Effects of allitride on quorum sensing-controled virulence factors production in Pseudomonas aeruginosa biofilm.

Objective Quorum-sensing(QS) system was a key regulator of virulence and biofilm development in P.aeruginosa.Allitride was examined in this study for its effects on P.aeruginosa virulence factors and biofilm formation in vitro.Method Sensitive sandwich enzyme-linked immunosorbent assay(ELISA) systems for the quantification of exotoxin A.Expression of elastase and pyoverdin were assessed semi-quantitatively using elastin Congo red and fluorescence respectively.Production of rhamnolipid was determined by H2SO4-anthrone analysis at the absorbance of 553 nm.Confocal laser scanning microscope(CLSM) was used to study the effects of allitride on mature biofilm in vitro.Result Allitride down regulated virulence factors exotoxin A,elastase,rhamnolipid and pyoverdin deceased from(19.630±0.573) pg/μl,(0.467±0.003),(2.009±0.063)g/L,(9325.833±367.675) to(6.529±0.289) pg/μl,(0.032±0.001),(0.269±0.009)g/L and(7819.167±111.800) respectively.Under the CLSM,P.aeruginosa in control group formed mature mushroom structures,while it formed flat undifferentiated biofilm,susceptible to treatment with allitride in the intervention group.Conclusion Allitride attenuates the virulence of P.aeruginosa significantly and supresses it biofilm formation by intervening the QS system of P.aeruginosa.