Average virulence factors production by genetic clusters of <i>P</i>. <i>aeruginosa</i>.

<p>Histograms reporting the levels of the indicated virulence-related phenotypes produced, on average, by the <i>P</i>. <i>aeruginosa</i> strains belonging to the milk isolate cluster (RAPD cluster G1 and PFGE clusters A plus B) and to the environmental clusters (RAPD clusters G2 and G3, corresponding to PFGE clusters B and C, respectively); (A) biofilm production; (B) elastase production; (C) gelatinase production; (D) hemolysins production; (E) protease production; (F) pyocyanin production; (G) swimming motility; (H) swarming motility (H). PAO1 was used as a control strain. The average of the independent experiments is reported with standard errors. Horizontal bars with asterisk indicate <i>p</i> < 0.05.