Medicine and Health Sciences Commons^™

Modulation Of Antibacterial Activity And Cytotoxicity In Amphipathic Cyclic Peptide [R4w4] Using Histidine Substitution, Ryan Stueber

Pharmaceutical Sciences (MS) Theses

Antibiotics have been the gold standard frontline defense against bacterial infections for decades. At the same time, these infecting bacteria have continued to evolve to resist developed antibiotics in an almost endless cycle. As such, we aim to take an alternative approach utilizing antimicrobial peptides (AMPs) as a means to end this cycle. [R4W4] is among known AMPs that demonstrated antimicrobial activity against methicillin-resistant staphylococcus aureus (MRSA) with a minimum inhibitory concentration (MIC) of 2.67 μg/mL. This peptide had notably effective antimicrobial activity, especially relative to linear (R4W4). However, it displayed a concerning level of cytotoxicity; eliciting a human embryonic …

Formulation Of Coffee Extract As Polymeric Nanoparticles And Studying Their Potential Biological Activities, Nouran Sharaf

Theses and Dissertations

Coffee extract was prepared and optimized (by solvent extraction) and subsequently entrapped into PLGA nanoparticles using single emulsion-solvent evaporation method (using Design Expert software). Dynamic Light Scattering, Scanning Electron Microscope, Fourier Transform-Infrared Spectroscopy and Folin Ciocalteau assay were used to characterize the NPs and to aid in selecting the optimum formulation conditions. The optimized NPs were in-vitro evaluated for their antimicrobial (by agar-well diffusion method), antioxidant (by DPPH assay) and anticancer (by MTT assay) activities. Finally, the release rate study was conducted for the NP sample showing the highly promising results.

The succeeded NP sample, in terms of the most …

A New All-Natural Wound Treatment Gel Shows Strong Inhibitory Activity Against Staphylococcus Aureus And Other Wound Pathogens, Tasha K. Nelson

Electronic Theses and Dissertations

Skin related injuries are some of the most dangerous forms of wounds. In addition to treating the wound itself, health care providers must be cautious of microbial infections. In this study, we evaluate a novel all-natural antimicrobial gel compound (AMG) designed to kill planktonic bacteria, penetrate bacterial biofilms, and accelerate wound healing. In -vitro experiments demonstrate that AMG is effective in inhibiting planktonic growth and biofilm development of eight common pathogens. LIVE/DEAD staining and confocal microscopy reveal that planktonic growth and three-dimensional structure of biofilms were significantly reduced. Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) was used to investigate a small …

Microevolution In Staphylococcus Aureus: Does Exposure To Sub-Lethal Levels Of Cinnamon Bark Oil Lead To Changes In Antimicrobial Susceptibility?, Heather Sandra Schuettner

Graduate College Dissertations and Theses

The emergence of antibiotic-resistant and multi-drug resistant bacteria presents a growing global health issue recognized by the World Health Organization and the Centers for Disease Control and Prevention. Infections caused by drug-resistant bacteria are associated with longer hospital stays, higher treatments costs, and increased mortality compared to infections caused by antibiotic-susceptible pathogens. The global increase in antibiotic resistance is driven in part by the misuse and overuse of antibiotics in healthcare and agriculture. Staphylococcus aureus can infect humans and animals, and strains that are resistant to one or more antibiotics are common. Many plant essential oils have antimicrobial properties. Essential …

Amixicile, A Novel Antimicrobial Agent, And Its Effect On The Salivary And Subgingival Microbiome In Rhesus Macaque Monkeys, Erin E. Block

Theses and Dissertations

Background/Purpose: Periodontitis is an inflammatory disease with a bacterial etiology in a susceptible host. A selective antibiotic with minimal systemic side effects could be a useful adjunct to traditional periodontal therapy. Amixicile is a novel antimicrobial agent that targets pyruvate: ferredoxin oxidoreductase (PFOR), an enzyme that is critical for anaerobic bacterial metabolism and has been found to have little-to-no side-effects in animal models. The aim of this study was to prospectively evaluate the effect of amixicile on clinical periodontal parameters and the composition of the oral microbiome in rhesus macaque monkeys. It was hypothesized that the amixicile would reduce growth …

Microevolution In Staphylococcus Aureus: Does Exposure To Sub-Lethal Levels Of Cinnamon Bark Oil Lead To Changes In Antimicrobial Susceptibility?, Heather Sandra Schuettner

Graduate College Dissertations and Theses

The emergence of antibiotic-resistant and multi-drug resistant bacteria presents a growing global health issue recognized by the World Health Organization and the Centers for Disease Control and Prevention. Infections caused by drug-resistant bacteria are associated with longer hospital stays, higher treatments costs, and increased mortality compared to infections caused by antibiotic-susceptible pathogens. The global increase in antibiotic resistance is driven in part by the misuse and overuse of antibiotics in healthcare and agriculture. Staphylococcus aureus can infect humans and animals, and strains that are resistant to one or more antibiotics are common. Many plant essential oils have antimicrobial properties. Essential …