Molecular Investigation of Tick-Borne Haemoparasites Isolated from Indigenous Zebu Cattle in the Tanga Region, Tanzania.

Tick-borne diseases (TBDs) are a major hindrance to livestock production in pastoral communities of Africa. Although information on tick-borne infections is necessary for setting up control measures, this information is limited in the pastoral communities of Tanzania. Therefore, this study aimed to provide an overview of the tick-borne infections in the indigenous cattle of Tanzania. A total of 250 blood samples were collected from the indigenous zebu cattle in the Tanga region, Tanzania. Then, we conducted a molecular survey using the polymerase chain reaction (PCR) and gene sequencing to detect and identify the selected tick-borne pathogens. The PCR was conducted using assays, based on Theileria spp. ( 18S rRNA ), Theileria parva ( p104 ), Theileria mutans and T. taurotragi (V4 region of the 18S rRNA ), Babesia bigemina ( RAP-1a ), B. bovis ( SBP-2 ), Anaplasma marginale (heat shock protein groEL ) and Ehrlichia ruminantium ( pCS20 ). The PCR screening revealed an overall infection rate of (120/250, 48%) for T. mutans , (64/250, 25.6%) for T. parva , (52/250, 20.8%) for T. taurotragi , (33/250, 13.2%) for B. bigemina and (81/250, 32.4%) for A. marginale. Co-infections of up to four pathogens were revealed in 44.8% of the cattle samples. A sequence analysis indicated that T. parva p104 and A. marginale groEL genes were conserved among the sampled animals with sequence identity values of 98.92-100% and 99.88-100%, respectively. Moreover, the B. bigemina RAP-1a gene and the V4 region of the 18S rRNA of T. mutans genes were diverse among the sampled cattle, indicating the sequence identity values of 99.27-100% and 22.45-60.77%, respectively. The phylogenetic analyses revealed that the T. parva ( p104 ) and A. marginale ( groEL ) gene sequences of this study were clustered in the same clade. In contrast, the B. bigemina ( RAP-1a ) and the T. mutans V4 region of the 18S rRNA gene sequences appeared in the different clades. This study provides important basement data for understanding the epidemiology of tick-borne diseases and will serve as a scientific basis for planning future control strategies in the study area.