Digital Commons Network^™

Characterizing The Role Of Pa5189 Of Pseudomonas Aeruginosa In Deletion And Overexpression Mutants, Seh Na Mellick

Theses/Capstones/Creative Projects

In the context of rising multidrug resistance in biofilm-forming pathogens like Pseudomonas aeruginosa, this study investigates the role of the understudied transcription factor PA5189 in antibiotic resistance and biofilm formation. PA5189 deletion and overexpression mutants were created in a parent P. aeruginosa strain using pEX18Tc-based recombinant suicide vectors, with genotypic verification of putative triparental conjugants achieved through restriction digestion and PCR. The study revealed that PA5189 overexpression significantly increases resistance to commonly used broad spectrum antibiotics such as ciprofloxacin and imipenem. Additionally, differential expression of PA5189 was found to notably affect biofilm formation, with variations contingent on the nutrient …

Evaluating The Effects Of Parasite Infections On Reproductive Ability In Maine Moose, Isabella Costa

Honors College

Despite conservation efforts, moose have experienced increasing mortality rates. Winter ticks are known to cause anemia and lower reproductive potential in moose. Moreover, a genus of bacteria, Anaplasma spp., is known to cause a reduction in reproductive efforts in other animals, such as cattle. Because both winter ticks and Anaplasma spp. may affect female reproductive ability, the overall goal of this research was to determine if Anaplasma bacterial infections could be impacting female moose reproduction within the state of Maine. To address this, samples and biological data from moose were collected during hunter harvest, in collaboration with hunters and the …

Antimicrobial Activity Of Cat Flea (Ctenocephalides Felis) Gut Proteins On Different Days After Blood Feeding, Dhruva K. Karnik

Honors College Theses

Cat fleas (Ctenocephalides felis) are a blood-feeding ectoparasitic insect and a common domestic pest found throughout the world. Because of their reliance on host blood, fleas are exposed to blood-borne pathogens; however, the flea gut lumen is a hostile environment for microbial colonization. For example, the gut epithelia differentially express immune genes in response to feeding. In the present study, we measured the antimicrobial activity of gut proteins from cat fleas at different days after feeding (2, 5, 7, and 14). Dissected flea guts were homogenized, passed through a syringe filter, and measured in a protein assay kit. …

Inactivation Of Escherichia Coli, Salmonella Enterica, And Listeria Monocytogenes Using The Contamination Sanitization Inspection And Disinfection (Csi-D) Device, Jennifer Mccoy Sanders, Vanessa Alarcon, Grace Marquis, Amanda Tabb, Jo Ann Van Kessel, Jakeitha Sonnier, Brad J. Haley, Insuck Baek, Jianwei Qin, Moon Kim, Fartash Vasefi, Stanislav Sokolov, Rosalee S. Hellberg

Food Science Faculty Articles and Research

The Contamination Sanitization Inspection and Disinfection (CSI-D) device is a handheld fluorescence-based imaging system designed to disinfect food contact surfaces using ultraviolet-C (UVC) illumination. This study aimed to determine the optimal CSI-D parameters (i.e., UVC exposure time and intensity) for the inactivation of the following foodborne bacteria plated on non-selective media: generic Escherichia coli (indicator organism) and the pathogens enterohemorrhagic E. coli, enterotoxigenic E. coli, Salmonella enterica, and Listeria monocytogenes. Each bacterial strain was spread-plated on non-selective agar and exposed to high-intensity (10 mW/cm²) or low-intensity (5 mW/cm²) UVC for 1–5 s. Control …

Effect Of Assay Medium Ph On Inhibitory Ability Of Streptomyces, Trevor Swan, Miriam Gieske

Undergraduate Research Symposium 2024

Streptomyces bacteria from soil often produce antibiotics which inhibit growth of other microbes. When comparing Streptomyces’ inhibitory ability between different soils, it may be important to match the pH of the medium used in assays to the pH of the soil they came from. We assayed Streptomyces isolates collected from a long-term agricultural experiment with nitrogen-fertilized and non-fertilized treatments to determine their ability to inhibit growth of other bacteria by producing antibiotics. Average soil pH was 6.8 in fertilized soil and 7.2 in non-fertilized soil. We dotted isolates on a glucose-asparagine agar medium adjusted to different pH values and overlaid …

Turbidimetric Bioassays: A Solution To Antimicrobial Activity Detection In Asymptomatic Bacteriuria Isolates Against Uropathogenic Escherichia Coli, Ciara Kenneally, Craig P. Murphy, Roy D. Sleator, Eamonn P. Culligan

Department of Biological Sciences Publications

Traditional bacteriocin screening methods often face limitations due to diffusion-related challenges in agar matrices, which can prevent the peptides from reaching their target organism. Turbidimetric techniques offer a solution to these issues, eliminating diffusion-related problems and providing an initial quantification of bacteriocin efficacy in producer organisms. This study involved screening the cell-free supernatant (CFS) from eight uncharacterized asymptomatic bacteriuria (ABU) isolates and Escherichia coli 83972 for antimicrobial activity against clinical uropathogenic E. coli (UPEC) strains using turbidimetric growth methods. ABU isolates exhibiting activity against five or more UPEC strains were further characterized (PUTS 37, PUTS 58, PUTS 59, S-07-4, and …

Synthesis, Molecular Characteristics, And Antibacterial Assessment Of Marine Hydroid Aqueous Extract-Based Silver Bio-Nanoparticles, Fredryk Mandey, Aulia Rhamdani Arfan, Rugaiyah Andi Arfah

Makara Journal of Science

This investigation aims to synthesize, analyze the molecularity, and test the ability of bacterial inhibition capability of silver nanoparticles that have been synthesized by simply mixing silver nitrate and aqueous extracts of marine natural products with and without the addition of amylum as a stabilizing agent. This research, with and without the addition of amylum as a stabilizing agent, obtained 39.0 and 55.2 mg of solids of round-shaped morphology silver nanoparticles with diameters of 87.9 and 103.0 nm., respectively. In addition, the antibacterial testing assay against Staphylococcus aureus and Escherichia coli showed some considerably good results. S. aureus with the …

Methionyl-Trna Synthetase Synthetic And Proofreading Activities Are Determinants Of Antibiotic Persistence, Whitney N. Wood, Miguel Angel Rubio, Lorenzo Eugenio Leiva, Gregory J. Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Bacterial antibiotic persistence is a phenomenon where bacteria are exposed to an antibiotic and the majority of the population dies while a small subset enters a low metabolic, persistent, state and are able to survive. Once the antibiotic is removed the persistent population can resuscitate and continue growing. Several different molecular mechanisms and pathways have been implicated in this phenomenon. A common mechanism that may underly bacterial antibiotic persistence is perturbations in protein synthesis. To investigate this mechanism, we characterized four distinct metG mutants for their ability to increase antibiotic persistence. Two metG mutants encode changes near the catalytic site …

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 …

Interplay Of Periodontal Bacterial Metabolites In The Progression Of Coronary Artery Disease: A System Biological Approach, Janakiraman V

Annual Research Symposium

Purpose:

The purpose of this study is to investigate the intricate relationship between periodontal disease (PD) and coronary artery disease (CAD), as evidenced by epidemiological associations. Metalloproteinase inhibitor (TIMP1) plays a pivotal role in cellular signaling, differentiation, cell death, and migration by binding to target metalloproteinases, forming complexes with other molecules (collagenases) to inactivate them. However, the expression of TIMP1 is reduced in both PD and CAD, leading to an upregulation of other metalloproteinases. This research explores the hypothesis that metabolites released from (Porphyromonas gingivalis), a prevalent bacterium in atherosclerotic patients, may inhibit TIMP1, thereby influencing CAD progression. …

The Diversity Of Wolbachia Across The Turtle Ants (Formicidae: Cephalotes Spp.), Corey Reese, Leland C. Graber, Manuela O. Ramalho, Corrie S. Moreau

Biology Faculty Publications

Wolbachia is a widespread and well-known bacterium that can induce a wide range of changes within its host. Ants specifically harbor a great deal of Wolbachia diversity and are useful systems to study endosymbiosis. The turtle ants (Cephalotes) are a widespread group of tropical ants that rely on gut microbes to support their herbivorous diet for their survival, yet little is known of the extent of this diversity. Therefore, studying their endosymbionts and categorizing the diversity of bacteria within Cephalotes hosts could help to delimit species and identify new strains and can help lead to a further understanding of how …

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

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 …

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 …

Mutational Analysis Of The Nitrogenase Carbon Monoxide Protective Protein Cown Reveals That A Conserved C‑Terminal Glutamic Acid Residue Is Necessary For Its Activity, Dustin L. Willard, Joshuah J. Arellano, Mitch Underdahl, Terrence M. Lee, Avinash S. Ramaswamy, Gabriella Fumes, Agatha Kliman, Emily Y. Wong, Cedric P. Owens

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nitrogenase is the only enzyme that catalyzes the reduction of nitrogen gas into ammonia. Nitrogenase is tightly inhibited by the environmental gas carbon monoxide (CO). Many nitrogen fixing bacteria protect nitrogenase from CO inhibition using the protective protein CowN. This work demonstrates that a conserved glutamic acid residue near the C-terminus of Gluconacetobacter diazotrophicus CowN is necessary for its function. Mutation of the glutamic acid residue abolishes both CowN’s protection against CO inhibition and the ability of CowN to bind to nitrogenase. In contrast, a conserved C-terminal cysteine residue is not important for CO protection by CowN. Overall, this work …

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 …

Novel Microbial Guilds Implicated In N2o Reduction, Guang He

Doctoral Dissertations

N₂O is a long-recognized greenhouse gas (GHG) with potential in global warming and ozone depletion. Terrestrial ecosystems are a major source of N₂O due to imbalanced N₂O production and consumption. Soil pH is a chief modulating factor controlling net N₂O emissions, and N₂O consumption has been considered negligible under acidic conditions (pH <6). In this dissertation, we obtained solids-free cultures reducing N₂O at pH 4.5. Furthermore, a co-culture (designated culture EV) comprising two interacting bacterial population was acquired via consecutive transfer in mineral salt medium. Integrated phenotypic, metagenomic and metabolomic analysis dictated that the Serratia population excreted certain …

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 …

The Discovery Of A Novel Bacteria From A Large Co-Assembly Of Metagenomes, Matthew Finkelberg

Masters Theses

In the summer of 2022, a co-assembly of metagenome was created using the microbes found at Barres Woods in Harvard Forest. 14 samples were taken, and sample was split into the organic and mineral layer, which totals 28 Bulk MAGs. Within this Co-assembly, 4 different genomes were found which were designated with the phylum of FCPU426. Three of which were considered medium quality and one being assigned high quality. The novel phyla first appeared in NCBI and GTDB databases in June 2018. The name FCPU426 dates to 2010 and was named based on the 16s amplicon sequencing.

The novel phylum …

Mycobacteriophage: A Demonstration Of The Reduction Of M. Smegmatis In Various Matrices., Laura O'Connell

ORBioM (Open Research BioSciences Meeting)

Background

Mycobacterial disease is a major cause of fatality worldwide, with approximately 1.5 million deaths for every 10 million infections. These infections are difficult to treat due to the intrinsic resistance of its mycolic acid rich cell wall to many antibiotics. There is potential for mycobacteriophage (MP) to be used therapeutically for multidrug- and extensively-drug resistant infections. Mycobacterium smegmatis mc² 155 is a useful substitute for slow-growing pathogenic mycobacteria, as it propagates quickly under lab conditions. This feature of M. smegmatis increases the pace of analysis, by ensuring the quick isolation and characterisation of MP and acting as a …

Bactericidal Effects Of Chlorine And Bacteriophages On Mycobacteria In Conventionally Treated Water., Max Kevane-Campbell

ORBioM (Open Research BioSciences Meeting)

Introduction

Mycobacteria are members of the order Actinomycetales and the only genus in the family Mycobacteriaceae. The distinguishing characteristics that are found in mycobacteria include acid-fastness and the presence of mycolic acids. Mycobacteria can be commonly classified as non-spore-forming, aerobic, slender rod-shaped, and are slow-growers. Natural reservoirs that mycobacteria can be found in are aquatic and terrestrial environments. Recent studies have shown that mycobacteria that can cause skin lesions, immune and/or pulmonary dysfunctions and chronic diseases, i.e., Mycobacterium avium subsp. Paratuberculosis, M. kansasii, and M. xenopi, can be isolated from common household tap water. Tap water can originate from …

Additive Effects Of Cyclic Peptide [R4w4] When Added Alongside Azithromycin And Rifampicin Against Mycobacterium Avium Infection, Melissa Kelley, Kayvan Sasaninia, Arbi Abnousian, Ali Badaoui, James Owens, Abrianna Beever, Nala Kachour, Rakesh Kumar Tiwari, Vishwanath Venketaraman

Pharmacy Faculty Articles and Research

Mycobacterium avium (M. avium), a type of nontuberculous mycobacteria (NTM), poses a risk for pulmonary infections and disseminated infections in immunocompromised individuals. Conventional treatment consists of a 12-month regimen of the first-line antibiotics rifampicin and azithromycin. However, the treatment duration and low antibiotic tolerability present challenges in the treatment of M. avium infection. Furthermore, the emergence of multidrug-resistant mycobacterium strains prompts a need for novel treatments against M. avium infection. This study aims to test the efficacy of a novel antimicrobial peptide, cyclic [R4W4], alongside the first-line antibiotics azithromycin and rifampicin in reducing M. avium survival. Colony-forming unit (CFU) …

Evaluation Of The Virulence Potential Of Avian Pathogenic Escherichia Coli Isolated From Broiler Breeders With Colibacillosis In Mississippi, Jiddu Joseph

Theses and Dissertations

Avian pathogenic Escherichia coli (APEC) is a bacterium that is responsible for colibacillosis in birds. However, information about broiler breeder APEC isolates is limited, but the data is critical due to the transfer of this bacteria down the production pyramid to progenies resulting in high mortality. Therefore, we evaluated the phenotypic virulence characteristics of 28 isolates using embryo lethality and day-old chick challenge assays. Also, the in vitro adhesion and invasion potential of selected nine isolates were identified. Results showed more than 1/3^rd of the isolates were highly virulent and the virulence increased as the number of virulence-associated genes …

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 …

Use Of Transposon Screening For Salicylic Acid-Assisted Desiccation Killing In Salmonella, Shannon D. Elliott

Electronic Theses and Dissertations

Salmonella enterica serovar Typhimurium is one of the most prevalent food-borne pathogens, affecting millions around the world every year, making it a threat to global health. Salmonella possesses the ability to survive the normally lethal condition of desiccation, however, discovery of the genes and mechanisms behind this phenomenon are still ongoing. Using a transposon mutagenesis approach to construct a broad transposon library, this study aimed to uncover genes that may be contributing to changes in Salmonella’s survivability under desiccation, particularly when exposed to the antimicrobial molecule salicylic acid. Building on previous findings showing salicylic acid can alter cell viability …

Effect Of Authentic Kefir And Nigella Sativa On Broilers Challenged By Coccidia And Clostridium Perfringens, Julian E. Nixon

All Dissertations

Black seed oil concentrations of 0%, 0.1%, 1% and 5% were added to milk inoculated with kefir grains and incubated at 25°C for 22 h. The pH and microbial count indicated 1% black seed oil caused low inhibition (P > 0.05) of fermentation, but 5% black seed oil caused significant inhibition of the kefir microorganisms (P < 0.05).

Cobb 500 male chicks (n = 256) were distributed in a randomized block design and received one of four treatments: CTRL1 (Non-medicated, no kefir, no Clostridium perfringens), CTRL2 (Non-medicated, no kefir, C. perfringens inoculated), CTRL3 (BMD medicated, no kefir, C. perfringens inoculated), KTRT (Non-medicated, …

Microbe Hunters, Paul De Kruif

Zea E-Books Collection

Microbe Hunters by Paul de Kruif was first published in 1926 by Harcourt, Brace and Company, New York. It dramatically recounts the breakthrough discoveries of the fundamental elements of bacteriology. It features exciting profiles of Antony Leeuwenhoek, Lazzaro Spallanzani, Louis Pasteur, Robert Koch, Émile Roux, Emil Behring, Élie Metchnikoff, Theobald Smith, David Bruce, Ronald Ross, Battista Grassi, Walter Reed, and Paul Ehrlich. Their development of germ theory and its scientific proofs led to the first effective treatments for human diseases like anthrax, rabies, diptheria, malaria, sleeping sickness, syphilis, and yellow fever. They also made discoveries that saved the dairy, wine, …

Sympatric Soil Microbe Interactions Between Streptomyces And Fusarium Isolates, Lehren A. Olk-Szost

All NMU Master's Theses

Interkingdom interactions between soil bacteria and fungi may play a critical role in occurrence of disease suppressive soils, yet our understanding of these interactions remains limited. Streptomyces are well-known producers of antimicrobial compounds important to medicine and agriculture. Production of these secondary metabolites is often mediated by quorum sensing. Most Streptomyces research occurs in single species experiments, yet new metabolites have been discovered in interspecies co-culture experiments. Interspecies, intergenic, and interkingdom co-culture research will likely reveal many valuable compounds, and strengthen our understanding of complex ecological interactions in soil microbiomes. Interactions between sympatric Streptomyces and Fusarium isolates from disease suppressive …

A Review On Antibiotic Resistance And The Use Of Medicinal Plants In The Management Of Uropathogenic Bacteria, Hubza Ruatt Khan, Mehvish Javeed, Iqra Batool, Rabeea Anwar, Asma Ashraf, Sara Janiad

Journal of Bioresource Management

UTIs are the most prevalent infections and are caused by uropathogenicmicrobes such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus spp. Antibiotic resistance has hampered the management of UTIs over the years, with direct repercussions on the treatment cost, the infection severity, and the duration of hospitalization. This review discussed the route of infections, risk factors connected to UTIs, antibiotic resistance issues as well as an alternative therapy to overcome the problem of antibiotic resistance. The medicinal plants which have been utilized for thousands of years to cure a variety of ailmentsrepresent a significant antibiotic …