Microbiology Commons^™

Interactions Of The Sars-Cov-2 Viral Genome 3’-Untranslated Region With Viral And Host Rnas, Caleb Frye, Mihaela Rita Mihailescu

Electronic Theses and Dissertations

This dissertation focuses on the characterization of RNA-RNA interactions within the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome and with host microRNAs. As the causative agent of coronavirus disease 2019 (COVID-19), SARS-CoV-2 has evolved rapidly since its appearance. This has warranted prompt characterization of the virus particularly of its single stranded RNA (ssRNA) genome. By using a combination of bioinformatics, biophysics, and/or biological assays, we analyzed the SARS-CoV-2 viral genomic RNA and uncovered interactions of genomic RNA with host RNAs, highlighting an underutilized method of targeting RNA viruses. We showed here that the conserved elements in the viral genomic …

Characterizing The Francisella Tularensis Universal Stress Protein, Benjamin Girardo

Theses & Dissertations

Francisella tularensis is an extremely virulent pathogen responsible for the zoonotic disease tularemia. F. tularensis employs various defense mechanisms to survive and persist under diverse environmental and host-induced stress conditions. Despite its significance, the full spectrum of stress factors that enable F. tularensis persistence remain inadequately understood. In many bacterial species, universal stress proteins (Usp) play a crucial role in managing adverse conditions. The aim of this study was to elucidate the role of Usp in F. tularensis as a means of clarifying the stress response mechanisms of this pathogen. The F. tularensis Usp is encoded by a single, highly …

Evaluating The Effectiveness Of Benguet Pine (Pinus Kesiya) Xylem For Deep Well Water Filtration, Allen Conner C. Hizon, Robert Zachary M. Santos, Juan Jose B. Lacson, Jefferson Danilo G. Villarin, Juan Carlo T. Gumangan

Sinaya: A Philippine Journal for Senior High School Teachers and Students

Even today, many rural and remote communities still do not have access to safe drinking water, which is a basic right of every human. To address this problem, the effectiveness of the Benguet pine tree (Pinus kesiya) xylem as a sustainable water filtration method for well water was investigated. The physical and chemical properties of the filtered and unfiltered deep well water were tested: the total dissolved solids (TDS) and the electrical conductivity using a 5-in-1 electronic water quality tester and the pH level using pH strips. On the other hand, the microbiological metrics, such as heterotrophic plate …

Population Dynamics In Myxococcus Xanthus Developmental Biofilm, Trosporsha Tasnim Khan

Dissertations - ALL

Myxococcus xanthus, a soil-dwelling bacterium, exhibits complex multicellular behaviors through self-organization into biofilms. M. xanthus cells traverse agar surfaces, forming either predatory biofilm or vegetative swarm that expands outward in the presence of nutrients. Upon nutrient depletion, the swarm reorganizes as cells “stream” inward, coalescing into aggregates that mature into spore-filled fruiting bodies. This starvation-induced biofilm development is a complex process, governed by stringent genetic controls and coordinated population interactions. Despite extensive research into the dynamics of this development, from the onset of starvation to fruiting body maturation, a comprehensive understanding is still missing. This dissertation sheds light on the …

Using Bivalves As An Indicator For Fecal Bacteria, Kamala Chuss

Honors Scholar Theses

This project focuses on the integration of fecal bacteria from warm-blooded animals into bivalve tissue, and the utilization of bivalves as an indicator for fecal bacteria in waterways. Bivalves may give a more representative long-term average of fecal bacteria in water as compared to direct water testing. The primary objective is to create a standard operating procedure to use bacterial testing of bivalves as a proxy for bacteria concentration in the water. This method can be used in places where bivalves do not already exist by adding them to a body of water, or by collecting bivalves that already exist …

Activities Of Cellulolytic, Amylolytic, And Secondary Metabolites From Thermophilic Actinomycetes Collected From The Heated Soil Around Cisolok Geyser, Dhian Chitra Ayu Fitria Sari, Fitria Ningsih, Mazytha Kinanti Rachmania, Akira Yokota, Wellyzar Sjamsuridzal

Makara Journal of Science

This study investigated the antimicrobial activity, cellulolytic, and amylolytic abilities of eight thermophilic Actinomy-cetes isolated from the heated soil around the Cisolok geyser, West Java, Indonesia. Cellulolytic and amylolytic abili-ties were screened for on media by adding 1% (w/v) soluble starch and carboxymethylcellulose (CMC), respectively. Antimicrobial activity was screened for using the agar-plug diffusion method by cultivating strains on various growth media. Growth at various temperatures showed that six strains could grow up to 50 °C. Seven out of eight strains showed amylolytic ability at 40 °C and 45 °C, and only four strains did so at 50 °C. Screening …

Presence Of The Ade Multidrug Systems And Response To Triclosan Exposure In Acinetobacter Baumannii From Animal Origins, Sirawit Pagdepanichkit, Rungtip Chuanchuen

The Thai Journal of Veterinary Medicine

Thirty Acinetobacter baumannii from animal origins were obtained from 210 animal carcasses submitted for post-mortem examination, including dogs (n=112), cats (n=45), rabbits (n=17), birds (n=15), pigs (n=7) and exotic animals (n=14). All the isolates were evaluated for antimicrobial susceptibility with absence and presence of efflux inhibitors i.e. reserpine and carbonyl cyanide m-chlorophenylhydrazone (CCCP) and expression profile of important six multidrug efflux systems (i.e. AdeABC, AdeDE, AdeFGH, AdeIJK, AbeM and AmvA). Fifteen isolates expressing different Ade multidrug efflux pumps were selected for determining transcription levels and regulatory mutations. A continuous in vitro exposure experiment with benzalkonium chloride, chlorhexidine and triclosan …

Current Status And The Significance Of Local Wisdom Biofertilizer In Enhancing Soil Health And Crop Productivity For Sustainable Agriculture: A Systematic Literature Review, Irwandhi, Fiqriah Hanum Khumairah, Emma Trinurani Sofyan, Nadia Nuraniya Kamaluddin, Anne Nurbaity, Diyan Herdiyantoro, Tualar Simarmata

Jurnal Kultivasi

Soil fertility is recognized as a crucial factor in supporting plant growth and productivity. The utilization of biofertilizers as environmentally friendly fertilizers is aimed at enhancing soil fertility and plant productivity. This study aims to explore the potential of local material for developing local wisdom biofertilizers (LWB) for achieving sustainable agriculture. A systematic literature review was conducted using bibliometric analysis, Preferred Reporting Items for Systematic Reviews, and Meta-Analyses (PRISMA) method, employing the Scopus search engine with the keywords "local AND wisdom AND biofertilizer" OR "biofertilizer" OR "local AND microorganism" OR "soil AND health OR crop AND productivity OR sustainable agriculture". …

Antibiotic Resistance Of Laboratory E. Coli Strains, Alexis H. Hart

Honors Projects

Antibiotic resistance is an ongoing global health crisis. The prevalence and distribution of antibiotic resistance in environmental microbial communities have become climactic areas of investigation due to their far-reaching implications for ecosystem health, human well-being, and the sustainability of antimicrobial efficacy.

An In-Depth Investigation Into Yersinia Pestis Phages: Isolating A Yersinia Pestis Phage From Soil And Constructing A Comprehensive Phylogenetic Analysis Of Known Yersinia Pestis Phages, Jacqueline Chavez

All HCAS Student Capstones, Theses, and Dissertations

Yersinia pestis, the causative agent of the plague, has become increasingly resistant to many antibiotics; therefore, alternatives such as phage therapy are necessary. Phage therapy uses combinations of bacteriophages or phages, which are viruses that only infect bacteria. However, phages—especially Y. pestis phages —are severely understudied. Thus, this research has sought to specifically isolate a phage from soil that infects Y. pestis. There were 146 samples that were collected from across the US, focusing on those with reported cases of plague. These samples were enriched with Y. pestis to maximize the amount of potential phage that target Y. pestis. …

Elucidating The Mechanism Of Interleukin-17a Signaling In The Pathogenesis Of West Nile Virus, Farzana Nazneen

Dissertations

West Nile Virus (WNV), a neurotropic flavivirus transmitted by mosquitoes, is a leading cause of viral encephalitis in the United States and remains a significant public health concern. Unfortunately, no vaccine or therapeutic intervention is available against WNV infection. Previous studies, including ours, demonstrated that interleukin-17A (IL-17A) signaling increases the cytotoxic potential of CD8⁺ T cells to facilitate WNV and parasite clearance; however, the molecular mechanism is not understood. IL-17 receptor C (IL-17RC) is an obligatory co-receptor with IL-17 receptor A (IL-17RA) for signaling induced by IL-17A, IL-17A/F, and IL-17F. In this study, we found that IL-17RC deficient ( …

Bactericidal Mechanism Of Peracetic Acid Against Salmonella Mediated By Reactive Oxygen Species, Mohammed Khalid Wheib Al-Doury

Graduate Theses and Dissertations

Peracetic acid (PAA) is extensively used as a bactericidal agent in poultry processing to reduce foodborne pathogens, including Salmonella enterica serotype Typhimurium (S. Typhimurium). Despite its widespread application, the exact mechanisms underlying its bactericidal effects, particularly the role of reactive oxygen species (ROS), remain incompletely understood. This dissertation examines the role of ROS in PAA-mediated bacterial killing and explores both genetic and metabolic factors that influence bacterial susceptibility to PAA. Findings from these studies have implications for enhancing the efficacy of PAA, thereby improving food safety practices in the industry.

The first study investigates ROS as a central component …

Differential Responses Of Human Neutrophils To Legionella Species., Hannah E. Hanford

Electronic Theses and Dissertations

Legionella species are Gram-negative facultative intracellular bacterial pathogens commonly found in freshwater or soil environments where they survive and replicate within their natural protozoan hosts. Humans serve as an accidental host for Legionella species after inhalation of contaminated aerosolized water droplets or soil particles enabling the bacteria to enter the lungs, infect alveolar macrophages, and result in severe pneumonia. Evasion of degradation and proliferation within alveolar macrophages by Legionella species and manifestation of “Legionnaires’ disease” is dependent on the Dot/Icm type IV secretion system (T4SS). The T4SS apparatus is a needle-like channel for translocation of over ~350 effector proteins, depending …

Induced Systemic Resistance Against Nematodes By Plant Growth-Promoting Microbes In Potatoes, Cole Grannan

Master's Theses

Biofertilizers consist of plant growth-promoting microorganisms that establish symbiotic relationships with plant roots and stems. These beneficial microbes play a crucial role in enhancing plant defenses against various threats including insects, nematodes, and microbial pathogens. The purpose of this study was to investigate the effectiveness of two fungal biofertilizers (an endophytic strain of Beauveria bassiana (BA) and a mixture of arbuscular mycorrhizal (AM) fungi), specifically their ability to induce systemic resistance against plant- parasitic nematodes (PPNs) in potatoes (Solanum tuberosum cv. Masquerade) under controlled greenhouse conditions. The study utilized soil collected from Colorado State University’s San Luis Valley (SLV) Research …

Evaluating The Duckweeds Lemna Minor And Spirodela Polyrhiza As Alternative Aquatic Hosts For The Spread Of The Bacterial Wilt Pathogen, Ralstonia Solanacearum, Irelynn Smith

Honors Theses

Ralstonia solanacearum is a plant pathogen that causes bacterial wilt disease in major crops such as tomatoes and potatoes. Recently, this bacterium was discovered in floating pennywort (Hydrocotyle ranunculoides) and Pennsylvania smartweed (Polygonum pennysylvanicum), two previously unsuspected aquatic plants. Duckweed is an aquatic plant with a high level of resilience and short doubling time. Common duckweed (Lemna minor) has previously demonstrated its capability as a versatile high-yield infection model for other types of pathogenic bacteria. Given this newfound branch of aquatic hosts and the fact that duckweed is a common pond weed previously identified in several ponds located nearby infected …

Lack Of Inflammatory Response In Mouse Embryonic Cells To Listeria Infection, Damilola Oyebode

Master's Theses

Approximately 1 in 5 pregnancies in the United States results in miscarriage, with a significant percentage of these losses attributed to failed implantation due to immunological challenges encountered by the early embryo. Recent research has shown that key cell types within mouse blastocysts, including embryonic stem cells (ESCs) and trophoblast stem cells (TSCs), exhibit remarkable resilience against the cytotoxic effects associated with viral infections and embryotoxic cytokines, such as TNFα and IFNγ, both of which are known to hinder blastocyst development. However, the immune properties of the preimplantation stage embryo, specifically the blastocyst, remain poorly understood. Using mouse cell model, …

Bioindicators Of Mercury In Riverine Systems, Kathryn Mudica

All-Inclusive List of Electronic Theses and Dissertations

This study focuses on the bioaccumulation and biomagnification of mercury in freshwater food webs, with emphasis on bioindicators, such as macroinvertebrates, crayfish, and river otters. Despite regulatory efforts and advancements in monitoring, significant gaps remain in understanding mercury dynamics in freshwater systems—especially regarding its transport, methylation, and bioavailability across different ecosystems. To address these knowledge gaps, this study adopts a biocentric approach, emphasizing the role of living organisms in their environment. By utilizing macroinvertebrates, crayfish, and river otters as bioindicators, we aim to assess mercury bioavailability and distribution. These organisms provide varying temporal and spatial scales of mercury accumulation, offering …

From Resistance To Host Response: An Integrative Study Of C. Difficile Infections, Amber Consul

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clostridioides difficile infection (CDI) is a major healthcare challenge, causing severe gastrointestinal illness and significant mortality. Understanding the mechanisms of antibiotic resistance, epidemiology, and immune response in CDI is critical for developing effective treatments and prevention strategies.

This dissertation encompasses three complementary studies. The first study investigates the genetic mechanisms underlying cephalosporin resistance in C. difficile strain 630 through differential gene expression analysis. The second study provides a descriptive epidemiological analysis of C. difficile ribotypes in a Las Vegas patient population, highlighting differences between healthcare-associated (HA-CDI) and community-associated (CA-CDI) cases. The third study integrates serum analyte profiling and transcriptomic analysis …

Enhancement Of Zika Virus Infection By West Nile And Dengue Virus Antibody Positive Cord-Blood Samples From Mothers In El Paso-Texas, Jeanette Orbegozo

Open Access Theses & Dissertations

The recent Zika virus (ZIKV) outbreak and its association with microcephaly cases and other neurological syndromes are important public health concerns. A phenomenon known as antibody-dependent enhancement (ADE) involves preexisting flavivirus antibodies to a specific flavivirus that enhances the severity of a second infection with a different flavivirus. Since ZIKV is related to flaviviruses like West Nile virus (WNV) and dengue virus (DENV), prior exposure to these viruses could elicit cross-reactive antibodies that may enhance a subsequent ZIKV infection. Therefore, this study aimed to determine if WNV and DENV antibodies from cord blood enhanced ZIKV infection in vitro. Initially, a …

Analysis Of Microbiome In Various Human Medical Conditions Using Next-Generation Sequencing Of The 16s Rrna Gene, Pallavi Sharma

Electronic Theses and Dissertations

Studies of human microbiomics, spanning diverse anatomical sites, offer a unique perspective into the complex microbial communities within the body. Influenced by age, gender, and disease, it mirrors broader microbial ecosystems. This study specifically delves into the ocular and gastrointestinal tract microbiome, comparing its composition in 43 healthy and diseased patients using 16S rRNA gene sequencing. We identified a rich microbial landscape, identifying over 338 bacterial taxa. Notably, Acinetobacter, Cutibacterium, Acidovorax and Herbaspirillum were prevalent in the ocular samples and Akkermansia, Faecalibacterium, and Anaerostipes were mostly prevalent in gut samples. Moreover, dry eye disease conditions were characterized by …