FIG. 1.

Lethal activity of fluoroquinolones in the presence and absence of chloramphenicol. Exponentially growing cultures of M. tuberculosis H37Rv were incubated with the indicated concentrations of fluoroquinolone for 6 days in the presence (filled circles) or absence (open circles) of chloramphenicol. Aliquots were then removed, diluted, and plated on drug-free 7H10 agar for determination of CFU. Names and structures of compounds tested are indicated in each panel. Data shown are averages, with error bars indicating ranges of values.