Anti-Biofilm Potential of and Cell-Free Supernatant Extracts against .

Background: Biofilm production is an important virulence factor in . Most of the infections associated with biofilms of this bacterium are very difficult to treat using antibiotics. The present research studied the effects of the two probiotic species and on biofilm.

Materials And Methods: Cell-free supernatant (CFS) extracts of ATCC 39392 and ATCC 7469 culture were prepared. The effects of sub-minimum inhibitory concentrations of the CFS extracts on cell surface hydrophobicity (CSH), initial attachment, biofilm formation, and their ability in eradicating ATCC 33591 biofilms were assessed. In addition, the effects of CFS extracts on expression of the genes involved in formation of biofilms (, , , , and ) were also evaluated through real-time polymerase chain reaction.

Results: CFSs of both spp. significantly reduced CSH, initial attachment, and biofilm formation and eradicated the biofilms. The above findings were supported by scanning electron microscopy results. These two CFSs significantly changed the expression of all studied biofilm-related genes. Expression levels of , , and genes significantly increased by 4.4, 2.3, and 4.76 fold, respectively, but and genes were significantly downregulated by 3.12 and 2.3 fold.

Conclusion: The results indicated that CFS extracts of and had desirable antagonistic and anti-biofilm effects against . Consequently, carrying out further research enables us to prepare pharmaceuticals from these CFSs in order to prevent and treat infections caused by biofilms.