Molecular Detection and Phylogenetic Analysis of Trypanosoma Evansi in Camels in North Eastern Nigeria

Abstract

Trypanosoma evansi is the first hemo-pathogenic trypanosome species of equines and dromedaries. Camels are the principal host of T. evansi; but, horses and other Equidae as well as a large range of other hosts can be infected mechanically. Diagnosis of T. evansi basically relies on conventional Giemsa staining of thin and thick blood smears, which are time consuming and require experienced personnel. Serological test used for parasite detection may suffer the disadvantages in reproducibility due to antigenic variation and significant levels of false negative and false positive results. To overcome the limits of sensitivity and specificity imposed by other diagnostic methods, molecular detection of T. evansi deoxyribonucleic acid (DNA) was carried out in this study on 50 dromedary camels. Five different isolates were obtained from this study. The 5 consensus sequences obtained were compared with other T. evansi isolated from other geographically dispersed locations. The result of this investigation present the first molecular (PCR) detection of T. evansi in camels from Borno and Yobe States of Nigeria and revealed that 5 isolates were identified from this study area which are phylogenetically related to other African isolates from the sub-saharan African, the Middle-East with extension to other parts of Asia and America. This study also revealed two phylogenetically distinct diverse strains base on the ITS-1 gene in the study area. There are no much phylogenetic diversities between the T. evansi strains using the ITS-1 gene. Therefore, it is highly recommended to look into other genes like the RoTat gene and other protein coding genes in order to establish more detailed variations.