Batumin—A Selective Inhibitor of Staphylococci—Reduces Biofilm Formation in Methicillin Resistant iStaphylococcus aureus/i

摘要

The antibiotic batumin, produced by Pseudomonas batumici, has been shown to be highly active against 123 type and reference strains and clinical isolates of 30 Staphylococcus species (including MRSA and small colony variants—(SSCVs) of S. aureus, S. epidermidis and S. haemolyticus). Batumin activity against these bacteria did not depend on the species, origin or resistance to other antibiotics and its MIC was 0.0625 - 0.5 mg/ml. Batumin influence on biofilm formation was studied in clinical isolates of S. aureus, S. epidermidis and S. intermedius. Addition of batumin at a concentration of half of the MIC in the broth, i.e. 0.125 μg/ml, decreased the biofilm of 16 out of 20 S. aureus strains to varying degrees. Batumin was more effective against Staphylococcus strains with strong biofilm formation. Using atomic-force microscopy, it could be shown that batumin reduced the number of S. aureus ATCC 25923 adherent cells more than fourfold. The adherent cells of staphylococci were visualized as monolayers of separate islets. A detailed study of the surface of bacterial cells treated with batumin allowed to establish significant reduction of their roughness values. Observed values were typical for planktonic S. aureus cells. The obtained data explain one of the mechanisms of the antimicrobial activity of batumin, which is based оn preventing the formation of S. aureus biofilm. As such, batumin could be considered as an agent offering opportunities for the treatment of staphylococcal biofilm-associated infections.