Vector Competence of Geographical Populations of Ornithodoros turicata for the Tick-Borne Relapsing Fever Spirochete Borrelia turicatae

Abstract

Several knowledge gaps exist in the vector competence of various geographical populations of O. turicata that transmit B. turicatae . A western population of this tick is distributed from California to Texas, and an eastern population exists in Florida. Utilizing western and eastern populations of the vector, we studied acquisition and transmission of two B. turicatae isolates. Regardless of the isolate used, infection frequencies were poor in mice after the eastern population feeding on them. Since salivary gland colonization is essential for B. turicatae transmission, these tissues were further evaluated. Interestingly, the salivary glands from the two populations were similarly colonized with B. turicatae. These findings suggest the role of tick saliva in the establishment of infection and that the salivary glands may be a bottleneck for successful transmission.