RESUMO

In the present study, we screened blood DNA samples obtained from cattle bred in Brazil (n=164) and Ghana (n=80) for Babesia bovis using a diagnostic PCR assay and found prevalences of 14.6% and 46.3%, respectively. Subsequently, the genetic diversity of B. bovis in Thailand, Brazil and Ghana was analyzed, based on the DNA sequence of merozoite surface antigen-1 (MSA-1). In Thailand, MSA-1 sequences were relatively conserved and found in a single clade of the phylogram, while Brazilian MSA-1 sequences showed high genetic diversity and were dispersed across three different clades. In contrast, the sequences from Ghanaian samples were detected in two different clades, one of which contained only a single Ghanaian sequence. The identities among the MSA-1 sequences from Thailand, Brazil and Ghana were 99.0-100%, 57.5-99.4% and 60.3-100%, respectively, while the similarities among the deduced MSA-1 amino acid sequences within the respective countries were 98.4-100%, 59.4-99.7% and 58.7-100%, respectively. These observations suggested that the genetic diversity of B. bovis based on MSA-1 sequences was higher in Brazil and Ghana than in Thailand. The current data highlight the importance of conducting extensive studies on the genetic diversity of B. bovis before designing immune control strategies in each surveyed country.

Assuntos

Babesia bovis/genética , Babesiose/parasitologia , Doenças dos Bovinos/parasitologia , Variação Genética/genética , Filogenia , Animais , Babesiose/epidemiologia , Sequência de Bases , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , DNA de Protozoário/química , DNA de Protozoário/genética , Gana , Proteína 1 de Superfície de Merozoito/química , Proteína 1 de Superfície de Merozoito/genética , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/veterinária , Prevalência , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Tailândia/epidemiologia