Varying degrees of susceptibility of different forms of B. burgdorferi to commonly used Lyme antibiotics.

a. Percentages of different forms of B. burgdorferi were calculated by measuring three representative microscope images with Image Pro-Plus software.b. Percentages of residual viable B. burgdorferi relative to drug-free control after drug treatment were calculated according to the regression equation and ratio of Green/Red fluorescence obtained by SYBR Green I/PI assay as described [16]. The samples were treated with antibiotics for 7 days before viability was assessed by the SYBR Green I/PI assay.c. Values in brackets indicate persister frequencies (percentage of live cells after antibiotic treatment). The number of B. burgdorferi assayed by epi-fluorescence microscope counting was calibrated using E. coli as a control.d. The log phase culture was obtained by subculture of a stationary phase culture at 1:50 dilution for 3 days in BSK medium.e. E. coli W3110 was 1:100 diluted and grown in LB broth. Three hour log phase E. coli culture (1.7 × 108 cfu/ml) was added with 50 µg/ml amoxicillin, and incubated at 37°C with shaking for 3 hours followed by persister frequency determination by SYBR Green I/PI viability staining or CFU count.f. Persister frequency calculated by epi-fluorescence microscope counting after SYBR Green I/PI viability staining.g. Persister frequency calculated by standard plate colony count assay.Varying degrees of susceptibility of different forms of B. burgdorferi to commonly used Lyme antibiotics.