SaePQRS regulates biofilm formation by <i>S</i>. <i>aureus</i> strain Newman.

<p>(<b>A</b>) Stationary phase cultures of the indicated strains were diluted to an OD₆₆₀ of 0.05 and inoculated into wells of a microtiter plate. The microtiter plate wells had been precoated with human plasma. After 16 h, biofilms were washed, fixed, and stained with crystal violet. The wells labeled “medium” indicates wells that contained sterile biofilm medium. (<b>B</b>) Inhibition of UAMS-1 biofilm formation by culture supernatants. Stationary phase culture supernatants of strain Newman and its derivatives were harvested, filter sterilized and added to microtiter plate wells preinoculated with <i>S</i>. <i>aureus</i> UAMS-1 suspended in biofilm medium. The source of each culture supernatant is listed to the right of the picture. The wells labeled “medium” indicates sterile TSB-0G medium was added in place of an exogenous culture supernatant. Plates were incubated and processed as described for A.