In Vitro Antifungal activity of Raphanus sativus L. var. niger (Black Radish) and Trachyspermum ammi (Ajwain) on resistant and susceptible Aspergillus fumigatus isolates

Aspergillus fumigatus is an opportunistic fungal pathogen that causes invasive aspergillosis in immunocompromised patients. Raphanus sativus L. var. niger and Trachyspermum ammi are two medical herbs which seemed to have an antifungal activity that can be integrated alternative medicine into conventional medicine. The aim of this study was to evaluate the effect of R. sativus and T. ammi on the resistant and susceptible species of A. fumigatus. In the present study, 185 environmental samples from 11 cities of Iran were processed and screened in terms of azole resistance using selective plates. The isolates were confirmed by partial sequencing of the b-tubulin gene. Afterwards, in vitro antifungal susceptibility tests against triazole agents and R. niger and T. ammi extract were performed based on the CLSI, M38-A2 document. The ingredients in the extract by gas chromatography method were isolated and identified by mass spectrometry. Overall, 51 A. fumigatus isolates were detected. According to in vitro antifungal susceptibility tests, 45 A. fumigatus isolates had high MICs of itraconazole (≥8 mg/L) and voriconazole (>2 mg/L) and 6 A. fumigatus isolates were susceptible. The MIC 50 and MIC 90 for R. sativus was 1.95 mg/ml and 3.9 mg/ml respectively. Also, The MIC 50 and MIC 90 for T. ammi was recorded as 2.30 mg/ml and 4.85 mg/ml respectively. The main identified compounds were Tramadol (58.37%), Butanol (23.42%), Benzofuran (18.21%). Our results indicated that R. sativus and T. ammi extracts significantly inhibited the growth of A. fumigatus isolates and have an appropriate antifungal activity.