Basarab V. Y., Voronkova O. S., Osadcha O. V.

Oles Honchar Dnipropetrovsk National University

THE IMPORTANCE OF BIOFILMS IN TREATING DISEASES

A biofilm is a combination of different species of bacteria, that are connected by exopolisaccharide matrix. Bacterial cells occupy about 5–35 % of the total mass of a biofilm. Another part is the matrix that includes mainly polysaccharides and some proteins. The matrix is laced with channels, through which nutrients, waste products, enzymes, metabolites and gases circulate. All of them have their own microenvironment, different levels of pH, efficacy nutrients assimilation and gases concentration. The life cycle of a biofilm has the next stages of development: attachment of bacteria to the surface, growth of the colonies and production of extracellular matrix, maturation, realization of individual cells for following colonization of the ecotype. Bacteria in biofilms communicate with each other by chemical signals, there are positive and negative bacteria.

Microorganisms in the biofilm are more resistant to antibiotics, antimicrobial agents and other active agents.

Knowing the structure of biofilms makes it possible to talk about the problems of studying them and the methods of dealing with them.

Biofilms have significant adherence to the substrate on which they grow, especially to human organism tissues, for example epithelium of mucosa. Besides them biofilm are adherent to inorganic substrate, such as silicon, PVC etc.

One of the optimal methods for biofilm studying is laser scanning monofocuse microscopy that allows investigating biofilms in their natural state. One of the actual questions is how to destroy biofilms? There are many strategies, but efficacy of them is not maximal. Metabolic activity of biofilm is studied by methods of O2 uptake- or CO2 outlet-registration. Cultural methods are use to study the biological properties of film and characteristics of film growth.

Biofilm is defended by polysaccharide matrix. In film there are some cells that have lower metabolic activity. That’s why standard concentration is damaging for the human organism. As an alternative treatment the phage therapy is seen. Bacterial cells are not resistant to phages, these viruses are highly specific for sensitive cells and do no damage to other bacteria and human cells.

Nowadays perspective research is devoted to finding the phage types specifically designed to kill bacteria in the biofilm. Researching biofilms is very important today, especially finding methods of their destruction.

In own study we showed that the use of piobacteriophage against staphylococci is effective in 70 % of film forming strains. The effect of phage drug is observed both in antibiotics resistant and non-resistant strains.