Comparison Of The Humoral Immune Response Following Both Bacterial Challenge And Rnai Of Major Factors On Proliferation Of Bartonella Quintana In The Human Louse, 2022 University of Massachusetts Amherst
Comparison Of The Humoral Immune Response Following Both Bacterial Challenge And Rnai Of Major Factors On Proliferation Of Bartonella Quintana In The Human Louse, Jake Zina
Masters Theses
Human body lice, Pediculus humanus humanus, and head lice, Pediculus humanus capitis, have been hematophagous ectoparasites of humans for thousands of years. Despite being ecotypes, only body lice are known to transmit bacterial diseases to humans, and it appears that lower humoral and cellular immune responses allow body lice to possess a higher vector competence. We previously observed that the transcription level of the defensin 1 gene was up-regulated only in head lice following oral challenge of Bartonella quintana, a causative agent of trench fever, and also that body lice excreted more viable B. quintana in their …
An Active Biodegradable Layer-By-Layer Film Based On Chitosan-Alginate-Tio2 For The Enhanced Shelf Life Of Tomatoes, 2022 Technological University Dublin
An Active Biodegradable Layer-By-Layer Film Based On Chitosan-Alginate-Tio2 For The Enhanced Shelf Life Of Tomatoes, Kalpani Y. Perera, Shubham Sharma, Brendan Duffy, Shiviani Pathania, Amit K. Jaiswal, Swarma Jaiswal
Articles
This work aims at developing biodegradable active chitosan-alginate layer-by-layer bio-nanocomposite film with TiO2NPs using the solvent casting method followed by CaCl2 crosslinking for food packaging applications. The developed films enhanced the tensile strength and elongation at break by 14.76 and 2 folds (p < 0.05) respectively. The UV barrier properties of CH-SA-0.3%TiO2 film increased by 88.6%, while the film transparency decreased by 87.23%. All films showed antimicrobial activity against foodborne pathogens E. coli, S. aureus, S. typhi, and L. monocytogene. The film with 0.1%TiO2 showed the complete killing of gram-positive bacteria. The CH-SA-0.1%TiO2 film was completely biodegraded during the …
Comparative Genomics And Virulence Studies Of Streptomyces Soil Rot And Scab Pathogen Species, 2022 Louisiana State University and Agricultural and Mechanical College
Comparative Genomics And Virulence Studies Of Streptomyces Soil Rot And Scab Pathogen Species, Natasha Soares
LSU Doctoral Dissertations
Comparative genomic analyses were performed to gain insights into the organization and content of the genome of Streptomyces ipomoeae, the soil rot pathogen that infects sweetpotatoes. Unlike Streptomyces scab pathogens, the thaxtomin phytotoxin gene cluster (txt) in S. ipomoeae does not appear to reside within a genomic island and has diverged from its scab pathogen counterparts. Increased usage of the rare TTA codon, particularly for the txt cluster, suggests greater translational control by the bldA tRNA in S. ipomoeae. Orthologous gene searches and secondary metabolite profiling yielded ortholog groups and metabolite gene clusters that were exclusive …
Novel Signal Sequences And Fusion Partners For Paratransgenesis In Asaia, 2022 Duquesne University
Novel Signal Sequences And Fusion Partners For Paratransgenesis In Asaia, Christina Grogan
Electronic Theses and Dissertations
Mosquitoes transmit many pathogens that cause human disease. One such disease, malaria, is caused by parasites in the genus Plasmodium, infecting over 200 million people and killing over 600,000 per year. Current strategies to control vector-transmitted diseases are increasingly undermined by mosquito and pathogen resistance. Research has turned to additional and novel methods of control, such as altering the microbiota of the vectors. In this method, called paratransgenesis, symbiotic bacteria are genetically modified to affect the mosquito’s phenotype by engineering them to deliver antiplasmodial molecules into the midgut to kill parasites. These molecules must be released by the …
Investigating Host Defenses Of North American Salamanders Against The Recently Emerged Chytrid Pathogen, Batrachochytrium Salamandrivorans, 2022 Duquesne University
Investigating Host Defenses Of North American Salamanders Against The Recently Emerged Chytrid Pathogen, Batrachochytrium Salamandrivorans, Kenzie Pereira
Electronic Theses and Dissertations
A recently emerged chytrid fungal pathogen, Batrachochytrium salamandrivorans (Bsal) threatens salamander biodiversity. Bsal susceptibility varies between and within salamander species, but little is known about the mechanisms underlying these differences. Susceptibility is likely influenced by numerous interacting factors, but my dissertation studied the role of host immune responses.
My first aim investigated between species differences by studying the bioactive properties of salamander skin peptides against Bsal and the related pathogen, B. dendrobatidis (Bd). Skin peptides were collected from five salamander species, used for in vitro assays, and analyzed by RP-HPLC. While skin peptides from one …
Identification And Characterization Of Genetic Elements That Regulate A C-Di-Gmp Mediated Multicellular Trait In Pseudomonas Fluorescens, 2022 Duquesne University
Identification And Characterization Of Genetic Elements That Regulate A C-Di-Gmp Mediated Multicellular Trait In Pseudomonas Fluorescens, Collin Kessler
Electronic Theses and Dissertations
Microbial communities contain densely packed cells where competition for space and resources are fierce. These communities are generally referred to as biofilms and provide advantages to individual cells against immunological and antimicrobial intervention, dehydration, and predation. High intracellular pools of cyclic diguanylate monophosphate (c-di-GMP) cause cells to aggregate during biofilm formation through the production of diverse extracellular polymers. Genes that encode c-di-GMP catalytic enzymes are commonly mutated during chronic infections where opportunists display enhanced resistance to phagocytosis and antibiotics. Our lab uses an emergent multicellular trait in the model organism Pseudomonas fluorescens Pf0-1 to study the emergence of c-di-GMP mutations …
Genome Sequence Of Sn1, A Bacteriophage That Infects Sphaerotilus Natans And Pseudomonas Aeruginosa, 2022 Université Laval
Genome Sequence Of Sn1, A Bacteriophage That Infects Sphaerotilus Natans And Pseudomonas Aeruginosa, K.M. Damitha Gunathilake, Denise M. Tremblay, Pier-Luc Plante, Ellen Jensen, Kenneth Nickerson, Sylvain Moineau
Kenneth Nickerson Papers
Phage SN1 infects Sphaerotilus natans and Pseudomonas aeruginosa strains. Its genome consists of 61,858 bp (64.3% GC) and 89 genes, including 32 with predicted functions. SN1 genome is very similar to Pseudomonas phage M6, which contains hypermodified thymidines. Genome analyses revealed similar base-modifying genes as those found in M6.
Phage SN1 was isolated in 1979 from activated sludge samples obtained from a wastewater treatment plant (Lincoln, Nebraska, USA) using S. natans ATCC 13338 as the host (1, 2). An early study showed that the siphophage SN1 has unusual bases in its genome as confirmed by cellulose thin-layer chromatography (1). Its …
Cyclic Di-Gmp Regulates Motility, Biofilm Formation, And Desiccation Tolerance In Acinetobacter Baumannii, 2022 East Tennessee State University
Cyclic Di-Gmp Regulates Motility, Biofilm Formation, And Desiccation Tolerance In Acinetobacter Baumannii, Garrett Reynolds
Electronic Theses and Dissertations
Acinetobacter baumannii is an increasingly multidrug-resistant pathogen contributing to hospital-acquired infections necessitating the discovery of novel treatments. A bacterial second messenger, cyclic diguanosine monophosphate (cyclic di-GMP), can regulate various persistence factors that are potentially advantageous for survival in hospital environments. Cyclic di-GMP–modulating enzymes and cyclic di-GMP–binding effectors predictively are encoded in the Acinetobacter baumannii genome. I hypothesized that cyclic di-GMP controls motility, biofilm formation, and desiccation tolerance in Acinetobacter baumannii. Disrupting cyclic di-GMP–modulating enzymes or cyclic di-GMP–binding effectors should alter the regulatory effectiveness of these phenotypes. I tested the multidrug-resistant isolate Acinetobacter baumannii strain AB5075 and identified several transposon …
The Effects Of Short Chain Fatty Acids On Clostridioides Difficile Growth, Sporulation, And Toxin Production, 2022 Clemson University
The Effects Of Short Chain Fatty Acids On Clostridioides Difficile Growth, Sporulation, And Toxin Production, Michelle Baldassare
All Theses
Short chain fatty acids (SCFAs) are products of bacterial fermentation that help maintain important gut functions such as the intestinal barrier, signaling, and immune homeostasis. The main SCFAs acetate, propionate, and butyrate have demonstrated beneficial effects for the host, including importance in combatting infections caused by pathogens such as Clostridioides difficile. C. difficile infection (CDI) is a public health concern and causes 30,000 deaths each year mainly due to the overuse of antibiotics. Despite the potential role of SCFAs in mitigating C. difficile infection, their direct effect on C. difficile remains unclear. Through a set of in-vitro experiments, we …
Weaving An Interdisciplinary Microbiome Career Using Threads From Different Ecosystems, 2022 University of Maine
Weaving An Interdisciplinary Microbiome Career Using Threads From Different Ecosystems, Sarah Hosler
Electronic Theses and Dissertations
Animals have trillions of microorganisms living in or on many body sites, these communities of microorganisms are called microbiomes. Microbiomes are typically host-specific, and a lot of information about the host can be determined from investigating them. Microbiome research has many real-world applications, and this thesis utilizes the One Health perspective, which acknowledges the connection of humans, animals, and environments, and emphasizes the need for collaborative, interdisciplinary research. The first interdisciplinary project is an investigation into the bacteria in wild and cultured Atlantic deep-sea scallop, Placopecten magellanicus larvae. Adults in hatcheries can be induced to spawn, but the last two …
Bacterial Chondronecrosis With Osteomyelitis In Broilers: Genomics, Phylogenomics, And Methods To Detect Specific Pathogens During Outbreaks., 2022 University of Arkansas, Fayetteville
Bacterial Chondronecrosis With Osteomyelitis In Broilers: Genomics, Phylogenomics, And Methods To Detect Specific Pathogens During Outbreaks., Abdulkarim Abdulaziz A. Shwani
Graduate Theses and Dissertations
Lameness is a major issue in animal welfare and the broiler industry. Bacterial chondronecrosis with osteomyelitis (BCO) is one of the main causes of lameness. Many staphylococcal species, including Staphylococcus agnetis isolate 908, have been isolated from the bones and blood of lame broilers at the University of Arkansas. Staphylococcus agnetis is a coagulase-variable, Gram-positive bacterial species that has been previously associated with subclinical or mild clinical cases of mastitis in dairy cattle. The annotated complete genome of hypervirulent strain 908 was published at NCBI. In this study, it has been compared to nine genomes we assembled for hypervirulent isolates …
Characterization Of Genetic Pathways Involved In Resistance To A Novel Antifungal Peptide, 2022 University of Arkansas, Fayetteville
Characterization Of Genetic Pathways Involved In Resistance To A Novel Antifungal Peptide, Kayla L. Haberman
Graduate Theses and Dissertations
Antibiotic resistance is increasing prevalence, particularly in Candida glabrata. This opportunistic pathogen is closely phylogenetically related to Saccharomyces cerevisiae; however, its characterization is limited. C. glabrata is only second to Candida albicans as a fungal pathogen in immunocompromised patients. Commonly resistant to azoles, the most common fungal therapy, it has become costly and challenging to treat. A histatin 5 derived antifungal peptide, KM29, has a high degree of efficacy in Candida species and S. cerevisiae. The objective of this work is to advance our understanding of the mechanism of action of KM29 against C. glabrata. Previous work in the lab …
The Role Of L-Alanine Signaling In Aspergillus Fumigatus Biofilm Adherence, Carbon Catabolism, And Echinocandin Susceptibility., 2022 Dartmouth College
The Role Of L-Alanine Signaling In Aspergillus Fumigatus Biofilm Adherence, Carbon Catabolism, And Echinocandin Susceptibility., Joshua D. Kerkaert
Dartmouth College Ph.D Dissertations
Aspergillus fumigatus is a saprophytic filamentous fungus that participates in environmental carbon and nitrogen cycles through the degradation of complex organic substrates. In addition to its ecological role, A. fumigatus is the primary causative agent of a spectrum of diseases depending on the immune status of the individual, the most lethal of which is invasive aspergillosis (IA). Treatment strategies for IA are limited and far too frequently fail. Despite the high rates of treatment failure, antifungal resistance remains relatively low, albeit rising at a concerning rate. Insights into this discrepancy between the rate of treatment failure and the rate of …
Molecular Mechanisms Underlying Mucosal Attachment And Colonization By Clostridioides Difficile, 2022 University of Nebraska-Lincoln
Molecular Mechanisms Underlying Mucosal Attachment And Colonization By Clostridioides Difficile, Ben Sidner
Department of Food Science and Technology: Dissertations, Theses, and Student Research
Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium which causes gastrointestinal disease and is a leading cause of nosocomial infections. Although infection typically occurs following antibiotic therapy, in recent years there has been an increase in infections which are not preceded by antibiotic use. Additionally, community-associated infections and rates of disease recurrence have increased. While it is understood that a healthy gastrointestinal microbiota provides protection against infection, the molecular mechanisms which underly C. difficile's ability to colonize and persist in the gut are mostly unknown. Building on work from others that suggests C. difficile associates with the outer mucus …
Biowill - Characterising Willow Bark Bio-Actives For Skin Therapies, 2022 Department of Biological and Pharmaceutical Sciences, Munster Technological University, Kerry, Ireland
Biowill - Characterising Willow Bark Bio-Actives For Skin Therapies, Arnold Marisa
ORBioM (Open Research BioSciences Meeting)
Willow bark is considered as a disposable by-product when processing willow for biomass. Willow (Salix) is known to contain high value bioactive compounds which include salicin and its derivatives, and other phytochemicals of interest such as polyphenols and flavonoids. The plant is historically known as the primary source of salicylates to which the well-known drug aspirin is derived from. The work forms part of the Interreg project BioWILL, which is focused on integrated “Zero Waste” biorefinery utilising all fractions of willow feedstock for the production of biochemicals and renewable energy. This project aims to investigate the crude and …
Investigation Of The Urobiome For The Production Of Novel Antimicrobials Against Uropathogenic E. Coli (Upec), 2022 Department of Biological Sciences, Munster Technological University, Cork, Ireland
Investigation Of The Urobiome For The Production Of Novel Antimicrobials Against Uropathogenic E. Coli (Upec), Jennifer Jones
ORBioM (Open Research BioSciences Meeting)
BACKGROUND: Urinary tract infections (UTIs) are one of the most common bacterial infections globally with antibiotic treatment becoming increasingly less effective. The urobiome remains a relatively understudied niche as a source of potentially novel antimicrobials (e.g., bacteriocins). Improvements to bacterial culturing and sequencing techniques have highlighted the potentially rich source of alternative treatments and control strategies to target uropathogenic E. coli (UPEC).
MATERIALS AND METHODS: (a) BAGEL 4 was used for bioinformatic screening of the genomes of urobiome isolates to identify bacteriocin gene clusters (BGC).
(b) Expanded quantitative urine culture (EQUC) was used to culture mid-stream urine samples to isolate …
Analysis Of Soxs In S. Typhimurium By Transposon Mutagenesis, 2022 University of Missouri-St. Louis
Analysis Of Soxs In S. Typhimurium By Transposon Mutagenesis, Joel Hanns, Brenda Pratte, Lon Chubiz Phd, Lauren Daugherty
Undergraduate Research Symposium
The mar-sox-rob regulon has been implicated in transcriptional regulation of several stress responses, such efflux of antibiotics, enzymes that break down reactive oxygen species, repression of biofilm formation, or repression of motility through downregulation of flagellar expression. This system is conserved among enteric bacteria and has been studied in species, such as E. coli and S. typhimurium. Some of these mechanisms can be costly and slow cell growth while increasing the probability of survival through tolerance of toxic environments. SoxS works in coordination with SoxR to respond to redox stress encountered by the cell. Interestingly, the overexpression of SoxS …
Resolving The Repression Pathway Of Virulence Gene Hila In Salmonella, 2022 University of Missouri-St. Louis
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 …
Invasion Properties Of Listeria Monocytogenes In Aged Cells, 2022 The University of Southern Mississippi
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 …
An Investigation On The Impact Of Intestinal Oxygen Availability On Survival And Regulation Of Virulence In Listeria Monocytogenes, 2022 The University of Southern Mississippi
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 …