EN
The study evaluated the antimicrobial properties of commercial preparations containing nanoparticles of silver, gold, copper and platinum against Escherichia coli, Streptococcus uberis, Staphylococcus aureus, Candida albicans and Candida krusei isolated from cases of mastitis in cattle. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) of the preparations in relation to the isolated microbes were determined. The highest growth-inhibiting activity against the pathogens was noted in the preparations containing nanoparticles of silver and copper, whereas the preparation containing gold nanoparticles had a significantly weaker effect. Platinum nanoparticles at the concentrations applied did not exhibit biocidal activity towards the microorganisms analysed. After 30 minutes the antimicrobial activity of the silver nanoparticles, at concentrations of both 50 and 25 ppm, resulted in the complete elimination of viable cells of the microbes isolated from cases of mastitis. The preparation containing copper nanoparticles exhibited biocidal activity only at a concentration of 50 ppm.