Table 2.

Frequency of colistin-resistant spontaneous mutants.

Strain	Frequency of Resistant Mutants (±SD) a
PAO1 lux	4.30 × 10−8 (±3.99 × 10−8)
PAO1 Parn::lux	6.64 × 10−8 (±8.32 × 10−8)
PAO1 PeptA::lux	3.72 × 10−8 (±8.45 × 10−8)

^a Values are the mean (±SD) of 12 biological replicates for each strain.