Mechanism Of Neutrophil Homeostasis And Immunity In Pneumonia And Sepsis,
2019
Louisiana State University and Agricultural and Mechanical College
Mechanism Of Neutrophil Homeostasis And Immunity In Pneumonia And Sepsis, Sagar Paudel
LSU Doctoral Dissertations
Severe bacterial pneumonia and septicemia are pressing health problems. A better understanding of cellular and molecular players of neutrophil immunity and homeostasis in bacterial pneumonia and sepsis is critical for inspiring novel therapeutics. Chemokine CXCL1 is a widely secreted neutrophil attractant and Nod-like receptor (NLRC4) is commonly expressed cytoplasmic pathogen sensor in hematopoietic compartments. How these innate mediators convert pathogen signals into molecular cues of immune response in context of Gram-positive bacterial pneumonia and septicemia largely remain unknown. Utilizing Cxcl1 gene deficient mice, we demonstrate CXCL1 regulates neutrophil influx, bacterial clearance, and host survival in pneumococcal pneumonia-derived sepsis. Furthermore, Cxcl1 …
Simulating Bacterial Growth, Competition, And Resistance With Agent-Based Models And Laboratory Experiments,
2019
The New School
Simulating Bacterial Growth, Competition, And Resistance With Agent-Based Models And Laboratory Experiments, Anne E. Yust, Davida S. Smyth
Annual Symposium on Biomathematics and Ecology Education and Research
No abstract provided.
Transposon Mutagenesis Facilitates Discovery Of Genotype-Phenotype Associations And Functional Interrogation Of The Mycobacterium Kansasii Genome,
2019
CUNY Graduate Center
Transposon Mutagenesis Facilitates Discovery Of Genotype-Phenotype Associations And Functional Interrogation Of The Mycobacterium Kansasii Genome, William C. Budell
Dissertations, Theses, and Capstone Projects
Mycobacterium kansasii (Mk) is a nontuberculous mycobacterium (NTM) and medically relevant opportunistic human pathogen. Mk causes dangerous disease pathologies ranging from tuberculosis-like chronic pulmonary disease (CPD) to non-pulmonary focal or disseminated infections that are exacerbated by comorbidities such as chronic obstructive pulmonary disease (COPD), co-infection with HIV, or cancer. Among the most frequently identified cause of NTM-linked CPD, Mk infections contribute to a globally increasing NTM disease burden and are difficult to treat, requiring a long-term, multi-drug regimen. Although a less virulent pathogen than Mycobacterium tuberculosis (Mtb), Mk elicits similar disease features and shares in vitro …
Characterization Of Early Biofilm Formation And Physiology In Neisseria Gonorrhoeae,
2019
CUNY Graduate Center
Characterization Of Early Biofilm Formation And Physiology In Neisseria Gonorrhoeae, Kelly Eckenrode
Dissertations, Theses, and Capstone Projects
Many bacteria rely on the dynamics of their extracellular appendages to perform important tasks, like motility and biofilm formation. Interestingly, these dynamics have been linked to physiological responses in some pathogenic bacteria; therefore, it is important to understand more about the role of physical forces in bacteria. I used the causative agent of the human disease gonorrhea, Neisseria gonorrhoeae, as a model system to study the role of physical force on early biofilm formation. The advantage of this system is that cell-cell interactions are controlled by extracellular filaments called type IV pili (tfp). Tfp is composed of monomers that give …
Characterization Of The Role Of Transcriptional Regulator Of Arac/Xyls Family In Tularemia Pathogenesis,
2019
Touro College and University System
Characterization Of The Role Of Transcriptional Regulator Of Arac/Xyls Family In Tularemia Pathogenesis, Dina Marghani
NYMC Student Theses and Dissertations
The Tier 1 Select Agent, Francisella tularensis causes an acute and fatal disease known as tularemia. Many studies have devoted enormous efforts to understand how F. tularensis avoids host defense mechanisms, replicates within an extremely secure immune system, and eventually causes the deadly disease tularemia. The extremely high virulence of Francisella depends on its ability to manipulate gene expression according to the surrounding environment. This process requires the involvement of unique transcriptional regulators. Francisella possesses very few transcriptional regulators, and a majority of them characterized to-date have been shown to regulate genes involved in virulence and cellular functions. The role …
The Evolutionary Diversity And Biological Function Of Phenazine Metabolite Biosynthesis In Burkholderia Spp,
2019
University of Southern Mississippi
The Evolutionary Diversity And Biological Function Of Phenazine Metabolite Biosynthesis In Burkholderia Spp, Samuel Hendry
Master's Theses
Burkholderia encompass a group of ubiquitous Gram-negative bacteria that include numerous saprophytes, as well as several species that cause infections in animals, immunocompromised patients, and plants. Some species of Burkholderia produce colored redox-active secondary metabolites called phenazines (Phz). In the model opportunistic pathogen Pseudomonas aeruginosa, phenazines strongly contribute to the competitiveness, formation of biofilms, and virulence in multiple models of infection. Similar depth of knowledge on the diversity, biosynthesis, and biological functions of phenazines in Burkholderiais missing. This project aimed to bridge this gap in knowledge by focusing on phenazine pathways of B. lata and closely related …
Investigation Of Microbiota In Health And Disease Of Poultry,
2019
University of Arkansas, Fayetteville
Investigation Of Microbiota In Health And Disease Of Poultry, Bishnu Adhikari
Graduate Theses and Dissertations
The microbiotas play vital roles in health and diseases of both humans and animals. 16S rRNA genes sequence analysis is one of the most popular and commonly used methods in the analysis of microbiotas associated with hosts. In this dissertation, the microbiotas of chickens (broilers, breeders, and layers) and turkeys were evaluated by 16S rRNA gene sequencing. Characterization of the culturable subpopulations of Lactobacillus in the chicken gut can serve as a valuable resource for probiotic development. In Chapter 2, Lactobacillus subpopulations recovered on MRS from chicken gut were defined comprehensively for the first time using 16S rRNA gene profiling, …
The Influence Of The Pep-Pts And Other Metabolic Systems On The Master Virulence Regulator Atxa And To Xin Gene Expression In Bacillus Anthracis,
2019
The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences
The Influence Of The Pep-Pts And Other Metabolic Systems On The Master Virulence Regulator Atxa And To Xin Gene Expression In Bacillus Anthracis, Naomi Bier-Reizes
Dissertations and Theses (Open Access)
AtxA, the master virulence gene regulator in Bacillus anthracis, is a PRD-containing virulence regulator (PCVR) as indicated by the crystal structure, post-translational modifications, and activity of the protein. PCVRs are transcriptional regulators, named for the regulatory domains subject to phosphorylation by the phosphoenolpyruvate phosphotransferase system (PEP-PTS), termed PTS Regulatory Domains (PRD), and for their impact on virulence gene expression. Generally, the phosphorylation of a PCVR regulates protein activity and multimerization. AtxA is phosphorylated at two histidine residues - one in each of its two PRDs. Phosphorylation at position 199 allows for AtxA to positively affect expression of virulence genes, whereas …
Taxonomic Features And Comparison Of The Gut Microbiome From Two Edible Fungus-Farming Termites (Macrotermes Falciger, M. Natalensis) Harvested In The Vhembe District Of Limpopo, South Africa,
2019
University of Nevada, Las Vegas
Taxonomic Features And Comparison Of The Gut Microbiome From Two Edible Fungus-Farming Termites (Macrotermes Falciger, M. Natalensis) Harvested In The Vhembe District Of Limpopo, South Africa, Stephanie L. Schnorr, Courney A. Hofman, Shandukani R. Netschifhefhe, Frances D. Duncan, Tanvi P. Honap, Julie Lesnik, Cecil M. Lewis
Anthropology Faculty Research
Background Termites are an important food resource for many human populations around the world, and are a good supply of nutrients. The fungus-farming ‘higher’ termite members of Macrotermitinae are also consumed by modern great apes and are implicated as critical dietary resources for early hominins. While the chemical nutritional composition of edible termites is well known, their microbiomes are unexplored in the context of human health. Here we sequenced the V4 region of the 16S rRNA gene of gut microbiota extracted from the whole intestinal tract of two Macrotermes sp. soldiers collected from the Limpopo region of South Africa. Results …
A Method For Improving The Accuracy And Efficiency Of Bacteriophage Genome Annotation,
2019
University of Nevada, Las Vegas
A Method For Improving The Accuracy And Efficiency Of Bacteriophage Genome Annotation, Alicia Salisbury, Philippos K. Tsourkas
Life Sciences Faculty Research
Bacteriophages are the most numerous entities on Earth. The number of sequenced phage genomes is approximately 8000 and increasing rapidly. Sequencing of a genome is followed by annotation, where genes, start codons, and functions are putatively identified. The mainstays of phage genome annotation are auto-annotation programs such as Glimmer and GeneMark. Due to the relatively small size of phage genomes, many groups choose to manually curate auto-annotation results to increase accuracy. An additional benefit of manual curation of auto-annotated phage genomes is that the process is amenable to be performed by students, and has been shown to improve student recruitment …
Infection Potential Of Rickettsia Felis Via Ingestion,
2019
Louisiana State University and Agricultural and Mechanical College
Infection Potential Of Rickettsia Felis Via Ingestion, Matthew M. Schexnayder
LSU Master's Theses
Rickettsia felis is the etiologic agent of flea-borne spotted fever (FBSF) in humans and a poorly described cause of fever in animals. It is transmitted by its primary arthropod vector and reservoir host, the cat flea Ctenocephalides felis. Known routes of Rickettsia felis transmission between Rickettsia felis-infected cat fleas and vertebrate hosts include cutaneous bites and contamination of cutaneous wounds with infective flea feces. The bulk of FBSF infections occur in young children in Africa, though infections of people at all ages all over the world have been confirmed. As mammals and young children frequently come into contact …
Molecular Detection Of Pathogenic Leptospira Throughout The Caribbean,
2019
Georgia College
Molecular Detection Of Pathogenic Leptospira Throughout The Caribbean, Zamara R. Garcia Truitt
Biology Theses
Leptospirosis is a common widespread zoonotic disease found throughout the Caribbean. The infection is produced by a pathogenic Leptospira species found in tropical and subtropical regions. The severity of the disease ranges from a mild asymptomatic infection to death. Leptospirosis is a neglected tropical disease due to the lack of public awareness and health approaches. Therefore, misdiagnosis is common because the symptoms are similar to that of other tropical endemic diseases. The aim of the study was to determine the presence of pathogenic Leptospira in water samples collected from Puerto Rico and Trinidad. Sixty-four environmental water samples were collected throughout …
A Rapid Viability And Drug‑Susceptibility Assay Utilizing Mycobacteriophage As An Indicator Of Drug Susceptibilities Of Anti‑Tb Drugs Against Mycobacterium Smegmatis Mc2 155,
2019
Department of Biological Sciences, Cork Institute of Technology, Cork, Ireland
A Rapid Viability And Drug‑Susceptibility Assay Utilizing Mycobacteriophage As An Indicator Of Drug Susceptibilities Of Anti‑Tb Drugs Against Mycobacterium Smegmatis Mc2 155, Gillian Catherine Crowley, Jim O'Mahony, Aidan Coffey, Riona G. Sayers, Paul D. Cotter
Department of Biological Sciences Publications
Background: A rapid in-house TM4 mycobacteriophage-based assay, to identify multidrug resistance against various anti-tuberculosis drugs, using the fast-growing Mycobacterium smegmatis mc2 155 in a microtiter plate format was evaluated, based on phage viability assays. Methods: A variety of parameters were optimized before the study including the minimum incubation time for the drugs, phage and M. smegmatis mc2 155 to be in contact. An increase in phage numbers over 2 h was indicative that M. smegmatis mc2 155 is resistant to the drugs under investigation, however when phage numbers remained static, M. smegmatis mc2 155 found to …
Culture-Based Analysis Of ‘Cave Silver’ Biofilms On Rocks In The Former Homestake Mine In South Dakota, Usa,
2019
Florida State University
Culture-Based Analysis Of ‘Cave Silver’ Biofilms On Rocks In The Former Homestake Mine In South Dakota, Usa, Amanpreet K. Brar, David Bergmann
International Journal of Speleology
Tunnels in a warm, humid area of the 1478 m level of the Sanford Underground Research Facility (SURF), located in a former gold mine in South Dakota, USA, host irregular, thin whitish, iridescent biofilms, which appear superficially similar to ‘cave silver’ biofilms described from limestone and lava tube caves, despite the higher rock temperature (32°C) and differing rock surface (phyllite) present at SURF. In this study, we investigated the diversity of cultivable bacteria constituting the cave silver by using several media: CN agar, CN gellan gum and 0.1X R2A agar. The highest colony count (CFU/g of sample) was observed on …
The Anti-Sigma Factor Muca Of Pseudomonas Aeruginosa: Dramatic Differences Of A Muca22 Vs. A Δmuca Mutant In Anaerobic Acidified Nitrite Sensitivity Of Planktonic And Biofilm Bacteria In Vitro And During Chronic Murine Lung Infection,
2019
University of Cincinnati College of Medicine
The Anti-Sigma Factor Muca Of Pseudomonas Aeruginosa: Dramatic Differences Of A Muca22 Vs. A Δmuca Mutant In Anaerobic Acidified Nitrite Sensitivity Of Planktonic And Biofilm Bacteria In Vitro And During Chronic Murine Lung Infection, Warunya Panmanee, Shengchang Su, Michael J. Schurr, Gee W. Lau, Xiaoting Zhu, Zhaowei Ren, Cameron T. Mcdaniel, Long J. Lu, Dennis E. Ohman, Daniel A. Muruve, Ralph J. Panos, Hongwei D. Yu, Thomas B. Thompson, Boo Shan Tseng, Daniel J. Hassett
Life Sciences Faculty Research
Mucoid mucA22 Pseudomonas aeruginosa (PA) is an opportunistic lung pathogen of cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) patients that is highly sensitive to acidified nitrite (A-NO2-). In this study, we first screened PA mutant strains for sensitivity or resistance to 20 mM A-NO2- under anaerobic conditions that represent the chronic stages of the aforementioned diseases. Mutants found to be sensitive to A-NO2- included PA0964 (pmpR, PQS biosynthesis), PA4455 (probable ABC transporter permease), katA (major catalase, KatA) and rhlR (quorum sensing regulator). In contrast, mutants lacking PA0450 (a putative phosphate transporter) and PA1505 (moaA2) were A-NO2- resistant. However, …
The Effect Of Intracellular Zinc Levels In Escherichia Coli On Metallo-Β-Lactamase Activity,
2019
Rowan University
The Effect Of Intracellular Zinc Levels In Escherichia Coli On Metallo-Β-Lactamase Activity, Jill Thompson
Graduate School of Biomedical Sciences Theses and Dissertations
Antibiotic resistance is a consequence of evolution via natural selection and poses a serious threat to the world's population. Escherichia coli, and other bacterial species, have acquired genes encoding Metallo-β-Lactamases (MBLs). MBLs are zinc-dependent enzymes that degrade most β-lactam antibiotics, and have emerged as important antibacterial resistance determinants in multidrug resistant pathogens. There are several different families of MBLs, and the major clinically relevant ones are Verona Integrated-encoded Metallo-β-Lactamases (VIMs), Imipenemases (IMPs), and New Delhi Metallo-β-Lactamases (NDMs). These enzymes confer high level resistance to penicillins, cephalosporins, and carbapenems, and are not inhibited by FDA-approved β-lactamase inhibitors. Variants of NDM have …
Characterization Of Bacterial Isolates Obtained From Commercial Poultry Feed And Retail Food Using Whole Genome Sequence Analysis And Selected Biochemical Tests,
2019
Pittsburg State University
Characterization Of Bacterial Isolates Obtained From Commercial Poultry Feed And Retail Food Using Whole Genome Sequence Analysis And Selected Biochemical Tests, Elena George Olson
Electronic Theses & Dissertations
The goals of this study is two-fold. The first part investigates bacterial isolates from commercial poultry feed and the second part deals with bacterial isolates recovered from retail food. In order to reduce pathogen contamination in poultry products identification of overall microbial populations in poultry production processing steps have always been considered an important monitoring tool for assessing sanitizer effectiveness and the corresponding responses of bacteria load levels on poultry carcasses. Bacterial isolates recovered from corn-based chicken feed were purified on aerobic plate count agar and eleven morphologically different colonies were selected for whole genome sequencing. In this part, the …
The Chelation Of Metal Ions By Vicibactin, A Siderophore Produced By Rhizobium Leguminosarum Atcc 14479,
2019
East Tennessee State University
The Chelation Of Metal Ions By Vicibactin, A Siderophore Produced By Rhizobium Leguminosarum Atcc 14479, Joshua Stinnett
Undergraduate Honors Theses
Vicibactin is a small, high-affinity iron chelator produced by Rhizobium leguminosarum ATCC 14479. Previous work has shown that vicibactin is produced and secreted from the cell to sequester ferric iron from the environment during iron-deplete conditions. This ferric iron is then transported into the cell to be converted into ferrous iron. This study uses UV-Vis spectroscopy as well as ion trap-time of flight mass spectroscopy to determine that vicibactin does form a complex with copper(II) ions, however, at a much lower affinity than for iron(III). Stability tests have shown that the copper(II)-vicibactin complex is stable over time. The results of …
The Importance Of Rnd-Type Efflux Pumps In The Interactions Of Pseudomonas Aeruginosa With 4-Methoxybenzaldehyde,
2019
University of Southern Mississippi
The Importance Of Rnd-Type Efflux Pumps In The Interactions Of Pseudomonas Aeruginosa With 4-Methoxybenzaldehyde, Sanchirmaa Namjilsuren
Honors Theses
Pseudomonas aeruginosa is a common hospital-acquired pathogen and is often associated with high mortality rates due to the development of multidrug-resistance. Antimicrobial plant-derived (phyto-) aldehydes present a promising alternative to antibiotics due to their broad-spectrum antimicrobial activity and low propensity to trigger resistance. However, two main problems preclude the widespread application of these compounds: chemical instability and low antimicrobial efficacy. The ongoing collaboration between the Mavrodi and Patton labs at USM has recently addressed the problem of chemical instability by incorporating plant aldehydes into polymer materials called Pro-Antimicrobial Networks via Degradable Acetals (PANDAs). Thus, this study aimed to address the …
The Impact Of Oxygen On The Intracellular Survival Of Listeria Monocytogenes,
2019
University of Southern Mississippi
The Impact Of Oxygen On The Intracellular Survival Of Listeria Monocytogenes, Amber N. Coats
Honors Theses
Listeria monocytogenes is an intracellular pathogen that is responsible for the foodborne disease listeriosis. In order to invade host cells and establish an infection, this pathogen must travel through the gastrointestinal tract where it is exposed to a variety of stressors, including low pH, bile, and variations in oxygen concentrations. These stressors necessitate this organism’s ability to sense and respond to its environment. Previous research has shown that bacteria use two-component systems to sense and regulate genes needed for improved survival in stressful environmental conditions. The goal of this study was to determine if the expression of the putative oxygen …
