Microbiology Commons^™

Extension Of The Ergot Alkaloid Gene Cluster, Samantha Joy Fabian

Graduate Theses, Dissertations, and Problem Reports (ETD)

Specialized metabolites produced by fungi impact human health. A large portion of the pharmaceuticals currently on the market are derived from metabolites biosynthesized by microbes. Ergot alkaloids are a class of fungal metabolites that are important in the interactions of environmental fungi with insects and mammals and also are used in the production of pharmaceuticals. In animals, ergot alkaloids can act as partial agonists or antagonists at receptors for 5-hydroxytryptamine (serotonin), dopamine, and noradrenaline as ergot alkaloids have chemical structures similar to those neurotransmitters. Therefore, they affect insects and mammals that consume them and can be used to produce drugs …

Early-Phase Drive To The Precursor Pool: Chloroviruses Dive Into The Deep End Of Nucleotide Metabolism, David Dunigan, Irina Agarkova, Ahmed Esmael, Sophie Alvarez, James L. Van Etten

Nebraska Center for Virology: Faculty Publications

Viruses face many challenges on their road to successful replication, and they meet those challenges by reprogramming the intracellular environment. Two major issues challenging Paramecium bursaria chlorella virus 1 (PBCV-1, genus Chlorovirus, family Phycodnaviridae) at the level of DNA replication are (i) the host cell has a DNA G+C content of 66%, while the virus is 40%; and (ii) the initial quantity of DNA in the haploid host cell is approximately 50 fg, yet the virus will make approximately 350 fg of DNA within hours of infection to produce approximately 1000 virions per cell. Thus, the quality and quantity of …

The Persistence And Stabilization Of Auxiliary Genes In The Human Skin Virome, Ema H. Graham, Wesley A. Tom, Alison C. Neujahr, Michael Adamowicz, Jennifer Clarke, Joshua R. Herr, Samodha C. Fernando

Nebraska Center for Virology: Faculty Publications

Background The human skin contains a diverse microbiome that provides protective functions against environmental pathogens. Studies have demonstrated that bacteriophages modulate bacterial community composition and facilitate the transfer of host-specific genes, potentially influencing host cellular functions. However, little is known about the human skin virome and its role in human health. Especially, how viral-host relationships influence skin microbiome structure and function is poorly understood.

Results Population dynamics and genetic diversity of bacteriophage communities in viral metagenomic data collected from three anatomical skin locations from 60 subjects at five different time points revealed that cutaneous bacteriophage populations are mainly composed of …

Soil And Compost Tea: A New Restoration Technique?, Carol E. Day

Master's Theses and Doctoral Dissertations

Historically, prairie restorations have lacked the plant diversity seen in remnant prairies. Most restoration practices focus on reestablishing the plant community but overlook the soil microbial community even though microbes are critical to habitat functioning. Developing techniques that increase soil microbes in prairie restorations is critical to ensuring diverse restored habitats. We compared how microbial communities differed between remnant and restored prairie sites. We also investigated if soil and compost teas could be used to reintroduce microbes to restored prairie soil and if the teas affected native plant establishment. We found significant differences in the levels of bacterial taxa between …

Community Ecology And Disease Dynamics In Pacific Oysters: Unraveling Microbiome-Pathogen Interactions In The Wild, Victoria E. Cifelli

Cal Poly Humboldt theses and projects

In the context of multispecies microbial assemblages, disruptions can occur when there are alterations in host conditions, such as the onset of a disease. Notably, viruses have the potential to reshape a host's microbial community. However, the role of the host's habitat and environment, which could be pivotal in communities with shifting niche space and habitat filters, is often overlooked in host-microbe-pathogen interactions. Recognizing the importance of these factors, I employed a field-based approach to understand microbial community dynamics in the presence of disease. To address the influence of geographical location, I conducted an analysis involving healthy and infected oysters …

Investigating The Effectiveness Of Microplastic Removal And The Relationship Between Microplastics, Bacterial Communities, And Nitrogen Cycling In The Natural Treatment Systems At The Arcata Wastewater Treatment Facility, Fiona Connor

Cal Poly Humboldt theses and projects

This thesis addressed two challenging aspects of microplastic research, including the quantification of microplastics in organic-rich water, and the investigation of how microplastics impact microorganisms and related nutrient-cycling. Two projects were designed and executed to address specific research objectives relating to these broad topics. The first objective was to develop and implement methods to determine the effectiveness of microplastic removal across the natural treatment systems at the Arcata Wastewater Treatment Facility (AWTF). The second objective was to observe how microplastics found in domestic wastewater impact the bacterial communities and nitrogen cycling in freshwater treatment wetland sediment through a bench-scale experiment, …

Fine-Scale Genetic Structure In Rhizosphere Microbial Communities Associated With Chamaecrista Fasciculata (Fabaceae), Mahboubeh Hosseinalizadeh Nobarinezhad, Lisa E. Wallace

Biological Sciences Faculty Publications

Soil microbiota of the rhizosphere are an important extension of the plant phenotype because they impact the health and fitness of host plants. The composition of these communities is expected to differ among host plants due to influence by host genotype. Given that many plant populations exhibit fine-scale genetic structure (SGS), associated microbial communities may also exhibit SGS. In this study, we tested this hypothesis using Chamaecrista fasciculata, a legume species that has previously been determined to have significant SGS. We collected genetic data from prokaryotic and fungal rhizosphere communities in association with 70 plants in an area of …

Understanding Human Gut Bacterial Interactions And Their Role In Colonization Resistance Against Clostridioides Difficile Using Mini-Bioreactor Array And Caenorhabditis Elegans As Model Systems, Achuthan Ambat

Electronic Theses and Dissertations

No abstract provided.

Indigenous Toxin Affects Cell Viability, While An Artificial Proteolytic Queueing Causes The Upregulation Of Specific Genes, Mohammed Salahuddin

Electronic Theses and Dissertations

Studying bacterial physiology is crucial to understand the fundamental mechanisms that govern bacterial growth, survival, and adaptation. This thesis combines two chapters investigating bacterial physiology by studying important cellular processes like bacterial toxin-antitoxin systems and proteolytic pathways. The first chapter involves studying bacterial toxin-antitoxin systems to understand the regulation and function of hypothetical toxin-antitoxin (TA) systems of bacteria and the effects of these TA systems on bacterial growth and survival. The emergence of these genetic modules in bacterial research and the unrevealing of some of their important roles in cell physiology in recent years has drawn much attention in scientific …

Control Of Persistent Environmental Listeria Monocytogenes Using Phenotypic And Genomic Approaches, Bhaswati Chowdhury

Electronic Theses and Dissertations

No abstract provided.

Evaluation Of Welded And Polished Stainless-Steel Surfaces In Supporting Sporeformer Biofilms In Dairy Plants, Taghreed Almalki

Electronic Theses and Dissertations

No abstract provided.

Microbial Communities In The Guana Tolomato Matanzas National Estuarine Research Reserve: An Assessment Of The Responses Of Spartina Alterniflora Epiphytes To Nitrogen Enrichment, And A Characterization Of Benthic Cyanobacterial Diversity, Anne C. Hurley

UNF Graduate Theses and Dissertations

Elevated nitrogen and phosphorus inputs from anthropogenic sources, which can lead to significant increases in algal biomass and changes in algal community composition, poses a serious threat to estuarine ecosystems worldwide. While numerous studies have addressed the impacts of nutrient enrichment on epiphytic algae in seagrass habitats, few have investigated potential nutrient-driven changes to epiphytes on emergent salt marsh plants, such as Spartina alterniflora. Epiphytic microalgae on S. alterniflora play an important role in food availability in salt marsh ecosystems, and epiphytic nitrogen-fixing cyanobacteria also provide an important source of nitrogen for salt marsh consumers. The first study included …

Effect Of Soil Ph And Indigenous Bacterial Populations In Selecting Rhizobial Endophytes Within Soybean Root Nodules, Brianne Danielle Edwards

Graduate Theses/Dissertations

Soybean plants fulfill most of their nitrogen requirement by developing symbiotic associations with four different rhizobial genera, including Bradyrhizobium, Sinorhizobium, Mesorhizobium, and genus Rhizobium. In general, members of Bradyrhizobium and Sinorhizobium have been reported as dominant root nodule endophytes under acidic soils and alkaline soil conditions, respectively. So far, it is unknown whether the selection of rhizobial endophytes is regulated by their ability to survive under different soil pH or driven by host plants regardless of their relative abundance in soil. This study was focused on the assessment of the potential role of soil pH in …

Screening For Compounds That Affect Innate Immune Memory In Macrophages, Intan Mukti Pratiwi

Chulalongkorn University Theses and Dissertations (Chula ETD)

Innate immunity, the first line of defense against pathogens, is characterized by a rapid response, limited specificity, and lack of memory for future insults. However, recent evidence indicates that components of innate immunity, such as monocytes, macrophages, and natural killer cells, exhibit memory-like responses, known as trained immunity. Trained immunity involves metabolic reprogramming and epigenetic modifications to regulate the expression of inflammation-related genes. Dysregulation of trained immunity can lead to diseases, making it a novel therapeutic target. In this study, the effects of synthetic saccharides derived from the cell wall of Mycobacterium tuberculosis and synthetic cannabinoids on innate immune memory …

Development Of Duplex Loop-Mediated Isothermal Amplification (Dlamp) For Detection Of Carbapenem Antibiotic-Resistant Genes Kpc And Ndm, Nindi Syahputri Lubis

Chulalongkorn University Theses and Dissertations (Chula ETD)

Carbapenems are regarded as a last-resort option for treating a wide range of Gram-positive and Gram-negative bacterial infections. Unfortunately, the prevalence of carbapenem-resistant genes has been on the rise among patients. Some factors contribute to this trend, including prolonged hospital stays, prior antibiotic usage, inappropriate or insufficient antibiotic treatment, and contamination through wounds or feces. The emergence of carbapenem-resistant (CR) genes gained significant attention, particularly after 2005. These CR genes are frequently carried on mobile genetic elements such as plasmids or transposons, enabling their transmission to other bacteria. Klebsiella pneumoniae carbapenemase (KPC) and New delhi metallo-β-lactamase (NDM) stand out as …

Distribution Patterns Of Allorhizobium Vitis In Missouri Vineyards And Non-Vineyard Soils, Jacquelyn M. Wray

Graduate Theses/Dissertations

Crown gall disease causes significant economic loss to the grape and wine industry. Preventive strategies are most effective for mitigating the loss of grapevines in vineyards, as there is no known cure for this disease. The bacterium Allorhizobium vitis carrying a tumor-inducing (Ti) plasmid is the causative agent. A. vitis bacteria live systemically in the grapevine before causing visible symptoms and can survive in residual plant tissues and soil for more than two years. Diagnostic methods have been developed to detect A. vitis bacteria in grapevines and soil. However, more reliable, specific, and high-throughput diagnostics are still needed for screening …

The Impact Of Nutrient Depletion On The Effect Of Hhq On Emiliania Huxleyi, Marley Gonsalves

Honors Theses and Capstones

Emiliania huxleyi is a ecologically important, bloom-forming coccolithophore. HHQ is a bacteria compound that causes cell stasis in E. huxleyi that can lead to bloom termination. This study analyzed the role that nutrient depletion plays in this relationship. Results show that nitrogen depletion protects cells from the effects of HHQ, affecting bloom dynamics.

Antimicrobial Resistance Profile Of Escherichia Coli Isolated From Poultry Litter, M. J. Khong, A. M. Snyder, M. M. Young, N. L. Barbieri, S. L. Weimer

Poultry Science Faculty Publications and Presentations

Antimicrobial resistance is a threat to animal and human health. As a commensal and zoonotic bacterium, Escherichia coli has the potential to be a pathogenic source of antimicrobial resistance. The purpose of this study aimed to investigate the antimicrobial resistance profile of E. coli isolated from litter collected from pens in a broiler chicken experiment. E. coli was isolated from litter samples (n = 68 isolates) of 16 pens housing broilers to d 53 of age. Resistance to 10 antimicrobials was observed by disc diffusion. The presence of 23 antimicrobial and heavy metal resistance genes, O serogroups, and avian pathogenic …

Host-Pathogen Interactions In A Changing World: Microbes, Mucosal Defenses, And Multiple Hosts, Brandon C. Labumbard

Graduate Doctoral Dissertations

As fungal diseases continue to emerge, research increasingly focuses on host-microbiome interactions and links to disease. Certain skin-associated microbes may benefit hosts by protecting them from invading pathogens. Seasonal changes in the host environment can also result in shifts in the microbial community and pathogen virulence – potentially influencing disease dynamics. I investigated how cutaneous microbial communities differ across hosts, seasons, and Batrachochytrium dendrobatidis (Bd) infection status by sequencing the microbial communities of 1,100 leopard frogs at five locations across the US. Percent anti-Bd function varied seasonally and with Bd infection status. Bacterial communities also varied across locations and time. …

Prevalence And Evaluation Of Multidrug Resistance Pattern Of Pseudomonas Aeruginosa Among Critical And Non-Critical Areas At A Tertiary Care Hospital Of Multan, Romah Ishfaq, Hubza Ruatt Khan, Mehvish Javeed, Muhammad Ikrama Tanveer, Asma Ashraf

Journal of Bioresource Management

Pseudomonas aeruginosa is an extremely wide spread microorganism linked to nosocomial illnesses. Effective inspection of variations in antimicrobial resistance patterns of P. aeruginosa is vital for selecting suitable antimicrobial drugs for pragmatic treatment. The current research has been performed for assessing antimicrobial sensitivity profile of P. aeruginosa isolated as of a variety of medical specimens collected from critical and non-critical admitted patients of Nishtar Hospital, Multan. The isolates were detected utilizing standard lab practices, as well as the sensitivity was examined employing Kirby-Bauer disk diffusion method corresponding to Clinical and Laboratory Standard Institute (CLSI) recommendations 2019. Out of 373 samples, …