Log10 CFU/ml of L. pneumophila L-1033 (A) and L. pneumophila L-1043 (B) at hour 3 following exposure to levofloxacin, ciprofloxacin, azithromycin, erythromycin, and doxycycline at 0 (▪), 1 (▩), 5 (▨), or 10 (▤) times the MIC. Data are the results of 3 to 5 assays (L-1033) and 2 to 3 assays (L-1043); standard deviations were 0.29 and 0.18 log10 CFU/ml for L-1033 and L-1043, respectively.