Acquisition of aneuploidy in evolved Candida albicans strains increases their fitness in the murine gastrointestinal tract

• Main Author: Tan, Alvin Yong Quan
• Other Authors: School of Biological Sciences
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Science::Biological sciences::Microbiology; DRNTU::Science::Biological sciences::Genetics; DRNTU::Science::Biological sciences::Evolution
• Online Access: http://hdl.handle.net/10356/59760
• Institution: Nanyang Technological University

Candida albicans is an important human fungal pathogen that behaves as a benign commensal in most healthy individuals, but becomes pathogenic when the host is under immunocompromised conditions. The high plasticity of the C. albicans genome has been associated to its ability to rapidly adapt to harsh environments. Aneuploid strains of C. albicans were generated through serial passage experiments in a commensal murine model and an in vivo competition methodology was developed to investigate the fitness of these strains against a fluorescent strain (dTOM) transformed from SC5314 (WT). The aneuploid strains out-competed the dTOM strain within 24-48 hours, and have higher colonizing ability (~108 CFU/g) compared to the control (~106 CFU/g). The average slopes of each competing groups generated in a linear regression model were compared using paired t-test. The increased fitness of the aneuploid strains was significant compared to the control (p<0.05). However, whether this increased fitness may be attributed to aneuploidy is not conclusive. Further studies are needed to better understand the underlying mechanisms behind this increased fitness in order to gain insights into how and when C. albicans behaves as a commensal or as a pathogen.