) was noted when 16 cattle sera containing antibodies to Leptospira interrogans serovars, Brucella sp., Anaplasma marginale, or A. phagocytophilum were tested by ELISA with separate whole-cell or recombinant B. burgdorferi antigens. An ELISA and Western blot analyses can be used to confirm the exposure of cattle to B. burgdorferi.
Asunto(s)
Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/inmunología , Borrelia burgdorferi/inmunología , Enfermedades de los Bovinos/diagnóstico , Enfermedad de Lyme/veterinaria , Anaplasma phagocytophilum/inmunología , Animales , Anticuerpos Antibacterianos/inmunología , Western Blotting/veterinaria , Bovinos , Enfermedades de los Bovinos/inmunología , Connecticut , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Técnica del Anticuerpo Fluorescente Indirecta/veterinaria , Enfermedad de Lyme/diagnóstico , Enfermedad de Lyme/inmunología , Masculino , Peso Molecular , Proteínas Recombinantes/inmunología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Infestaciones por Garrapatas/veterinariaRESUMEN
Enzyme-linked immunosorbent assays (ELISA) with a purified recombinant 44-kDa protein and indirect fluorescent antibody (IFA) staining methods incorporating whole-cell antigens of the human granulocytic ehrlichiosis (HGE) agent were used to detect antibodies to Ehrlichia phagocytophila genogroup organisms in cattle sera. The cattle lived in tick-infested areas of Connecticut, USA and were healthy at the times blood samples were collected in 1990, 1999 and 2000. Of the 339 serum samples analysed, 40 (12%) and 15 (4%) were positive by ELISA and IFA, respectively. Western immunoblots of a subset of sera verified antibody reactivity of six serum samples, positive by ELISA with titres of 640-2,560, to a protein with a molecular mass of c. 44 kDa. Although seroprevalence rates were low, cattle were exposed to the HGE agent at different sites and should be monitored for anaemia, leukopenia or thrombocytopenia, especially if there is evidence of unexplained decreased milk production. Different serological testing methods should be used to detect immunoglobulins.