Phylogenetic analysis of Ehrlichia canis and Rhipicephalus spp. genes and subsequent primer and probe design.

Abstract

A phylogenetic analysis was made targeting six different Ehrlichia canis genes was made (VIRB9, GP36, GP28, GLTA, GP200, and 16S rRNA). The same was done for the ITS2 gene of Rhipicephalus species including R. sanguineus, vector of Ehrlichia canis. Furthermore, multiple matching (q)PCR primer sets and RLB probes were designed. This will prove useful in distinguishing Rhipicephalus spp., since determination solely based on phenotype is not always reliable. A beginning was made in validating the designed GLTA primer sets. A great deal of variation was found between the different E. canis genes and to a lesser degree between the different Rhipicephalus genes. Asian (Taiwanese) strains of E. canis appeared as a stable group, branching off at an early stage. Brazilian and other South American strains tended to show the same characteristics within phylogenetic trees of several of the mentioned genes.