[Effect of antibacterial peptide LL-37 on the integrity of Acinetobacter baumannii biofilm].

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.