Abstract:Objective To explore the effect of tannin extracted from Pomegranate rind combined with Ciprofloxacin (CIP) on the biofilm of Aacinetobacter baumanni(Ab). Methods The minimal inhibitory concentrations (MIC) of tannin and CIP to Ab ATCC19606 were determined by broth dilution method. The 1/2MIC, MIC and 2MIC of tannin, CIP and their combination acted on Ab for 4, 8, 24 and 48 h,respectively; then the biofilm formation of Ab was observed by crystal violet staining assay and fluorescence microscopy. Results The MIC of tannin and CIP to Ab ATCC19606 were 1.95 mg/ml and 0.50 mg/ml respectively. The effect of tannin or CIP separately on the biofilm of Ab was weaker than that of their combination. And their combination could have some effect on the biofilms, of which the combined use of 2MIC tannin and 2MIC CIP for 24 h had the greatest effect on biofilm formation of Ab. Conclusions Combined use of tannin extracted from Pomegranate rind and CIP has more obvious effect on the biofilm formation of Ab, moreover, the combination of 2MIC tannin and 2MIC CIP for 24 h has the best effect.