[Morpho-functional changes of Staphylococcus aureus biofilms under the effect of batumin].

Aim: Study the effect of batumin isolated from metabolites of Pseudomonas batumici bacteria on the formation of biofilms by staphylococci under the control of atomic force microscopy. MATERIALS AND METHODS; S. aureus 25923 (ATCC) and S. aureus 104 were used as test cultures. Batumin with the degree of purification of 80% was used in the experiments. Microscopy of the preparations was carried out on atomic force microscope SMM-2000 (Proton-MIET Closed Joint-Stock Company, Russia) in contact mode in air environment. Biofilm formation (BFF) was studied by photometric method (O'Toole G.A., 2000). Dissociation of microbial population was detected during seeding of staphylococci into agarized LB medium.

Results: Changes of structural component of biofilm were noted visually under the effect of the preparation--exopolymeric matrix and reduction of quantity of adherent staphylococci in the form of separate islet formations. Similar pattern was detected during determination of staphylococci biofilm formation by photometric method. Redistribution of S. aureus clonal structure with the appearance of dissociants that do not possess the ability to form biofilms and reduction of quantity of clones with high values of BFF also occurred under the effect of batumin.

Conclusion: The data obtained reveal one of the mechanisms of antimicrobial effect of batumin based on suppression of staphylococci biofilm formation by the preparation.