Table 1.

Type IV pili-mediated twitching motility of P. aeruginosa strains

Strain	Relevant genotype	Twitch area, % WT ± SEM*
PAO1	WT	100  ± 4
PAOM5	Δppk	63  ± 2
PAO-D	ΔfliD	93  ± 4
PAO-NP	ΔpilA	0
PAO1 (pMMB66HE)	WT + vector	100  ± 5
PAOM5 (pMMB66HE)	Δppk + vector	55  ± 2
PAOM5 (pHEPAK11)	Δppk + PPK+++	97  ± 4

^*Twitch area was measured after a 24-h incubation at 37°C on LB agar (1%, wt/vol) plates. The standard error of the mean (SEM) equals σ_n−1, where n = 6.