Molecular Identification and Prevalence of Ehrlichia canis and Rhipicephalus sanguineus (Acari: Ixodidae) Infecting Pet Dogs in Wenzhou, China

Ehrlichia canis is an important zoonotic tick-borne pathogen transmitted by the tick Rhipicephalus sanguineus (Latrielle) that causes canine monocytic ehrlichiosis (CME) in dogs. We have investigated the prevalence of R. sanguineus and E. canis infection in pet dogs in Wenzhou, China. Serum samples were obtained from animal hospitals were examined for antibodies by commercial rapid in-clinic ELISA kits. Ticks were collected from dogs and molecular detection methods were used to identify the tick species and CME by amplification of the cytochrome oxidase subunit I and disulfide oxidoreductase gene, respectively. The results indicated that 1.29% of the serum samples were positive for E. canis, and 5.50% of dogs were infested with ticks. The Wenzhou samples of R. sanguineus exhibited a high homology (99.7%-99.8%) and these parasites showed a 99.1%-100% homology to previously reported isolates. The E. canis derived from R. sanguineus in the current study showed a similarity of 98.7%-99.7% to previously published isolates. Our results indicate that precaution should be employed for the potential threat posed by these ticks, especially to pet owners.