LIMASI and infection: The requirement for pqsA in autolysis and in phage JBD4439*-driven growth enhancement of the PA14 ΔlasI strain (Fig. 4A), coupled with our finding that cells that overgrow in the plaques produce pyocyanin, which is normally made in response to LasI/R-mediated activation of PQS QS (Fig. 2B), suggested that phage JBD4439* infection activated the PQS QS system in the absence of LasI.