Antifungal Effect of Some Natural Substances on Fluconazole-resistant Candida species Recovered from Mastitis

Abstract

A wide range of essential plant oils and extracts have been shown to be fungal inhibitors and could provide attempting alternative for treating animal infections. The current study screened the in-vitro antifungal properties of propolis in addition to Eucalyptus and Moringa essential oils on some fluconazole-resistant Candida isolates recovered from cases of bovine and ovine mycotic mastitis through determination of their Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC). Propolis recorded MIC and MFC ranged from 44 mg/mL to 175 mg/mL and the isolates of C. albicans were the most sensitive. Eucalyptus was the most effective essential oil with MIC and MFC ranged from 2 mg/mL to 16 mg/mL and was mostly effective against C. tropicalis, C. albicans and C. kefyr. Regarding Moringa essential oil, the recorded MIC and MFC ranged from 31.25 mg/mL to 125 mg/mL and the most sensitive isolates were C. tropicalis and C. kefyr. The molecular characterization of azole-resistance genes revealed that all tested isolates harbored CDR gene 100%, while MDR1 and ERG11 genes were represented as 80% and 40%, respectively. Therefore, the antifungal effect of propolis and essential oils of Eucalyptus and Moringa against fluconazole-resistant Candida species were highlighted in the current study and can be employed as useful alternatives for the treatment of bovine and ovine mycotic mastitis.