Karaleen Anderson; Mariel Hatch, Utah Valley University
Fungal infections caused by opportunistic pathogens have gained clinical importance in the last decade, with a significant increase in infections due to the Zygomycetes, Mucor, Rhizopus and Absidia. These serious and sometimes fatal infections are often associated with biofilm formation. The formation of biofilms often increases resistance to antifungal agents when compared to free living colonies. This study investigates both the biofilm formation and the antifungal susceptibility of two species known to cause mucormycosis infections namely: Rhizopus oryzae and Absidia corymbifera. Upon successful biofilm formation, the synergistic effects between thyme oil and amphotericin B were tested. Results indicate that both R. oryzae and A. corymbifera form biofilms under specific conditions, and that these biofilms were significantly inhibited by thyme oil. The MIC50 of thyme oil on Absidia corymbifera and Rhizopus oryzae was 0.0005 μL/mL and 0.0001 μL/mL respectively. Results also indicate a strong synergistic relationship between amphotericin B and thyme oil when used in combination against fungal biofilms.