Nanoparticles as New Antifungals in the Prevention of Bovine Mycotic Mastitis Caused by Candida spp. and Diutina spp.-In Vitro Studies.

Bacterial infections are the primary cause of mastitis in dairy cattle. Fungal mastitis occurs in 1-12% of cases. Antibiotic therapy, the standard treatment for mastitis, has led to antibiotic-resistant bacteria, reducing treatment efficacy and increasing fungal mastitis occurrence. Antibiotics lack biocidal effects on fungi, which often exhibit resistance to antifungal agents. This study evaluated the antifungal properties of nanoparticles (NPs) against Candida albicans, Candida glabrata, Candida parapsilosis, Diutina rugosa var. rugosa, Diutina catenulata, and Diutina rugosa. Tested NPs included gold (AuNPs), silver (AgNPs), copper (CuNPs), iron with hydrophilic carbon coating (FeCNPs) (1.56-25 mg/L), and platinum (PtNPs) (0.625-10 mg/L), along with their complexes. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) at 0.75-25 mg/L for AuNPs, AgNPs, CuNPs, and FeCNPs and 0.313-10 mg/L for PtNPs, as well as fungal sensitivity to standard antifungals, were determined. Each strain showed different sensitivities depending on the NPs used and their concentrations. C. glabrata was the most resistant to nanoparticles, while D. catenulata was the most susceptible. PtNPs and FeCNPs showed no or weak biocidal properties. Some mycotic-resistant strains were sensitive to nanoparticles. This study indicates a high in vitro antifungal potential for the application of nanoparticles, especially AgCuNPs, as a new effective non-antibiotic agent for the prevention and control of mycotic mastitis in dairy cattle.