Ecological relationships between ticks and rickettsiae.

Ticks play important roles as vectors and sometimes as reservoirs in the ecology of rickettsiae. The obligate association between ticks and rickettsiae has been elucidated in studies concerning the maintenance of rickettsiae in ticks, agent dissemination in various tick organs, rickettsial developmental cycles in the tick organism, transfer among various developmental stages in tick hosts, the effect of rickettsiae on the tick organism, the interaction between microorganisms other than rickettsiae and rickettsiae is a tick body, as well as the release of rickettsiae from ticks into the environment.