Characterization of biofilm production in different strains ofand the effects of chemical compounds on biofilm formation.

, an important emerging pathogen of nosocomial infections, is known for its ability to form biofilms. Biofilm formation increases the survival rate ofon dry surfaces and may contribute to its persistence in the hospital environment, which increases the probability of nosocomial infections and outbreaks. This study was undertaken to characterize the biofilm production of different strains ofand the effects of chemical compounds, especially antibiotics, on biofilm formation. In this study, no statistically significant relationship was observed between the ability to form a biofilm and the antimicrobial susceptibility of theclinical isolates. Biofilm formation caused byATCC 17978 after gene knockout of two-component regulatory system gene, efflux pump genesand outer membrane coding generevealed that all mutant strains had less biofilm formation than the wild-type strain, which was further supported by the images from scanning electron microscopy and confocal laser scanning microscopy. The addition of amikacin, colistin, LL-37 or tannic acid decreased the biofilm formation ability of. In contrast, the addition of lower subinhibitory concentration tigecycline increased the biofilm formation ability of. Minimum biofilm eradication concentrations of amikacin, imipenem, colistin, and tigecycline were increased obviously for both wild type and multidrug resistant clinical strainVGH2. In conclusion, the biofilm formation ability ofvaried in different strains, involved many genes and could be influenced by many chemical compounds.