Microbiology Commons^™

Resolving The Repression Pathway Of Virulence Gene Hila In Salmonella, Alexandra King, Lon Chubiz Phd, Brenda Pratte, Lauren Daugherty

Undergraduate Research Symposium

Salmonella is a relatively abundant, virulent species of bacteria that is most known for spreading gastrointestinal diseases through food. These illnesses result in approximately 1.35 million infections, including over 25,000 hospitalizations each year, in the U.S. alone (CDC.gov). As antibiotic resistance becomes an increasingly urgent public health problem, the importance of developing alternative treatment methods is only becoming more crucial. One of the genes responsible for this virulence is known as hilA. HilA is the main transcriptional regulator of Salmonella Pathogenicity Island-1 gene (UniProt). SPI-1 plays an important role in the invasion of Salmonella into epithelial cells. The proteins encoded …

The Interaction Of Sulfate And Perchlorate And Its Implications On Bacterial Survival On Mars, Jack M. Richardson, Dylan Clark, Karly Kenny

2022 Symposium

Escherichia coli, Bacillus subtilis, and Staphylococcus aureus are all known spacecraft contaminants. This makes their viability to arrive and survive on Mars feasible, however, this could prove to be a great risk to the Martian environment. In order to test this possibility, all three species were grown within brines containing differing salts and salt concentrations. These salts and their corresponding concentrations are based on known data regarding Martian soil. Growth was measured over a course of 20 hours in solutions containing MgSO₄ at concentrations of 4.6% and 9.2%, Mg(ClO₄)₂ at concentrations of 0.6% and …

Delineating The Role Of The Msaabcr Operon In Staphylococcal Overflow Metabolism, Gc Bibek, Gyan S. Sahukhal, Mohamed O. Elasri

Faculty Publications

Staphylococcus aureus is an important human pathogen that can infect almost every organ system, resulting in a high incidence of morbidity and mortality. The msaABCR operon is an important regulator of several staphylococcal phenotypes, including biofilm development, cell wall crosslinking, antibiotic resistance, oxidative stress, and acute and chronic implant-associated osteomyelitis. Our previous study showed that, by modulating murein hydrolase activity, the msaABCR operon negatively regulates the proteases that govern cell death. Here, we report further elucidation of the mechanism of cell death, which is regulated by the msaABCR operon at the molecular level in the USA300 LAC strain. We showed …

College Of Natural Sciences Newsletter, May & June 2022, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 3, Issue 4

Page 1 Dean's Message
Page 2 Awards and Recognition
Page 3-4 The path to a Doctorate Degree
Page 4 American Indian Student Center Native Graduate Honoring Ceremony
Page 5 Celebrating the lives of those who touched the College
Page 6 Media coverage of CNS
Page 7 Open PRAIRIE
Page 8-10 CNS Graduation Festivities
Page 11-14 Spring 2022 Dean's List
Page 16 Richard and Janice Vetter Endowed Professorship in Biotechnology.position

The Urinary Microbiome And Biological Therapeutics: Novel Therapies For Urinary Tract Infections, Ciara Kenneally, Craig P. Murphy, Roy D. Sleator, Eamonn P. Culligan

Department of Biological Sciences Publications

The discovery of microbial communities in the urinary tract (the urobiome) has fundamentally altered the previous doctrine regarding urine sterility and associated urinary disorders. Recent advances in culturing and culture-independent DNA sequencing technologies have characterised the resident microbial community in the urobiome, and has, in turn, demonstrated how community imbalances potentially contribute to infection and disease. As we enter a post-antibiotic era, the effectiveness of standard antimicrobial treatments against multi-drug resistant (MDR) uropathogens is vastly diminished. Preliminary research is accumulating surrounding microbiome-based therapies, and their potential as non-antibiotic therapeutics. In this context, the urobiome is significantly underexplored, and knowledge regarding …

Invasion Properties Of Listeria Monocytogenes In Aged Cells, Mina Lane Chasteen Burton

Honors Theses

Listeriosis is a bacterial infection caused by the gram-positive pathogen Listeria monocytogenes. When compared to other foodborne illnesses, listeriosis has a higher death rate due to an increased incidence of complications such as meningitis, hydrocephalus, and sepsis in immunocompromised populations. Elderly individuals experience a condition known as immunosenescence, which is a gradual compromisation of the immune system brought on by natural aging. Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder causing premature aging, which allows HGPS cell lines to be used as models to further research in the field of biogerontology. This study utilizes the F2365 strain of …

Biomass Estimation Of Marine Biofilms On Plastic Surfaces, Kian Banihashemi, Fernando Javier Gil

Biological Sciences

Plastics have become a major source of marine pollution, which threatens food safety and quality, human health, and marine ecosystems. Due to the drastic negative effects of plastics in a marine environment, alternative biodegradable plastics are being generated that are more eco-friendly and have less environmental impact. Though some of these plastics are known to biodegrade, the process of degradation for bioplastics has not been heavily studied in a marine environment. This pilot project sought to both quantify the process of biodegradation and compare across different methods for effectiveness of biomass estimation, which serves as an indicator of biodegradation. Plastics …

Factors Affecting The Antibacterial Activity Of Cefiderocol On Klebsiella Pneumoniae With Diverse Characteristics, Lana Jamal Rashed Daoud

Theses

Antimicrobial resistance (AMR) is a growing serious threat that poses a burden on the healthcare system. Spread of AMR bacteria limits treatment options; thus, new antimicrobial agents are required. Cefiderocol (CFDC) is a novel siderophore cephalosporin, approved by the FDA in 2019 for use in treating infections caused by multi-drug resistant (MDR) pathogens; but it is not yet in clinical use in the UAE. CFDC is equipped with stabilizers against β-lactamases as well as a siderophore side chain that allows it to penetrate the outer membrane of bacteria through the iron uptake pathways. The aim of this study is to …

Discovery Of The First Lyticstaphylococcus Pseudintermedius/ Staphylococcus Aureus Polyvalent Bacteriophages, Haroldo Hernandez Santos, Justin Clark, Austen Terwilliger, Anthony Maresso

Faculty, Staff and Students Publications

Background:

There are no verified lytic Staphylococcus pseudintermedius phages in the literature and few temperate phage genomes in databases. S. pseudintermedius is an opportunistic zoonotic pathogen of great importance in veterinary and human medicine.

Materials and Methods:

We discovered phages against canine-derived S. pseudintermedius isolates by screening dog feces, hair, and skin swabs. Fourteen new phages were isolated and characterized by genomic analysis, transmission electron microscopy, and host range determination.

Results:

Three phages—DH2, DH5, and DS10, a phage K variant—were predicted lytic by sequencing, a designation supported by mitomycin C induction. All three are S. pseudintermedius and Staphylococcus aureus polyvalent …

Discovering Novel Polyextremotolerant Fungi And Determining Their Ecological Role Within The Biological Soil Crust Consortium, Erin C. Carr

School of Biological Sciences: Dissertations, Theses, and Student Research

The ecological niche of polyextremotolerant fungi within oligotrophic ecosystems such as biological soil crusts has not yet been determined. These fungi persist in locations where nutrients are depleted while simultaneously surrounded by autotrophic microbes such as algae and cyanobacteria. Yet it has not been shown that they are engaging in any exchange of nutrients the way lichens do. However, there is seemingly no other way for these fungi to obtain vital nutrients, such as carbon or nitrogen, other than from these microbes. Here we have isolated polyextremotolerant fungi from cold desert biological soil crusts which are a microbial biofilm that …

Microbial Sociality In Biofilms, Swetha Kasetty

Dartmouth College Ph.D Dissertations

Biofilms are communities of microorganisms attached to surfaces through various self-secreted matrix materials. Biofilms are dynamic communities with extensive interactions between their residents. Microorganisms compete, cooperate, and communicate with each other in biofilms. These ecological interactions determine the emergence or loss of strains/species and are critical in the formation and proliferation of biofilms. Furthermore, most natural biofilms are formed by multiple microbial species and strains and these interactions within the biofilm dramatically influence community composition and structure over time. Microbial interactions also influence clinically relevant outcomes such as antibiotic resistance and host virulence. In this thesis we explore the potential …

Assessing The Activity Of Antimicrobial Peptides Against Common Marine Bacteria Located In Rotifer (Brachionus Plicatilis) Cultures, Chelsea Woods, Lindsey Woolley, Gavin Partridge, Mengqi Chen, Evan F. Haney, Robert E.W. Hancock, Nicky Buller, Andrew Currie

Fisheries Research Articles

Rotifers are used as the first feed for marine fish larvae and are grown in large cultures that have high loads of organic matter and heterotrophic bacteria; these bacteria are passed on to the developing fish larvae and can potentially lead to bacterial infections. A modified minimum inhibitory concentration (MIC) protocol for antimicrobial peptides was used to determine the potency of ten antimicrobial peptides (AMPs) in artificial seawater relevant to a rotifer culture (salinity of 25‰) against common marine pathogens. All of the AMPs had antimicrobial activity against the bacterial isolates when the salt concentration was approximately zero. However, in …

An Investigation On The Impact Of Intestinal Oxygen Availability On Survival And Regulation Of Virulence In Listeria Monocytogenes, Damayanti Chakravarty

Dissertations

The deadly foodborne pathogen Listeria monocytogenes is a gram positive facultative anaerobic bacterium. It is the third leading cause of death from food-borne illnesses. Once ingested, it encounters various stressors in the gastrointestinal (GI) tract, including acidic pH, bile, and alterations in oxygen availability. Various studies have been done regarding the pathogen’s survival mechanism against acid and bile. Since the lower parts of the GI tract are anaerobic, it is imperative to investigate how physiologically relevant anaerobic conditions impact L. monocytogenes’s survival. Transcriptomic analysis of L. monocytogenes under conditions mimicking the GI tract was performed. A large number of genes …

Flippase Inhibitors As Antimicrobial Agents, Robert Tancer

Seton Hall University Dissertations and Theses (ETDs)

Drug resistant microbes are a considerable challenge for modern medicine to overcome. The research described in this dissertation involved development of lipid flippase inhibitors and investigating their potential as antimicrobial agents against various drug resistant microbes. The microbes primarily investigated were methicillin resistant Staphylococcus aureus (MRSA) & Cryptococcus neoformans. Chapter 1 reviews the historical perspective and summarizes the current state of the field of research. In Chapter 2, the design space of an antimicrobial peptide known as humimycin was explored and the effects of modifications on its structure were observed against MRSA. Several key observations resulted. Most notably, the …

Parameter Estimation Using Nudging On The Logistic Growth Equation, Susan Rogowski

Biology and Medicine Through Mathematics Conference

No abstract provided.

Elevated Substitution Rates Among Wolbachia-Infected Mosquito Species Results In Apparent Phylogenetic Discordance., James E. Russell, Michael Saum, Rebekah Williams

Georgia Journal of Science

As one of the most widely distributed bacterial cytoplasmic symbionts on earth, Wolbachia pipientis Hertig serves as a model organism for the understanding of host-symbiont interactions. Many mosquito species are infected with Wolbachia strains that induce a form of reproductive manipulation called cytoplasmic incompatibility, in which infected females gain a reproductive advantage over uninfected females in mixed infection populations. The selective advantage of cytoplasmic incompatibility often results in a population sweep of Wolbachia and co-transmitted mitochondrial genomes. Mitochondrial evolution and phylogenetic inferences drawn from mitochondrial gene sequences are thus potentially compromised by reproductive manipulating symbionts, like Wolbachia. Our initial …

The Nature Of Phenotypes: Provoking And Measuring The Dynamic Processes Of Swarm Expansion, Predation, And Antibiotic Resistance In Myxococcus Xanthus, Linnea Judith Ritchie

Dissertations - ALL

The question of how genotype affects phenotype has fascinated and puzzled scientists for generations. Regardless of organism, the correlation between observation and underlying condition is necessary for scientists to understand the world around us. Myxococcus xanthus, a fascinating organism with a large genome (7,314 genes), is known for complex social behaviors and is an excellent model system for the study of this relationship. Upon starvation, M. xanthus cells condense into large multicellular aggregates to await renewed nutrient availability. M. xanthus cells swarm together on surfaces as a predatory biofilm, lysing and killing prey as a singular unit. During predation, swarms …

Assembly Of The Peripheral Arm Subunits Of Escherichia Coli Complex I And Analysis Of Clinical Mutations, Hind Alkhaldi

Biological Sciences Theses and Dissertations

Respiratory Complex I from E. coli is a proto-type of the mitochondrial enzyme, consisting of a 6-subunit peripheral arm (B-CD-E-F-G-I) and a 7-subunit membrane arm. When subunits E-F-G (N-module), were expressed alone they formed an active complex as determined by co-immunoprecipitation and native gel electrophoresis. When co-expressed with subunits B and CD, only a complex of E-F-G was found. When these five subunits were co-expressed with subunit I and two membrane subunits, A and H, a complex of B-CD-E-F-G-I was membrane-bound, constituting the N- and Q-modules. Assembly of Complex I was also followed by splitting the genes between two plasmids, …

Evaluating Soil Health Changes Following Cover Crop And No-Till Integration Into A Soybean (Glycine Max) Cropping System In The Mississippi Alluvial Valley, Alexandra Gwin Firth

Theses and Dissertations

The transition of natural landscapes to intensive agricultural uses has resulted in severe loss of soil organic carbon (SOC), increased CO₂ emissions, river depletion, and groundwater overdraft. Despite negative documented effects of agricultural land use (i.e., soil erosion, nutrient runoff) on critical natural resources (i.e., water, soil), food production must increase to meet the demands of a rising human population. Given the environmental and agricultural productivity concerns of intensely managed soils, it is critical to implement conservation practices that mitigate the negative effects of crop production and enhance environmental integrity. In the Mississippi Alluvial Valley (MAV) region of Mississippi, USA, …

Optimized Selenium Status, Gut Microbiota, And Type 2 Diabetes, Ying-Chen Huang

Theses and Dissertations

We have previously demonstrated that long-term dietary Se deficiency in old Terc^-/- mice with humanized telomeres induces type-2 diabetes and exacerbates age-dependent increases in the abundance of A. muciniphila and Lachnospiraceae, which are related to obesity and metabolic syndromes. The objectives of this dissertation are: 1) to determine the minimum intake of Se required for type 2 diabetes prevention in middle-aged mice; 2) to evaluate the efficacy of A. muciniphila and R. torques (a Lachnospiraceae family member) to intervene dietary Se deficiency-induced type 2 diabetes and the underlying mechanisms; 3) to assess sex differences in the responses to …

Identification Of Pneumococcal Membrane Proteins Involved In Colonization/Biofilm Formation And Cognate Host Cellular Receptors, Yoonsung Hu

Theses and Dissertations

Colonization is prerequisite for infection and transmission of Streptococcus pneumoniae, or pneumococcus. Currently available pneumococcal conjugate and pneumococcal polysaccharide vaccines can provide protection against a limited number of capsular serotypes. Implementation of vaccines has decreased the frequency of invasive pneumococcal disease and their colonization rates, but only in a serotype-dependent manner. This has led to serotype replacement in pneumococcal ecology and increased invasive disease caused by non-vaccine serotypes. Development of conserved protein-based vaccine that can provide protection against all pneumococcal serotypes is needed. Numerous surface proteins are conserved in all serotypes, and some are known to be involved in …

The Impact Of Iaa And Tryptophan On Microcystis Bloom Community Dynamics, Hunter R. Baylous

Masters Theses, 2020-current

Microcystis aeruginosa is a freshwater cyanobacterial species that degrades freshwater and brackish ecosystems due to its capacity to form toxic cyanobacterial harmful algal blooms (cyanoHABs). There both abiotic and the biotic factors that exacerbate the presence of cyanoHABs. Current research is looking at the microbial interactions that occur between microbes and phytoplankton. Microbes interact with cyanobacteria in the phycosphere, where nutrients are exchanged between the two. Understanding the chemical currencies exchanged can help to show interactions that are beneficial for cyanoHAB formation A key player in the growth promotion of cyanoHABs is hypothesized to be auxins, which are synthesized by …

Characterization Of A Helicobacter Pylori Small Rna By Rt-Pcr, Roxanne Mcpeck, Andrea Castillo

2022 Symposium

Helicobacter pylori, a bacterial gastric pathogen infecting approximately 50% of the human population, produces gastritis, ulcers, and gastric cancers. Colonizing the inhospitable and fluctuating environment in the stomach requires tight genetic control. However, H. pylori lacks many genetic regulatory elements present in other bacteria to control gene expression. Instead, over 200 small RNAs (sRNAs; noncoding RNAs shorter than 300 nucleotides) have been found in this bacterium, but few have been fully characterized. Of those, many are antisense to virulence genes. Characterizing these sRNAs is important in understanding the mechanisms of molecular genetics and potentially supporting medical management of this …

Eskape Pathogens: The Clinical Prevalence And Molecular Mechanisms Of Antibiotic Resistance, Anusha Attre

Honors Scholar Theses

The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are the leading cause of all nosocomial, or healthcare-associated (HAI), infections (Navidinia, 2016). The purpose of this research study is to determine the burden of ESKAPE infections on healthcare and study the antibiotic resistance in these high-risk pathogens to provide direction for researchers to develop new antimicrobial innovations to reduce ESKAPE infectivity and improve patient outcomes. To study the burden of ESKAPE infections, this review analyzes the current statistics explaining the clinical prevalence of each pathogen in causing HAIs. Additionally, each pathogen is …

The Development Of A Global Shoreland Information Database May Help Determine The Appropriate Bacteria And Nutrient Technology Needed To Remediate Oil Contaminated Shorelands, Tiffany Ann Veeder

Honors Projects

The use of oil and its derivative products is well known world-wide. The benefits of oil are many and its products, for example, range from gasoline used in our automobiles to its use in plastics, building products, and medical supplies. Oil spill hazards associated with oil extraction, production, and transportation can have devastating impacts on the environment and local economies. When oil spills happen in the water, for instance, major shorelands are placed at risk of significant harm. As oil contaminates shorelands, the impacts can range from killing sea creatures and seabirds to destroying entire ecosystems. To help mitigate the …

Antibiotic-Resistant Bacteria In Freshwater Crayfish, Colby Finch

Honors Theses

The presence of antibiotic-resistant bacteria is increasing in natural aquatic environments. Alongside this, organisms that live in these ecosystems are increasingly harboring antibiotic-resistant bacteria. In this study, I analyzed the capacity for the crayfish species Procambarus vioscai paynei to harbor antibiotic-resistant bacteria. Crayfish, as well as water and sediment, were sampled from a pond at the University of Mississippi Field Station. The guts of crayfish were plated on TSA agar, as well as agar containing vancomycin, erythromycin, penicillin, tetracycline, or ciprofloxacin. Following incubation, counts of bacteria were determined. Selected bacterial isolates were tested for multiple antibiotic-resistance. Bacterial isolates were also …

A Comparison Of Heterotroph Isolation And Sequencing Methods From Various Cyanobacterial And Algal Microbiomes, Victoria Starks

Honors Theses

Cyanobacteria have provided a vast, new source of natural products to be utilized in drug development. Because of their non-axenic nature, cyanobacteria typically have an abundance of symbiotic heterotrophs living in association with them. These bacteria can play significant roles in the survival of its cyanobacterial host as well as provide the potential production of unique compounds. The possibility of unknown natural products is only increased by the flexible nature of these bacteria, as altering its environmental state can change the activity of biosynthetic pathways and even activate novel production. Our research team’s intent is to isolate cyanobacterial strains from …

Metagenome-Wide Associations And Metabolic Modeling To Predict The Biomarkers For Colorectal Cancer, Nagavardhini Avuthu

Theses & Dissertations

Colorectal cancer (CRC) is the most common malignancy and the second most common cause of cancer-related deaths in the world. It is a multifactorial disease mediated by genetic, environmental, and lifestyle factors. Over time, the accumulation of genetic and epigenetic changes results in the activation of oncogenes and deactivation of tumor suppressor genes in the colon and rectal region which finally leads to tumor development. The gut microbiome is the main factor linking the effects of diet and environmental factors to host metabolism. Several studies showed the dysbiosis of gut microbiota in CRC patients with an increased proportion of pathogenic …

Gut Commensals Modulate Siv/Shiv Pathogenesis And Therapeutics, Samuel Johnson

Theses & Dissertations

Despite significant advancements in combination antiretroviral therapy (cART), ongoing inflammation in the brain and gut remain two of the most significant hurdles in the health of people living with human immunodeficiency virus (HIV). Additionally, a viral reservoir in each compartment inhibits cure efforts by allowing rapid viral rebound following cART interruption. Emerging understanding of the gut-brain axis (GBA) implicates each compartment in the modulation of the other in a complex bi-directional interaction mediated by vagus innervation, circulating lymphocytes, and microbiome composition and biproducts. Using multiple models of the simian (and simian-human) immunodeficiency virus (SIV/SHIV) and therapeutic intervention, I present how …

Detecting Potentially Neurotoxic Pseudo-Nitzschia Species In The Grand Strand Area, Chesney Price

Honors Theses

Pseudo-nitzschia is a globally distributed diatom genus which contains 26 neurotoxin (domoic-acid) producing species. In shallow coastal waters these diatoms are associated with both the development of harmful algal blooms and the bio-accumulation of toxins in shellfish that can impact human health. Pilot data recovered in 2018 indicated the presence of multiple species of Pseudo-nitzschia, including domoic-acid producing taxa. We hypothesize that we will recover a similar species diversity using multiple sampling dates during the summer of 2021. Environmental DNA (eDNA) samples taken from the public shellfish harvesting area waters at Huntington Beach State Park (SC) over a two month …