Bacterial persistence is considered as one of the primary reason for antibiotic tolerance besides genetically acquired antibiotic resistance. Persisters are the subpopulation of a clonal bacterial population, which can survive environmental extremes and become invulnerable to stresses due to limited metabolic activities and physiological functions. Cognate toxin and antitoxin (TA) pairs, which are transcribed simultaneously from the same or different operons within the bacterial chromosomes or plasmids, play an important role for bacterial survival during stressful growth environments. Pseudomonas aeruginosa PAO1 is one of the most versatile microorganisms in the environment. Despite its ubiquitous presence, no studies have shown the differential expression pattern of its toxin-antitoxins, and persistence related genes. The purpose of the following study is to analyze differential expression of P. aeruginosa PAO1 type II toxin-antitoxins and persistence related genes under different growth conditions and to show how their stoichiometric ratio changes during different growth conditions. Differential expression analysis indicated that the toxins and antitoxin pairs behave differently under different growth conditions. In addition, the genes related to persistence presented relatively consistent differential expression pattern under different growth environment. / Master of Science / Bacterial persistence is one of the main reason for antibiotic tolerance and recurrent infections. Toxin-antitoxin molecules play an important role during bacterial persistence. Change in the expression of toxin, antitoxins, and persistence related genes and the ratio of the toxin to antitoxin mRNA molecules are important for bacterial survival in stressful environments. Pseudomonas aeruginosa PAO1 is one of most ubiquitous bacteria and responsible for recurrent infection in patients with weaker and compromised immunity. This mRNA sequence (RNA-Seq) analysis study of P. aeruginosa PAO1 showed different expression levels of toxin, antitoxin, and persistence related genes in various stressful growth conditions. This expression also showed the different ratios of the toxin to antitoxin mRNA molecules under different stress conditions. These implicate the different hypothetical roles of these toxin and antitoxin molecules in different growth conditions.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/83841 |
| Date | 02 July 2018 |
| Creators | Haque, Anamul |
| Contributors | Biological Sciences, Jensen, Roderick V., Schubot, Florian D., Chen, Jing, Scharf, Birgit E. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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