Related Experiment Video
Updated: Jan 25, 2026

The MODS method for diagnosis of tuberculosis and multidrug resistant tuberculosis
Published on: August 11, 2008
In vitro polymyxin activity against clinical multidrug-resistant fungi
Hanane Yousfi1, Stéphane Ranque2, Jean-Marc Rolain1
1Aix Marseille Univ, IRD, APHM, MEPHI, IHU Méditerranée Infection, 19-21 boulevard Jean Moulin, 13005 Marseille, France.
Background:
Although antifungals are available and usually used against fungal infections, multidrug-resistant (MDR) fungal pathogens are a growing problem for public health. Moreover, fungal infections have become more prevalent nowadays due to the increasing number of people living with immunodeficiency. Thus, previously rarely-isolated and/or unidentified fungal species including MDR yeast and moulds have emerged around the world. Recent works indicate that polymyxin antibiotics (polymyxin B and colistin) have potential antifungal proprieties. Therefore, investigating the in vitro activity of these molecules against clinical multidrug-resistant yeast and moulds could be very useful.
Methods:
In this study, a total of 11 MDR yeast and filamentous fungal strains commonly reported in clinical settings were tested against polymyxin antibiotics. These include strains belonging to the Candida, Cryptococcus and Rhodotorula yeast genera, along with others belonging to the Aspergillus, Fusarium, Scedosporium, Lichtheimia and Rhizopus mould genera. The fungicidal or fungistatic action of colistin against clinical yeast strains was determined by the time-kill study. Further, a checkerboard assay for its combination with antifungal agents, usually used in clinical practices (amphotericin B, itraconazole, voriconazole), was carried out against multi-drug resistant fungal strains.
Results:
Polymyxin B and colistin exhibited an antifungal activity against all MDR fungal strains tested with MICs ranging from 16 to 128 μg/ml, except for the Aspergillus species. In addition, colistin has a fungicidal action against yeast species, with minimum fungicidal concentrations ranging from 2 to 4 times MICs. It induces damage to the MDR Candida albicans membrane. A synergistic activity of colistin-amphotericin B and colistin-itraconazole associations against Candida albicans and Lichtheimia corymbifera strains, respectively, and colistin-fluconazole association against Rhodotorula mucilaginosa, was demonstrated using a checkerboard microdilution assay.
Conclusion:
colistin could be proposed, in clinical practice, in association with other antifungals, to treat life-threatening fungal infections caused by MDR yeasts or moulds.
More Related Videos
08:46Implementation of In Vitro Drug Resistance Assays: Maximizing the Potential for Uncovering Clinically Relevant Resistance Mechanisms
Published on: December 9, 2015
09:29In Vivo Investigation of Antimicrobial Blue Light Therapy for Multidrug-resistant Acinetobacter baumannii Burn Infections Using Bioluminescence Imaging
Published on: April 28, 2017
Related Concept Videos
The Roles of Bacteria and Fungi in Plant Nutrition
Overview of Fungi
Resistivity
Resistance
Resistance and Conductance
Various factors impact the resistance of a conductor. Spiraling in stranded conductors increases their...
Equivalent Resistance