Microbiology Commons^™

Characterization Of The Extracellular Proteome Of A Natural Microbial Community With An Integrated Mass Spectrometric / Bioinformatic Approach, Brian Keith Erickson

Doctoral Dissertations

Proteomics comprises the identification and characterization of the complete suite of expressed proteins in a given cell, organism or community. The coupling of high performance liquid chromatography (LC) with high throughput mass spectrometry (MS) has provided the foundation for current proteomic progression. The transition from proteomic analysis of a single cultivated microbe to that of natural microbial assemblages has required significant advancement in technology and has provided greater biological understanding of microbial community diversity and function.

To enhance the capabilities of a mass spectrometric based proteomic analysis, an integrated approach combining bioinformatics with analytical preparations and experimental data collection was …

Analysis Of Polymorphism In Human Cytomegalovirus (Hcmv) Chemokine, Vcxcl-1, And Its Role In Cellular Activation, Jinho Heo

Doctoral Dissertations

The human cytomegalovirus (HCMV) viral chemokine gene, UL146, shows a high degree of variability in clinical isolates. The UL146-produced viral chemokine, vCXCL-1, has homology to CXC chemokines and is predicted to be an immune modulator that may contribute to the pathogenesis of HCMV infections. In the analysis of clinical isolates from congenitally infected infants, we found 11 distinct vCXCL-1 clades. Although the four cysteine residues that create two disulfide bonds providing the essential structure for CXC chemokines,are conserved, the N-loop region, which is important for receptor binding and activation, was hypervariable. One clade also contained a modified glutamic acid-leucine-arginine (ELR) …

Mechanisms Of Antimicrobial Peptide Resistance In Campylobacter, Ky Van Hoang

Doctoral Dissertations

Campylobacter is the major bacterial cause of human gastroenteritis in the United States and other developed countries. Poultry are considered a main source of human Campylobacter infections. Thus, reduction of Campylobacter load in poultry is significant in food safety and public health. However, no effective measure is commercially available to prevent Campylobacter colonization in poultry to date. Antimicrobial peptides (AMPs) are short and bactericidal peptides widely present in intestine to limit bacterial infections. Recently, AMPs have been increasingly recognized as a novel class of antibiotics (peptide antibiotics) to control foodborne pathogens. Notably, several potent anti-Campylobacter bacteriocins, a group of AMPs …

An Analysis Of Global Gene Expression Resulting From Exposure To Energetic Materials, Vernon L. Mcintosh Jr.

Doctoral Dissertations

AN ANALYSIS OF GLOBAL GENE EXPRESSION RESULTING FROM EXPOSURE TO ENERGETIC MATERIALS

A Dissertation

Presented for the Doctor of Philosophy Degree

University of Tennessee, Knoxville

VERNON LASHAWN MCINTOSH JR.

August 2010

Dedication

This dissertation is dedicated to my family. My mother and father Debra and Vernon McIntosh instilled in me the respect for academic excellence and the drive maximize my potential. Early on, my younger brother Kyle started showing signs of a shared interest in biology thus my desire to be a positive role model for him kept me motivated. Last but certainly not least, my loving wife and best …

5’-Proximal Cis-Acting Rna Signals For Coronavirus Genome Replication, Bo-Jhih Guan

Doctoral Dissertations

RNA sequences and higher-order structures in the 5’ and 3’ untranslated regions (UTRs) of positive-strand RNA viruses are known to function as cis-acting elements for translation, replication, and transcription. In coronaviruses, these are best characterized in the group 2a bovine coronavirus (BCoV) and mouse hepatitis virus (MHV), yet their precise mechanistic features are largely undefined. Here, we use a reverse genetics system in MHV to exploit the ~30% nt sequence divergence between BCoV and MHV to establish structure/function relationships of 5’ UTR cis-replication elements. It had been previously shown that a precise replacement of the 391-nt MHV 3’ UTR with …

Methicillin Resistance In Staphylococcus Pseudintermedius, Chad Christopher Black

Doctoral Dissertations

Staphylococcus pseudintermedius affecting dogs is analogous to S. aureus on humans, acting as both normal flora and opportunistic pathogen. Methicillin resistance in S. pseudintermedius is recent, with the first documented occurrence of an isolate bearing the methicillin resistance gene, mecA, in 1999. This gene encodes penicillin binding protein 2a, which renders all beta-lactam drugs ineffective and functions as a “gateway” antibiotic resistance determinant. In the presence of ineffective antibiotics, opportunities for mutational events and acquisition of mobile genetic elements increase as microbial densities increase, often leading to multi-drug resistance. Methicillin-resistant S. pseudintermedius (MRSP) infections have become increasingly common. For …

Campylobacter Pathogenesis And Subunit Vaccine Development, Ximin Zeng

Doctoral Dissertations

Campylobacter jejuni is the leading bacterial cause of human gastroenteritis in the United States. Increasing resistance of Campylobacter to clinical antibiotics raises an urgent need for novel strategies to prevent and control infections in humans and animal reservoirs, which necessitates a better understanding of Campylobacter pathogenesis. We hypothesize that multidrug efflux pump CmeABC and ferric enterobactin (FeEnt) iron acquisition systems, which play a critical role in Campylobacter pathogenesis, are novel targets for developing effective measures against Campylobacter. To test this, the molecular, antigenic, functional, and protective characteristics of two outer membrane proteins, CmeC (an essential component of CmeABC drug efflux …

Use Of Proteomics Tools To Investigate Protein Expression In Azospirillum Brasilense, Gurusahai K. Khalsa-Moyers

Doctoral Dissertations

Mass spectrometry based proteomics has emerged as a powerful methodology for investigating protein expression. “Bottom up” techniques in which proteins are first digested, and resulting peptides separated via multi-dimensional chromatography then analyzed via mass spectrometry provide a wide depth of coverage of expressed proteomes. This technique has been successfully and extensively used to survey protein expression (expression proteomics) and also to investigate proteins and their associated interacting partners in order to ascertain function of unknown proteins (functional proteomics). Azospirillum brasilense is a free-living diazotrophic soil bacteria, with world-wide significance as a plant-growth promoting bacteria. Living within the rhizosphere of cereal …