Comparison of a “true” QSI resistance competition
to the experimental mimic competition in this study. “R”
circles represent QS receptor proteins, and “I” circles
represent QS signal synthase proteins. In the true case (A), the wild-type
bacteria have chemically knocked down QS (red), and the resistant
mutants are still capable of QS even in the presence of the QSI (blue).
In the mimic case (B), a P. aeruginosa ΔlasR ΔrhlR mutant has a genetically
knocked down QS system (red) to mimic the QSI-sensitive strain, and
the resistant mimic is wild-type PAO1 (blue), which is fully capable
of QS under the experimental conditions. In both panels, substantial
native AHL signals are shown, but if the resistant bacteria are rare,
much less signal will actually be present (due to poor signal production
by the QS-inhibited strains).