Fig. 1

The spirochete loads of B. afzelii in I. ricinus nymphal ticks decreased over time. The panels show two different strains of B. afzelii: A3 and A10. For each strain, the spirochete load was compared between nymphs that are 1 and 4 months old. A3- or A10-infected mice were infested with larval ticks on 22 and 21 occasions, respectively (total of 43 infestations). 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). The spirochete loads in the nymphs were estimated using a qPCR that targeted a 132 bp fragment of the flagellin gene. The spirochete loads were log10-transformed to improve their fit to the normal distribution. Shown are the medians (black line), the 25th and 75th percentiles (edges of the box), the minimum and maximum values (whiskers), and the outliers (solid circles)