Mixed species biofilms of Candida albicans and Staphylococcus epidermidis.
A simple catheter disk model system was used to study the development in vitro of mixed species biofilms of Candida albicans and Staphylococcus epidermidis, two organisms commonly found in catheter-associated infections. Two strains of S. epidermidis were used: a slime-producing wild type (strain RP62A) and a slime-negative mutant (strain M7). In mixed fungal-bacterial biofilms, both staphylococcal strains showed extensive interactions with C. albicans. The susceptibility of 48-h biofilms to fluconazole, vancomycin and mixtures of the drugs was determined colorimetrically. The results indicated that the extracellular polymer produced by S. epidermidis RP62A could inhibit fluconazole penetration in mixed fungal-bacterial biofilms. Conversely, the presence of C. albicans in a biofilm appeared to protect the slime-negative staphylococcus against vancomycin. Overall, the findings suggest that fungal cells can modulate the action of antibiotics, and that bacteria can affect antifungal activity in mixed fungal-bacterial biofilms.
Adam
Berit
B
Division of Infection and Immunity, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
Baillie
George S
GS
Division of Infection and Immunity, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
Douglas
L Julia
LJ
Division of Infection and Immunity, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D002176:Candida albicans / Q000187:drug effects / Q000502:physiology*; D002408:Catheters, Indwelling / Q000382:microbiology; D004338:Drug Combinations; D015725:Fluconazole / Q000494:pharmacology; D006801:Humans; D008855:Microscopy, Electron, Scanning; D013212:Staphylococcus epidermidis / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D014640:Vancomycin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D004338:Drug Combinations; D014640:Vancomycin; D015725:Fluconazole