Abstract

Ticks and tick-borne diseases are widely distributed in southern Africa and limit livestock production of commercial farmers and the subsistence economy of the resource-poor farmers. Reverse line blot hybridization was used to survey the prevalence of tick-borne pathogens in cattle of commercial and small scale resource-poor farmers within the north-eastern region of the Free State Province, South Africa. Blood was collected from 74 clinically healthy cattle in five farms at Ficksburg and Reitz. DNA was extracted and subjected to two different polymerase chain reactions (PCRs): an 18S rRNA-based PCR for amplification of Theileria and Babesia species and a 16S rRNA-based PCR for amplification of Ehrlichia and Anaplasma species. Reverse line blot (RLB) assay was then performed with family and species-specific DNA probes. Forty nine percent of the samples were positive for Anaplasma marginale, 35.1% for Theleria taurotragi, 18.9% forEhrlichia sp. (Omatjenne), 2.7% for Babesia bigemina and 1.4% for both Anaplasma bovis and Babesia bovis. The phylogenetic analysis of three representative strains tested in this study also indicated that Anaplasma sp. clone SAFS01 and Anaplasma sp. clone SAFS02 clustered with their corresponding species, while the Ehrlichia sp. clone SAFS03 clustered separately from another strain of the same species published in the GenBank database.

Key words: Reverse line blot hybridization, Anaplasma, Babesia, Ehrlichia, Theileria, 16S rDNA, phylogeny