Molecular detection of Cercopithifilaria bainae in brown dog ticks collected from dogs across the United States

• Published in: Veterinary parasitology 2021-11, Vol.299, p.109583-109583, Article 109583
• Main Authors: Lineberry, Megan W., Sundstrom, Kellee D., Little, Susan E., Allen, Kelly E.
• Format: Article
• Language: English
• Subjects: Brown dog tick; Cercopithifilaria bainae; Filarioid; Mitochondrial 12S rDNA; Mitochondrial cox1; Rhipicephalus sanguineus sensu lato
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/j.vetpar.2021.109583

•Broad geographic distribution of C. bainae in ticks the United States.•C. bainae DNA detected in larval, nymphal, and adult brown dog ticks.•C. bainae DNA detected in engorged and unengorged brown dog ticks.•Dogs commonly infested with brown dog ticks harboring C. bainae DNA. Cercopithifilaria bainae is a filarioid nematode of dogs shown to use Rhipicephalus sanguineus sensu lato (s.l.), the brown dog tick, as the vector. Previously in the United States, C. bainae infections have been reported in a dog from Florida, and in dogs and ticks in Oklahoma, but data are lacking from other areas of the country. Here, we tested brown dog ticks from across the United States for C. bainae DNA to assess the geographic distribution of where this novel parasite may be cycling in ticks and dogs. Archival brown dog ticks were available for testing through the national tick survey Show Us Your Ticks. Ticks were morphologically identified, dissected, and tested by PCR to detect filarioid mitochondrial DNA. A total of 1400 brown dog ticks were tested from 321 separate animals from 23 states, with 5.7 % (80/1400) of the ticks testing positive for C. bainae DNA. At least one positive tick was detected in submissions from 9 states in addition to Florida and Oklahoma. Cercopithifilaria bainae DNA was detected in larval, nymphal, and adult stages of brown dog ticks and only in ticks removed from dogs. Of all dogs with brown dog ticks collected from them, 17.6 % (55/312) were infested with at least one tick that harbored C. bainae DNA. Findings from this study demonstrate a wider geographic range of C. bainae than previously known, and that dogs are commonly infested with brown dog ticks with molecular evidence of C. bainae infection.