OLIVEIRA, Márcia Cristina de Sena.; OLIVEIRA-SEQUEIRA, Teresa Cristina Goulart de.; REGITANO, Luciana Correia de Almeida.; ALENCAR, Mauricio Mello de.; NÉO, Thalita Athiê.; SILVA, Ana Mary.; OLIVEIRA, Henrique Nunes de.
Résumé:
Babesia bigemina infections were investigated in four genetic groups of beef cattle and in Rhipicephalus (Boophilus) microplus
engorged female ticks. Blood samples and engorged female ticks were collected from 15 cows and 15 calves from each of the
following genetic groups: Nelore, Angus Nelore, Canchim Nelore, and Simmental Nelore. Microscopic examination of
blood smears and tick hemolymph revealed that merozoites of B. bigemina (6/60) as well as kinetes of Babesia spp. (9/549) were
only detected in samples (blood and ticks, respectively) originated from calves. PCR-based methods using primers for specific
detection of B. bigemina revealed 100% infection in both calves and cows, regardless the genetic group. Tick infection was detected
by nested-PCR amplifications showing that the frequency of B. bigemina was higher (P < 0.01) in female ticks collected from
calves (134/549) than in those collected from cows (52/553). The frequency of B. bigemina was similar in ticks collected from
animals, either cows or calves, of the four genetic groups (P > 0.05).
