Graduation Year


Document Type




Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Biology (Cell Biology, Microbiology, Molecular Biology)

Major Professor

Lindsey N. Shaw, Ph.D.

Committee Member

Prahathees Eswara, Ph.D.

Committee Member

James Riordan, Ph.D.

Committee Member

Burt Anderson, Ph.D.


Energy, Gene Regulation, Iron, Metabolism


Acinetobacter baumannii is an opportunistic pathogen that overtime has evolved into one of the most problematic pathogens due to its ability to overcome antibiotic pressures and harshly environments in the host and hospital environments. In this context, its genomic evolution due to its capacity to acquire genes that contribute to its pathogenic and antibiotic resistance nature has been the subject of research in the last decades providing with the identification of several proteins aiding in the process of pathogenicity. Although these findings have contributed to our understanding of A. baumannii pathogenic traits, the regulatory network that control their expression are less understood. As such, our first efforts to study gene regulation in this organism were focused on defining the complete set of regulatory proteins in A. baumannii. As such, we examined the genome of a highly pathogenic multidrug resistance (MDR) A. baumannii strain AB5075 and comparative analyses to understand evolution of regulatory networks were performed using A. baumannii strains with different MDR profiles. This work generated a complete set of regulatory proteins identified in AB5075. This tool serves us as a foundation to investigate the function of uncharacterized regulatory proteins in this organism. As a result of this, we characterized the role of a two-component system in controlling metabolic pathways and found that its disruption is detrimental for energy generation processes. In addition, we defined the role of an extracytoplasmic sigma factor that is required for efficient growth in the presence of hemin as a sole iron source. Overall, the work of this dissertation presents findings describing regulatory roles of a novel TCS and a sigma factor that will extend the knowledge of gene regulation in A. baumannii.

Included in

Microbiology Commons