Molecular Assays for the Detection of Tick-Borne Protozoa in Cattle and Ticks in Benin

Cattle are important domesticated animals, whose products (i.e. milk and meat) are nutritious and commonly welcomed food products. The contribution of these products to the food security is particularly relevant in marginal and pastoral areas of African countries, such as in Benin, that constitutes the study area of the present thesis. Among the different health threats for cattle in these areas, they may act as hosts for several tick species. Ticks are obligate arthropods feeding on blood. They can serve as vectors for bacterial, protozoan, and viral pathogens, transmitting diseases to their hosts, which include not only domestic and wild animals, but also humans. Tick borne diseases (TBDs) (e.g., babesiosis, anaplasmosis, Lyme barreliosis, rickettsiosis) may lead to severe and sometimes fatal negative impacts on cattle and humans, which in turn causes public health threat and economic losses. Piroplasms are the main concern of the study and they are induced by Babesiidae and Theileriidae families. Bovine babesiosis is a possible fatal disease caused by Babesia bigemina and Babesia bovis, transmitted by tick species of the genus Rhipicephalus. Babesiosis pathogens invade erythrocytes and may cause fever and anorexia in adult cattle. Theileriidae can infect both erythrocytes and white blood cells, leading to similar symptoms like fever, anorexia, and anaemia. Therefore, the investigation into the prevalence of tick-borne pathogens in Benin can contribute to a comprehensive understanding of their epidemiology and facilitate the development of more effective control strategies in the future. In this study, 246 ticks and 73 blood samples were collected from cattle, in five areas from Benin, including Banikoara and Tanguiéta in Northern Benin and Kpobè, Ouidah, and Zakpota in Southern Benin. Ticks were collected during cattle blood sampling. Tick samples were morphologically identified and molecularly confirmed. All samples (i.e., blood samples and ticks) were screened by real-time PCR targeting LSU gene of Babesia and Theileria genera. Subsequently, positive samples were analyzed by conventional PCR targeting the 18S gene in order to determine pathogens species. By far, cattle showed a high percentage of positivity for both Babesia and Theileria genera. On the contrary, ticks showed a low prevalence (PCR assays showed positivity in 19 samples based on melting temperatures). The findings of the present study provide a better understanding of the presence and distribution of piroplasms in Benin, which can contribute to improved tick control plans.