Nymphs infected with HrpA-deficient B. burgdorferi are unable to transmit infection.

a 3 mice per isolate.b Based on immunoblot using whole cell lysates derived from temperature-shifted B. burgdorferi strain B31 5A4 NP1.c The area of skin below capsules used to contain feeding nymphs was excised within 24 hours of repletion (∼96 hour post-placement), divided into 6 equal portions for each mouse (5 mice per isolate), and cultured in BSK II medium containing the appropriate antibiotic as described previously [48].d One mouse in this group yielded no positive bite site cultures (0/6), most likely due to significantly lower spirochete burdens in the cohort of nymphs placed in this capsule (See Fig. S1).