Microbiology Commons^™

Mechanistic Characterization Of Resistome And Microbiome Dynamics Across Diverse Microbial Habitats, Andrew John Gasparrini

Arts & Sciences Electronic Theses and Dissertations

Increasing antibiotic resistance in pathogens is a serious public health challenge, with over two million antibiotic resistant infections in the United States leading to at least 23,000 deaths and an estimated $55 billion in excess healthcare and societal costs. Antibiotic resistance has risen steadily in both pathogenic and benign bacteria since antibiotics’ introduction to agriculture and medicine 70 years ago. A dramatic reduction in the number of antibiotics approved for human use has accompanied this rise in antibiotic resistance, leading to the alarming prospect of a post-antibiotic era. Understanding the evolutionary origins, genetic contexts, and molecular mechanisms of antibiotic resistance …

Thermal And Microbial Effects On Brown Macroalgae: Heat Acclimation And The Biodiversity Of The Microbiome, Charlotte Tc Quigley

Electronic Theses and Dissertations

This dissertation examines effects of stress on brown algal biology from a macroscopic scale by examining the whole aquaculture crops, and at a microscopic level by examining the macroalgal microbiome, across the vertical stress gradient of the intertidal zone and across the latitudes of their biogeographic ranges. Thermal stress negatively affected seedstock gametophytes of the kelp Alaria esculenta isolated from northern and southern locations in Maine. However, previous thermal stress had a positive effect on growth of the next-generation sporophytes. Alaria esculenta has potential as a kelp crop in Maine’s sea vegetable aquaculture sector and implementing this protocol may allow …

Mycobacterium Tuberculosis Inhibitors: Action And Resistance, Pamela K. Garcia-Moreno

FIU Electronic Theses and Dissertations

Tuberculosis, an infectious disease caused by Mycobacterium tuberculosis, has been a global health problem for years. The emergence of drug resistance in this organism generates the necessity of exploring novel targets and developing new drugs. Topoisomerases are enzymes found in all kingdoms of life responsible for overcoming the topological barriers encountered during essential cellular processes. The genomes of mycobacteria encode only one type IA topoisomerase (MtopI), which has been validated as a novel TB drug target. The goal of this study is to obtain new information on the mechanism and resistance of endogenous and synthetic inhibitors of MtopI.

Rv1495 is …

Identification And Characterization Of Nitrogen Fixing Bacteria Associated With Kudzu Root Nodules, Chasity Lawless, Michelle Zedonek, Debbie Curtis, Jonda Scharringhausen, Jared Bryant, Wendy A. Dustman, Alexandra M. Kurtz, Bekah Ward Dr.

Georgia Journal of Science

Pueraria montana, better known as kudzu, is an invasive species rapidly spreading throughout the southeastern United States. This plant can form root nodules which house nitrogen-fixing bacteria, allowing atmospheric nitrogen to be converted into biologically available forms of nitrogen for use by the plant host. Given the centrality of these bacteria to the spread of kudzu, isolates from nodules were characterized after collection from seven different locations across the metropolitan Atlanta area. Twenty-five isolates were grown on two different variants of nitrogen free media. Four different carbon sources were evaluated as well. Finally, growth under both aerobic and anaerobic …

Green Tea Polyphenol Epigallocatechin-3-Gallate-Stearate Inhibits The Growth Of Streptococcus Mutans: A Promising New Approach In Caries Prevention, Amy Lynn Melok, Lee Lee, Siti Ayuni Mohamed Yussof, Tinchun Chu

Department of Biology Faculty Scholarship and Creative Works

Streptococcus mutans (S. mutans) is the main etiological bacteria present in the oral cavity that leads to dental caries. All of the S. mutans in the oral cavity form biofilms that adhere to the surfaces of teeth. Dental caries are infections facilitated by the development of biofilm. An esterified derivative of epigallocatechin-3-gallate (EGCG), epigallocatechin-3-gallate-stearate (EGCG-S), was used in this study to assess its ability to inhibit the growth and biofilm formation of S. mutans. The effect of EGCG-S on bacterial growth was evaluated with colony forming units (CFU) and log reduction; biofilm formation was qualitatively determined by Congo red assay, …

Microbial Ecology Of South Florida Surface Waters: Examining The Potential For Anthropogenic Influences, Chase P. Donnelly

HCNSO Student Theses and Dissertations

South Florida contains one of the largest subtropical wetlands in the world, and yet not much is known about the microbes that live in these surface waters. These microbes play an important role in chemical cycling and maintaining good water quality for both human and ecosystem health. The hydrology of Florida’s surface waters is tightly regulated with the use of canal and levee systems run by the US Army Corps of Engineers and The South Florida Water Management District. These canals run through the Everglades, agriculture, and urban environments to control water levels in Lake Okeechobee, the Water Conservation Areas, …

The Evolution Of Molecular Compatibility Between Bacteriophage Φx174 And Its Host, Alexander Kula, Joseph Saelens, Alyxandria M. Schubert, Michael Travisano, Catherine Putonti

Bioinformatics Faculty Publications

Viruses rely upon their hosts for biosynthesis of viral RNA, DNA and protein. This dependency frequently engenders strong selection for virus genome compatibility with potential hosts, appropriate gene regulation and expression necessary for a successful infection. While bioinformatic studies have shown strong correlations between codon usage in viral and host genomes, the selective factors by which this compatibility evolves remain a matter of conjecture. Engineered to include codons with a lesser usage and/or tRNA abundance within the host, three different attenuated strains of the bacterial virus ФX174 were created and propagated via serial transfers. Molecular sequence data indicate that biosynthetic …

Evolution Of Bordetella Pertussis Genome May Play A Role In The Increased Rate Of Whooping Cough Cases In The United States, Kevin Loftus

Senior Honors Projects, 2010-2019

Bordetella pertussis is the bacterium responsible for pertussis, a disease commonly referred to as whooping cough. Recently, pertussis has made a resurgence in the U.S. despite high-vaccination coverage. Possible causes of the increased number of pertussis cases include genetic evolution of B. pertussis, increased awareness of the disease, better laboratory diagnostics, and the switch from a whole-cellular (wP) vaccine to an acellular vaccine (aP) in the 1990s. Fortunately, just as B. pertussis is evolving, so is the arsenal of technologies used to understand and combat this pathogenic bacterium. Whole genome sequencing is one technology that helps researchers better understand …

Isolation, Sequencing, And Characterization Of Four Transmissible Antibiotic Resistance Plasmids Captured From Bacteria In Stream Sediments, Curtis J. Kapsak

Masters Theses, 2010-2019

Self-transmissible plasmids are key vectors in the transfer of resistance, catabolic, and other genes among bacteria native to environments such as streams and wetlands. The evolution of antibiotic resistance in particular is known to be powerfully affected by conjugative plasmid transfer due to the ease in which some plasmids can be horizontally transferred into a broad range of host bacteria and their ability to exchange mobile genetic elements that often contain antibiotic resistance genes.

In this study, we captured tetracycline resistance plasmids from stream sediments impacted by agricultural runoff. We selected for resistance plasmids using tetracycline, an antibiotic commonly used …

Functional Studies Of The E. Coli Proc And A Putative Ortholog Mrub_1345, Maureen Azar, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

This project is part of the Meiothermus ruber genome analysis project, which uses the bioinformatics tools associated with the Guiding Education through Novel Investigation –Annotation Collaboration Toolkit (GENI-ACT) to predict gene function. We investigated the biological function of Escherichia coli and Meiothermus ruber proC genes using the complementation assay. In this research project, mutants of varying severity to the functional state of the protein were developed. The results showed that two or more amino acid deletions reduced or eliminated ProC function. Amino acid substitutions, on the other hand, were not severe enough to impact ProC function. Double and triple mutants …

Changes In The Microbial Community Of Lubomirskia Baicalensis Affected By Red Sponge Disease, Colin Rorex

Electronic Theses and Dissertations

Lake Baikal is the oldest known lake and a unique ecosystem, home to several species of fresh water sponge. A disease outbreak affecting the dominant species, Lubormirskia baialensis, was recently reported. The cause of the disease has not been determined but one of the current hypothesis is that the increase in methane concentration is correlated to the disease outbreak. This pilot study characterized the microbiomes of sick and healthy sponges through the use of 16S rRNA sequencing. Sick sponge microbiomes shared a conserved group of taxa while the healthy sponge microbiomes had greater diversity. Indicator species analysis identified two significant …

Binding Of Maize Necrotic Streak Virus (Mnesv) 3’ I-Shaped Structure (3’ Iss) To Eukaryotic Translation Factors (Eifs) And Implication In Eif4f Mediated Translation Initiation, Qiao Liu

Dissertations, Theses, and Capstone Projects

5' m⁷GpppN cap and the 3' poly adenosine (A) tail of eukaryotic mRNAs are key elements for recruiting translation initiation machinery in canonical translation initiation. Unlike host mRNAs, many viruses lack these elements and yet they are translated efficiently. Plant viruses, in particular, have complex structures within their untranslated regions (UTR) that allow them to bypass some cellular translation control steps. In Maize necrotic streak virus (MNeSV) 3' UTR, an I-Shaped RNA Structure (ISS) has been reported to mediate the virus translation initiation progress. 3’ ISS binding with eIF4F has been shown to facilitate translation. 5’ -3’ kissing …

Impacts Of Genome And Nuclear Architecture On Molecular Evolution In Eukaryotes, Xyrus Maurer-Alcalá

Doctoral Dissertations

The traditional view of genomes suggests that they are static entities changing slowly in sequence and structure through time (e.g. evolving over geological time-scales). This outdated view has been challenged as our understanding of the dynamic nature of genomes has increased. Changes in DNA content (i.e. polyploidy) are common to specific life-cycle stages in a variety of eukaryotes, as are changes in genome content itself. These dramatic genomic changes include chromosomal deletions (i.e. paternal chromosome deletion in insects; Goday and Esteban 2001; Ross, et al. 2010), developmentally regulated genome rearrangements (e.g. the V(D)J system in adaptive immunity in mammals; Schatz …

A Cure For Salmonella: Engaging Students In Pathogen Microbiology And Bioinformatics, Sophie Jurgensen

Senior Honors Projects, 2010-2019

Advances in Next Generation Sequencing (NGS) technology have generated a vast amount of publicly available genomic data, creating a need for students with training in computational analysis. This laboratory lesson is a course-based undergraduate research experience (CURE) focusing on environmental Salmonella, a common foodborne pathogen that is of great interest to public health laboratories but is relatively less virulent than most other such pathogens. As discovery is a central tenet of CUREs, students isolate novel Salmonella enterica and related strains from stream sediment, poultry litter, or other sources in the first half of the lesson (Module 1). They also …

Mrub_2120, Mrub_2121, Mrub_2122, Mrub_2123 And Mrub_2124 Are Orthologs Of E. Coli Genes B3458, B3457, B3456, B3455 And B3454, Respectively, And Make Up An Operon That Codes For The Branched-Chain Amino Acid Abc Transporter In Meiothermus Ruber Dsm 1279, Aaron Jones, Madelyn Huber, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

In this project we investigated the biological function of the genes Mrub_2120, Mrub_2121, Mrub_2122, Mrub_2123 and Mrub_2124 (KEGG map number 02010). We predict these genes encode components of a branched-chain amino acid ATP Binding Cassette (ABC) transporter: 1) Mrub_2120 (DNA coordinates 2169247-2170416 on the reverse strand) encodes the branched-chain amino acid binding protein that is localized to the periplasm; 2) Mrub_2121 (DNA coordinates 2170433..2171353 on the reverse strand) encodes the first TMD; 3) Mrub_2122 (DNA coordinates 2171365..2172279 on the reverse strand) encodes the second TMD; 4) Mrub_2123 (DNA coordinates 2172276..2173028 on the reverse strand) encodes the first NBD; 5) Mrub_2124 …

Seastar: Systematic Evaluation Of Alternative Transcription Start Sites In Rna, Zhiyi Qin, Peter Stoilov, Xuegong Zhang, Yi Xing

Faculty & Staff Scholarship

Alternative first exons diversify the transcriptomes of eukaryotes by producing variants of the 5′ Untrans- lated Regions (5′UTRs) and N-terminal coding se- quences. Accurate transcriptome-wide detection of alternative first exons typically requires specialized experimental approaches that are designed to iden- tify the 5′ ends of transcripts. We developed a compu- tational pipeline SEASTAR that identifies first exons from RNA-seq data alone then quantifies and com- pares alternative first exon usage across multiple bi- ological conditions. The exons inferred by SEASTAR coincide with transcription start sites identified di- rectly by CAGE experiments and bear epigenetic hall- marks of active promoters. To …

An Interdisciplinary Approach To The Target Elucidation Of Novel Antibiotic 31g12, Larissa A. Walker

Graduate Student Theses, Dissertations, & Professional Papers

Staphylococcus aureus is a Gram-positive bacterial pathogen responsible for nosocomial and community-acquired infections that can quickly acquire antibiotic resistance. We have identified a novel triazole antimicrobial 31G12 based on the natural product core of nonactin isolated from the fermentation of Streptomyces griseus, that is active against many Gram-positive bacteria as well as antibiotic resistant methicillin-resistant S. aureus and vancomycin-resistant Enterococcus. The synthesis and characterization indicate that 31G12 exists as a mixture of two rotamers at room temperature and displays bacteriostatic activity against S. aureus with moderate mammalian cell toxicity. We have currently identified potential protein targets of 31G12 in …

Biosynthetic Mechanism Of The Antibiotic Capuramycin, Erfu Yan

Theses and Dissertations--Pharmacy

A-102395 is a member of the capuramycin family of antibiotics which was isolated from the culture broth of Amycolatopsis sp. SANK 60206. A-102339 is structurally classified as a nucleoside antibiotic, which like all members of the capuramycin family, inhibits bacterial MraY (translocase I) with IC₅₀ of 11 nM which is the lowest among the capuramycin family. A semisynthetic derivative of capuramycin is currently in clinical trials as an antituberculosis antibiotic, suggesting high potential for using A-102395 as a starting point for new antibiotic discovery. In contrast to other capuramycins, A-102395 has a unique arylamine-containing polyamide side chain. The biosynthetic …

Photosynthetic Activity Under Low Light, Danijela Lonco

Williams Honors College, Honors Research Projects

Are bacteria capable of undergoing oxygenic photosynthesis under low-light conditions inside of caves? Inside of an Australian cave, Chlorophyll f was recently discovered. This chlorophyll pigment was found to demonstrate the capability for photosynthesis, suggesting that Chlorophyll f extends the spectrum of usable light needed for oxygenic photosynthesis (Lars, 2015). Due to the findings in this study, a team went to Carlsbad Caverns to see if there were any bacteria capable of undergoing oxygenic photosynthesis under low light.

Evaluating The Resistome And Microbial Composition During Food Waste Feeding And Composting On A Vermont Poultry Farm, Korin Eckstrom

Graduate College Dissertations and Theses

While commonly thought of as a waste product, food scraps and residuals represent an important opportunity for energy and nutrient recapture within the food system. As demands on production continue to increase, conservation of these valuable resources has become a priority area. In the wake of new legislation in Vermont, Act 148, the Universal Recycling Law, the fate of microbial species in food waste, scraps and residuals is increasingly important. The presence of antimicrobial resistance genes in all types of foods calls for an increased need to estimate risk of antibiotic resistance transfer and maintenance across all segments of food …

Bioinformatic Interrogation Of Phosphonate Tailoring Pathways, Monica Papinski

Theses and Dissertations (Comprehensive)

Phosphonates represent an underexploited class of natural products despite their tremendous potential for use in medicine and agriculture. Even less characterized are phosphonate-containing macromolecules such as cell wall lipids and glycans, distinguished by a P-C bond known to provide stability towards hydrolysis. Despite some progress made in revealing cell wall phosphonate tailoring (Pnt) pathways, several barriers impede the discovery and characterization of novel phosphonate biosynthetic pathways. Specifically, a large diversity of gene composition and arrangement is evident surrounding key genes established to participate in phosphonate tailoring pathways, which are identified alongside the presence of the ppm gene encoding the P-C …

Characterization Of Two Cyclic Di-Gmp Phosphodiesterases Hypothesized To Regulate Virulence In Streptomyces Scabies, Madison Flasco

Undergraduate Honors Thesis Projects

Common scab is a devastating disease that affects the marketability of potatoes. The disease results in raised and pitted lesions seen on the surface of the potato and is caused by the soil pathogen, Streptomyces scabies. The S. scabies genome has two cyclic-di-GMP phosphodiesterases, RmdA and RmdB, both regulators of morphology and development. These proteins break down the ubiquitous second messenger molecule cyclic di-GMP, a molecule in charge of cell cycle progression and virulence. Both proteins contain diguanylate cyclase domains and phosphodiesterase domains, GGDEF and EAL, respectively, while RmdA contains an additional PAS_4 domain. Despite similar domain configurations, the two …