Isolation of a Pseudomonas aeruginosa Aspartate Transcarbamoylase Mutant and the Investigation of Its Growth Characteristics, Pyrimidine Biosynthetic Enzyme Activities, and Virulence Factor Production

Description:

The pyrimidine biosynthetic pathway is an essential pathway for most organisms. Previous research on the pyrimidine pathway in Pseudomonas aeruginosa (PAO1) has shown that a block in the third step of the pathway resulted in both a requirement for exogenous pyrimidines and decreased ability to produce virulence factors. In this work an organism with a mutation in the second step of the pathway, aspartate transcarbamoylase (ATCase), was created. Assays for pyrimidine intermediates, and virulence factors were performed. Results showed that the production of pigments, haemolysin, and rhamnolipids were significantly decreased from PAO1. Elastase and casein protease production were also moderately decreased. In the Caenorhabditis elegans infection model the nematodes fed the ATCase mutant had increased mortality, as compared to nematodes fed wild type bacteria. These findings lend support to the hypothesis that changes in the pyrimidine biosynthetic pathway contribute to the organism's ability to effect pathogenicity.

Creator(s): Hammerstein, Heidi Carol
Creation Date: December 2004
Partner(s):
UNT Libraries
Collection(s):
UNT Theses and Dissertations
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Total Uses: 354
Past 30 days: 14
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Publisher Info:
Publisher Name: University of North Texas
Place of Publication: Denton, Texas
Date(s):
  • Creation: December 2004
  • Digitized: December 6, 2007
Description:

The pyrimidine biosynthetic pathway is an essential pathway for most organisms. Previous research on the pyrimidine pathway in Pseudomonas aeruginosa (PAO1) has shown that a block in the third step of the pathway resulted in both a requirement for exogenous pyrimidines and decreased ability to produce virulence factors. In this work an organism with a mutation in the second step of the pathway, aspartate transcarbamoylase (ATCase), was created. Assays for pyrimidine intermediates, and virulence factors were performed. Results showed that the production of pigments, haemolysin, and rhamnolipids were significantly decreased from PAO1. Elastase and casein protease production were also moderately decreased. In the Caenorhabditis elegans infection model the nematodes fed the ATCase mutant had increased mortality, as compared to nematodes fed wild type bacteria. These findings lend support to the hypothesis that changes in the pyrimidine biosynthetic pathway contribute to the organism's ability to effect pathogenicity.

Degree:
Level: Master's
Discipline: Molecular Biology
Language(s):
Subject(s):
Keyword(s): ATCase | pyrimidine | virulence
Contributor(s):
Partner:
UNT Libraries
Collection:
UNT Theses and Dissertations
Identifier:
  • OCLC: 58751635 |
  • ARK: ark:/67531/metadc4704
Resource Type: Thesis or Dissertation
Format: Text
Rights:
Access: Public
License: Copyright
Holder: Hammerstein, Heidi Carol
Statement: Copyright is held by the author, unless otherwise noted. All rights reserved.