In vitro utility of zinc oxide nanoparticles and antifungal drugs for the treatment of mycotic mastitis in dairy cows in Egypt

Abstract Bovine mastitis is an inflammation of mammary gland parenchyma in cows. It is caused by multiple pathogens including bacteria and fungi. Mycotic mastitis is a secondary disease following improper frequent use of antibiotics or an unhygienic environment. The treatment of rising cases of mycotic mastitis is still controversial because of the rapid resistance acquired by the traditional use of antifungal drugs. The present study aims to investigate the use of zinc oxide nanoparticles (ZnO-NPs), alternative therapy for traditional antifungal drugs, to combat fungal isolates from mastitic cows by examining the in vitro antifungal activity of ZnO-NPs. One hundred milk samples were aseptically collected from cows suffering from clinical mastitis in a governorate in Egypt. The fungal isolates were identified by their colony morphology and microscopical examination and subsequent underwent determining the MIC of traditional antifungal drugs and ZnO-NPs using the disc diffusion methods. Our results showed that 70% of milk samples were positive for mycotic mastitis with 30% yeasts, 15% molds, and 25% yeast and molds. Candida was the most common yeast species isolated. Rhodotorula, c. guilliermondii, c. parapsillosis, and c. albicans showed entire resistant (100%) to all traditional antifungal drugs whereas, the same isolates, except c. albicans, were susceptible to ZnO-NPs. Mold spp. were susceptible to ZnO-NPs and only Itraconazole, and Clotrimazole. ZnO-NPs are highly effective and promising inexpensive antimicrobial agent for the treatment of bovine mycotic mastitis.