FIG. 4.

Late stages of φRSB1 development are resistant to rifampin. Cells of R. solanacearum M4S were infected with φRSB1 at a multiplicity of infection of 5. At the indicated times p.i., aliquots of the infected culture were withdrawn and incubated with 100 μg/ml rifampin for 2.5 h before CHCl₃ treatment and determination of phage titers (PFU) (open circles). For a control, phage titers were also determined at the indicated times after CHCl₃ addition without rifampin treatment (closed circles). The method is as described by Liao et al. (15).