Bacterial Infections and Mycoses Commons^™

The Large And Small Of It: The Microbiome And Metagenomics, Austin Hopkins, Elaina Gollmar, Jessica Fernandez, Shawn Wolf, Austin Hilverding, Andrew M. Roecker

Pharmacy and Wellness Review

Metagenomics, the analysis of the microbial genome, permits scientists to understand the influences of external sources including diet, metabolism and antibiotics on the human microbiome. Research has revealed the possibility of a core symbiosis between humans and bacteria. The main role of the human microbiome is to aid in digestion, but identified ancillary roles include immunologic homeostasis and infection prevention. Quantifying the composition and variability of the microbiome will help lead to future treatments or preventive strategies against unhealthy change. A variety of methods may be used to define the microbiome, and 16S amplicon sequencing is primarily utilized today. Probiotics …

Isolating Bacteriophage For Potential Treatment Of Chronic Multi-Drug Resistant Escherichia Coli Infections, Leila Oswalt

Honors Projects

The misuse and overuse of antibiotics has led to the intense rise in antibiotic resistance. As society transitions into the post antibiotic era, there will be a great need for new therapeutic strategies to address multiple drug resistant bacterial infections. One such method, called bacteriophage therapy, allows for specific targeting of certain pathogenic bacteria through the use of viruses that attack bacteria; termed “bacteriophage” or simply “phage”. Urinary tract infections are among the most common pathological human infections that rely heavily on the use of antibiotics, the major cause of which is the bacterium Escherichia coli. During the Spring 2021-Spring …

Antibiotic Permeation In Gram-Negative Bacteria And Contribution Of Inflammasome Activation And Pyroptosis In Pathogenesis Of Salmonella Systemic Infection, Ankit Pandeya

Theses and Dissertations--Chemistry

Antibiotic resistance is one of the major global issues in the field of public health and medicine. Good antibiotic candidates need to be selectively toxic, inhibit cellular target, and effectively penetrate and accumulate in bacterial cells. The last factor is a formidable barrier in the development of antimicrobials effective in Gram-negative bacteria, due to the presence of two layers of cell envelope. The first half of my thesis focuses on understanding the permeation of small molecules through this formidable cell envelope, distribution inside the cell of Gram-negative bacteria, and design of novel methods to make small molecules effectively cross the …

Associations Between Eight Earth Observation-Derived Climate Variables And Enteropathogen Infection: An Independent Participant Data Meta-Analysis Of Surveillance Studies With Broad Spectrum Nucleic Acid Diagnostics, Josh M. Colston, Benjamin F. Zaithcik, Hamada S. Badr, Eleanor Burnett, Syed Asad Ali, Ajit Rayamajhi, Syed M. Satter, Daniel Eibach, Ralf Krumkamp, M Imran Nisar, Anita K. M. Zaidi, Zulfiqar Ahmed Bhutta

Department of Paediatrics and Child Health

Diarrheal disease, still a major cause of childhood illness, is caused by numerous, diverse infectious microorganisms, which are differentially sensitive to environmental conditions. Enteropathogen‐specific impacts of climate remain underexplored. Results from 15 studies that diagnosed enteropathogens in 64,788 stool samples from 20,760 children in 19 countries were combined. Infection status for 10 common enteropathogens—adenovirus, astrovirus, norovirus, rotavirus, sapovirus, Campylobacter, ETEC, Shigella, Cryptosporidium and Giardia—was matched by date with hydrometeorological variables from a global Earth observation dataset—precipitation and runoff volume, humidity, soil moisture, solar radiation, air pressure, temperature, and wind speed. Models were fitted for each pathogen, accounting …

Genomic Epidemiology Of Clostridium Difficile Colonization And Transmission In An Intensive Care Unit Cohort, Brianne Ciferri

Dissertations and Theses

Abstract

Genomic epidemiology of Clostridium difficile colonization and transmission in an intensive care unit cohort

by Brianne Ciferri, MPH

Advisor: C. Mary Schooling, PhD

Introduction: Clostridiodes difficile (C. difficile) is a leading cause of healthcare associated infections (HAI) in the United States and responsible for an estimated incidence of 223,900 cases and 12,800 deaths per year^1,2. C. difficile can cause gastrointestinal illness with symptoms ranging from mild diarrheal illness to a life-threatening condition. C. difficile is an opportunistic pathogen in which spores can live in an undisturbed dormant state within the intestinal tract and become …

Genital Chlamydia Infection Is Influenced By The Female Sex Hormones Estrogen And Progesterone In Vivo, Amy Gail Gravitte

Electronic Theses and Dissertations

Chlamydia is the most common bacterial sexually transmitted infection in the United States and worldwide. It often goes unnoticed due to lack of symptoms and left untreated it can ascend the female genital tract to cause sequelae like pelvic inflammatory disease and irreversible tubal infertility. In reproductive-aged women, female sex hormones estrogen (E2) and progesterone (P4) concentrations fluctuate during the menstrual cycle and are influenced by hormonal contraceptives and hormone replacement therapy. E2 and P4 influence genital Chlamydia infection in women and mice, but these multifactorial interactions are not entirely mapped out. The complex interplay of E2 and P4 with …

Structural Analysis And Vaccine Efficacy Of Hla Mutants, Kelly Tomaszewski

Arts & Sciences Electronic Theses and Dissertations

Staphylococcus aureus is a commensal of the human skin and also a major human pathogen. Currently, there has been no successful vaccine despite many approaches over the last two decades. S. aureus α-hemolysin (Hla), a potent cytotoxin, plays an important role in the pathogenesis of S. aureus diseases, through the activation of its receptor, ADAM10. We utilized three distinct Hla mutants with differing structural and ADAM10 binding properties to examine for vaccine efficacy. Our studies have demonstrated immunization with each vaccine candidate antigens provided significant protection against S. aureus skin infection yet elicited distinguishable immune responses. We have also generated …

Type Vi Secretion System Mutations Reduced Competitive Fitness Of Classical Vibrio Cholerae Biotype, Benjamin Kostiuk, Francis J. Santoriello, Laura Diaz-Satizabal, Fabiana Bisaro, Kyung-Jo Lee, Anna N. Dhody, Daniele Provenzano, Daniel Unterweger, Stefan Pukatzki

Publications and Research

The gram-negative bacterium Vibrio cholerae is the causative agent of the diarrhoeal disease cholera and is responsible for seven recorded pandemics. Several factors are postulated to have led to the decline of 6th pandemic classical strains and the rise of El Tor biotype V. cholerae, establishing the current 7th pandemic. We investigated the ability of classical V. cholerae of the 2nd and 6th pandemics to engage their type six secretion system (T6SS) in microbial competition against non-pandemic and 7th pandemic strains. We report that classical V. cholerae underwent sequential mutations in T6SS genetic determinants that initially exposed 2nd pandemic strains …

Mara Repression Of Virulence Gene Hila In Salmonella, Alexandra King, Lauren Daugherty, Lon Chubiz Phd

Undergraduate Research Symposium

Salmonella is a bacteria most commonly known for causing the eponymous food-related illness. Due to their rapid reproduction rate and their ability to be propogated and maintained in a lab setting, they are commonly used in lab studies so that we can better understand how Salmonella causes disease in organisms that are more difficult to study. One area of interest is analyzing how Salmonella controls expression of the mechanisms that actually cause disease, called virulence traits, in response to the environment. In this study, antibiotic stress was used to analyze virulence gene expression. MarA is a gene that regulates ampicillin …

Assesment Of Antibiotic Resistant Gene Expression In Clinical Isolates Of Pseudomonas Aeruginosa, Dustin Esmond

Biology Theses

Increasing prevalence of nosocomial infections by antimicrobial resistant pathogens resulting in higher mortality rates and financial burden is of great concern. Pseudomonas aeruginosa represents one of six highly virulent “ESKAPE” pathogens that exhibit considerable intrinsic drug resistance as well as mechanisms for acquiring further resistance. As many of these mechanisms are regulated through gene expression, we sought to identify regulatory strategies and patterns at play in 23 clinical isolates collected from Baku, Azerbaijan and Tyler, Texas, USA. Real-time quantitative polymerase chain reaction was performed on six gene targets implicated in resistance and contrasted with antibiotic phenotypes. We found AmpC cephalosporinase …

Nanomaterial-Based Biosensors For Detection Of Salmonella Typhimurium And Avian Influenza Virus H5n1 In Poultry, Xinge Xi

Graduate Theses and Dissertations

This research focused on developing biosensing method and biosensing device for rapid detection of pathogens in poultry: Salmonella Typhimurium and avian influenza virus H5N1. The first part of the dissertation reports an original research on the development of a portable biosensing device for Salmonella detection. The device was designed and constructed based on a previously developed optical biosensing method, using immuno-magnetic nanoparticles to specifically capture target bacteria, and immuno-quantum dot beads to label the target bacteria for fluorescence detection. All the actions of sample mixing, magnetic separation, and fluorescence detection were controlled automatically in a disposable microfluidic chip in the …

Type I Topoisomerases As Potential Targets For Therapeutics, Ahmed Seddek

FIU Electronic Theses and Dissertations

DNA topoisomerases are universal enzymes that control the topological features of DNA in all forms of life. This study aims to find potential inhibitors of some of the DNA topoisomerases in bacteria and humans that can be developed into potential therapeutics.

The first aim of this study is to find potential inhibitors of bacterial topoisomerase I that can be developed into antibiotics. There is an urgent need to develop novel antibiotics to overcome the world-wide health crisis of antimicrobial resistance. Virtual screening and biochemical assays were combined to screen thousands of compounds for potential inhibitors of bacterial topoisomerase I. NSC76027 …

Formulation Of Coffee Extract As Polymeric Nanoparticles And Studying Their Potential Biological Activities, Nouran Sharaf

Theses and Dissertations

Coffee extract was prepared and optimized (by solvent extraction) and subsequently entrapped into PLGA nanoparticles using single emulsion-solvent evaporation method (using Design Expert software). Dynamic Light Scattering, Scanning Electron Microscope, Fourier Transform-Infrared Spectroscopy and Folin Ciocalteau assay were used to characterize the NPs and to aid in selecting the optimum formulation conditions. The optimized NPs were in-vitro evaluated for their antimicrobial (by agar-well diffusion method), antioxidant (by DPPH assay) and anticancer (by MTT assay) activities. Finally, the release rate study was conducted for the NP sample showing the highly promising results.

The succeeded NP sample, in terms of the most …

Lipoxin A 4 (Lxa 4 ) Promotes Reduction And Antibiotic Efficacy Against Pseudomonas Aeruginosa Biofilm, Julianne M. Thornton, Jean Walker, Prem Y.K. Sundarasivarao, Bernd Spur, Ana Rodriguez, Kingsley Yin

Rowan-Virtua Research Day

Pseudomonas aeruginosa (P aeruginosa) is an opportunistic bacterium commonly found in wound infections and airways of cystic fibrosis patients P aeruginosa readily forms biofilms which can reduce the efficacy of antibiotics used to eradicate the pathogen We have previously shown that a Specialized Pro resolving Mediator ( Lipoxin A 4 (LxA 4 is a quorum sensing inhibitor which can reduce P aeruginosa virulence In this study, we examined the direct actions of LxA 4 and RvD 2 on P aeruginosa biofilm formation and virulence gene expression The influence of LxA 4 on antibiotic efficacy and the combined effects on biofilm …

Challenges And Opportunities In Food Safety-A Review, Iram Asim, Humaira Yasmeen

Journal of Bioresource Management

Food-borne diseases are the group of disorders that are caused by consuming food having microbial existence in it. So safe food handling is to make sure the lessening of detrimental effects in growth to the packaging of food to minimize health issues on consumers which otherwise can lead to large scale disease outburst. This review concludes the findings of the studies on how food is being handled from farm to fork, how airlines are contributing towards the spreading of diseases, how any negligence in any one of the steps can cause havoc to mankind in the light of the recent …

When The Pandemic Opts For The Lockdown: Secretion System Evolution In The Cholera Bacterium, Francis J. Santoriello, Stefan Pukatzki

Publications and Research

Vibrio cholerae, the causative agent of the diarrheal disease cholera, is a microbe capable of inhabiting two different ecosystems: chitinous surfaces in brackish, estuarine waters and the epithelial lining of the human gastrointestinal tract. V. cholerae defends against competitive microorganisms with a contact-dependent, contractile killing machine called the type VI secretion system (T6SS) in each of these niches. The T6SS resembles an inverted T4 bacteriophage tail and is used to deliver toxic effector proteins into neighboring cells. Pandemic strains of V. cholerae encode a unique set of T6SS effector proteins, which may play a role in pathogenesis or pandemic …

Amphiphilic Cell-Penetrating Peptides Containing Natural And Unnatural Amino Acids As Drug Delivery Tools And Antimicrobial Agents, David Salehi

Pharmaceutical Sciences (MS) Theses

Cell-penetrating peptides containing arginine as positively charged residues and tryptophan or diphenylalanine as hydrophobic residues were synthesized. The synthesis was accomplished through the Fmoc solid-phase peptide synthesis in the presence of HBTU and DIPEA. The side-chain protected linear peptides were cleaved from the resin and cyclized in the presence of DIC and HOAt in the solution phase overnight. MALDI-TOF mass spectrometry was used to characterize the peptides.

The cytotoxicity of the synthesized peptides was determined in CCRF-CEM (human, lymphoblast peripheral blood), and HEK-293 (human, embryonic epithelial kidney healthy) cells using the MTS assay. A concentration of 10 µM was found …

Pandemic Vibrio Cholerae Shuts Down Site-Specific Recombination To Retain An Interbacterial Defence Mechanism, Francis J. Santoriello, Lina Michel, Daniel Unterweger, Stefan Pukatzki

Publications and Research

Vibrio cholerae is an aquatic microbe that can be divided into three subtypes: harmless environmental strains, localised pathogenic strains, and pandemic strains causing global cholera outbreaks. Each type has a contact-dependent type VI secretion system (T6SS) that kills neighbouring competitors by translocating unique toxic effector proteins. Pandemic isolates possess identical effectors, indicating that T6SS effectors may affect pandemicity. Here, we show that one of the T6SS gene clusters (Aux3) exists in two states: a mobile, prophage-like element in a small subset of environmental strains, and a truncated Aux3 unique to and conserved in pandemic isolates. Environmental Aux3 can be readily …

Carbapenem-Resistant Enterobacteriaceae (Cre): Epidemiology, Duration Of Carriage, And Progression To Infection In A Large Healthcare System In Miami, Fl, Adriana Jimenez

FIU Electronic Theses and Dissertations

Carbapenem-resistant Enterobacteriaceae (CRE) are multidrug-resistant organisms (MDRO) considered by the CDC as an urgent public health threat that is spreading globally. Little is known about the epidemiology of CRE in Miami, FL. The purpose of this dissertation was to 1) Evaluate trends in the epidemiology of CRE among patients admitted to the acute care facilities of the largest healthcare system in Miami, FL between 2012 and 2016, 2) Identify factors associated with progressing to infection among patients colonized with carbapenemase-producing Enterobacteriaceae (CPE), and 3) Determine the duration of CPE carriage and factors associated with long-term carriage in our cohort.

A …

Investigating Microbial And Host Factors That Modulate Severity Of Clostridioides Difficile Associated Disease, Armando Lerma

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Clostridioides difficile is recognized as one of the most important pathogens in hospital and community healthcare settings. The clinical outcome of infection of toxigenic C. difficile infection (CDI) ranges from asymptomatic colonization to fulminant pseudomembranous colitis and death. In recent studies, it has been suggested that a high proportion of nosocomial CDI cases are transmitted from asymptomatic carriers which might be acting as infection reservoirs. Understanding what causes the different responses to infection could lead to the development of novel prevention and treatment strategies. Although several explanations have been proposed to explain variations in susceptibility, understanding of the exact mechanisms …

Chain-Selective Isotopic Labeling Of The Heterodimeric Type Iii Secretion Chaperone, Scc4:Scc1, Reveals The Total Structural Rearrangement Of The Chlamydia Trachomatis Bi-Functional Protein, Scc4, Thilini O. Ukwaththage, Samantha M. Keane, Li Shen, Megan A. Macnaughtan

School of Medicine Faculty Publications

Scc4 is an unusual bi-functional protein from Chlamydia trachomatis (CT) that functions as a type III secretion system (T3SS) chaperone and an RNA polymerase (RNAP)-binding protein. Both functions require interactions with protein partners during specific stages of the CT developmental cycle. As a T3SS chaperone, Scc4 binds Scc1 during the late stage of development to form a heterodimer complex, which chaperones the essential virulence effector, CopN. During the early-middle stage of development, Scc4 regulates T3SS gene expression by binding the σ66-containing RNAP holoenzyme. In order to study the structure and association mechanism of the Scc4:Scc1 T3SS chaperone complex using nuclear …

Intensive Animal Farming Conditions Are A Major Threat To Global Health, Cynthia Schuck-Paim

Animal Sentience

Wiebers & Feigin accurately propose that reducing the risks posed by infectious disease outbreaks and other global health challenges will depend critically on transitioning away from intensive animal farming practices. Creating the right incentive structure for this transition to happen is one of the great challenges in the years to come, but a much-needed step to ensure the health and well-being of current and future generations.

Plasmodium Impairs Antibacterial Innate Immunity To Systemic Infections In Part Through Hemozoin-Bound Bioactive Molecules., Christopher Lynn Harding

Electronic Theses and Dissertations

Despite efforts to decrease the global health burden of malaria, infections with Plasmodium species continue to cause over 200 million episodes of malaria each year which resulted in 405,000 deaths in 2018 [1]. One complication of malaria is increased susceptibility to invasive bacterial infections. Plasmodium infections impair host immunity to non-Typhoid Salmonella (NTS) through activities of heme oxygenase I (HO-I) )-induced release of immature granulocytes and myeloid cell-derived IL-10. Yet, it is not known if these mechanisms are specific to NTS. We show here, that Plasmodium yoelii 17XNL (Py) infected mice had impaired clearance of systemic Listeria monocytogenes (Lm) during …

A Race Against Time: Reduced Azithromycin Susceptibility In Salmonella Enterica Serovar Typhi In Pakistan, Junaid Iqbal, Irum Fatima Dehraj, Megan E. Carey, Zoe A. Dyson, Denise Garrett, Jessica C. Seidman, Furqan Kabir, Senjuti Saha, Stephen Baker, Farah Naz Qamar

Department of Paediatrics and Child Health

Antimicrobial resistance is an ongoing issue in the treatment of typhoid fever. Resistance to first-line antimicrobials and extensively drug resistant (XDR) Salmonella Typhi isolates in Pakistan have left azithromycin as the only remaining effective oral treatment. Here, we report the emergence of organisms with a single point mutation in acrB gene, implicated in azithromycin resistance, in a S. Typhi isolate from Pakistan. The isolation of this organism is worrisome and highlights the significance of the introduction of typhoid conjugate vaccine in South Asia.
Importance: The emergence of XDR Salmonella Typhi in Pakistan has left azithromycin as the only viable oral …

Contributions Of Gyra And Parc Mutations And Qnrs2 Acquisition To Ciprofloxacin Resistance In Aeromonas Veronii Hm21, Daniel J. Silverstein

Honors Scholar Theses

In recent years, ciprofloxacin resistant (CpR) Aeromonas veronii and A. hydrophila strains have been isolated from the wounds of patients receiving leech therapy. Genome comparisons of these CpR isolates revealed the presence of chromosomal mutations in gyrA and parC as well as the gain of qnrS2 on either a large, 34 kb, conjugatable, low-copy plasmid, pAv42, or on a small, 6.8 kb, high-copy plasmid, pAh1471. The minimum inhibitory concentration, MIC, for Cp of these clinical isolates ranged from 1 to ≥32 µg/mL and some harbored a qnrS2 containing plasmid. We wanted to assess the contributions of these factors in an …

Network Modeling The Impact Of Community-Based Male-Screening On The Chlamydia Trachomatis Prevalence In Women, Zhuolin Qu

Biology and Medicine Through Mathematics Conference

No abstract provided.

Molecular Mechanisms Of Antimicrobial Resistance In Multi-Drug Resistant Enterococci, Ayesha Khan

Dissertations & Theses (Open Access)

Antibiotic resistance is a major global public health threat. Enterococci are recalcitrant, nosocomial pathogens that can be intrinsically resistant to valuable antibiotics, like beta-lactams, or evolve resistance to all existing antimicrobials. The LiaFSR system regulates resistance to cell membrane (CM) stressors like daptomycin (DAP), a front-line drug for multi-drug resistant infections. DAP resistance (DAP-R) in E. faecalis is mediated by CM phospholipid alterations. Emergence of DAP-R often leads to b-lactam resensitization, a phenomenon called the seesaw effect. The molecular mechanism of DAP-R and the seesaw effect are unknown. Here we show that LiaX is a surface exposed protein whose C-terminal …

The Effect Of Staphylococcus Aureus Exposure On White-Tailed Deer Trabecular Bone Stiffness And Yield, Emily Brooke Long

Graduate Theses

Osteomyelitis is an infection of the bone or bone marrow caused by the infiltration of bacteria, resulting in destructive inflammation, bone necrosis and abnormal bone remolding. With a growing number of osteomyelitis diagnoses, many of which are linked to Staphylococcus aureus (S. aureus), it is imperative to understand the pathology of S. aureus in relation to bone to provide better diagnostics and patient care. While the cellular mechanisms of S. aureus and osteomyelitis have been studied, little information exists on the biomechanical effects of such infections. We postulated that exposure to S. aureus for 72 hours would significantly decrease both …

Food Safety Risk In An Indoor Microgreen Cultivation System, Gina Marie Misra

Graduate Theses and Dissertations

Microgreens are immature sprouts of edible plants, sharing some similarities with sprouted seeds and petite leafy greens. Since they are most often grown in containers in buildings or greenhouses, they present a new area for food safety research at the intersection of the built environment and produce farming. Contamination by human pathogens has been extensively studied in other types of produce typically eaten raw, including sprouted seeds, which have been implicated in numerous outbreaks of salmonellosis over the last several decades. There is a paucity of knowledge about the microgreen sector of the fresh-cut industry; thus, it was determined that …

The Effects Of Farnesol, A Quorum Sensing Molecule From Candida Albicans, On Alcaligenes Faecalis, Savannah Hutson

Undergraduate Honors Theses

Quorum sensing molecules have become a recent focus of study to learn if and how they can be used, both on their own and in conjecture with current antimicrobial methods, as a means of bacterial control. One such quorum sensing molecule is the sesquiterpene alcohol, Farnesol, which is synthesized and released by the fungus, Candida albicans. In most in-vivo cases, our laboratory has shown that Alcaligenes faecalis overtakes C. albicans, preventing its growth. However, as a way to counteract this inhibitory effect, Farnesol may be one way that Candida has found to fight back. In this study, we …