Isolation of <i>swrW</i> and its role in surfactant production and hemolysis. A.

<p>Sample genetic screen plate shows <i>crp</i> mutants with random transposon insertions. The white arrow indicates a colony deficient in secreted hemolysis production with a transposon insertion that mapped to the <i>swrW</i> gene. This image is illuminated from the back, so that the gold surface coloration is not apparent. <b>B.</b> Surface coloration of <i>crp swrW</i> double mutants is metallic gold compared to the red-orange color of the <i>crp</i> mutant. <b>C.</b> Surfactant zones (mm) measured from the colony to the maximum extent of the surfactant zone (n≥4 per genotype). Asterisk represents a statistically significant increase in surfactant zone compared to the WT (p<0.05) by ANOVA with Tukey’s post-test. <b>D.</b> Mutation of <i>swrW</i> reduced or eliminated the ability of laboratory strain Nima and three of five clinical keratitis isolates to make zones of hemolysis on blood agar plates. Representative images from reproducible experiments are shown.