Estudo epidemiológico de Borrelia burgdorferi, Babesia bovis, Babesia bigemina e Anaplasma marginale em búfalos (Bubalus bubalis) do Estado do Rio de Janeiro

Abstract

The increasing economic interest on the buffalo breeding activity has stimulated research regarding the health buffalo. This study aimed to determine the frequency of serological and molecular agents Borrelia burgdorferi, Babesia bigemina, Babesia bovis and Anaplasma marginale in buffaloes in Rio de Janeiro state. Seventeen properties were selected, with at least one per micro region with buffalo breeding in Rio de Janeiro state, where the blood was collected from the buffalo by non-probability sampling. Were used 316 serum samples and 295 DNA samples analyzed by ELISA and PCR techniques, respectively. For B. burgdorferi, only DNA samples from 12 animals with a higher seropositivity in the ELISA were subjected to PCR. Serologic testing revealed that 59.2% of the animals were positive for B. burgdorferi, 51.3% for B. bovis, 45.9% for B. bigemina and 42.0% for A. marginale. There was no association between the sex of the buffalo and the frequencies of animals positive for all agents (p>0.05), but females had higher capacity to produce IgG against infection by B. burgdorferi, B. bigemina and A. marginale (p<0.05). The age of the animals showed influence on the frequency of seropositive animals and intensity of immune response to all agents, since both increased progressively until the age of 36 months of age. After seven months of age showed higher levels of optical density against all agents tested, which may indicate the onset of active immunity. The PCR for gene amplification flgE of Borrelia sp. resulted in one positive sample, whose sequencing revealed 99% homology with B. burgdorferi. For B. bigemina, the PCR technique with sensitivity to detect up to 58 parasites/μL of blood was used and revealed only one positive animal. The PCR used in analysis for B. bovis, with sensitivity to detect up to 21 parasites/μL of blood, has not revealed any positive in an initial pilot conducted with samples from 36 buffaloes highly seropositive and 36 negative by ELISA. From this result, not the other DNA samples were tested for B. bovis. The PCR for A. marginale was effective for animals up to 7.33 parasites/μL blood, revealing a frequency of 5.42% (16/295) of positive buffaloes. For all agents, there was no association between the results of serology and PCR. The percentage of buffaloes in Rio de Janeiro state seropositive to B. burgdorferi and the existence of one buffalo PCR positive for this agent suggest the presence this spirochete, or other similar antigenic and molecular level, this animal population. Babesia bigemina, B. bovis and A. marginale are present at low parasitemia in the population studied, most often not detectable by simple PCR used.