## 3 Results and Discussion  
The results of the antibacterial activity (log\({}_{10}\) CFU/cm\({}^{2}\) reduction) of triclosan-containing polyester surfaces in a concentration range between 400 and 850 ppm under dry and humid conditions against _S. aureus_ are shown in Table 1. According to the results, these concentrations demonstrated sufficient activity to inhibit bacterial growth at the lowest used concentration of 400 ppm (0.99 log\({}_{10}\) and 0.19 log\({}_{10}\) reduction for dry and humid conditions, respectively). For the highest concentration of 850 ppm, these reductions were 1.17 log\({}_{10}\) and 0.20 log\({}_{10}\). Furthermore, at 500 and 650 ppm, the highest activities of 0.68 log\({}_{10}\) and 1.02 log\({}_{10}\), respectively, were observed for dry condition. According to these results, when comparing the concentrations (400, 500, 650 and 850 ppm), in each condition, no significant differences were found in their antibacterial activities (\(p>0.05\)). When each concentration was compared between the conditions, statistically significant differences were observed (\(p<0.05\)), finding a decrease in the bacteriostatic activity when the samples were tested in humid conditions. However, the activity of triclosan was not very high. In fact, neither the samples preserved in dry or humid conditions achieved a reduction of equal to or greater than 2 log\({}_{10}\). These results indicate that the antibacterial capacityof triclosan at the studied concentrations (400 to 850 ppm) is bacteriostatic instead of bactericidal. Therefore, at these concentrations triclosan showed a bacteriostatic activity, and more effective in dry conditions. In our study not bactericidal activity was detected, probably due to the triclosan concentrations selected. Moreover, high humidity was a positive factor for triclosan activity, inhibiting _S. aureus_. Previous studies have shown that in concentrations above 1000 ppm, there is a rapid loss of the activity of triclosan as an antibacterial agent in environmental conditions of refrigeration and in a flood system. [PERSON] [44] observed that with 1500 ppm of triclosan, they did not have an effect to reduce bacterial populations on refrigerated, vacuum-packaged meat surfaces. In another study, no bactericidal effect was observed with biofilm populations on acrylonitrile-butadiene-styrene (ABS) plastic with 50,000-ppm triclosan, when the tests were performed in a continuous flow of culture reactors with drinking water [45]. According to these studies, an increase in the concentrations of triclosan could be used to observe a bactericidal effect. However, the bacteriostatic or bactericidal activity of triclosan is controversial. These results agree with those observed by [PERSON] et al. [46], who evaluated the ability of _Staphylococcus aureus_, _Escherichia coli_, _Salmonella_, _C_ogualase-negative staphylococci (CNS) and _Serratia_ spp. to develop and multiply on humid surfaces. In this study, the authors noted that there is a potential danger caused by bacterial cross-contamination from humid surfaces to food. Although the humid condition favored the development of the bacterial cells, the effectiveness of triclosan under this condition also inhibited the growth of _S. aureus_. To this effect, humidity is a determining factor in the survival of bacteria, which can be counteracted by the use of materials with bacteriostatic properties [47; 48; 49]. Also, in our study, the use of bovine albumin as an interfering substance to represent real conditions may have had an influence on the action of triclosan, reducing its effect on the surfaces. This fact is in line with [PERSON] et al. [50] and [PERSON] et al. [51], who observed that the presence of bovine albumin produces protective effects, as it interferes with the action of antimicrobials, increasing the survival of microorganisms. Furthermore, bovine albumin may end up acting as a conditioning protein layer, which stimulates a greater adhesion of bacteria and increases their growth in the form of biofilms [52].