Molecular Characterization of Tandem Repeat Protein 36 Gene of Ehrlichia canis Detected in Naturally Infected Dogs from Peru

Abstract

<i>Ehrlichia</i> spp. are emerging infectious pathogens, especially in the Americas. Although <i>Ehrlichia canis</i> is primarily a parasite of dogs, polymerase chain reaction-confirmed human infections have been reported from Mexico, Venezuela, and Costa Rica. This study reports the presence of <i>E. canis</i> DNA in 13.7% of 205 dogs from urban areas in Peru and of those, five were analyzed for phylogenetic variation using the Tandem Repeat Protein 36 (TRP36) gene. The use of the TRP36 gene for such analysis was validated against 16S rRNA and heat shock protein genes using Shannon's entropy bioinformatic approach. When compared with other <i>E. canis</i> strains previously reported, three unique and novel <i>E. canis</i> strains were detected. In addition, the TRP36 amino acid tandem repeat sequences of the Peruvian strains share close similarity to an <i>E. canis</i> strain detected from four human blood bank samples in Costa Rica. This study reports for the first time domestic dogs infected with <i>E. canis</i> strains closely related to a zoonotic strain, which may be of public health concern as dogs can be chronically infected with this pathogen.