FIG 5 .

Subtherapeutic ciprofloxacin increases bacterial burden and recurrence frequency. (A) The fraction of resolved C3H/HeN mice presenting with clinically significant (>10⁴ CFU/ml) bacterial urine titers following subtherapeutic ciprofloxacin dosing over time (n = 10 mice). The antibiotic dosing period is indicated on the upper x axis as fractions of the therapeutic dose. (B) Urine titers of chronically infected mice receiving either no antibiotic or subtherapeutic ciprofloxacin for 3 days. Means from at least two independent experiments are shown. Significance was determined using a log rank test (panel A; P = 0.0131) or Mann-Whitney test (panel B; P = 0.0142).