Resistance of Yeasts and Algae Isolated from Cow Mastitic Milk to Antimicrobial Agents

The objective of this study was to determine the antimicrobial resistance of 319 yeast strains and 168 algae strains isolated from cows` mastitic milk. The in vitro susceptibility to 10 antifungals and 10 antibiotics was examined by disc diffusion method. Above 75% of yeast strains were resistant to amphotericin B, 66% to fluconazole, and 40% to pimaricin and itrakonazole. Algae strains were resistant to the most of the tested antifungals. Only nystatin, amphotericin B, and pimaricin were active against the most of these microorganisms. Algae showed the high resistance to antibiotics too. Only the aminoglycosides: gentamycin (75.5% of strains), kanamycin (71.7%), and neomycin (30.6%) inhibited the growth of these organisms in vitro. This study demonstrates that only a few antifungal and antimicrobial agents are active in vitro against algae; however, yeast strains show the high in vitro susceptibility to the most antifungals.