In vitro ACTIVITY OF THE ANTIBIOTIC BATUMIN AGAINST Candida albicans BIOFILM

The aim of this work was to study action of batumin on the strains of Candida albicans and Candida krusei in planktonic and biofilm form and also to obtain more detailed insights into the influence of batumin on biofilm formation by using atomic-force microscopy. The Minimum Inhibitory Concentration (MIC) of batumin was studied according to CLSI standards. Formation of a biofilm was studied by the photometric O'Toole method by means of a plate photometer ELx808 (BioTek, USA) at wavelength of 630 nanometers. The polyketide antibiotic batumin has a high selective activity against staphylococci (MIC ≥ 0,25 μg/ml), at the same time, antibiotic, being not active concerning yeast of the genus Candida (MIC ≥ 512 μg/ml) showed the inhibiting action on biofilm formation of these microorganisms. Batumin influence on biofilm formation was studied in type, collection strains С. albicans, C. kruise and clinical isolates. Presence 0,125 µg/ml of batumin in the broth (1/2 MIC for staphylococci) reduced the biofilm formation at 55.6% of the studied strains. Their biofilm formation values varied for C. albicans from 1.5‒3.9 CU (conventional unit: OD630 in experimental samples / OD630 in control samples), for C. krusei of 2.3‒3.0. Batumin was more effective against Candida strains with strong biofilm formation. Atomic force microscopy revealed qualitative changes in the exopolymeric matrix due to batumin treatment, as well as a significant reduction in the number of cells adhered to the coverslip, preventing formation of C. albicans 127 biofilm, However, C. albicans ATCC 24433 a significant reduction in the number of cells adhered to the coverslip weren't observed. The data obtained by an Аtomic force microscopy confirm ability of a batumin to prevent formation of a biofilm at the studied strains that allows to consider it as the preventive agent at treatment of the infections caused by yeast-like fungi of the genus Candida.