Antibiofilm formation and anti‐adhesive (to HE p‐2 cells) effects of rosemary water extract against some food‐related pathogens

Summary The present work aimed to determine the bioactive compounds in two rosemary water extracts ( RWE 1 and RWE 2) and to assess their antimicrobial, anti‐adhesive and antibiofilm potentials against the food‐related B acillus and P seudomonas species at concentrations; 4, 8, 12, 16 and 20 mg mL −1 . Phenolic compounds and isoflavones in the RWE s were determined using HPLC . The concentrations of most bioactive compounds of RWE 1 (benzoic, ellagic, gallic and rosmarinic acids, daidzein and genistein) were higher than that of RWE 2. The MIC 90 of RWE 1 and RWE 2 against all tested bacteria was 12 and 16 mg mL −1 , respectively. The anti‐adhesive and antibiofilm doses were higher than MIC 90 . RWE 1 and RWE 2 showed potential reduction in the bacterial cell adhesion to HE p‐2 cells – 17.5–64.7 and 12.2–52.9%, respectively. In conclusion, this study emphasises the effective use of RWE as a natural anti‐adhesive and antibiofilm agent against B acillus and P seudomonas , without difficult extraction procedure.