FIG. 8.

Intracellular B. burgdorferi cells are metabolically active. (A) Transcripts of borrelial recA were detected following infection with B. burgdorferi MSK5 of pelleted L929 fibroblasts (18-h infection at an MOI of 1), in the absence and presence gentamicin (at 200 μg/ml for 5 h postinfection) as indicated and normalized to their respective DNA targets. The values shown are the ratio of borrelial recA transcripts per borrelial genome equivalents relative to β-actin transcripts per β-actin genomic copies (divided by two). Error bars represent standard deviation. (B) Added gentamicin dramatically reduces the amount of transcripts from extracellular B. burgdorferi. Pelleted fibroblasts (black bars) and the resulting supernatant (gray bars) were tested for their levels of recA transcripts relative to recA genomic copies following standard cultivation (no treatment) and incubation with gentamicin. The values shown indicate the ratio of the recA transcripts to recA genomic equivalents within the samples tested. Error bars indicate standard deviation.