Molecular detection of Rickettsia felis in Dermacentor albipictus from Mississippi

Dermacentor albipictus (Packard), the winter tick, is a one-host tick often found in high numbers on horses, moose, elk, and deer in the northern United States and parts of Canada. In Mississippi, there have been very few collections of D. albipictus. Herein we report the collection and molecular screening of 5 male specimens and 3 nymphs of the winter tick for rickettsial organisms. Broad PCR screening using a PanRickettsia TaqMan PCR assay targeting a portion of the 23 s gene was utilized, and a family-wide Anaplasmataceae SYBR real-time PCR assay was chosen for initial screening of tick eluates. PanRickettsia PCR-positive samples were then amplified using a conventional PCR targeting the citrate synthase (gltA) gene for species identification. One resultant amplicon was 99.75% identical to Rickettsia felis DNA. This is the first report of R. felis in the winter tick, D. albipictus.