Therefore, in the current work, the ability of nano-molar concentrations of CDA to induce dispersal in pre-established biofilms, formed by four main food-borne biofilm producer bacteria as well as to remove and kill their Chlormethiazole hydrochloride biofilms when combined with biocides or antibiotics were studied? Besides, the ability of CDA to increase the inhibitory effects of antimicrobials on the growth of tested microorganisms�� planktonic cells was investigated. Biofilms were also grown on the interior surfaces of tubing reactors. A continuous once-through tube reactor system was configured by using eight silicone reactor tubes, connected to an eight-roller head peristaltic pump and medium reservoir, via an additional silicone tubing. Medium was pumped through the tubing to a closed effluent medium reservoir. The entire system was closed to the outside environment but maintained in equilibrium with atmospheric pressure by a 0.2-mmpore- size gas-permeable filter fitted to medium reservoir. The assembled system was sterilized by autoclaving prior to inoculation. The silicone tubes were inoculated by syringe injection through a septum 1 cm upstream from each reactor tube, with 3 ml of overnight cultures of each microorganism. Bacteria cells were allowed to attach to the tubing for 1 h, after which the flow was started at an elution rate of 280 ml.min21. After 5 days of biofilm cultures, the influent medium was switched from fresh medium in the test lines to one of the three concentrations of CDA. Control lines were switched to
s containing just the carrier. Samples were collected in test tubes on ice and were subsequently homogenized and cell density was determined as mentioned above. All experiments were repeated three times. The concentration of CDA that induced the most dispersal in the examined biofilms in both petri dish and tube reactor cultures was used for further studies. To examine the effect of CDA combined antimicrobial agents on removal of biofilms; we tested Epimax S and Percidine against pre-established biofilms grown on the surface of SS discs, in the presence and absence of 310 nM CDA. When 120 h biofilms were treated in the absence of CDA, both disinfectants caused Chloro-APB hydrobromide approximate two-fold decrease in CFU counts compared to the untreated controls, while combined exposure of cultures to 310 nM CDA and 70 ppm Percidine or 120 ppm Epimax S, resulted in approximate five-fold decrease in CFU counts. No significant differences were observed between these two different combinational treatments in reduction of CFU counts.