Publication Date
2020
Document Type
Dissertation/Thesis
First Advisor
Calvo, Ana M.
Degree Name
Ph.D. (Doctor of Philosophy)
Legacy Department
Department of Biological Sciences
Abstract
The fungus Aspergillus fumigatus is a ubiquitous opportunistic human pathogen capable of causing a life-threatening disease called invasive aspergillosis, or IA, with an associated 40–90% mortality rate in immunocompromised patients. Of the approximately 250 species known in the genus Aspergillus, A. fumigatus is responsible for up to 90% of IA infections. This study focuses on examining the role of the putative polysaccharide synthase cpsA gene in A. fumigatus virulence. Additionally, we evaluated its role in cellular processes that influence invasion and colonization of host tissue. Importantly, our results support that cpsA is indispensable for virulence in A. fumigatus infection of non-neutropenic hosts. Our study revealed that cpsA affects growth and sporulation in this fungus. Absence of cpsA resulted in a drastic reduction in conidiation and forced overexpression of cpsA produced partially fluffy colonies with low sporulation levels, suggesting that wild-type cpsA expression levels are required for proper conidiation in this fungus. This study also showed that cpsA is necessary for normal cell wall integrity and composition. Furthermore, both deletion and overexpression of cpsA resulted in a reduction in the ability of A. fumigatus to adhere to surfaces and caused increased sensitivity to oxidative stress. Interestingly, composition analysis of EPS sample indicated that forced overexpression of cpsA causes altered composition and metabolomics analysis indicated that cpsA affects A. fumigatus secondary metabolism. Forced overexpression of cpsA resulted in a statistically significant difference in the production of fumigaclavine A, fumigaclavine B, fumigaclavine C, verruculogen TR-2, and tryprostatin A
Recommended Citation
Nepal, Binita, "Characterization of The Putative Polysaccharide Synthase cpsA and Its Effects on The Virulence of The Human Pathogen aspergillus Fumigatus" (2020). Graduate Research Theses & Dissertations. 7491.
https://huskiecommons.lib.niu.edu/allgraduate-thesesdissertations/7491
Extent
58 pages
Language
eng
Publisher
Northern Illinois University
Rights Statement
In Copyright
Rights Statement 2
NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.
Media Type
Text
