Borrelia coriaceae in its tick vector, Ornithodoros coriaceus (Acari: Argasidae), with emphasis on transstadial and transovarial infection.

Abstract

Field and laboratory studies demonstrated that transovarial passage of the recently described spirochete Borrelia coriaceae occurs occasionally in the soft tick Ornithodoros coriaceus Koch, but this process appeared to be inefficient for maintaining and distributing the spirochete. Borreliae were detected in only 5 (0.6%) of 883 wild-caught O. coriaceus larvae and in a low percentage of the F1 (larval) progeny from only one of nine spirochete-infected females. Infected and uninfected females did not differ statistically in fecundity or fertility. Transstadial survival of spirochetes also occurred in O. coriaceus , but experimental evidence suggests that some ticks may lose their infections during or after ecdysis. The distribution of spirochetes in tissues of infected nymphs and adult ticks that fed to repletion and later molted or oviposited was generalized or semigeneralized. Neither the coxal fluid nor the hemolymph test was found to be reliable for detecting spirochetes in ticks. Borreliae in tissue smears prepared from 1 of 18 spirochete-infected O. coriaceus nymphs and adults reacted with a monoclonal antibody (H5332) that is reportedly specific for Borrelia burgdorferi . The potential significance of this finding is discussed briefly.