[Assessment of essential oils activity used in liquid or volatile phase against biofilm cultures of Staphylococcus aureus and Candida albicans. The methodological study].

Biofilm formation is a significant factor in chronic infections with fungal and bacterial pathogens. Due to the high drug resistance of biofilm populations and the frequent failures of chemotherapy i such infections, it seems necessary to take recourse to unconventional treatment methods involving e.g. the use of some phytocompounds such as essential oils or their components. In order to evaluate the effect of their action on the microbial biomass a variety of techniques are used. However, there is still a need to develop new tests or modifications of these known, for the biofilm viability assessment. They should be adapted to the physico-chemical nature of the tested compounds and should decrease the risk ofbiofilm damage during staining procedure. We described a test assessing the effect of essential oils on bacterial and fungal biofilm formed on the membrane of cell culture inserts. The proposed model provides a minimal violation of the biofilm integrity during the test. It allows easily explore the activity of essential oil volatile fraction and is useful in determination of the kinetics of their action. Using this test it is also easy to examine the relationship between antimicrobial activity and the cytotoxic effect, known as the biocompatibility index (BI, biocompatibility index). Moreover, it allows qualitative and quantitative analysis of metabolic products, released into the growth medium from biofilm's cells. In successively repeated experiments high reproducibility of results has been obtained, thus the developed methodology seems to be useful in our future studies in this field.