Bacteriology Commons^™

In Vivo Expression Profiling Of Listeria Monocytogenes Internalins (Inlf, Inlp, Inlj) And Their Corresponding Host Receptors (Vim, Afdn, Muc2) Using A Rabbit Ligated Intestinal Loop Model, Nawar Al-Janabi, Nadhim Mushtaq Hashim Al-Bderee, Zahraa M. Madania, Mohanad Jawad Kadhim

Karbala International Journal of Modern Science

Listeria monocytogenes is a Gram-positive pathogen that causes severe infections, particularly in immunocompromised individuals. Internalin genes are important virulence factors that facilitate the bacterium's invasion of host cells. This research aimed to quantify in vivo expression of selected internalin genes (inlF, inlP, and inlJ) and their corresponding host receptors (VIM, AFDN, and MUC2) during L. monocytogenes infection. To achieve this aim, a rabbit ligated intestinal loop model was constructed comprising two intestinal loops. The first loop was injected with 1 mL of L. monocytogenes (1 × 10⁷ CFU/mL), while the second loop was injected with 1 mL of PBS as …

Elasmobranchii Oral Microbiome Diversity Within Southeast Florida: Implications Of Shark Zoonotic And Antibiotic Resistant Pathogens Associated With Human Interactions, Amanda Finnefrock

All HCAS Student Capstones, Theses, and Dissertations

Sharks are incredibly common in the Atlantic and Gulf waters surrounding Florida. Despite the prevalent nature of these animals, little research exists on the composition of their microbial communities (or “microbiomes”). Here we aim to determine the microbial makeup of the oral environment of sharks so that we can determine if there are any bacteria of clinical significance to humans, such as being antibiotic-resistant or having elevated capability for pathogenicity. A total of 41 samples were collected from the mouths and teeth of bull, Caribbean reef, great hammerhead, lemon, nurse, and sandbar sharks caught in Southeast Florida using sterile swabs …

Population Genomics And Evolution Of Pseudomonas Aeruginosa, Samara T. Choudhury

Electronic Theses & Dissertations (2024 - present)

Pseudomonas aeruginosa is a Gram-negative bacterium ubiquitous in diverse environments and an opportunistic pathogen in humans. It is a leading cause of chronic lung infections in cystic fibrosis patients and of hospital-acquired pneumonia and sepsis. With a large flexible genome and abundant mobile genetic elements, P. aeruginosa exhibits high levels of antimicrobial resistance (AMR), making it a significant public health threat. Evolutionary processes such as homologous recombination, and horizontal gene transfer generate extensive genomic diversity in this species and facilitate the spread of resistance genes. In this dissertation, I investigate the genetic and evolutionary factors shaping P. aeruginosa population structure …

Requirement Of Prepiilin Peptidase Activity For Variovorax Paradoxus Eps Flp/Fap Pilus Assembly, Jenny L. Lanthripp

Electronic Theses, Projects, and Dissertations

Variovorax paradoxus is a Gram-negative aerobic bacterium present in both soil and the human oral microbiome. This species contributes to biotransformation of xenobiotics and promotes plant growth. Interestingly, although the genome of strain EPS lacks the flagellum operon annotated in strain S110, the microbe remains motile, and flagella can be observed microscopically. To investigate this unexpected phenotype, motility mutants were enriched from a Tn5 mutant library using a liquid culture settling strategy. A total of 122 isolates were screened for motility defects, and 57 exhibited significantly reduced motility compared to the wild type. Rescue cloning revealed that over 60% of …

Clinical Applications Of Probiotics: A Comprehensive Review Of Benefits And Challenges, Riyam Wissam Hassan

Maaen Journal for Medical Sciences

Probiotics are beneficial microorganisms that help balance microbes in intestines and promote growth beneficial bacteria, they vary between bacteria, yeasts, and fungi and they are helpful to human health when taken in adequate and suitable amounts. In addition to maintaining intestinal health and help with digestion and absorption, also inhibiting development and preventing spread of harmful microorganisms. It exists in different forms, in the intestines and in the foods, products fermented, and in the pharmaceutical supplements. Because human health depends largely on the interaction between humans and these microorganisms known as probiotics, it has found that these organisms have vital …

Abstract 2587 Recombinant Expression And Purification Of A. Vinelandii Cown In E. Coli, Julie Takei, Cedric P. Owens, Katie Sanders, Neeraja Gajendran

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The goal of this project is to study the protein CowN in the diazotroph Azotobacter vinelandii (Av) in comparison to CowN in Gluconacetobacter diazotrophicus (Gd). Nitrogenase is an enzyme that catalyzes the reduction of nitrogen gas into ammonia in diazotrophic bacteria. In many diazotrophs, the protein CowN prevents nitrogenase inhibition from the environmental gas carbon monoxide (CO). Previous work studied CowN in the diazotroph G. diazotrophicus. In G. diazotrophicus, CowN binds to nitrogenase and weakens CO binding to its active site. The mechanism of CowN has only been investigated in G. diazotrophicus. Thus, we are interested in determining if CowN's …

From Epidemics To Experimental Treatments: Amphibian Mass Mortality Events And A Potential Treatment For Chytridiomycosis, Daniel Callahan

Graduate Masters Theses

Worldwide, amphibian populations have experienced dramatic declines due to a variety of threats. Among them, disease has been particularly deleterious and continues to impact populations. In the United States and Canada, the three leading causes of amphibian mass mortality events are ranavirosis, chytridiomycosis, and severe perkinsea infection, all caused by infectious pathogens. While research and policy have helped populations recover from these diseases, more work needs to be done to develop practical and efficient treatments for these infections. Of these three diseases, chytridiomycosis has had the most devastating effects on amphibian populations globally. Caused by the chytrid fungi Batrachochytrium dendrobatidis …

Impacts Of Land Development On Soil Microdiversity And Antibiotic Production, Dennis Guillen Castro, Robert Garcia, Jonathan Castro, Davida Smyth

Masters Theses (Archived)

The impact of land development on soil microbial diversity and antibiotic production is critical due to industrial expansion and the scarcity of effective antibiotics. Low Impact Development (LID) aims to preserve ecosystems, but its effectiveness in maintaining microbial diversity is uncertain. This study compares soil samples from nine sites: undisturbed (UD), residential (RD), and Madla Greenway (GW) within the VIDA development area and Texas A&M University-San Antonio campus. Isolated microbes were screened for antibiotic production and genetically characterized. Preliminary findings indicate that UD sites harbor greater microbial abundance, and a higher proportion of antibiotic-producing microbes compared to GW and RD …

Pseudomonas Parafulva Confirmed To Have Antifungal Properties When Grown In Conjunction With Botrytis Cinerea, Caden Dupee, Kylee Eldredge, Zachary Elmer, Joshua Hartvigsen

Student Research Symposium

Widespread antibiotic use has led to antibiotic resistance of infectious bacteria. (Young, 2017) As part of the TinyEarth Program, the lab group collected and tested local soil samples for bacteria with hopes of finding novel antibiotic properties. From the soil samples, a bacteria was isolated, subsequently sequenced, and determined to be Pseudomonas parafulva. P. parafulva is a Gram-negative bacterium that has been known to frequent rice paddies of eastern Asian countries and has been collected in select regions of North America, including that of Cache Valley. P. parafulva has been linked to anti-fungal activities on plants. (Lui et …

Gastric Survivability Of Streptomyces Narbonensis, Laramie Johnson, Laurel Hilterbrand, Ephraim Mohr, Eliza Lewis

Student Research Symposium

Human sciences and medicine have continually been advancing, and taken off in the last few centuries. This has included the development of many new medicines, antibiotics, and disinfectants. Antibiotics have to be able to survive and perform its duty within the human body, despite the changes in pH that occur naturally within the body in response to stimuli (Cotter, 2003). If a bacteria is unable to adapt to the pH environment of the human body in which it is placed, it will not be able to survive and continue to reproduce. The bacteria may be able to adapt via membrane …

Peribacillus Simplex Does Not Exhibit Antimicrobial Properties Against Staphylococcus, Dallin Thomas, Jordan Wheeler, Natalie Yoho

Student Research Symposium

Antibiotics are powerful drugs that combat previously fatal diseases. These miracle drugs have saved countless lives, but have the tendency to be misused. They are used incorrectly to treat patients who don't need them, and given to animals for non therapeutic use. Antibiotics are also known to pollute soils and groundwater all around the world (3). As antibiotics are found more readily in the environment, they encourage evolution, recombination, and dissemination of antibiotic resistant bacteria (5). According to the Centers for Disease Control and Prevention (6) antibiotic resistance kills at least 1.27 million people worldwide for diseases that used to …

Resistant & Persistent Bacterial Cells, Jean-Louis Bru

Open Educational Resources

An activity on the difference between resistant & persistent bacterial cells. This activity aims to build on the pre-lecture materials about resistant bacterial cells, so that students can make a connection toward persistent cells. In both cases, they make antibiotics less effective.

Learning Objectives

Recognize the importance of antibiotics in fighting bacterial infections. Understand how bacterial species become antibiotic resistant. Determine the difference between resistant and persistent bacterial cells.

Social and Collaborative

Students work together on this in-class activity in groups of 2-4 (3, ideally). Each student will have one of the following roles: encourager, recorded, investigator, and time keeper. …

A Novel Silver-Ruthenium-Based Antimicrobial Kills Gram-Negative Bacteria Through Oxidative Stress-Induced Macromolecular Damage, Patrick O. Tawiah

Theses and Dissertations

The rise in drug-resistant bacteria, together with the decline in antibiotic development, requires new strategies for infectious disease control. Gram-negative pathogens are particularly challenging to combat due to their outer membrane. This study highlights the effectiveness of the silver-containing antimicrobial AGXX® against the Gram-negative bacterium Escherichia coli. AGXX® is a promising silver coating that presumably kills bacteria through the generation of reactive oxygen species (ROS). However, neither AGXX®’s mode of action is fully understood, nor have its effects on Gram-negative bacteria or bacterial response and defense mechanisms towards AGXX® been studied in detail. Here, I report that the bactericidal …

Reversible Degradation Of Peptidoglycan By Lytic Transglycosylases, Aaron Devereaux

Theses and Dissertations (Comprehensive)

Antimicrobial resistance continues to be a burden on the global healthcare system with an estimated cost of billions of dollars and millions of deaths each year. Recently, there has been little to no development on new antibiotics to treat bacterial infection, and any that are developed become resisted to within a few years. Both Gram-positive and Gram-negative bacteria contain a mesh-like layer called peptidoglycan (PG) that surrounds their cells providing strength, cell shape, and protection from their environments. This layer is a polymer of N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) connected via a b-1,4-glycosidic bond, with each strand being cross-linked …

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. …

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 …

Limits Of Longwood's Electron Microscope: A Study In Biological Imaging, Rachel Danzitz, Bjoern Ch. Ludwar

Fall Showcase for Research and Creative Inquiry

This study evaluates the imaging capabilities and limitations of the Hitachi TM4000II Plus Scanning Electron Microscope (SEM) and its Scanning Transmission adapter in biological imaging. A variety of specimens, including protozoans (e.g., Volvox and nematodes), bacteria (e.g., Magnetospirillum gryphiswaldense, Bacillus cereus, and Escherichia coli), tissue samples, and blood, were analyzed. While the SEM effectively imaged protozoans and bacteria, its ability to visualize viruses was deemed impractical. Despite claims of magnification up to 100,000x, clarity significantly decreased beyond 5,000x. The transmission adapter proved functional but challenging to operate consistently. The study highlights the microscope's limitations in producing high-clarity, …

Host-Microbiome Interactions In The Teleost Brain, Amir Mani Varnoosfaderani

Biology ETDs

This dissertation investigates host-microbial interactions within the teleost brain, previously considered sterile. Reviewing current literature highlights significant gaps in understanding teleost brain immunity, despite prevalent neurotropic diseases. We mapped the immune profiles of rainbow trout brains and meninges, revealing the olfactory bulbs as the immune effector part of the brain and the optic tectum as a nod2 expression hub. High il6 and il10 levels were noted in the telencephalon. A persistent bacterial community within healthy salmonid brains shares diversity with gut and blood microbiota. Brain bacterial isolates exhibit genomic signatures for brain colonization and polyamine biosynthesis. The microbiota shifts across …

Lmpact Of Salmonella Enterica Effector Proteins On Plant Physiology And Immunity, Sara Qader

Honors Theses

Salmonella enterica serovar Typhimurium are primarily recognized as pathogens associated with foodborne illnesses in humans. Salmonella also can colonize plant tissue effectively. The pathogen relies on type III secretion systems (T3SS) to infect mammals and plants successfully and counteract the immune response. Understanding the molecular mechanisms underlying Salmonella’s interactions with plants is essential for developing effective strategies to reduce its impact on human health and agriculture. Effector proteins, known for their role in modulating host-pathogen interactions, have been implicated in the virulence and pathogenicity of Salmonella. However, their specific functions and contributions to Salmonella’s interactions with plants remain largely unknown. …

An Exploration Of The Effectiveness Of Xanthorrhiza Simplicissima And Its Secondary Alkaloids As Antibiotics Against Staphylococcus Aureus With The Use Of Reserpine, Donald Bothe, Savita Chaurasia

Undergraduate Theses

Xanthorhiza simplicissima is a plant that is steeped in medical history. It has been used for hundreds of years by the Native Americans, and later by the Europeans, of Appalachia for its medicinal properties. One of the most useful medical applications of this plant are its antibiotic properties, as typified by its use as a tea that was consumed to treat mouth sores. These antibiotic properties can be attributed to some of its secondary alkaloids such as berberine, liriodenine, oxyacanthine, and magnoflorine. These compounds have been studied in other systems; however, oxyacanthine and magnoflorine have not been researched in tandem …

Novel Microbiological Medium Developed For The Isolation Of Bacteria Associated With Estuarine Anemones, Parker K. Lund, Catalina Cuellar-Gempeler

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

Out of the nearly one trillion species of microbiota estimated to inhabit Earth only ten thousand have been cultured in the laboratory. Culturing continues to play a vital role in determining the physiology and ecologic function of individual bacteria in microbial communities and for microbes associated with host organisms one of the major challenges is developing microbiological media that mimics the bacteria’s natural environment enough to promote growth. Here, we target bacteria associated with the estuary anemones Diadumene lineata and Metridium senile by developing a novel medium that uses anemone tissue as the sole source of nutrients. We further measured …

Development And Evaluation Of A Mitochondrial Dna Marker For The Detection Of Rattus Rattus And Rattus Norvegicus Fecal Contamination, A'Aden Redhead

Graduate Research Showcase

No abstract provided.

Managing Stress: A Study Of Stress Response Mechanisms In Mycobacteria, Augusto C. Hunt Serracin

Biology Dissertations - Archive

Mycobacteria encompass many pathogenic species known to cause severe disease in humans. A well-known example is Mycobacterium tuberculosis (Mtb), the causative agent of the lung disease tuberculosis, which kills millions of humans worldwide yearly. Pathogenic mycobacteria like Mtb are challenging to treat because of their innate ability to adapt to environmental stress. Their unique cell physiology and conserved stress responses allow them to combat biological insults, regulate growth, and regulate genes involved in stress; all these responses increase tolerance to antibiotics. The current therapies to treat mycobacterial infections are lengthy and, at times, unsuccessful, partly due to antibiotic tolerance. A …

Ribosome Hibernation Factor Induces Antibiotic Persisters Of Mycobacterium Tuberculosis In Neutrophil-Rich Lung Lesions, Jamie Corro

Electronic Theses & Dissertations (2024 - present)

Mycobacterium tuberculosis (Mtb), the etiological agent of tuberculosis, is a prescient global health threat and the leading cause of death by an infectious agent. Treatment of Mtb infection involves administering 2-4 antibiotics for a minimum of 6 months. This extended drug regimen is required to target a subpopulation of persistent bacilli. As their name implies, these bacteria can “persist” by acquiring nonhereditary and transient antibiotic tolerance. Although the precise mechanism is unknown, it’s often attributed to slowing cellular growth and metabolic processes. During zinc deprivation, bacteria can remodel their ribosomes by replacing their zinc-binding paralogues containing the CXXC motif (C+) …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

The Potential Of Endophytic Bacteria As The Biocontrol Agents Of Fusarium Proliferatum, Rima Ernia, Nisa Rachmania Mubarik, Lisdar Idwan Sudirman

Makara Journal of Science

Fusarium proliferatum decreases the productivity of shallot (Allium cepa L.). Endophytic bacteria are potential biocontrol agents in controlling the growth of F. proliferatum. This study aimed to select and characterize endophytic bacteria producing bioactive compounds that inhibit the growth of F. proliferatum. The endophytic bacteria used were isolated from the roots, stems, leaves, and soil of shallot plants from healthy and diseased shallot farming fields. The endophytic bacteria were selected using the dual culture method and extracted using ethyl acetate solvent. The results of the 16S rRNA identification suggested that isolate ABP5.2 is similar to Pseudomonas …

Pathogenicity Of Acinetobacter Calcoaceticus, Kaitlan A. Sullivan

MUSC Theses and Dissertations

Acinetobacter is a genus of gram-negative bacteria that have been appearing frequently in hospitals contributing to infections in the blood, lungs, urinary tract, and other parts of the body. It infects patients with weakened immune systems that are placed on ventilators, after the use of catheters, or have any other open wounds produced by prolonged hospital stays. This genus of bacteria is problematic due to its high probability of becoming resistant to multiple classes of antibiotics. Thus, we are determining the pathogenicity of clinical isolates of Acinetobacter calcoaceticus using the organism Caenorhabditis elegans as a model.

We are testing …

Breaking Virulent: The Coincidental Evolution Of Virulence Factors In Bacteria., Rhiannon Emmanuelle Cecil

Electronic Theses and Dissertations

Understanding how innocuous organisms can evolve to be pathogenic to humans is of increasing global concern. Further, understanding how existing pathogens may evolved to be more virulent is also vital to our ability to provide healthcare to people afflicted with diseases that promote chronic bacterial infections, such as cystic fibrosis. With the rise of antibiotic resistance in both bacteria and fungi it is paramount that new therapeutics are identified. Understanding what mutations occur that result in increased virulence in microbes can potentially provide new targets for antimicrobial drugs to combat antibiotic resistance. The Coincidental Evolution Hypothesis is a fundamental hypothesis …

Evaluating The Immunogenicity Of Colonization Proteins Of S. Pneumoniae For Identification Of Vaccine Candidates, Isidora Fereday

Theses and Dissertations

Streptococcus pneumoniae is typically an asymptomatic colonizer of the upper respiratory tract but can cause invasive disease in susceptible populations. Pneumococcal vaccines which are currently in use have failed to significantly reduce colonization by S. pneumoniae. To control invasive pneumococcal disease, novel strategies must be utilized. One such strategy is to reduce or eradicate colonization by pneumococcus. Supplementary vaccination with pneumococcal proteins important for colonization could serve to prime the immune system against these targets. This study serves as an initial step towards identification of crucial pneumococcal colonization proteins which may previously have been uncharacterized. Assessing the immune reactivity …

Analyzing Pseudomonas Aeruginosa With Bacteriophage Tags Using Photoacoustic Flow Cytometry, Jennifer C. Schinke

Electronic Theses and Dissertations

The number of daily bacterial infections is climbing and the CDC explains that this is due to the antibiotic-resistant threat in the United States. Finding a faster way of bacterial identification is necessary as it currently takes 1-4 days for a medical lab to culture and identify bacteria. Photoacoustic flow cytometry (PAFC) can be used as an alternative method resulting in swift identification within an hour (Edgar, 2019). Pseudomonas aeruginosa, cell line PA01, will be coated in up to a few hundred red dyed phages making it detectible by the photoacoustic flow cytometry system. Bacteriophages (phages) are viruses that …