Investigating the antimicrobial and antibiofilm effect of some preservatives used in drug, cosmetics and food products

In our study, it was aimed to determine the antimicrobial and antibiofilm effects of some preservatives used in drug, cosmetics and food products and to compare the Minimum Biofilm Inhibition Concentration (MBIC) of biofilm formed on ?glass? surfaces which has a widespread use area and the Minimum Inhibition Concentration (MIC) values of the planktonic forms.As microorganisms; Pseudomonas aeruginosa ATCC 27853, Salmonella Thyphimurium SL1344, Staphylococcus aureus ATCC 6538, Staphylococcus epidermidis NCTC 11047, Enterococcus faecalis ATCC 29212, Candida albicans ATCC 10231 standard strains, as preservatives; sodium nitrate, methylparaben, prophylparaben, potassium sorbate and sodium benzoate and as antimicrobial agents; ampicillin, vancomycin, gentamicin, ciprofloxacin, amphotericin B and itraconazole were used.MIC values were determined through the guidelines of Clinical Laboratory Standards Institute (CLSI) M100-S18 and M27-A3 protocols. BioTimer (BT) method was used to determine the MBIC values. ?CFU/glass beads? was calculated using the graphics drawn by plotting the time of color change for fenol red or resazurin against log10CFU. All experiments were done with 4 different pH valued media with pH7, pH6.5, pH6 ve pH5.5.According to the effect to the planktonic forms of the microorganisms, sodyum benzoate was determined to be the most effective preservative against all of the microorganisms except S. aureus and E. faecalis. For these bacteria, the most effective preservative was prophylparaben. Prophylparaben was also found to be effective against S. epidermidis. However, in our study it was determined that preservatives were not effective against biofilm forms even if the inoculum was lower, equal to or higher than the inoculums of the planktonic forms. Our study which will be held in this regard is thought to be a guide for further studies.