| Autor: |
Duncan KT; Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA., Grant A; Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA., Johnson B; Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA.; Rickettsial Zoonoses Branch, Division of Vector-Borne Disease, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA., Sundstrom KD; Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA., Saleh MN; Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA.; Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA., Little SE; Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma, USA. |
| Abstrakt: |
In the United States, Dermacentor variabilis and Dermacentor andersoni are considered key vectors for Rickettsia rickettsii , the causative agent of Rocky Mountain spotted fever. Through regional surveillance, a wide diversity of Rickettsia spp. have been documented in D. variabilis , and Dermacentor spp. has been suggested as potential vectors for various other pathogens, including Babesia spp. and Ehrlichia canis . To better define the prevalence and diversity of pathogens in Dermacentor spp. across the United States, 848 ticks collected from dogs and cats in 44/50 states in 2018-2019 were tested by PCR for Rickettsia spp.-specific 17 kDa and ompA gene fragments; a subset of Dermacentor spp. was also tested with PCR, targeting fragments of the 18S and large subunit region rRNA genes of Babesia spp. and 16S rRNA genes of E. canis . Rickettsia spp. was identified in 12.5% (106/848) of ticks. Species detected include Rickettsia montanensis ( n = 64 ticks), Rickettsia bellii ( n = 15 ticks), Rickettsia rhipicephali ( n = 13 ticks), Rickettsia peacockii ( n = 8 ticks), Rickettsia amblyommatis ( n = 3 ticks), Rickettsia cooleyi ( n = 1 tick), and unclassified Rickettsia spp. ( n = 2 ticks). Ticks with R. montanensis and R. bellii were submitted from every U.S. region; R. rhipicephali was predominantly detected in ticks from the southern half of the United States, and all R. peacockii -positive ticks were D. andersoni that originated from the Rocky Mountain states. Ehrlichia canis was not detected in any Dermacentor spp., and Babesia conradae was detected in two Dermacentor albipictus . Because most ticks had fed on dogs or cats before submission, these findings do not implicate a given Dermacentor sp. as a primary vector of these agents, but in regard to Rickettsia spp., the data do support other published work showing D. variabilis harbors a diversity of Rickettsia species with unknown implications for animal and human health. |
