Antibiofilm activities of the cinnamon extract againstVibrio parahaemolyticusandEscherichia coli

Vibrio parahaemolyticusandEscherichia coliare two major foodborne pathogens. In this paper, the antibiofilm activities of the ethanol extract of cinnamon against these two bacteria were studied in detail.The antibacterial activity and the MIC of the extract were determined, and the inhibition and removing effects of the extract on the biofilms ofV. parahaemolyticusandE. coliwere investigated. The biofilms stained with fluorescein isothiocyanate (FITC) and concanavalin A (Con A) were also observed by confocal laser scanning microscope (CLSM). The results indicated that the extract exhibited high antibacterial activity, with the MIC againstV. parahaemolyticusandE. coliwas 6.25 mg/mL. The effects onV. parahaemolyticusbiofilm were significant with the inhibition rate of 75.46% at MIC, and the eradication rate of 93.26% at 32MIC, respectively. As toE. coli, the inhibition rate was 48.18% at MIC, and the eradication rate was 46.16% at 8MIC. Meanwhile, the extract could notably reduce the metabolic activities and the secretion of EPS in biofilm, it inhibited 78.57% EPS formation inV. parahaemolyticusbiofilm at MIC, and eliminated 61.28% EPS in mature biofilm at 4MIC. CLSM images showed that the EPS of the treated biofilm became thinner and biofilm structure was looser, when compared with the untreated control. This study elucidated that the cinnamon extract was effective to prevent biofilm formation and eradicate mature biofilms ofV. parahaemolyticusandE. coli.