Synergistic action of amphotericin B and rhamnolipid in combination on Candida parapsilosis and Trichosporon cutaneumOlga Maťátková, Irena Kolouchová, Eva Kvasničková, Richard Ježdík, Jan Masák, and Alena Čejková Department of Biotechnology, University of Chemistry and Technology, Prague 6, Czech Republic
E-mail: olga.matatkova@vscht.cz Abstract: Emerging resistance of microbial cells towards antibiotics or disinfectants leads to an increase of nosocomial diseases, often biofilm related, and gives rise to the need for research for new antimicrobial substances. These studies are often focused on substances that are able to support the efficacy of currently used antimicrobials, reduce their required dosage and reduce the probability of resistance development. This work brings new insights into the in vitro interaction of rhamnolipid biosurfactant and amphotericin B against Candida sp. or Trichosporon sp.. The minimum inhibitory concentrations and fractional inhibitory concentration indexes for both planktonic and biofilm cells were determined by the chequerboard microdilution method. Combination effect of rhamnolipid and amphotericin B was observed for both yeasts. Synergy, defined as a fractional inhibitory concentration (FICi) index of 0.50, was observed in both planktonic and biofilm cells of Trichosporon cutaneum. For C. parapsilosis, synergistic effect (FICi 0.5) was observed for planktonic cells, and additive effect (FICi 0.8) for biofilm cells. The influence of concentrations established as FICi on biofilm formation and susceptibility was studied by light microscopy. The highest inhibition (90% colonized area reduction) of initial adhesion of C. parapsilosis was observed when biofilm FIC was applied. Keywords: Biofilm; Candida sp.; Trichosporon sp.; Rhamnolipid; Amphotericin B; Drugs interaction Full paper is available at www.springerlink.com. DOI: s11696-017-0141-8
Chemical Papers 71 (8) 1471–1480 (2017) |
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