Effects of coumermycin A1 on protein expression. B. burgdorferi was incubated with 0.001, 0.003, 0.01, 0.03, and 0.1 μg of coumermycin A1/ml for 30 min, 4 h, and 4 days, followed by Western blot analysis. Top row, membranes incubated with MAb B11 directed against ErpA/I/N. Lower row, membranes incubated with MAb B5 directed against OspC.