Francisella-like endosymbiotic bacteria (FLEs) have also been detected in Dermacentor occidentalis as well as other tick species (Burgdorfer, Brinton & Hughes, 1973; Noda, Munderloh & Kurtti, 1997; Scoles, 2004; Kugeler et al., 2005). FLEs share 16S rRNA gene homology with Francisella spp., are vertically transmitted, have been observed within tick ovaries and Malpighian tubules, and vary by tick species (Rounds et al., 2012). Although Burgdorfer et al. demonstrated pathogenicity of a Francisella endosymbiont derived from Dermacentor andersoni Stiles ticks (previously categorized as Wolbachia persica, Forsman, Sandström & Sjöstedt, 1994) to guinea pigs and hamsters via injection, most FLEs are not transmitted by tick bites and are considered non-pathogenic (Burgdorfer, Brinton & Hughes, 1973; Niebylski et al., 1997).