Abstract: Objective To investigate the effect of antibacterial peptide LL-37 on the integrity of Acinetobacter baumannii biofilm.
Methods A model of Acinetobacter baumannii biofilm in vitro was constructed by plates and crystal violet staining method, and
the minimal inhibitory concentration of LL-37 was determined by broth dilution. The biofilm morphology was observed by
scanning electron microscopy and biofilm formation was analyzed by the crystal violet staining of the adherent biofilm in the
presence of antibacterial peptide LL-37. Results In the Acinetobacter baumannii biofilm model, the minimal inhibitory
concentration of LL-37 was 64 μg/ml; LL-37 caused structural damage of the biofilm at a low concentration of 2.5 μg/ml. The
biofilm was decreased gradually as the concentration of LL-37 increased. Conclusion LL-37 even at a concentration far below
its minimal inhibitory concentration can cause structural damage of Acinetobacter baumannii biofilm in vitro.