PROJECT SUMMARY
There is a critical need to identify important parameters involved in adaptation to environmental stresses in fungal
biofilms, in order to develop effective therapeutic strategies against fungal infections. Treatment of fungal
infections by Candida spp, including the emerging pathogen Candida glabrata (C. glabrata), remains a clinical
challenge especially in immunocompromised individuals. C. glabrata is now the second most frequently isolated
Candida spp in North America. In vivo, microbes mostly exist in biofilms, which serve as protective layers. Cells
in biofilms exhibit increased resistance to environmental stresses. Since biofilms are an integral part of
pathogenesis, the adaptation of fungal pathogens inside a biofilm is an important aspect that requires a deeper
understanding. However, existing knowledge of fungal adaptation in biofilms is limited, partly due to the lack of
established experimental methods for the long-term propagation of fungal biofilms. With a long-term goal of
contributing to the development of therapeutic strategies for candidiasis, the overall objective of the project is to
develop a fungal biofilm propagation method for use in experimental adaptive evolution, and to apply the system
to identify essential genes involved in C. glabrata biofilms. In Aim 1, a biofilm culture system suitable for long-
term in vitro evolution will be developed and characterized. A key feature of the method being developed is the
ability to grow multiple biofilms from the same seed biofilm, allowing multiple procedures for analysis and
characterization of biofilms at each passage during in vitro evolution. Aim 2 will Implement the fungal biofilm
propagation system for in vitro evolution of C. glabrata to environmental stressors. Key properties, such as
amount of biofilm formation and changes in biofilm structure will be monitored. Molecular mechanisms
associated with adaptation to environmental stressors in fungal biofilms will be elucidated based on genome-
sequencing and phenotypic analyses. Aim 3 will combine the biofilm propagation method with transposon
sequencing to identify essential genes involved in biofilm formation in C. glabrata. The method being developed
can be broadly applied to other microbial pathogens to better identify how pathogens adapt and evolve in a more
host-relevant environment, and enables the identification of potential therapeutic strategies against difficult-to-
treat biofilms. This R16 will fund the research of approximately 20 undergraduates (UGs) over four years,
including many minority trainees. UGs will perform the majority of the proposed work, with training and
mentorship from a technician and the PI. This funding would allow the PI to continue to develop a strong track
record in research, give meaningful research experiences to underrepresented minority students, and enhance
the research capacity at San Jose State University.