Phenotypic Analysis of Selected TB mutants 
Several of the clones recovered were mutated in genes putatively associated with adherence and motility, such as cheB2 (PA0173), motB (PA4953) and pilY1 (PA4554).
It has been shown that adherence is an essential first step in the process of P. aeruginosa colonization, allowing the bacteria to persist, expand in numbers and develop a biofilm or establish intimate contact with host cells [45],[46].
We wished to determine if our selected mutants showed a reduction in their capacity to adhere to a biological surface such as the human epithelial cell line 16HBE14o-.
In addition to TB4953s (motB, p<0.0001) and TB0173s (cheB2, p<0.001), that presented strongly reduced adherence, five other clones were significantly affected in their adherence to cells when compared to the parental TB isolate (Figure S1 and Table 1).
These mutants were TB2588s (araC-like, PA2588, p<0.001), TB4380s (colS-like, PA4380, p<0.001), TB3080s (hypothetical, PA3080, p<0.01), TB2769s (hypothetical, PA2769, p<0.05) and TB5479s (gltP-like, PA5479, p<0.05).
Motility is also an important factor for P. aeruginosa colonization and spread.
We evaluated each of the twelve attenuated mutants for both swarming and swimming motility (data not shown, Table 1 and Figure 2).
The TB0173s (cheB2) (Figure 2 and Table 1) and TB4953s (motB) (Table 1) mutants showed a reduction in swimming and swarming motility, respectively.
Furthermore, the mutants TB0260s (hypothetical, PA0260) and TB5479s (gltP-like) had a significant reduction in swimming motility (Table 1) whereas the mutants TB2588s (araC-like) and TB3080s (hypothetical) had a significant reduction in swarming motility (Table 1).
