Microbiology Commons^™

Confocal Analysis Of Sindbis Virus In Aedes Aegypti Unveils Novel Infection Site At Pyloric Armature, Katie Gillian Peters

UNF Graduate Theses and Dissertations

Arthropod-borne viruses (arboviruses), such as Sindbis virus (SINV), generate foci of infection within the midgut of viremic blood-fed mosquitoes. Arboviruses can disseminate out of the midgut into the surrounding musculature and hemolymph, eventually making it to the salivary glands where virus can be transmitted by saliva during a subsequent blood-feed. In this study, the virus SINV containing the reporter gene GFP, combined with immunohistochemistry, was imaged using confocal microscopy and used to evaluate the infection within the vector mosquito Aedes aegypti. The spatial distribution of SINV infection revealed two common characteristics of foci generated in the midgut. (1) There …

The Type Iv Pilus Secretin Bfpb: Structural Analysis And Binding Interactions, Janay I. Little

Theses and Dissertations

Enteropathogenic Escherichia coli (EPEC) causes severe diarrhea in young children. The type IV pilus (T4P) of EPEC, known as the bundle-forming pilus (BFP), plays an important role in EPEC pathogenesis. T4Ps are a family of surface appendages that are important for adhesion, colonization, biofilm formation, virulence, twitching motility and many other functions. One essential component of the BFP system is the secretin, BfpB. Secretins are a large family of integral outer membrane proteins found in T4Ps as well as type II and type III secretion systems, and filamentous phages. Details of the secretin structure have been limited to the overall …

Treponema Denticola Synthesizes C-Di-Amp And Encodes The Cdaa-Type Diadenylate Cyclase Cdaa, Claire R. O'Brien

Theses and Dissertations

Periodontitis is a form of oral disease characterized by dysbiosis of the oral microbiome, leading to inflammation, bone resorption, and in severe cases, entire tooth loss, affecting 42% of adults in the US. One of the bacteria most associated with periodontal disease progression is Treponema denticola (Td), an oral spirochete which inhabits the mouth in small quantities during health but which can dominate the biofilms that form during periodontal disease. The ability of Td to survive in a disease environment and contribute to the progression of disease requires the use of robust signaling networks. Analysis of Td cultures …

Probing The Porphyromonas Gingivalis Nitrosative Stress Response Network, Alexandra Galina

Theses and Dissertations

Objective: To persist in the oral cavity, the perio-pathogen Porphyromonas gingivalis must have an efficient nitrosative stress response mechanism. To better understand how P. gingivalis responds to nitrite (NO₂^-) we must determine what genes are involved in the nitrosative stress response network.

Methods: Through genomic screening, a list of genes was generated that were hypothesized to be part of the nitrosative stress response network and believed to be involved in nitrate/nitrite metabolism or redox state of the cells. Protein coding regions were replaced with the ermF sequence by allelic exchange mutagenesis. 15 mutants were created …

Triclosan Degrading Bacteria From Wastewater Treatment Plants In Central Illinois, Mohammed Alsulami

Masters Theses

Triclosan is an antimicrobial agent that has been used in personal care products and has been identified to cause malformation on cartilage and bone development in zebrafish and influence on thyroid hormone system in humans. Due to its widespread usage and insufficient removal from wastewater treatment plants, triclosan has emerged as a pervasive contaminant that poses a potential threat to the environment and human health. The goal of the study was to isolate and characterize triclosan-degrading bacteria from WWTPs in central Illinois. Using enrichment culture with NMS media containing triclosan as sole carbon source, eighteen bacterial strains were isolated. The …

Comparing The Microbiomes Of Dental Plaques In 19th Century Ancestral Remains, Ananya Udyaver

UROP Posters

During the construction of VCU’s Hermes A. Kontos Medical Sciences Building in April 1994, nineteenth century ancestral remains were found in an abandoned well on the Medical College of Virginia (MCV) campus. This well, now known as the East Marshall Street Well (EMSW), is thought to have been used as a disposal location for cadaver dissection for surgical and other medical waste in the past. VCU is now seeking to use DNA sequencing technology to match and assemble bones from each individual for a proper burial, uncover the cultural and historical context in which these people lived, and bring a …

Elucidating The Role Of A Staphylococcal Glucosaminidase In Host Innate Immune Responses, Zachary Resko

Dissertations

The peptidoglycan of Staphylococcus aureus is a critical cell envelope constituent and virulence factor that subverts host immune defenses and provides protection against environmental stressors. Peptidoglycan chains of the S. aureus cell wall are processed to characteristically short lengths by the glucosaminidase, SagB. It is well established that peptidoglycan is an important pathogen-associated molecular pattern (PAMP) that is recognized by the host innate immune system and promotes production of pro-inflammatory cytokines, including IL-1β. However, how bacterial processing of peptidoglycan drives IL-1β production is comparatively unexplored. Here, we tested the involvement of staphylococcal glucosaminidases in shaping innate immune responses and identified …

Identification Of Conditions That Promote Biofilm Formation By Vibrio Fischeri And Elucidation Of The Underlying Signal Transduction Pathway, Courtney Noelle Dial

Dissertations

Biofilms are communities of microorganisms that have intrinsically antimicrobial properties and are difficult to treat in the clinical setting. The marine bacterium Vibrio fischeri efficiently colonizes its symbiotic squid host, Euprymna scolopes, by producing a transient biofilm dependent on the symbiosis polysaccharide (SYP), making it the perfect model system to study biofilm dynamics. In vitro, however, wild-type (WT) strain ES114 fails to form SYP – dependent biofilms. Instead, genetically engineered strains, such as those lacking the negative regulator BinK, have been developed to study SYP biofilms. Historically, V. fischeri has been grown using LBS, a complex medium containing tryptone and …

Characterization Of Mroq-Dependent Regulation Of Staphylococcus Aureus Quorum Sensing, Madison Ruth Stock

Dissertations

Gram-positive bacteria produce small autoinducing peptides (AIPs), which act to regulate expression of genes that promote adaptive traits including virulence. The Gram-positive pathogen Staphylococcus aureus generates a cyclic AIP that controls expression of virulence factors via the accessory gene regulatory (Agr) system. S. aureus strains belong to one of four Agr groups (I, II, III, and IV), and each group harbors allelic variants of AgrD, the precursor of AIP. In a prior screen for S. aureus virulence factors, the Alonzo lab identified MroQ, a putative peptidase. A ΔmroQ mutant closely resembled a Δagr mutant and had significant defects in AIP …

Host-Microbe Interactions In Non-Native Estuarine Anemones: Biogeography And Temperature, Parker K. Lund

Cal Poly Humboldt theses and projects

Non-native species are increasing in prevalence around the world, resulting in negative economic and ecological impacts. However, the broad distributions of non-native species also offer a system for investigating the response of host-associated microbial communities to environmental factors across a range of ecological scales. At the broadest scale, I investigated the geography of microbial communities in the non-native estuarine anemone Diadumene lineata on the west coast of the United States of America. Across latitudes, microbial community composition was very similar and displayed a high percentage of Klebsiella spp. at all sites. However, the communities in California tended to exhibit higher …

Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder

Cal Poly Humboldt theses and projects

Soil acidity is a common agricultural problem worldwide, as approximately 50% of all potentially arable soils are affected by pH limitations. At soil pH 3+) is considered to be the chemical form of aluminum in acid soil that hinders plant growth the most. Potentially, soil organic matter (SOM) can ameliorate the toxic effects of Al³⁺ on plants and microbes by binding with Al³⁺, thus preventing Al³⁺ (and other species of aluminum) from interacting in the rhizosphere. Increasing SOM also increases soil health indicators (i.e., microbial activity, soil water holding capacity, aggregate stability, porosity, etc.) while the …

Marineepi: A Gui-Based Matlab Toolbox To Simulate Marine Pathogen Transmission, Gorka Bidegain, Tal Ben-Horin, Eric N. Powell, John M. Klinck, Eileen E. Hofmann

CCPO Publications

The Graphical User Interface (GUI) MarineEpi is presented as a Matlab toolbox for easily (i) constructing disease transmission models for different marine host-pathogen systems, (ii) running simulations by specifying initial conditions and model parameters, and (iii) interpreting the resulting time series of the host and pathogen population dynamics. MarineEpi users can generate models for systems in which pathogen transmission occurs through contact with infected individuals (SI), contact with dead infected individuals (SID), contact with environmental pathogens released by infected individuals (SIP), and contact with environmental pathogens released by dead infected individuals (SIPD). MarineEpi is a freely available GUI that provides …

Connecting Antibiotic Resistance To The Environment (Care): Introducing A Novel Framework Integrating Chemical Cross-Resistance And Place-Based Engagement To The Blue Marsh Watershed In Reading, Pennsylvania, Jill Felker

Antioch University Dissertations & Theses

Antibiotic resistance is a serious health threat around the world. Millions of individuals are infected with antibiotic-resistant bacteria yearly, and thousands die from previously curable illnesses. Although antibiotic resistance occurs naturally, misuse of antibiotics accelerates the loss of their effectiveness. Public health campaigns focusing on antibiotic awareness have not effectively communicated and educated the public on this health crisis. New efforts to combat antibiotic resistance are urgently needed. This dissertation focuses on the ecological and public health components of antibiotic resistance research that must be addressed to decelerate antibiotic resistance. A new interdisciplinary theoretical framework was developed to Connect Antibiotic …

Identification Of Novel Biosynthetic Gene Clusters Encoding For Polyketide/Nrps-Producing Chemotherapeutic Compounds From Marine-Derived Streptomyces Hygroscopicus From A Marine Sanctuary, Hannah Ruth Flaherty

Honors Theses and Capstones

Nearly one out of six deaths in 2020, around ten million people, were caused by cancer, making it a leading cause of death worldwide (WHO, 2022). This major public health issue, in addition to the rise of multidrug-resistant (MDR) pathogens, provides a high demand for the discovery of new pharmaceutical drugs to be used clinically to treat these conditions. The Streptomyces genus accounts to produce 39% of all microbial metabolites currently approved for human health, indicating its potential as an important species to study for antimicrobial and anticancer agents. The long linear genome of Streptomyces contains specialized sequences known as …

Odd Bedfellows & Marriage Of Necessity: Public Health And Politics In American Federalism, Gabriella Victoria Chianese

Honors Theses and Capstones

In the wake of the coronavirus disease 2019 (COVID-19) pandemic, while the public disagrees over mask mandates, required vaccinations, and social distancing, it seems like one common sentiment exists – a distaste for the odd bedfellows of politics and public health. There are those who cry for the compartmentalization of the science of public health and the art of politics to rectify this situation. In the wake of so much confusion and chaos, it is not unjustified to demand the depoliticization of public health; however, this response is unrealistic given the modern political climate, demonstrates a narrow understanding of the …

Effects Of Altering Physiologically Relevant Cholesterol Levels And Media Types On Porin Gene Expression In Klebsiella Pneumoniae And The Resulting Impact On Antibiotic Resistance, Megan R. Camden

UNF Graduate Theses and Dissertations

Klebsiella pneumoniae is a Gram-negative, non-motile bacterium belonging to the Enterobacteriaceae family. K. pneumoniae is a rising threat in the clinical setting, as there has been a large increase in the presence of antibiotic resistant isolates. While much research is conducted on laboratory and clinical strains of bacteria, not much is known regarding the impact that human physiology can have on bacterial gene expression, and in response, to antibiotic susceptibility. The goal of this study is to determine if physiologically relevant cholesterol levels and media types impact porin gene expression and antibiotic resistance in K. pneumoniae. To accomplish this, …

Monitoring Archaeal Persistence In Cultivation, Payton Hall

Honors Program Theses

It was previously thought that microbes in the domain Archaea were only found in extreme environments such as hot thermal vents at the bottom of the ocean and hypersaline environments, but as scientists began to use environmental DNA to survey soil, they detected archaea from the phylum Thaumarchaeota in relatively benign environments including farm fields, forests, and prairies. In spite of their widespread global distribution, relatively few of these species have been grown in laboratory culture. It is now known that Thaumarchaeota play an important role in the nitrogen cycle because they can generate energy through ammonia-oxidation. To increase the …

Evaluation Of Methods To Analyze Microbial Composition In Soils, Joseph Correa

Honors Program Theses

DNA testing has become a vital tool for studying microbes in their natural environments, but there is a lack of standardization in the protocols for extracting environmental DNA. Cave systems provide a special and unique area to research how life thrives in extreme environments. Many parts of caves receive no sunlight and very little nutrients yet harbor microbial communities. Previous work in our lab developed a DNA extraction protocol that works with a wide range of microbial species and with different soil types. I updated this protocol by adding a pre-lysis rinse step and tested whether it performed better with …

Staff Education To Promote Probiotic Breastfeeding Therapy, José Diaz

Walden Dissertations and Doctoral Studies

Preterm birth is the leading cause of death in children under 5. In addition, there are 22 million babies born underweight each year which also contributes to the infant mortality rate. Some reasons for the inability to thrive and survive are the infants' immature system, allostatic load inadaptability, and undiversified and underdeveloped microbiota. Human breast milk (HBM) provides lifesaving nutrients, which prevents necrotizing enterocolitis and mortality. In addition, probiotic supplementation helps reduce late-onset sepsis, morbidities, and mortality. A literature review provided substantial evidence that HBM and probiotics can improve an infant's microbiota, thus improving thrivability and survivability. Probiotics offset the …

Staff Education To Promote Probiotic Breastfeeding Therapy, José Diaz

Walden Dissertations and Doctoral Studies

Preterm birth is the leading cause of death in children under 5. In addition, there are 22 million babies born underweight each year which also contributes to the infant mortality rate. Some reasons for the inability to thrive and survive are the infants' immature system, allostatic load inadaptability, and undiversified and underdeveloped microbiota. Human breast milk (HBM) provides lifesaving nutrients, which prevents necrotizing enterocolitis and mortality. In addition, probiotic supplementation helps reduce late-onset sepsis, morbidities, and mortality. A literature review provided substantial evidence that HBM and probiotics can improve an infant's microbiota, thus improving thrivability and survivability. Probiotics offset the …