Microbiology Commons^™

Investigating The Driving Mechanisms Behind Differences In Bleaching And Disease Susceptibility Between Two Scleractinian Corals, Pseudodiploria Strigosa And Diploria Labyrinthiformis, Zoe A. Pratte

FIU Electronic Theses and Dissertations

Disease and bleaching are two conditions which commonly lead to coral death. Among coral species, susceptibility to disease and bleaching is variable, and Pseudodiploria strigosa tends to be diseased more than Diploria labyrinthiformis, while D. labyrinthiformis bleaches more readily. The focus of this dissertation was to investigate and compare multiple components of these two coral species, and identify how they may relate to disease and bleaching resistance. Compenetnts examined included the surface mucopolysacharide layer (SML) thickness, gene expression, microbial associates, and a white plague aquarium study. The SML thickness decresased with increasing temperature regardless of coral species, indicating that SML …

Biofilm Binding Capabilities Of Yersinia Pseudotuberculosis Mutants, Bailey Benson, Dr. David Erickson

Journal of Undergraduate Research

Yersinia pestis — the causative agent of the deadly bubonic plague, which killed over one-third of Europe in the 14th century – spreads quickly from person to person due to its ability to create a biofilm, characterized by bacterial adhesion to themselves and surfaces. The bacteria infects fleas and forms a biofilm in their midgut, which causes the flea to both feed more often and cough up bacteria biofim into each new host. In this way, the formation of a strong biofilm is essential for the rapid spread of the bubonic plague. In my experiment, I analyzed which genes would …

Vibrio Cholera: Detection And Destruction, Amber Brown, Dr. Julianne Grose

Journal of Undergraduate Research

Cholera, the Disease: Cholera is a disease that affects three to five million people each year with approximately 100,000 deaths. Transmitted mainly by the drinking-­‐water supply, it causes an infection in the small intestine leading to severe diarrhea and vomiting. If left untreated, it can cause death within hours. The disease is caused by the bacterium Vibrio cholerae which was first isolated by Filippo Pacini in 1854. Vibrio cholerae is gram negative, comma shaped, and flagellated. It is easily treated with modern water purification techniques, and as such it is most prevalent in developing countries that lack this infrastructure. Countries …

Understanding The Role Of Estrogen In The Mucosal Immune Response, Youna Choi, Dr. Eric Wilson

Journal of Undergraduate Research

Most antigens (foreign substances) enter an organism via mucosal surfaces. Thus, understanding the mechanisms involved in immune protection at these surfaces is of paramount importance. Immune responses are highly dependent on homing mechanisms responsible for directing lymphocyte (white blood cell) migration and accumulation at target tissues. Estrogen control of lymphocyte homing within the uterus has recently been established (2).

A Computational Analysis Of The Structural Determinants Of Apobec3'S Catalytic Activity And Vulnerability To Hiv-1 Vif, Shivender Shandilya, Markus-Frederik Bohn, Celia Schiffer

Celia A. Schiffer

APOBEC3s (A3) are Zn(2+) dependent cytidine deaminases with diverse biological functions and implications for cancer and immunity. Four of the seven human A3s restrict HIV by 'hypermutating' the reverse-transcribed viral genomic DNA. HIV Virion Infectivity Factor (Vif) counters this restriction by targeting A3s to proteasomal degradation. However, there is no apparent correlation between catalytic activity, Vif binding, and sequence similarity between A3 domains. Our comparative structural analysis reveals features required for binding Vif and features influencing polynucleotide deaminase activity in A3 proteins. All Vif-binding A3s share a negatively charged surface region that includes residues previously implicated in binding the highly-positively …

Streptococcus Pyogenes Superantigens: Studies Into Host Specificity And Functional Redundancy, Adrienne T. Wakabayashi

Electronic Thesis and Dissertation Repository

Streptococcus pyogenes is a human-specific globally prominent bacterial pathogen that secretes extremely potent exotoxins known as superantigens. Superantigens function to overstimulate T lymphocytes, capable of inducing excessive cytokine responses, potentially leading to toxic shock syndrome. Each strain of S. pyogenes encodes multiple distinct superantigens, yet the reasons why S. pyogenes retains multiple superantigens has remained elusive. Using a murine model of acute nasopharyngeal infection, the role of each superantigen encoded by S. pyogenes MGAS5005 was evaluated using isogenic superantigen-deletion or -complemented strains, and passive immunization with superantigen-neutralizing antibodies. The superantigen SpeG, and likely SpeJ, were not required for infection. However, …

Effects Of Temperature, Nutrients, Organic Matter And Coral Mucus On The Survival Of The Coral Pathogen, Serratia Marcescens, Erin Looney, Kathryn Sutherland, Erin Lipp

Kathryn Patterson Sutherland PhD

Serratia marcescens is an enteric bacterium that causes white pox disease in elkhorn coral, Acropora palmata; however, it remains unclear if the pathogenic strain has adapted to seawater or if it requires a host or reservoir for survival. To begin to address this fundamental issue, the persistence of strain PDL100 was compared among seawater and coral mucus microcosms. Median survival time across all conditions ranged from a low of 15 h in natural seawater [with a first-order decay constant (k) = −0.173] at 30°C to a maximum of 120 h in glucose-amended A. palmata mucus (k = −0.029) at 30°C. …

Human Sewage Identified As Likely Source Of White Pox Disease Of The Threatened Caribbean Elkhorn Coral, Kathryn Sutherland, James Porter, Jeffrey Turner, Brian Thomas, Erin Looney, Trevor Luna, Meredith Meyers, J. Futch, Erin Lipp

Kathryn Patterson Sutherland PhD

Caribbean elkhorn coral, Acropora palmata, has been decimated in recent years, resulting in the listing of this species as threatened under the United States Endangered Species Act. A major contributing factor in the decline of this iconic species is white pox disease. In 2002, we identified the faecal enterobacterium, Serratia marcescens, as an etiological agent for white pox. During outbreaks in 2003 a unique strain of S. marcescens was identified in both human sewage and white pox lesions. This strain (PDR60) was also identified from corallivorious snails (Coralliophila abbreviata), reef water, and two non-acroporid coral species, Siderastrea siderea and Solenastrea …

Human Pathogen Shown To Cause Disease In The Threatened Elkhorn Coral Acropora Palmata, Kathryn Patterson Sutherland, Sameera Shaban, Jessica L. Joyner, James W. Porter, Erin K. Lipp

Kathryn Patterson Sutherland PhD

Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments …

Changes In Microbial Communities Along Redox Gradients In Polygonized Arctic Wet Tundra Soils, David A. Lipson, Ted K. Raab, Melanie Parker, Scott T. Kelley, Colin J. Brislawn, Janet Jansson

Ted K. Raab

This study investigated how microbial community structure and diversity varied with depth and topography in ice wedge polygons of wet tundra of the Arctic Coastal Plain in northern Alaska, and what soil variables explain these patterns. We observed strong changes in community structure and diversity with depth, and more subtle changes between areas of high and low topography, with the largest differences apparent near the soil surface. These patterns are most strongly correlated with redox gradients (measured using the ratio of reduced Fe to total Fe in acid extracts as a proxy): conditions grew more reducing with depth and were …

Genetic Changes To A Transcriptional Silencer Element Confers Phenotypic Diversity Within And Between Drosophila Species, Winslow C. Johnson, Alison J. Ordway, Masayoshi Watada, Jonathan N. Pruitt, Thomas M. Williams, Mark Rebeiz

Biology Faculty Publications

The modification of transcriptional regulation has become increasingly appreciated as a major contributor to morphological evolution. However, the role of negative-acting control elements (e.g. silencers) in generating morphological diversity has been generally overlooked relative to positive-acting “enhancer” elements. The highly variable body coloration patterns among Drosophilid insects represents a powerful model system in which the molecular alterations that underlie phenotypic diversity can be defined. In a survey of pigment phenotypes among geographically disparate Japanese populations of Drosophila auraria, we discovered a remarkable degree of variation in male-specific abdominal coloration. In testing the expression patterns of the major pigment-producing enzymes, …

Fungi Inhabiting The Healthy Human Gastrointestinal Tract: A Diverse And Dynamic Community, Heather E. Hallen-Adams, Stephen D. Kachman, Jaehyoung Kim, Ryan Legge, Inés Martínez

Department of Food Science and Technology: Faculty Publications

Fungal DNA was selectively amplified, and the ITS region sequenced, from fecal samples taken from 45 healthy human volunteers at one (21 volunteers) or two (24 volunteers) time points. Seventy-two operational taxonomic units, representing two phyla and ten classes of fungi, were recovered. Candida yeasts, notably C. tropicalis (present in 51 samples), and yeasts in the Dipodascaceae (39 samples), dominated, while 38 OTUs were detected in a single sample each. Fungi included known human symbionts (Candida, Cryptococcus, Malassezia and Trichosporon spp.), common airborne fungi (Cladosporium sp.) and fungi known to be associated with food ( …

The Biological Consequences Of Kaolin Geophagia, Deloris Alexander, Desire Richardson, Lakisha Odom, Kara Cromwell, Dejuana Grant, Micoya Myers, Eddy Cadet, Hamid Mahama, Vijaya Rangari, Ralphenia Pace, Ramble Ankumah, Kokoasse Kpomblekou-A, Curtis Fluker

Professional Agricultural Workers Journal

Abstract

Kaolin geophagia is associated with the relief of gastrointestinal distress, but it may also cause adverse health effects on the body. This study was designed to: assess kaolin composition; test if 129SvEv mice would consume kaolin and determine the consequences of consumption; and assess rotational stress modulation of consumption. Thirteen kaolin samples were purchased from Alabama and Georgia stores. Chemical and physical properties were characterized for each sample using a Munsell chart, pH meter, Energy Dispersive Spectroscopy, Transmission Electron Microscopy, Visible Near-InfraRed Spectra, and Inductively Coupled Plasma-Optical Emission Spectrometry. Kaolin was then given to mice as food supplements and …

Isquest: Finding Insertion Sequences In Prokaryotic Sequence Fragment Data, Abhishek Biswas, David T. Gauthier, Desh Ranjan, Mohammad Zubair

Computer Science Faculty Publications

Motivation: Insertion sequences (ISs) are transposable elements present in most bacterial and archaeal genomes that play an important role in genomic evolution. The increasing availability of sequenced prokaryotic genomes offers the opportunity to study ISs comprehensively, but development of efficient and accurate tools is required for discovery and annotation. Additionally, prokaryotic genomes are frequently deposited as incomplete, or draft stage because of the substantial cost and effort required to finish genome assembly projects. Development of methods to identify IS directly from raw sequence reads or draft genomes are therefore desirable. Software tools such as Optimized Annotation System for Insertion Sequences …

Virulence Gene Expression Of Vibrio Parahaemolyticus In The Viable But Nonculturable State, Tiffany Pui-Yun Tse

Master's Theses

Vibrio parahaemolyticus is a food-borne pathogen commonly associated with the consumption of raw or undercooked seafood resulting in primary infections of the human gastrointestinal tract. It is estimated to cause about 4500 illnesses each year in the United States. However, infection from this food-borne pathogen can be avoided if this organism is detected in the implicated food, prior to consumption. Current standard methods of detecting this organism are dependent on the culturability of the bacteria. Detection based on an organism’s culturability may be problematic as V. parahaemolyticus has been known to exist in a viable but nonculturable (VBNC) state. Bacteria …

Isolation And Epidemiological Analysis Of Verotoxigenic E. Coli From Patients With Acute Gastroenteritis: A Prospective Study Aiming To Reduce The Burden Of Infection In The Cork Region., Shirley Ross

Masters

Verotoxigenic Escherichia coli (VTEC) is a serious gastrointestinal pathogen associated with morbidity and mortality in the first world, as accentuated by the O104 VTEC outbreak in Germany in 2011. Molecular detection of Verotoxin (VT) has increased the detection of VTEC across Europe however, Ireland still has the highest incidence and isolation is still a key step in the confirmation of infection and the control and prevention of outbreaks. Currently no standard protocol exists for the detection, isolation and characterisation of non-O157 VTEC and it is feared that due to this that the prevalence of VTEC is under-reported. This body of …

The Antioxidant And Dna Repair Capacities Of Resveratrol, Piceatannol, And Pterostilbene, Justin Ryan Livingston

Theses and Dissertations

Lifestyle diseases represent a large burden on developed societies and account for much morbidity worldwide. Research has shown that eating a diet rich in fruit and vegetables helps to ameliorate and prevent some of these diseases. Antioxidants found in fruits and vegetables may provide a substantial benefit in reducing disease incidence. This thesis examines the antioxidant properties of resveratrol, piceatannol, and pterostilbene, and the ability of Burkitt's Lymphoma (Raji) cells to uptake these three antioxidants. It also studies the effect of the antioxidants in protecting against DNA damage and their role in DNA repair following oxygen radical exposure in Raji …

High Salinity Stabilizes Bacterial Community Composition And Activity Through Time, Tylan Wayne Magnusson

Theses and Dissertations

Dormancy is a plausible strategy for bacteria to overcome the effects of temporal fluctuations in resources or stresses and await more “optimal” conditions to resume metabolic activity and growth. Seasonal changes in environmental conditions force microbes to adjust their metabolic activity accordingly, and community composition drastically shifts. In extreme environments, however, the overriding effects of a constant stress may constrain the need or benefit of bacteria entering dormancy. In hypersaline lakes, high metabolic activity is required to maintain adaptations that permit survival. Sampling from six lakes on a salinity gradient (0.05% – 30.3%), we measured seasonal fluctuations in bacterial dormancy …

Secretion Of Heat-Labile Enterotoxin By Porcine-Origin Enterotoxigenic Escherichia Coli And Relation To Virulence, Prageeth R. Wijemanne

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Heat-labile enterotoxin (LT) is an important virulence factor secreted by some strains of porcine-origin enterotoxigenic Escherichia coli (pETEC). The prototypic human-origin strain H10407 secretes LT via a type II secretion system (T2SS), but its presence or importance in pETEC has not been established. Exposure of pETEC to glucose has been shown to result in different secretion levels of LT. Furthermore, the relationship between the level of LT secreted and the virulence potential of the respective pETEC strain has not been established. To determine the relationship between the capacity to secrete LT and virulence in wild-type (WT) pETEC, 16 strains isolated …

Isolation And Host Range Of Staphylococcus Aureus Bacteriophages And Use For Decontamination Of Fomites, Kyle C. Jensen

Theses and Dissertations

Staphylococcus aureus is a common bacterium found on the skin and mucosal membranes of about 20% of the population. S. aureus growth on the skin is harmless, but if it bypasses the skin it can causes life-threatening diseases such as pneumonia, meningitis, bacteremia, and sepsis. Antibiotic-resistant strains of S. aureus, called Methicillin Resistant S. aureus (MRSA), are resistant to most antibiotics except vancomycin. However, vancomycin resistant strains of MRSA are becoming more common. In this study, 12 phages were isolated capable of infecting human S. aureus and/or MRSA strains. Five phages were discovered through mitomycin C induction of prophages and …