Life Sciences Commons^™

Antimicrobials Produced By Ants: Chemical Properties And Microbe Specificity, Katy Chon, Clint A. Penick

Master's Theses

Antibiotic resistance is a growing public health concern worldwide, and for over a decade, we have been witnessing the growth of difficult to treat infectious diseases caused by bacteria that are becoming resistant to antibiotics. This resistance can be mostly related to the misusing and improper use of antibiotics in both humans and animals. To restore this problem, humans have turned to new sources for the production of antibiotics. In this study, we focused on using ants. Social insects, including ants and bees, have faced strong disease pressures during their evolution and have developed a range of methods to fight …

Distribution Of Micropredators In The Longleaf Pine Soil Microbiome, Faith Arends, Eithar Mirghani

Symposium of Student Scholars

Bacterial micropredators of the soil, like their larger-scale counterparts, play a key role in shaping their ecosystem and are thus of particular interest from an ecological standpoint. An important micropredator to study are Myxobacteria. Myxobacteria are gram-negative rod-shaped social bacteria that hunt in wolf packs to lyse their prey and facilitate their growth. Myxobacteria are a potential source of novel antibiotics, therefore, the isolation of new strains is of great interest. We investigated longleaf pine soil as a source of novel isolates. The Longleaf Pine Ecosystem is an endangered ecosystem that is of crucial importance due to its ability to …

Guano Among Bat Species From Two Regions Shows Influence Of Geography And Diet On Bacterial Community, Rahma Ahmed, Thomas Mcelroy, Shannon Whitney, Lydia Moore

Symposium of Student Scholars

Studies of bat guano have shown that the diversity and structure of associated microbial communities can be related to factors such as host phylogeny, life history and reproductive stage, geography, and diet. Many insectivorous bat species in the southeastern U.S. have generalist diets that may shift seasonally to take advantage of abundant prey species or maximize caloric intake. Seasonal shifts in prey availability or consumption should be reflected in a guano microbiome change. We also expected to detect distinct guano microbiomes within species. Within species, distinct microbial communities related to geography, and finally life history and reproductive stage. We compared …

Alternative Precautionary Measures Yielding Lower C. Diff Infection Rates In Healthcare Facilities, Matthew Kramer

Symposium of Student Scholars

Background: An international healthcare concern is the persistent spread of Clostridium difficile, a Gram-positive spore forming bacterium that is responsible for the most common hospital-acquired infection, amongst patients.

Objective: A systematic review was performed to summarize evidence that the interventions utilized in healthcare facilities which indicate a patient’s precautionary status are insufficient, outdated, and commonly lead to infection in neighboring patient rooms. Databases such as PubMed, NCBI, Google Scholar, and APHA’s Medical Care were searched, covering the period from 2017-2022. Studies were included if their focus concentrated on C. diff and the precautionary measures taken by employees at healthcare …

Detecting Bacterial Species From Ancient Human Skeletal Samples, Ariel Owens, Daisy Mcgrath, Tsai-Tien Tseng

Symposium of Student Scholars

Diagnosis of tuberculosis (TB) via morphological analysis is difficult and often inconsistent. With next-generation sequencing (NGS), ancient host microbiomes can be subjected to metagenomic analyses for the detection of TB in silico. Suitable bioinformatic workflows are needed for reliable ancient DNA (aDNA) analysis of causative agents. This study aims to enhance available bioinformatic screening methods to create more suitable bioinformatic processes and generate insights in relation to TB.

This research utilizes publicly available NGS data accessed through the Sequence Read Archive (SRA) of the National Center for Biotechnology Information (NCBI). Initial quality control steps included adapter trimming with Trim …

Growth Outcomes Of Pseudomonas Aeruginosa Inhibitor Of Vertebrate Lysozyme Knockouts In Conditions Mimicking The Cystic Fibrosis Lung Environment, Amani Gaddy

Master of Science in Chemical Sciences Theses

Pseudomonas aeruginosa (PA) is a Gram-negative bacterium, often found in cystic fibrosis (CF) patients and can lead to the decline of lung functioning and premature death in 80% of infected patients when microcolonies form within the mucin of the lung. Due to its major capacity for antibiotic resistance, an alternative strategy towards defending against the bacterial invasion of PA is by the antibacterial activity of our own innate immune system with use of elements such as lysozyme. Pseudomonas aeruginosa inhibitor of vertebrate lysozyme class 1 (Ivyp1) is a periplasmic protein produced by gram-negative bacteria that inhibits the enzymatic activity of …

Pseudomonas Aeruginosa Evades Predation By Myxococcus Xanthus, Sarah Joie Beauvais

Symposium of Student Scholars

Multidrug-resistant Pseudomonas aeruginosa causes an estimated 32,600 hospital-acquired-infections and 2,700 estimated deaths in the US in 2017(CDC). Myxococcus xanthus is a strain of myxobacteria that preys on Pseudomonas sp, through the production of antibiotics and digestive enzymes. In previous experiments, P. aeruginosa evaded predation, through an unknown mechanism. Using confocal microscopy, this research investigates if quorum sensing, a cell density-dependent signaling pathway, could be a factor in motility and evasion of M. xanthus. Liquid suspensions of log-phase PA01 were dyed with two fluorescent dyes: SYTO 9 for marking live cells and Propidium iodide (PI) for marking dead cells. …

Microbial Diversity And Community Structure In Sediments Associated With The Seagrass (Thallassia Testudinum) In Apalachicola Bay, Florida, Rahma Ahmed, Thomas Mcelroy, Troy Mutchler

Symposium of Student Scholars

Seagrass is an angiosperm which provides many ecosystem services in coastal areas, such as providing food, shelter and nurseries for many species, and decreasing the impact of waves on shorelines. A global assessment reported that 29% of known seagrass meadows are in a state of decline due to the effects of human activity. Seagrass is commonly found in shallow marine waters where they form meadows containing a microbiome that plays an important role in providing nutrients for seagrass growth, though little is known about the microorganisms within the seagrass meadow sediments. Our project collected sediments from seagrass meadows and adjacent …

Biocontrol Of Foodborne Pathogens Using Bacteriophages, Dzhuliya Ignatova, Erion Hogan, Simone Dakare, Jean Lu

Symposium of Student Scholars

Biocontrol of Foodborne Pathogens Using Bacteriophages

Dzhuliya Ignatova, Erion Hogan, Simone Dakare, and Jean Lu

Department of Molecular and Cellular Biology

Abstract

Salmonella and Shigella are two important groups of foodborne bacterial pathogens. Salmonella cause an illness called salmonellosis while Shigella cause shigellosis (bacillary dysentery). The most common symptoms of these illnesses are abdominal cramps, diarrhea, and fever. Shigella can also cause bloody diarrhea. It was estimated that each year Salmonella cause 93.8 million cases of gastroenteritis and 155,000 deaths globally. Shigella causes 164.7 million cases and 1.1 million deaths throughout the world yearly. People get these illnesses mainly by …

S-Layer Increases Predation Ability Of Myxococcus Xanthus

Symposium of Student Scholars

Background: Myxococcus xanthus is a gram-negative soil bacterium that exhibits micro-predatory activities. When starved, M. xanthus produces resistant spores within fruiting bodies for survival. The S-layer is a paracrystalline structure intertwined in many different patterns and is composed of proteins or glycoproteins. A species that produces the S-layer is Aeromonas. A. salmonicida is a strain of Aeromonas that infects fish. A. hydrophila is another pathogenic strain that causes a wide range of human diseases. We investigated the ability of the S-layer to protect Aeromonas from predation by Myxobacteria. Methods: Myxococcus and prey Aeromonas cultures were standardized to a concentration …

Bacteriophages Infecting Enterobacter Cloacae To Reduce Bloater Damage In Fermented Cucumbers

Symposium of Student Scholars

Fermented cucumbers are one of the most important fermented vegetables consumed worldwide. During cucumber fermentations, certain undesirable changes may occur. One of such changes is known as bloater defect (hollow cavities in fermented cucumbers), which is primarily caused by gas-producing bacteria including Enterobacter cloacae. Bloater defect lowers product quality and leads to significant economic loss to the pickle industry, and effective preventative methods are needed. Bacteriophages (phages) are highly host-specific bacterial killers. Use of phages to control unwanted bacteria in foods is a promising approach because phages do not change food properties. This research was to isolate, characterize, and …

Effectiveness Of Bacteriophages Against Bloater-Causing Bacteria Enterobacter Cloacae In A Model Food System, Ashley Reed, Dzhuliya Ignatova, Sandra Kopic, Unique Sardeneta

Symposium of Student Scholars

Effectiveness of bacteriophages against bloater-causing bacteria Enterobacter cloacae in a model food system

Department of Molecular and Cellular Biology

Ashley Reed, Dzhuliya Ignatova, Sandra Kopic, Unique Sardeneta, and Jean Lu

Abstract

Cucumber fermentation is one of the most important vegetable fermentations in the United States and Europe. Enterobacter cloacae and other gas-producing bacteria can cause bloater defect (the gas pockets or hollow cavities formed in fermented cucumbers) which lowers the quality and the yield of fermented cucumbers, thereby resulting in significant economic losses to the pickling industry. Cost-effective strategies to control E. cloacae and other microbiota need to be …

Examining Effects Of The Dna Regulator Lrp On Quorum Sensing Gene Expression In Pseudomonas Aeruginosa, Bradley Lumsden

Symposium of Student Scholars

Pseudomonas aeruginosa is an opportunistic human pathogen that has the capacity to express multiple virulence factors that are regulated through an extensive quorum sensing network. Three major quorum sensing systems have been identified in Pseudomonas species: the acyl homoserine lactones of las and rhl, and the Pseudomonas Quinolone Signal (PQS). We seek to investigate the involvement of a global regulator, Lrp with the expression of these three networks. Specifically, we will compare expression levels of las, rhl, and pqs in wild type P. aeruginosa (MPAO1) with an lrp transposon insertion mutant using quantitative PCR. Through this comparative …

The Role Of Proneural Transcription Factor Ngn-1/Neurogenin During Caenorhabditis Elegans Embryonic Development, Michaela Diane Crego

Symposium of Student Scholars

Accurate control of neuronal cell identification and movement is crucial to embryonic development. Defects in this process can lead to neurodevelopmental disorders, creating an imperative for further study. The transcription factor neurogenin is required for multiple neurodevelopmental processes during vertebrate embryonic development and mutations in this gene underpin multiple human neurological disorders. Despite this, little is known about how this gene controls nervous system development and function. Neurogenin is deeply conserved across phyla. As such, we can investigate neurogenin function in simple systems such as the nematode Caenorhabditis elegans, which has a close ortholog of neurogenin, ngn-1. Previous work in …

Soil Bacteria: Metabolic Diversity In A Wildlife Management Area, Nicholas Green

Symposium of Student Scholars

This research is part of a larger study linking the soil microbiome and processes to the aboveground plant community.

Soil samples were collected from six plots under closed canopy in the Sheffield Wildlife management area in the Piedmont ecoregion of Georgia in Paulding County. Two of the plots were located in the longleaf pine savanna where restoration of longleaf pine has been in place since 2010. Samples were collected in sterile plastic tubes at the center of each plot and 10 meters above and below the center. For each sample, soil pH and the concentration of nitrogen (N), phosphorus (P), …

Efficacy Of Volatile Organic Compounds As Treatment For Bats Affected With White-Nose Syndrome, Whitney Jones

Symposium of Student Scholars

Pseudogymnoascus destructans, the causative agent of white-nose syndrome (WNS), is a fungal pathogen implicated in the widespread mortality of hibernating bats across North America. Since its arrival to the United States in 2006, the pathogen has spread rapidly to 34 US states and 7 Canadian provinces. Researchers have been searching for disease management strategies to minimize the spread and severity of this fungal pathogen, as bats are an important aspect of a healthy regional and global ecosystem as insect predators and pollinators. Volatile organic compounds (VOCs), produced by a variety of microorganisms, have been found to exhibit antimicrobial properties …

Glide Another Day: Characterization Of Wild Isolates Of Predatory Myxobacteria, Daniella Krakue, Juan Vasquez, Simone Dakare

Symposium of Student Scholars

Myxobacteria belongs to a group of predatory bacteria that are found in various soil environments. They are exceptionally unique microbes who use their gliding motility to move towards prey microbes and consume them. They also have the remarkable ability to produce secondary metabolites that have antibacterial, antifungal, antiviral, and antitumor properties. For this reason, they are of interest to us so that we can understand their abilities and apply them to discover their potential as a source of novel metabolites with potential therapeutic applications. Our methodology began by collecting soil samples from various sites around the country. We then standardized …

Community Level Physiological Profiling Of The Longleaf Pine Savannah Microbiome, Gavin Treadaway

Symposium of Student Scholars

Soil microorganisms secrete chemicals into their surroundings, which the root system will uptake and in return release root exudates, which usually consist of low-molecular-weight organic compounds. These root exudates behave as signaling molecules and substrates for microorganisms to recruit beneficial soil bacteria to the plant root system, which will provide the plants with immunity to foliar diseases and pathogen infection. Studies have shown that bacteria on the root surface can protect aerial sections of the plant by promoting induced systemic resistance, a mechanism of increasing physical or chemical barriers of the plant.

The longleaf pine is an endangered species of …

Manipulation Of The Microbiome In The Gut Of The Fruit Fly To Alleviate Cadmium Bioaccumulation, Natasya Tamba

Symposium of Student Scholars

Cadmium (Cd) poisoning contributes to severe bodily detriments characterized by kidney failure, osteomalacia, and osteoporosis, otherwise known as Itai-Itai disease. The ingestion of cadmium contaminated foods primarily causes these conditions. There are no treatments to remove cadmium once absorbed, resulting in bioaccumulation. In this study, we are developing a method to manipulate the community of microorganisms (microbiome) living within the gastrointestinal (GI) tract of the fruit fly (Drosophila melanogaster), intending to use microorganisms to reduce the availability of ingested cadmium.

The biodiversity of microorganisms within the GI tract is responsible for metabolizing substances that the body cannot perform. …

Detecting Bacterial Species From Ancient Human Skeletal Samples, Ariel Owens, Daisy Mcgrath, Tsai-Tien Tseng

Symposium of Student Scholars

This paleopathological study aims to identify Mycobacterium tuberculosis complex (MTBC), Mycobacterium avium complex (MAC) and other Mycobacterium species in silico from skeletal samples that belonged to 28 Polish individuals in the Neolithic period under PRJNA422903 from the Sequence Read Archive (SRA). After next-generation sequencing (NGS), bioinformatics methods are heavily relied upon for identification of pathogens from complex samples. We implemented a bioinformatics pipeline, with custom-built databases, utilizing the following software tools: Trim Galore! and Kraken2. After adapter trimming, Kraken2 was used for taxonomic classifications. We have found that Mycobacterium is present in all 28 individuals. The average percentage of MAC …

Identification And Comparison Of Arbuscular Mycorrhizal Fungi And Soil Microbiomes Between American Chestnuts And Surrounding Hardwoods, Sarah Andrews, Geoffrey Eger, Isabella Vahle

Symposium of Student Scholars

Background/Questions/Methods

The introduction of the Chinese chestnut blight in 1904 decimated native American chestnut (Castanea dentata (Marshall) Borkh.) populations. In this study we aim to: 1) document the location of individual chestnuts in our vicinity; 2) document healthy versus blight infected individuals; 3) characterize putative differences in the soil microbiome between infected and non-infected individuals, as well as between chestnuts and hardwood neighbors. With this information we hope to provide new insights into mechanisms that may enhance blight and fungal resistance in American chestnuts through the understanding of the interactions between the trees and their surrounding soil microbiome.

Soil …

Investigating The Sars-Cov-2 Orf 8 Accessory Protein: Expression, Purification, And Structural Determination, Laney Hedgeman, Caroline Salha

Symposium of Student Scholars

Abstract

In order to provide insight into potential therapeutic breakthroughs for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), more research must be done to understand the structure and function of its proteins. The open reading frame 8 (ORF 8) accessory protein is particularly unstable on its own outside of the viral envelope but can be stabilized when bound to the small ubiquitin-related modifier (SUMO) protein. The stable ORF 8-SUMO protein complex can be expressed and purified using familiar techniques and later characterized with nuclear magnetic resonance (NMR) spectroscopy, thus allowing us to gain knowledge about the role it plays …

Evaluating Volatile Organic Compounds For Contact-Independent Antagonism Of Pseudogymnoascus Destructans

Symposium of Student Scholars

White-nose syndrome (WNS), a disease caused by the fungus Pseudogymnoascus destructans, is responsible for the extensive mortality of bats in the United States. In an effort to develop tools to reduce bat mortality attributed to WNS, an in vitro experiment was conducted to quantify the inhibitory effects of select volatile organic compounds (VOCs) as well as explore potential synergistic activities. The experiment involved exposing mycelial plugs of P. destructans to various concentrations of B23 as well as B23 and decanal together at equimolar ratios. Measurements of the plugs were taken over the course of the 13 day experiment allowing …

Substrate Utilization Of The Emerging Fungal Pathogen, Candida Auris, And The Antifungal Activity Of Select Essential Oils, Ryan Parker

Master of Science in Integrative Biology Theses

Candida auris is an emerging fungal pathogen that commonly causes nosocomial blood infections in the immunocompromised. Three factors make this emerging pathogen a global threat. First, it is frequently misidentified by commonly used diagnostic platforms. Second, it is able to survive for weeks on fomites. Third, it is almost always drug resistant, sometimes to all three classes of antifungal drugs used to treat Candida infections. The objectives of this study are three-fold. First, two existing methods, population estimation using absorbance-based standard curves and methylene blue viability staining, were investigated as to application in determining Candida auris cell population size and …

Weak Interactions Between Salmonella Enterica Flhb And Other Flagellar Export Apparatus Proteins Govern Type Iii Secretion Dynamics, Jonathan L. Mcmurry, Tohru Minamino, Yukio Furukawa, Joshua W. Francis

Faculty Articles

The bacterial flagellum contains its own type III secretion apparatus that coordinates protein export with assembly at the distal end. While many interactions among export apparatus proteins have been reported, few have been examined with respect to the differential affinities and dynamic relationships that must govern the mechanism of export. FlhB, an integral membrane protein, plays critical roles in both export and the substrate specificity switching that occurs upon hook completion. Reported herein is the quantitative characterization of interactions between the cytoplasmic domain of FlhB (FlhBC) and other export apparatus proteins including FliK, FlhAC and FliI. FliK and FlhAC bound …

A Synthetic Lethal Screen Identifies A Role For Lin-44/Wnt In C.Elegans Embryogenesis, Samanth N. Hartin, Martin L. Hudson, Curtis Yingling, Brian D. Ackley

Faculty Articles

Background The C. elegans proteins PTP-3/LAR-RPTP and SDN-1/Syndecan are conserved cell adhesion molecules. Loss-of-function (LOF) mutations in either ptp-3 or sdn-1 result in low penetrance embryonic developmental defects. Work from other systems has shown that syndecans can function as ligands for LAR receptors in vivo. We used double mutant analysis to test whether ptp-3 and sdn-1 function in a linear genetic pathway during C. elegans embryogenesis. Results We found animals with LOF in both sdn-1 and ptp-3 exhibited a highly penetrant synthetic lethality (SynLet), with only a small percentage of animals surviving to adulthood. Analysis of the survivors demonstrated that …

How Does The Exploitation And Degradation Of Finite Natural Resources By Industrial Oil Producers Effect Our Future Planetary Environment?, Zachary J. King Mr.

Symposium of Student Scholars

Zachary King

Dr. Tu

26 March 2015

GEOG 3700

Abstract

The purpose of this presentation is to communicate content of the reports given by credible institution on the degradation and exploitation of finite natural resources by corporate institutions, for short term financial gain, and how it will effect the future planetary environment. Methods used in obtaining this research range from point source observation directly from oil spills in the Gulf or pipe leaks in the Mid-West, to analytical and numerical data quantifications gathered over a period of two decades. This presentation encompasses a wide scope of information concerning the way …

Characterization Of Myxococcus Xanthus Mazf And Implications For A New Point Of Regulation, Tye O. Boynton, Jonathan L. Mcmurry, Lawrence J. Shimkets

Faculty Articles

During development, Myxococcus xanthus cells undergo programmed cell death (PCD) whereby 80% of vegetative cells die. Previously, the MazF RNA interferase has been implicated in this role. Recently, it was shown that deletion of the mazF gene does not eliminate PCD in wild-type strain DK1622 as originally seen in DZF1. To clarify the role of MazF, recombinant enzyme was characterized using a highly sensitive assay in the presence and absence of the proposed antitoxin MrpC. In contrast to previous reports that MrpC inhibits MazF activity, the hydrolysis rate was enhanced in a concentration-dependent manner with MrpC or MrpC2, an N-terminally …

Bacteriophage Ecology In A Commercial Cucumber Fermentation, Jean Lu, Ilenys M. Perez-Diaz, Janet S. Hayes, Fred Bredit Jr.

Faculty Articles

To reduce high-salt waste from cucumber fermentations, low-salt fermentations are under development. These fermentations may require the use of starter cultures to ensure normal fermentations. Because potential phage infection can cause starter culture failure, it is important to understand phage ecology in the fermentations. This study investigated the phage ecology in a commercial cucumber fermentation. Brine samples taken from a fermentation tank over a 90-day period were plated onto deMan-Rogosa-Sharpe agar plates. A total of 576 lactic acid bacterial isolates were randomly selected to serve as potential hosts for phage isolation. Filtered brine served as a phage source. Fifty-seven independent …

Helicobacter Pylori Hydrogenase Accessory Protein Hypa And Urease Accessory Protein Ureg Compete With Each Other For Uree Recognition, Stéphane L. Benoit, Jonathan L. Mcmurry, Stephanie A. Hill, Robert J. Maier

Faculty Articles

Background: The gastric pathogen Helicobacter pylori relies on nickel-containing urease and hydrogenase enzymes in order to colonize the host. Incorporation of Ni2+ into urease is essential for the function of the enzyme and requires the action of several accessory proteins, including the hydrogenase accessory proteins HypA and HypB and the urease accessory proteins UreE, UreF, UreG and UreH. Methods: Optical biosensing methods (biolayer interferometry and plasmon surface resonance) were used to screen for interactions between HypA, HypB, UreE and UreG. Results: Using both methods, affinity constants were found to be 5nM and 13nM for HypA–UreE and 8μM and 14μM for …