Over-expression of SspA induces mucoidy in CF149.

<p>The <i>sspA</i> and <i>sspB</i> genes from <i>P</i>. <i>aeruginosa</i> were cloned behind the P_BAD promoter in the pHERD20T vector, and conjugated into CF149. (A) Western blot analysis of SspA and SspB proteins using an anti-HA monoclonal antibody. Lanes 1, 2 and 3 represent total cellular proteins extracted from CF149 carrying pHERD20T-<i>sspA</i>, pHERD20T-<i>sspB,</i> and pHERD20T, respectively. (B) Morphology of CF149 containing pHERD20T-<i>sspA</i>, pHERD20T-<i>sspB</i> and pHERD20T. These strains were streaked on PIA plates supplemented with 300 µg/ml of carbenicillin, 0.1% L-Ara and incubated overnight at 37°C. Alginate production (µg/ml/OD₆₀₀) was measured as described in Materials and Methods.