Effect of macrolides and ciprofloxacin, ceftazidime on biofilm of pseudomonas aeruginosa

Objective To observe the effect of and Ceftazidime, Ciprofloxacin with on biofilm of Pseudomonas aeruginosa. Methods Modified plate culture method was used to establish in vitro bacterial biofilm model, which was identified by silver nitrate staining. The biofilm in different time was treated by Erythromycin, azithromycin alone or combined with Ceftazidime and Ciprofloxacin. Bacterial adherence and the number of viable bacteria in biofilm was measured by Safrani staining and M-H plate. Results 1/16 MIC Erythromycin and azithromycin of alone or combined with Ciprofloxacin, Ceftazidime significantly reduced the adherence of Pseudomonas aeruginosa(P0.05)and the number of viable Pseudomonas aeruginosa (P0.05; P0.01). The resistances of biofilm in 48 hours were higher than that of biofilm in 24 hours. Conclusion Erythromycin and azithromycin could prevent and inhibit the biofilm formation of Pseudomonas aeruginosa, and enhance the antibacterial activity of Ceftazidime Ciprofloxacin against Pseudomonas aeruginosa. There are more resistance in mature biofilm.