FIGURE 2.

C. jejuni 81-176 Δpgp1Δpgp2 double mutant straight morphology and defects in motility, biofilms, and CFW reactivity. A, negatively stained TEM images of the straight Δpgp1Δpgp2 double mutant strain with intact flagella showing a similar morphology to Δpgp2. B, Δpgp1Δpgp2 exhibited a 27.0% decrease in motility identical to that of Δpgp2, as assayed by measuring halo diameters in soft agar plates. S.E. (error bars) was calculated from 10 measurements. C, Δpgp1Δpgp2 was defective for biofilm formation to the same extent as both Δpgp1 and Δpgp2 and is shown after 3 days. Biofilm formation was assessed by crystal violet staining of standing cultures in borosilicate tubes and quantification of dissolved crystal violet at 570 nm. S.E. values were calculated from triplicate cultures and are representative of three independent experiments. D, on plates containing 0.002% CFW, Δpgp1Δpgp2 was hypofluorescent relative to wild-type 81-176 after 24 h (like Δpgp1 and Δpgp2) but at 48 h of growth showed intermediate fluorescence to Δpgp1 and Δpgp2. *, statistically significant difference using the unpaired Student's t test, with *, **, and *** indicating p < 0.05, p < 0.01, and p < 0.0001, respectively.