Serological occurrence for tick-borne agents in beef cattle in the Brazilian Pantanal.

This study investigated the seropositivity for five different tick-borne agents, namely Anaplasma marginate, Babesia bovis, Babesia bigemina, Coxiella burnetii, Anaplasma phagocytophilum, and Trypanosoma vivax in beef cattle in the Brazilian Pantanal. The serum samples collected from animals (200 cows; 200 calves) were used in indirect enzyme-linked immunosorbent assays (iELISA) to detect IgG antibodies against A. marginate, B. bovis, B. bigemina, and T. vivax, and Indirect Fluorescent Antibody Test (IFAT) for detecting IgG antibodies against C. burnetii and A. phagocytophilum. No correlation was observed between seropositivity for C. burnetii and A. phagocytophilum with other agents whereas moderate correlation was observed for A. marginate x B. bigemina x B. bovis. Cows were more seropositive for T. vivax whereas calves were more seropositive for B. bovis and B. bigemina. The highest number of seropositive animals by a single agent was observed for T. vivax (15.2%). Co-seropositivity for T. vivax + A. marginate was higher in cows (25.5%) and for T. vivax + B. bovis + B. bigemina + A. marginate was higher in calves (57.5%). The high seropositivity correlation for A. marginate x B. bovis x B. bigemina is probably due to the presence of the tick biological vector, Rhipicephalus microplus, in the studied farms. Common transmission pathways, mediated by hematophagous dipterans and fomites, may explain the high co-seropositivity of cows for A. marginate and T. vivax. Low seropositivity to C. burnetii is probably due to the type of breeding system employed (extensive). Seropositivity for A. phagocytophilum in only one animal suggests the occurrence of a cross-serological reaction with another agent of the genus Anaplasma.