FIG. 5.

Invasion of A549 cell monolayers by B. cepacia strain J2315 (wild type), mutant CM58 (fliI::cat), and CM100 (CM58 complemented with fliI) with (A) or without (B) centrifugation. The invasion values were calculated by determining the percentages of the bacterial inocula that survived after 2 h of antibiotic treatment and were normalized to the value for wild-type strain J2315, which was arbitrarily set at 100%. The actual invasion frequencies for strain J2315 with and without centrifugation were 0.67% ± 0.03% and 0.26% ± 0.02%, respectively. The asterisk indicates that the P value was <0.0007, and the double asterisks indicate that the P value was <0.00004.