Microbiology Commons^™

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 …

Investigating Vital Neutrophil Extracellular Trap Pathogen Response In Neutropenic Individuals, Ryan Illig

Thinking Matters Symposium

Neutrophils, also called polymorphonuclear leukocytes (PMNs), constitute the majority of innate immune cells. These cells possess a complex arsenal of functions that allow them to detect and eliminate a broad spectrum of pathogens. Neutropenia is characterized by decreased levels of neutrophils in the bloodstream, typically falling below the normal range. Moderate to severe neutropenia can increase the risk of pathogenic infections and without treatment can be life-threatening. Although the concentration of neutrophils in neutropenic individuals is decreased, upon activation, neutrophils still release neutrophil extracellular traps (NETs). NETs are pivotal in combating a spectrum of pathogens through their non-selective nature. Overreactive …

Adherent-Invasive Escherichia Coli (Aiec) Promotes Mild Colitis In The C57bl/6 Il-10 Ko Mouse Model Of Crohn's Disease, Sarah Sm Zaw

Senior Theses

Crohn's disease (CD) is a chronic inflammatory bowel disease. Interleukin-10 knockout (IL-10 KO) mice are crucial in CD research. Adherent-invasive Escherichia coli (AIEC) is a subgroup of E. coli. In one study, IL-10 KO mice colonized with AIEC developed colitis in the distal colon compared to wild-type (WT) mice. I investigated how AIEC NC101 WT affects colitis severity in IL-10 KO mice of the C57BL/6 genetic background. Similar results in both genotypes would enhance mouse strain accessibility. Germ-free C57BL6 IL-10 KO mice were divided into groups: colonized with AIEC NC101 for 12, 15, or 18 weeks, or kept germ-free. Histopathological …

Knowledge, Attitude, And Practice Regarding Deep Dentinal Caries Removal Before Root Canal Treatment And Restoration Among Practicing Dental Surgeons, Sangram Panda, Anamika Sinha, Shakti Rath, Kajal Kiran Sahoo

Palestinian Medical and Pharmaceutical Journal

This article aims to determine the knowledge, attitude, and practice regarding Deep Dentinal Caries Removal before Root Canal Treatment (RCT) and Restoration among practicing dental surgeons. A descriptive cross-sectional study was executed amongst dental surgeons practicing with undergraduate and post-graduate degrees. A Google questionnaire form was developed and distributed, and 111 authentic entries were short-listed. Data obtained from the study were recorded in Microsoft Excel 2007 version, and SPSS version 18.0 was used for statistical analysis. Most dental surgeons who participated in the study practiced for over 15-20 years. Among them, 60% believe in removing dentinal caries before RCT; 83.8% …

Listeria Adhesion Protein Orchestrates Caveolae-Mediated Apical Junctional Remodeling Of Epithelial Barrier For Listeria Monocytogenes Translocation, Rishi Drolia, Donald B. Bryant, Shivendra Tenguria, Zuri A. Jules-Culver, Jessie Thind, Breanna Amelunke, Donqi Liu, Nicholas L. F. Gallina, Krishna K. Mishra, Manalee Samaddar, Manoj R. Sawale, Dharmendra K. Mishra, Abigail D. Cox, Arun K. Bhunia

Biological Sciences Faculty Publications

The cellular junctional architecture remodeling by Listeria adhesion protein-heat shock protein 60 (LAP-Hsp60) interaction for Listeria monocytogenes (Lm) passage through the epithelial barrier is incompletely understood. Here, using the gerbil model, permissive to internalin (Inl) A/B-mediated pathways like in humans, we demonstrate that Lm crosses the intestinal villi at 48 h post-infection. In contrast, the single isogenic (lap− or ΔinlA) or double (lap−ΔinlA) mutant strains show significant defects. LAP promotes Lm translocation via endocytosis of cell-cell junctional complex in enterocytes that do not display luminal E-cadherin. In comparison, InlA facilitates …

Host-Defense Piscidin Peptides As Antibiotic Adjuvants Against Clostridioides Difficile, Adenrele Oludiran, Areej Malik, Andriana C. Zourou, Yonghan Wu, Steven P. Gross, Albert Siryapon, Asia Poudel, Kwincy Alleyne, Savion Adams, David S. Courson, Myriam L. Cotten, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

The spore-forming intestinal pathogen Clostridioides difficile causes multidrug resistant infection with a high rate of recurrence after treatment. Piscidins 1 (p1) and 3 (p3), cationic host defense peptides with micromolar cytotoxicity against C. difficile, sensitize C. difficile to clinically relevant antibiotics tested at sublethal concentrations. Both peptides bind to Cu²⁺ using an amino terminal copper and nickel binding motif. Here, we investigate the two peptides in the apo and holo states as antibiotic adjuvants against an epidemic strain of C. difficile. We find that the presence of the peptides leads to lower doses of …

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 …

The Identification Of Small Molecule Inhibitors To Candida Albicans Phosphatidylserine Synthase, Yue Zhou

Doctoral Dissertations

Candida albicans phosphatidylserine (PS) synthase, encoded by the CHO1 gene, has been identified as a potential drug target for new antifungals against systemic candidiasis due to its importance in virulence, absence in the host and conservation among fungal pathogens. This dissertation is focused on the identification of inhibitors for this membrane enzyme. Cho1 has two substrates: cytidyldiphosphate-diacylglycerol (CDP-DAG) and serine. Previous studies identified a conserved CDP-alcohol phosphotransferase (CAPT) binding motif present within Cho1, and here we revealed that mutations in all but one conserved amino acid within the CAPT motif resulted in decreased Cho1. For serine, we have predicted a …

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 …

A Biochemical Approach To Characterize A Divergent Trypanosoma Brucei Mitochondrial Dna Polymerase, Polib, Stephanie B. Delzell

Doctoral Dissertations

Trypanosoma brucei is a single-celled parasitic protist that causes African sleeping sickness in people and nagana in cattle in sub-Saharan Africa. T. brucei and related trypanosomatid parasites contain an unusual catenated mitochondrial genome known as kinetoplast DNA (kDNA) composed of dozens of 23 kb maxicircles and thousands of 1 kb minicircles. The kDNA structure and replication mechanism are divergent from other eukaryotes and essential for parasite survival. POLIB is one of three Family A DNA polymerases that are independently essential to maintain the kDNA network, and has been implicated in minicircle replication. However, the division of labor among the paralogs, …

Connecting The Nebraska Water Quality Index To The Aquatic Microbial Community Of The North Platte River Basin, Nebraska, Paula R. Guastello

School of Natural Resources: Dissertations, Theses, and Student Research

The Nebraska Water Quality Index, under development by the Nebraska Department of Environment and Energy, summarizes in a single value eight environmental parameters that have been monitored in Nebraska for nearly 20 years. Water quality parameters including those used in the Nebraska Water Quality Index have been shown in previous studies to impact bacterial growth. As such, this index has the potential to correlate with the freshwater microbial community. Here, I relate the Nebraska Water Quality Index to microbial community composition and structure using 16S rRNA gene amplicon sequence data collected from the North Platte River Basin, Nebraska. This index …

Molecular Mimicry Of Noda Genes By An N-Acetylmuramoyl-L-Alanine Amidases Gene In A Nodule Forming Staphylococcus Cohnii [Research Note], Aberathne Herath Mudiyanselage Nadeeshani Ruwandika Aberathne, Wedage Methsala Madurangi Wedage, Dilantha Gunawardana

The Philippine Agricultural Scientist

A rare, nodule-forming, Gram-positive bacterium (Sub4) was isolated from the forage and cover crop Pueraria phaseoloides, which aligned at 99.26% sequence identity to a partial 16S rDNA sequence of Staphylococcus cohnii sp. This was the first record of a strain/species of Staphylococcus capable of independent, unassisted nodule formation in a legume host. When a nodA gene was sought by PCR using a pair of gene-specific primers synthesized using a related (Firmicutes) Paenibacillus sp. nodA gene, the reaction yielded a PCR product of similar size but a distinct identity. The resulting ~400bp PCR product coded for a likely N-acetylmuramoyl-L-alanine amidase …

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 …

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, …

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 …

Evaluating Vaccine Management Strategies For Edwardsiella Ictaluri Infections In Zebrafish (Danio Rerio), Brandy Malbrough

LSU Master's Theses

Aquaculture is a globally important industry that faces significant challenges due to infectious diseases, which can result in substantial financial losses. In 2011, a new strain of Edwardsiella ictaluri emerged as a major pathogen affecting zebrafish in the ornamental fish industry, leading to high mortality rates and posing a severe threat to the sector. Vaccines provide potential benefits for disease prevention in aquaculture, particularly live-attenuated vaccines (LAVs), which induce strong host immune responses. Bacterial attenuation for vaccine development has evolved from serial passage to more targeted genetic modification techniques. However, regulatory constraints limit the availability of licensed LAVs for aquaculture. …

Characterization Of Antimicrobial Properties Of Excrement And Functional Microbiome Of Black Vultures (Coragyps Atratus), Bridgette Gray

Theses

Black vultures, Coragyps atratus, are obligate scavenging birds that consume and dispose of decaying carcasses and carrion. They fulfill a key ecological niche in the environments in which they live. It has been observed that these vultures sometimes excrete bodily waste onto their legs. This adaptive behavior could help aid them in controlling bacteria and other microbes they encounter while stepping into a carcass to eat. This study directly examined the antimicrobial properties of the excrement of black vultures across various bacterial species utilizing a zone of inhibition test and a nematode species utilizing a survival assay. The black vulture …

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 …

Investigating The Mammillary Bodies As An Early Target Of Alzheimer's Disease, Cole Martinson

University Honors Theses

Alzheimer's disease (AD) is the most common form of dementia. With minimal treatment options and no cure, developing a deeper understanding of the pathology of the disease is crucial. For nearly four decades, the accumulation of beta-amyloid (Aβ) plaques has been correlated with the disease and its progression. Previous studies mapping this accumulation show that the mammillary bodies (MB) are an early target of the disease. Glutamatergic neurons are of key interest due to their prevalence in the central nervous system, specifically the MB. To understand the effects of AD on the glutamatergic system, we used vesicular glutamate transporter 2 …

Overexpressing Two Helicobacter Pylori Small Rnas From A Bacterial Pathogenicity-Related Chromosomal Region To Investigate Their Regulation Of Virulence Genes, Roxanne N. Mcpeck, Olivia F. Morgan, Andrea R. Castillo Phd

2023 Symposium

The bacterial pathogen Helicobacter pylori infects the stomachs of approximately 50% of humanity, causing symptomatic disease (e.g., stomach ulcers, gastric cancer, and MALT lymphoma) in 10-15% of the infected. Colonizing the acidic, inhospitable stomach requires H. pylori to tightly regulate gene expression despite lacking many common bacterial genetic regulatory elements. The pathogen may compensate by using abundant non-protein-coding small RNAs (sRNAs) to regulate gene expression, including of infection-intensifying virulence genes. Additionally, severe disease and cancer correlate with infection by H. pylori strains that contain a nonessential chromosomal region, the cytotoxin-associated gene pathogenicity island (cagPAI). This encodes powerful virulence …

Characterization Of Lps As A Virulence Factor In Burkholderia Cepacia During Plant And Human Infection, Jack Klahr, Elizabeth Danka

Biology Senior Theses

Burkholderia cepacia is a gram-negative bacterium first characterized as the causative agent of sour skin in onion crops. More recently, B. cepacia has become a clinical concern as an opportunistic pathogen that can colonize the upper respiratory tract of cystic fibrosis patients and increase mortality in these patients. Infection is exacerbated by the intrinsic resistance to antibiotics found in this genus of organisms. Additional virulence factors help the bacteria persist in the host during infection. However, few of these factors have been described. In this work, we characterized a putative virulence factor that was first identified through an onion infection …

The Development Of A Primer Payload With Microparticles For Uti Pathogen Identification Using Polythymidine- Modified Lamp Primers In Droplet Lamp, Jonas Otoo

KGI Theses and Dissertations

Nucleic acid amplification tests (NAATs) are among the diagnostic tests with the highest sensitivity and specificity. However, they are more complex to develop than other diagnostic tests such as biochemical tests and lateral flow immunoassay tests. Polymerase chain reaction (PCR) is the gold standard for NAATs. PCR requires thermal cycling to achieve clonal amplification of the target pathogen DNA for diagnosis. Thermal cycling poses a challenge in the development of PCR diagnostics for point-of-care (POC) settings. Loop-mediated isothermal amplification (LAMP) offers an isothermal method for NAATs diagnostics. The advancement of the microfluidics field significantly enhances the development of LAMP diagnostics …

Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield

Honors Scholar Theses

Antibiotic treatment failure is a public health crisis, with a 2019 report stating that roughly 35,000 deaths occur in the United States yearly due to bacterial infections that are unresponsive to antibiotics (1). One complication in the treatment of bacterial infection is antibiotic persistence which further compromises our battle to effectively treat infection. Bacterial persisters can exist in clonal bacterial cultures and can tolerate antibiotic treatment by undergoing reversible phenotypic changes. They can survive drug concentrations that their genetically identical kin cannot. Some persisters remain in a slow growing state and are difficult to target with current antibiotics. A specific …

Induction And Evasion Of Neutrophil Extracellular Traps By Campylobacter Jejuni And Its Implication In Disease, Sean M. Callahan

Doctoral Dissertations

Campylobacteriosis, the foodborne disease caused by Campylobacter spp., infects one out of 10 individuals every year. C. jejuni accounts for 90% of these infections resulting in numerous postinfectious disorders including the development of colorectal cancer, Guillain-Barré syndrome, irritable bowel syndrome, and reactive arthritis. Despite its large impact on human health, the host immune response to the bacterium is largely uncharacterized. Chapter two of this dissertation addresses the development of neutrophil extracellular traps (NETs) within human and ferret campylobacteriosis. We observed NET-associated proteins increase in the feces of C. jejuni-infected patients and that in vitro C. jejuni induces NETs, which …

The Stringent Response In Pseudomonas Aeruginosa Influences The Phenotypes Controlled By The Gac/Rsm System, Michael Shawn Hooker

Electronic Theses and Dissertations

Pseudomonas aeruginosa is a ubiquitous, opportunistic pathogen that causes acute and chronic infections. Infection is typically initiated via motile and virulent strains. After exposure to stressors, acute infections make both genotypic and phenotypic switches to a chronic, sessile strain. This is due to intricate regulatory networks directing gene expression in response to stressors. One network, GacA/GacS, has been established to control virulence factors. The stringent response of bacteria is mediated by alarmones produced primarily by RelA which responds to starvation.

To study the effect of the stringent response on the virulence switch. A series of experiments were run in both …

Impacts Of Bacterial Evolution On Host Lethality In Drosophila, Andrew Preston

College of Arts & Sciences Senior Honors Theses

Evolution is the process by which species change their genetic traits, such as the pathogenicity of bacteria, over time in response to changes in their environment. Although the genetic mechanisms underlying many evolutionary processes have been revealed, it is still not well understood how opportunistic pathogens, such as Pseudomonas aeruginosa, become virulent. The overall goal of this thesis is to test the Coincidental Evolution Hypothesis, which proposes that the virulence of opportunistic pathogens evolves coincidentally as a by-product of their interaction with their natural predators. I hypothesized that the virulence of ancestral Pseudomonas aeruginosa changes over time if it co-evolves …

Identification Of A Role Beyond Iron Acquisition For Yersiniabactin During Yersinia Pestis Infection., Sarah Price

Electronic Theses and Dissertations

Yersinia pestis is a Gram-negative re-emerging bacterial pathogen that is responsible for bubonic, septicemic, and pneumonic plague. Y. pestis and other bacteria require transition metals, such as iron, zinc, and manganese, to maintain intermediary metabolism, transcriptional regulation, and virulence. To inhibit infection, eukaryotic organisms have developed distinct mechanisms, called nutritional immunity, to sequester these important nutrients from invading bacteria. For pathogens to colonize the vertebrate host, they have evolved dedicated acquisition systems for transition metals. During infection, Y. pestis overcomes iron limitation by secreting the siderophore yersiniabactin. Additionally, Y. pestis requires zinc for infection and utilizes high affinity transporters to …

Immunomodulatory Effects Of Resolvin D2 In A Model Of Infection, Prem Yugandhar Kadiyam Sundarasivarao

Graduate School of Biomedical Sciences Theses and Dissertations

Dysregulated hyperinflammatory host immune response to underlying bacterial infections is a characteristic of sepsis. In sepsis, bacteria often trigger abnormal hyperinflammatory responses which can cause multiple organ failure and if sustained can lead to an immunosuppressive phase where the host is susceptible to secondary infections caused by opportunistic bacteria like Pseudomonas aeruginosa (P. aeruginosa). In our studies, we used a 2-hit model of cecal ligation and puncture (CLP) followed by P. aeruginosa secondary lung infection to investigate cellular and molecular mechanisms in the beneficial action of resolvin D2 (RvD2). Resolvins of the D-series are a group of fatty acids known …

The Effect Of Different Types Of Plastic And Rubbers Often Found In Healthcare Facilities On The Survival Of Potentially Pathogenic Bacteria, Ashely George

Honors Theses

This study focused on the survival of different species of bacteria on different types of plastics and rubbers found in healthcare facilities. The gram-positive coccus Staphylococcus aureus and the gram negative bacillus Escherichia coli, known to have importance as potential pathogens in healthcare facilities, were tested on two types of plastic (polyurethane and Polyvinyl Chloride (PVC)) and two types of rubbers (latex and nitrile) typically found on reusable healthcare surfaces. Known quantities of bacteria were aseptically placed on disinfected plastic surfaces in triplicate, air-dried, and then incubated at room temperature for 30 minutes, 20 hours, and 40 hours. After incubation, …

Staphylococcus Aureus Strains Exhibit Exclusivity In Regards To It’S Toxin Prevalence, Especially With Toxins Responsible For Food Poisoning And Necrotizing Pneumonia, Malia Braiedy, Taylor Mach, Amanda Brosnahan

Research and Scholarship Symposium Posters

Staphylococcus aureus is a bacteria that can exist asymptomatically, but can be dangerous due to it’s individual toxin profile. These various toxins, however, seem to be mutually exclusive from another in some cases. Samples of S. aureus often have superantigen SELX and some samples have Staphylococcal Enterotoxin (SE) A, B, or C. Through the use of Airtable and various methods of data organization and comparison on the strains we’ve collected on campus, we found that SELX exhibits an inverse relationship with SE- A/B/C, and that SE- A/B/C also exhibits exclusivity between the three toxins. Through thorough research on S. aureus, …