Molecular analysis reveals the diversity of Hepatozoon species naturally infecting domestic dogs in a northern region of Brazil

This study aimed to optimize molecular methods for detecting DNA of Hepatozoon spp. as well as identify the phylogenetic relationships of Hepatozoon strains naturally infecting domestic dogs in Belém, Pará, northern Brazil. Blood samples were collected from 138 dogs, and screened for Hepatozoon spp. using a new nested PCR assay. Positive samples were subjected to genetic characterization based on amplification and sequencing of approximately 670 bp of the Hepatozoon spp. 18S rRNA. Of the positive dogs, four shared the haplotype Belém 01, one dog presented the haplotype Belém 02 and two dogs shared the haplotype Belém 03. A Bayesian inference indicates that haplotypes Belém 01 and Belém 02 are phylogenetically related to H. canis, while Belém 03 is related to H. americanum. Overall, based on the first molecular evidence of H. americanum in Brazilian domestic dogs, the proposed protocol may improve the epidemiological investigation of canine hepatozoonosis.