FIGURE 1.

TRQ inhibits the production of virulence factors in P. aeruginosa. (A) TRQ treatment does not affect P. aeruginosa growth. (B) TRQ inhibits pyocyanin production in a dose-dependent manner. (C) TRQ inhibits pyocyanin production in a time-dependent manner. (D) Effect of TRQ on elastase activity. PAO1 was cultivated in LB medium at 37°C for 24 h in the presence of TRQ and then added to elastin-Congo red. Elastolytic activity was performed in elastin-Congo red buffer. (E) Effect of TRQ on rhamnolipid production. PAO1 was cultivated in fresh LB broth with and without TRQ at 37°C for 24 h and added to agar-free CTAB medium and incubated for 48 h. The amount of rhamnolipid-CTAB-methylene blue complex biomass in the presence of TRQ was determined. (F) Effect of TRQ on alkaline protease activity. The production of alkaline protease was measured using skimmed milk agar plate. A colony from overnight cultures of PAO1 was inoculated using a toothpick at the center of the plates and then incubated at 37°C for 12 h. The production of alkaline protease was confirmed by the formation of a clear zone around bacterial colony. The halo diameters were determined and shown in corresponding region (mm in unit). The upper half plate is untreated control and the bottom half plate is TRQ-containing plate. The dashed lines indicate the halo. Statistical analysis was based on pairwise comparisons (Student’s t-test). **P < 0.01; ***P < 0.001. Error bars represent the SD of three replicates.