RESUMO
Objective To explore the effects of aspirin on formation and dispersion of Pseudomonas aeruginosa (P.aeruginosa) biofilm.Methods The broth microdilution method was used to detect the minimal inhibitory concentration(MIC) of aspirin for P.aeruginosa.The anti-biofilm effects of aspirin on P.aeruginosa were determined on the microtiter plates combined with crystal violet staining.The serial dilution method for counting colony number on microtiter plate was used to explore the effects of aspirin on initial adherence of P.aeruginosa.Results The MIC values of aspirin against PAO1,PA18,PA53 and PA67 strains of Pseudomonas aeruginosa were 5,2.5,5 and 5 mg/mL respectively.Aspirin significantly inhibited the formation and dispersion of the biofilm of PAO1 and PA18 strains (t =5.65,P ＜ 0.05 and t =5.06,P ＜ 0.05 for inhibition;t =6.45,P ＜ 0.05 and t =6.26,P ＜ 0.05 for dispersion) at the concentration of 2.5 mg/mL.Similar effects were also found in the determination for PA67 and PA53 strains(t =6.45,P ＜0.05 and t =6.26,P ＜ 0.05 for inhibition;t =7.82,P ＜ 0.05;t =9.18,P ＜ 0.05 for dispersion) at aspirin concentration of 1.25 and 0.313 mg/mL respectively.Aspirin inhibited the initial adherence of P.aeruginosa at the concentration of 2.5 mg/mL(P ＜0.05).Conclusion Aspirin could significantly inhibit the initial adherence and biofilm formation of P.aeruginosa and disperse the 24 hour-formed mature bioiflm.