Figure 2.

Alkyl quinolone production in P. aeruginosa biofilms is reduced by the presence of E. faecalis. The amount of alkyl quinolones and pyocyanin detected by MALDI-MSI relative to P. aeruginosa alone (i.e. 1.0) indicates E. coli and E. faecalis have opposite effects on alkyl quinolone production. Error bars show ± one standard deviation. A. Presence of E. coli elicits an increased PQS, C9-PQS, HQNO and NQNO response while E. faecalis reduces production for each. B. Additionally, pyocyanin production increased in the presence of E. coli (10.3× P. aeruginosa alone) but decreased near E. faecalis (0.59× P. aeruginosa alone).