A ceramide synthase is important for filamentous fungal biofilm morphology and antifungal drug susceptibility

Contributions to fitness include the development of emergent properties resulting in the recalcitrance to external stressors such as environmental stress or drug stress in the context of a pathogen. The biofilm developed by the filamentous fungal pathogen Aspergillus fumigatus develops zones of low oxygen which contribute to a reduction in antifungal drug susceptibility, however the mechanisms driving this have remained elusive.

Here we have utilized a transcriptomic approach to probe the biofilm structure in comparison to a planktonic lifestyle to identify unique biofilm transcriptional patterns. Importantly we utilized two phenotypically diverse strains. From this analysis we have identified biofilm specific gene co-expression networks as well as a ceramide synthase, designated barA, with a striking increase in transcript abundance specifically in the biofilm.