Fig. 3

qRT-PCR analysis of ospC transcript levels in various tissue sites of infected mice. ospC expression profile of spirochetes recovered from the bladder (a), heart (b), and ear tissue (c) of mice infected with wild type, Bb∆1-18, Bb∆19-22 or Bb∆27-30 is shown. ospC expression was normalized against flaB and compared to mRNA of in vitro-grown B. burgdorferi wild-type cells grown to late log phase. Asterisks show mutant clones with ospC expression levels that were statistically different from the wild type using statistical analyses described in Methods. a) In bladder tissue, no difference in ospC expression was observed at day 21. At day 91, spirochetes from wild type-infected tissues had a statistically significant difference when compared to Bb∆1-18 infected tissues (p = 0.007). b) Spirochetes in heart tissue samples showed no significant difference when compared to wild type-infected tissues at both days 21 and 91. c) Spirochetes in the ear tissue showed a general decline in ospC expression from day 13, which was lowest at day 21 and started to rise at day 56. There was no significant difference in ospC expression noted at day 13, 21 and 91. At day 56, spirochetes from mice infected with Bb∆19-22 had a higher expression of ospC when compared to those infected by the wild type (p = 0.043). **flaB and ospC transcripts were detected at day 13 in tissues collected from mice infected with BbΔlp28-1 clone, which correlated with culture results (see Table 3). Data for this clone was not collected after day 21 as all mice successfully cleared infection after this time point