Fig. 2

The log10-transformed nymphal spirochete loads of B. afzelii are highly correlated between the 1-month-old and the 4-month-old I. ricinus nymphs. Strains A3 and A10 are shown with white and black circles, respectively. A3- or A10-infected mice were infested with larval ticks on 43 different occasions. The engorged larval ticks from these infestations were allowed to moult into nymphs and were killed at 1 or 4 months after the larva-to-nymph moult. The spirochete loads of the 1-month-old nymphs and the 4-month-old nymphs therefore represent paired data. Each data point is a mean of the subset of infected nymphs (i.e. uninfected nymphs were excluded) that originated from the same infestation event. The spirochete loads in the nymphs were estimated using a qPCR that targeted a 132 bp fragment of the flagellin gene