Prevalence and phylogenetic analysis of Babesia bigemina and Babesia bovis hemoparasites from cattle in South Africa

Abstract Introduction Babesia parasites , mainly Babesia bovis and B. bigemina , are tick-borne hemoparasites inducing bovine babesiosis in cattle globally. The clinical signs of the disease include anaemia, fever and hemoglobinuria. Babesiosis is known to occur in tropical and subtropical regions. Objective We aimed at providing information about the occurrence and phylogenetic relationship of B. bigemina and B. bovis species in cattle from different locations in nine provinces of South Africa. Methods A total of 430 blood samples were randomly collected from healthy animals in different locations. These samples were tested for Babesia parasitic infections using nested PCR assays with species-specific primers. Neighbour-joining trees were constructed to study the phylogenetic relationship between B. bigemina and B. bovis sequences of randomly selected isolates. Results & Discussion Nested PCR assays with Group I primer sets revealed that the overall prevalence of B. bigemina and B. bovis in all bovine samples tested was 64.7% (95% CI = 60.0-69.0) and 35.1% (95% CI = 30.6-39.8), respectively. Only 117/430 (27.2%) animals had a mixed infection. The highest prevalence of 87.5% (95% CI = 77.2–93.5) for B. bigemina was recorded in the Free State province, while North West had the highest number of animals infected with B.bovis (65.5%; 95% CI = 52.7-76.4). Phylograms were inferred based on B. bigemina -specific gp45 and B. bovis -specific rap-1 nucleotide sequences obtained with Group II nested PCR primers. Phylogenetic analysis of gp45 sequences revealed clearly distinct strains in the genotypes of B. bigemina isolates investigated, including those of published in GenBank. A phylogeny based on B. bovis rap-1 sequences indicated a similar trend of clustering among the sequences of B. bovis isolates. Conclusion This study demonstrates the occurrence of Babesia parasites in cattle from different provinces of South Africa. It was also noted that the situation of Babesia parasitic infection in cattle from certain areas within the provinces had either reached endemic stability or was progressing towards stability.