Figure 1.

In vitro antimicrobial susceptibility of Borrelia burgdorferi sensu strictu. Reduction of viable spirochetes in the presence of different concentrations of antibiotics (ceftriaxone, doxycycline). Cotrimoxazole, which is considered ineffective, is used as a control. Only in high doses does cotrimoxazole show a reduction in the amount of spirochaetes after a few days. Tests were performed on microtitre plates by broth dilution; spirochete count determined by dark-field microscopy.