A Quorum Sensing Regulated Small Volatile Molecule Reduces Acute Virulence and Promotes Chronic Infection Phenotypes
Figure 4
2-AA reduces P. aeruginosa virulence.
(A) Survival kinetics of flies injected with a PA14 bacterial suspension with (∼1.6 ng/fly) and without 2-AA. Data were averaged from two experiments with n(PA14) = 55 and n(PA14+2-AA) = 56. Significance of difference of survival rate was calculated using the log-rank test of the Kaplan Meier survival estimate (p = 0.0056). (B) Survival rates of mice infected with PA14 versus PA14 + 67 µg of 2-AA/mouse. The data correspond to the averages of two independent experiments, with n(PA14) = 20 and n(PA14+2-AA) = 20. Significance of difference of survival rates was calculated using the Kaplan-Meier method (p = 0.03), with a hazard ratio of 1.8932 (95% CI, 1.0664 to 6.0718). (C and D) Bacterial loads in the local and adjacent muscle and in blood were determined for control and 2-AA treated mice, at 20 h post-burn and infection. The statistical significance of the CFU/mg muscle tissue differences between the control and experimental mice were determined using the Mann-Whitney test for independent samples, with p = 0.43 for the difference in the underlying and adjacent muscle in response to 2-AA, and p = 0.045 for the difference in the blood in response to 2-AA. CFU data are presented as log 10. Black PA14, red PA14+2-AA, green 2-AA only.