Life Sciences Commons^™

Optimizing Transposon Mutagenesis In Vibrio Strains To Identify Genes Involved In Antibiotic Production, Mahnur Khan

Honors Projects

Based on previous studies that have shown the competitive nature of non-pathogenic environmental strains of Vibrio, we hypothesize that environmentally derived bacteria can inhibit Vibrio pathogens, and possibly be a source of novel antibiotics. A previous experiment performed in the lab tested environmental Vibrio strains from various habitats against the pathogenic strains, Vibrio cholerae and Vibrio parahaemolyticus. Of the 3,456 strains collected, members of the Wildschutte lab identified 102 environmental strains of Vibrio that inhibited the growth of both pathogens. The data suggests that environmental Vibrio strains directly inhibit the growth of related pathogens. Our project involves the …

Comparing The Effectiveness Of Alternative And Prescription Antibiotics Against Gram-Positive Bacteria, Rachel Jenkins, Roan Dickenson, Sam Turnbull, Marcela Torres

Senior Theses

The rapid emergence of antibiotic-resistant bacteria is a global public health concern that threatens the efficacy of antibiotic drugs. We found that natural remedies, specifically coconut oil, honey and cinnamon essential oil, have the potential to be used as a clinical alternative to treat antibiotic-resistant infections. In this experiment, we performed a disk diffusion test and measured the area of inhibition of each treatment to compare the effectiveness of natural and prescription antibiotics. Cinnamon essential oil showed significantly greater antibiotic activity compared to a prescription treatment, amoxicillin. With bacterial resistance continuously expanding, more work needs to be done to determine …

Emergence Of The L Phenotype In Group B Streptococci In The South Of Ireland, Katherine Hayes, Lesley Cotter, L. Barry, Fiona O'Halloran

Department of Biological Sciences Publications

Group B Streptococcal isolates (n = 235) from the South of Ireland were characterised by serotyping, antimicrobial susceptibility and determination of the phenotypic and genotypic mechanisms of resistance. Resistance to erythromycin and clindamycin was observed in 21·3% and 20·4% of the total population, respectively. The c-MLSB phenotype was the most common phenotype detected (62%), with ermB being the predominant genetic determinant, present in 84% of resistant isolates. The rare L phenotype was observed in 2·9% (n = 7) of isolates, four of which harboured the lsaC gene responsible for clindamycin resistance. Serotypes Ia, III and II were the most common …

Is Tb Testing Associated With Increased Blood Interferon-Gamma Levels?, Aideen E. Kennedy, Jim O'Mahony, Noel Byrne, John Macsharry, Riona G. Sayers

Department of Biological Sciences Publications

The Republic of Ireland reports a relatively low prevalence of Johne’s disease (JD) compared to international counterparts. Postulated reasons for this include a lower average herd size and a grass-based production system. Ireland also engages in high levels of bovine tuberculosis (bTB) testing. As interferon-gamma (IFN-γ) is believed to play a key role in protecting against JD, it is our hypothesis that administration of purified protein derivative (PPD), as part of the bTB test, is associated with a systemic increase in IFN-γ production, which may potentially limit clinical progression of the disease. We studied 265 cows (202 Friesian and 63 …

Microbiology For Allied Health Students, Molly Smith, Sara Selby

Biological Sciences Open Textbooks

This open textbook is a remix of Openstax Microbiology, CC-BY 4.0, and created through an Affordable Learning Georgia Round Six Textbook Transformation Grant.

The textbook has the following supplemental materials within this repository:

This is a collection of instructional materials for the following open textbook and lab manual:

• Microbiology for Allied Health Students Lab Manual
• Microbiology for Allied Health Students Instructional Materials

Authors' Description:

Microbiology for Allied Health Students is designed to cover the scope and sequence requirements for the single semester Microbiology course for non-majors and allied health students. The book presents the core concepts of microbiology …

Sequence Extension Of The Tryptophan And Shikimate Operons In Clostridium Scatologenes Atcc 25775, Shawn Johnston Smiley

Masters Theses & Specialist Projects

3-Methylindole and 4-methylphenol are cytotoxic and malodorant compounds derived from tryptophan and tyrosine, respectively. Each is present in swine waste lagoons and contributes to malodorous emissions from agricultural facilities. Clostridium scatologenes ATCC 25775 produces both compounds and serves as a model organism to study their metabolism and function. Through the repeated assembly and annotation of the Clostridium scatologenes genome, we propose a novel pathway for tryptophan degradation and 3-methylindole production by this organism. The genome of Clostridium scatologenes was sequenced, and re-assembled into contigs. Key elements of the tryptophan and shikimate pathways were identified. Contigs containing these elements were extracted …

Growth And Survivability Of Microorganisms At Martian Temperatures And Pressures, Rebecca Lynne Mickol

Graduate Theses and Dissertations

The discovery of methane in the martian atmosphere via numerous ground- and space-based sources has prompted the study of methanogens as models for life on Mars. Methanogens are microorganisms within the domain Archaea, many of which utilize carbon dioxide (CO2) and hydrogen to produce methane. The non-photosynthetic nature of methanogens indicates that they could exist in sub-surface environments, protected from harmful UV and ionizing radiation on the surface of Mars. These organisms also do not require organics, which are sparse on the planet.

Additionally, the wide variety of environments we find life in on Earth, as well as evidence for …

Microbial Community Richness Distinguishes Shark Species Microbiomes In South Florida, Rachael Cassandra Karns

HCNSO Student Theses and Dissertations

The microbiome (microbial community) of individuals is crucial when characterizing and understanding processes that are required for organism function and survival. Microbial organisms, which make up an individual’s microbiome, can be linked to disease or function of the host organism. In humans, individuals differ substantially in their microbiome compositions in various areas of the body. The cause of much of the composition diversity is yet unexplained, however, it is speculated that habitat, diet, and early exposure to microbes could be altering the microbiomes of individuals (Human Microbiome Project Consortium, 2012b, 2012a). To date, only one study has reported on microbiome …

Genetic Diversity Of Mycobacteriophages And The Unique Abilities Of Cluster K, Shea A. Morris

The Corinthian

Mycobacteriophage are a diverse set of viruses that infect a broad host range of mycobacterium. Genome analysis of this phage group reveals its diversity and provides evidence that they have experienced substantial horizontal gene transfer Collectively they have a large range of host bacteria they can infect, although each viral type may have a limited host range. However, this range is easily expanded and constantly changing in nature by mutation within and between virus types. These phages can lytically destroy their host mycobacteria, and it is this viral ability that have many mycobacteriophage researchers excited about the potential that phage …

Characterizing The Intact Prophage Of Mycobacterium Chelonae Bergey, Erica Sewell

Honors College

Mycobacteriophage (phage), are viruses that infect bacteria. All bacteria can be

infected by phage, and each bacterial species has a unique set of phage that infect them, making phage prime candidates for studying viral diversity and evolution. Some phage integrate their genome into the host genome upon infection (prophage), where they may potentially remain indefinitely, coevolving with the host, and providing growth factors and other benefits to the host. The purpose of my research is to characterize a prophage within the genome of the bacterial host Mycobacterium chelonae Bergey to determine if it is still functional and potentially impacting the …

Accumulation And Expression Of Multiple Antibiotic Resistance Genes In Arcobacter Cryaerophilus That Thrives In Sewage, Jess A. Millar, Rahul Raghavan

Biology Faculty Publications and Presentations

We explored the bacterial diversity of untreated sewage influent samples of a wastewater treatment plant in Tucson, AZ and discovered that Arcobacter cryaerophilus, an emerging human pathogen of animal origin, was the most dominant bacterium. The other highly prevalent bacteria were members of the phyla Bacteroidetes and Firmicutes, which are major constituents of human gut microbiome, indicating that bacteria of human and animal origin intermingle in sewage. By assembling a near-complete genome of A. cryaerophilus, we show that the bacterium has accumulated a large number of antibiotic resistance genes (ARGs) probably enabling it to thrive in the wastewater. We also …

Impact Of Cations On The Sorption Capabilities Of Kaolin Towards Biofilm-Forming Bacteria, Rachel E. Brineman

Georgia College Student Research Events

Biofilm-forming bacteria cause problems for industries such as medical, food, and water treatment. Due to its heterogeneous charges, kaolin is capable of sorption of these microorganisms. These charges are impacted by pH and cations, which change the electrostatic interactions between kaolin particles and microorganisms. Proper pH and cation composition may lead to enhanced sorption. The impact of Al3+ cations on kaolin sorption of Gram negative (E. coli and P. aeruginosa) and Gram positive (B. megaterium and S. aureus) was investigated. Calcined kaolin and Diatomaceous Earth kaolin, which were selected in previous studies, were incubated in triplicates with the above organisms …

A Novel Periplasmic Protein Involved In The Mannan Chain Elongation Step Of Lipomannan And Lipoarabinomannan Biosynthesis In Mycobacterium Smegmatis, Stephanie A. Ha

Masters Theses

Mycobacteria are atypical bacteria possessing unusual cell envelopes comprised of an outer membrane, covalently linked to an arabinogalacatan-peptidoglycan structure via waxy mycolic acids, in addition to the conventional inner membrane. This thick and highly impermeable cell envelope is a major deterrent to antibiotic treatment of clinically relevant mycobacterial pathogens, including Mycobacterium tuberculosis (Mtb), which infects a third of the world’s population and kills millions each year. Thus, the regulation of mycobacterial cell envelope biosynthesis is of great interest for the development of more effective therapeutics for treating Mtb infections. Using the model organism Mycobacterium smegmatis (M. smegmatis …

Intestinal Microbiota And Weight-Gain In Preterm Neonates, Silvia Arboleya, Pablo Martinez-Camblor, Gonzalo Solís, Marta Suárez

Dartmouth Scholarship

The involvement of the gut microbiota on weight-gain and its relationship with childhood undernutrition and growth has been reported. Thus, the gut microbiota constitutes a potential therapeutic target for preventing growth impairment. However, our knowledge in this area is limited. In this study we aimed at evaluating the relationship among early microbiota, growth, and development in preterm infants. To this end we assessed the levels of specific microorganisms by qPCR, and those of short chain fatty acids by mean of gas-chromatography, in feces from 63 preterm newborns and determined their weight-gain during the first months. The statistical analyses performed indicate …

Hidden Diversity Revealed By Genome-Resolved Metagenomics Of Iron-Oxidizing Microbial Mats From Lō’Ihi Seamount, Hawai’I, Heather Fullerton, Kevin W. Hager, Sean M. Mcallister, Craig L. Moyer

Biology Faculty and Staff Publications

The Zetaproteobacteria are ubiquitous in marine environments, yet this class of Proteobacteria is only represented by a few closely-related cultured isolates. In high-iron environments, such as diffuse hydrothermal vents, the Zetaproteobacteria are important members of the community driving its structure. Biogeography of Zetaproteobacteria has shown two ubiquitous operational taxonomic units (OTUs), yet much is unknown about their genomic diversity. Genome-resolved metagenomics allows for the specific binning of microbial genomes based on genomic signatures present in composite metagenome assemblies. This resulted in the recovery of 93 genome bins, of which 34 were classified as Zetaproteobacteria. Form II ribulose 1,5-bisphosphate carboxylase genes …

Antibiotic Resistance Genes In Minnesota Soil Bacteria From Areas Of High And Low Ferric Iron, Gunner L. Drossel, Presley Martin Phd

Departmental Honors Projects

Naturally-occurring antibiotic resistance genes in soil bacteria represent a potentially important reservoir of genes that could contribute to antibiotic resistance of human pathogens. It has been reported that over 40 genes in bacterial genomes are controlled by concentrations of ferric iron. We examined the effect of soil metal content on the level of resistance to two antibiotics, ampicillin (Amp) and tetracycline (Tet), and the presence of multiple genes that code for efflux pump-mediated resistance. These pumps act to export toxins (e.g. heavy metals and antibiotics, perhaps). Because of this, growth in heavy metal-contaminated soils might select for antibiotic resistance. Ninety-six …

Structure-Function Investigation Of Proteins Involved In Cellulose Biosynthesis By Escherichia Coli, Thomas Brenner

Theses and Dissertations (Comprehensive)

Bacteria thrive within multicellular communities called biofilms consisting of a self-produced matrix. Biofilm matrices improve bacterial adherence to surfaces while creating a barrier from host immune responses, disinfectants, antibiotics and other environmental factors. Persistent colonization by the widely distributed pathogens, Escherichia coli and Salmonella spp., has been linked to production of biofilms composed of the exopolysaccharide cellulose. Cellulose-containing biofilms are also important to Acetobacter, Sarcina, Rhizobium and Agrobacterium species to form symbiotic and pathogenic interactions. In Enterobacteriaceae, two operons (bcsABZC and bcsEFG) are proposed to encode for proteins that form a cellulose biosynthetic complex that spans the …

Metabolic Characteristics Of Macrophage Activation With Phenotype Microarrays, Tanya Kathryn D'Souza

Theses

Inflammation is a natural protective response and is characterised by the activation of numerous immune cells, including macrophages which can release a variety of inflammatory mediators. Macrophages play a flexible role in the initiation and effector phases of the immune response and change their behaviour to respond to environmental stimuli. The main objectives in this study were to create and characterise different macrophage behaviours and employ a novel metabolic characterisation platform the Phenotype Microarray^TM to attribute additional characteristics to the currently well recognised phenotypes. Five activated macrophage states were demonstrated and characterised. Unactivated macrophages (MO) demonstrated undetectable levels of …

The Impact Of Socs1 And Socs3 Peptide Mimetics On Rho And Cdc42 Proteins Expression, F-Actin Cytoskeleton Rearrangements, And Cytokines Production Of Uninfected And Hsv-1 Infected M1 And M2 Raw 264.7 Murine Macrophages, Maha A. Elwardany

Browse all Theses and Dissertations

The immune system plays an essential role in the pathogenesis of HSV-1 during the lytic phase of the disease, orchestrating the inflammatory response, retaining the virus in its latent phase and preventing the recurrence of HSV-1 infection. Macrophages display a vital role in the innate and adaptive immune responses during multiple phases of HSV-1 infection. Polarized macrophages are categorized into two distinct classes with diverse functions. The classically activated M1 can engulf and destroy the microbial agents, produce proinflammatory cytokines, and participate in the pathogenesis of many inflammatory diseases. The alternatively activated M2 induces anti-inflammatory mediators and stimulates tissue remodeling …

Effect Of Exposure Of Raw264.7 Macrophages To Salmonella Typhimurium Components On Cell Viability, Cytoskeleton Re-Arrangement And Cytokine Secretion, Khalid Abdullah Alyahya

Browse all Theses and Dissertations

Innate immune system plays an important role in individual's protection against pathogens and in activation of adaptive immune system. Utilizing RAW 264.7 murine macrophages as an innate immune response representative in this study, we analyzed the effect of invasive pathogen's components (e.g. flagellin) on the arrangement of macrophage's cytoskeleton, on viability of immune cells and on secretion of pro-inflammatory and anti-inflammatory cytokines and on fluorescence intensity of cytoskeleton after rearrangement. Additionally, we studied the similarity and differences between bacterial (Salmonella typhimurium) and synthetic TLR4 agonist (synthetic lipid-A) on viability, fluorescence intensity, cytokine secretion, and cytoskeleton rearrangements. Similarly, we studied the …

Characterization Of A Putative Hemolysin Expressed By Sneathia Amnii, A Preterm Birth-Associated Pathogen, Lizette Carrasco, Kimberly Jefferson

Undergraduate Research Posters

The gram-negative bacteria Sneathia amnii is a poorly-characterized commensal of the female urogenital tract frequently associated with adverse clinical outcomes such as bacterial vaginosis (BV), amnionitis, and preterm labor. To investigate its potential role in virulence, we sought to identify and characterize virulence determinants produced by S. amnii in an effort to better understand the pathogenesis of infectious preterm birth. Through sequencing of the Sn35 genome (type strain of S. amnii), we identified two genes with amino acid sequence similarity and structural similarity to the filamentous hemagglutinin (FHA) protein of Bordetella pertussis and its Type Vb transporter. Because S. amnii …