Passive transfer of rabbit tick-immune serum to mice impairs the ability of B. burgdorferi infected nymphs to transmit spirochetes to mice.

A. The ability of nymphs to feed on rabbits upon repeated infestation was decreased. Inset. Immunoblot of B. burgdorferi protein extract probed with anti-Borrelia antiserum (lane 1) or nymph-immune rabbit serum (lane 2). B. Inset. Quantitative RT-PCR assessment of Borrelia burden as scored by levels of flaB amplicons in the midguts (MG) and salivary glands (SG) of nymphs feeding on mice that received rabbit tick-immune serum (RTIS) or naive serum (NRS); and quantitative PCR assessment of Borrelia burden in the bladder and skin of mice that received rabbit tick-immune serum (RTIS) or naïve (NRS) serum.