Medicine and Health Sciences Commons^™

Mechanistic Study Of Antimicrobial Effectiveness Of Cyclic Amphipathic Peptide [R4W4] Against Methicillin-Resistant Staphylococcus Aureus Clinical Isolates, Ajayi David Akinwale, Keykavous Parang, Rakesh Kumar Tiwari, Jason Yamaki

Pharmacy Faculty Articles and Research

Antimicrobial peptides (AMPs) are being explored as a potential strategy to combat antibiotic resistance due to their ability to reduce susceptibility to antibiotics. This study explored whether the [R₄W₄] peptide mode of action is bacteriostatic or bactericidal using modified two-fold serial dilution and evaluating the synergism between gentamicin and [R₄W₄] against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) by a checkered board assay. [R₄W₄] exhibited bactericidal activity against bacterial isolates (MBC/MIC ≤ 4), with a synergistic effect with gentamicin against E. coli (FICI = 0.3) but …

The Role Of Coagulase-Negative Staphylococcal Secreted Products On Staphylococcus Aureus And Staphylococcus Lugdunensis Infections, Denny Chin

Electronic Thesis and Dissertation Repository

The Staphylococcus genus is comprised of over 40 bacterial species. The most well-studied species in this genus is the notorious human pathogen Staphylococcus aureus, a bacterium that produces coagulase among many other virulence factors. Since S. aureus is a major health burden and causes a plethora of diseases in humans, it has received significant attention and much research has been done to understand its biology to treat diseases caused by this pathogen. However, the coagulase-negative staphylococci (CoNS) make up most of the staphylococcal species and have received less attention since they are thought to have a lesser impact on …

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 …

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 …

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 …

Colicins - A Sound Antimicrobial Approach For The Prevention Of Catheter-Associated Urinary Tract Infections, Sandra M. Roy

Doctoral Dissertations

The emergence and spread of antibiotic resistance has created one of the greatest challenges in fighting infectious disease. We address the rise of antibiotic-resistant pathogens by examining the evolutionary history of a class of resistance determinants, the SHV b-lactamases. We isolated the genes that encode the SHV beta-lactamases (bla_SHV genes) from clinical settings and from an environment essentially devoid of antibiotic use. Our data suggests that, counter to current dogma, the use of antibiotics in the clinic is not creating these resistance genes; genes for antibiotic resistance already exist in nature and our use of antibiotics in clinical …

Polymer Antimicrobial Synergy Research, Samuel Smith, Charles V. Rice, Phd

Journal of Health Disparities Research and Practice

Recent studies have shown that certain polymers, such as branched polyethylenimine (BPEI), have the potential to be antimicrobial. We have been growing certain strains of Bacillus subtilis (B. subtilis) and Escherichia coli (E. coli) and adding in concentrations of ampicillin to find the minimum inhibitory concentrations (MICs). This allows us to add in different concentrations of BPEI to test for synergy between our antibiotic and our polymer.

To find the MIC of each antibiotic, we grew an overnight of the bacteria in Lysogeny Broth (LB) and let it inoculate for 20 hours. We then inoculated a 24 well culture cluster …

Determining The Antibacterial Efficacy Of Ylang Ylang (Cananga Odorata) Plant Extract On Staphylococcus Aureus, Maria T. Dizon, Johnny Aldan, Bsn

Journal of Health Disparities Research and Practice

The Ylang Ylang (Cananga odorata) plant extract is highly popular among the Commonwealth of the Northern Marianas Islands (CNMI) and is frequently used in local medicine. This can be attributed to its properties as an antiseptic, antidepressant, antiseborrheic, hypotensive, sedative, and nervine substance. It is also used in aromatherapy treatments, perfume, and cosmetic products all over the world. The key chemical constituents of the Ylang Ylang are linalool, germacrene, geranyl acetate, methyl benzoate, and p-cresyl methyl ether, which all contribute to its medicinal effects. With the presence of antibacterial properties, it may be used as an alternative to conventional …

Enhancement Of Antimicrobial Activity Of Naturally Occuring Phenolic Compounds By Nano-Particle Mediated Delivery Against Listeria Monocytogenes, Escherichia Coli O157:H7, And Salmonella Typhimurium, Madhuram Ravichandran

Graduate Theses and Dissertations

Food-borne illnesses are of major concern in the U.S. and worldwide. Salmonella,Listeria,E. coli O157:H7 continue to be some of the major foodborne pathogens. Recurring recalls due to these pathogens demand critical antimicrobial strategies to decontaminate the food through its procession from farm to fork. In our study, we combined the effectiveness of naturally occurring phenolic compounds individually, with/ without ethylenediamine tetraacetic acid (EDTA) and/or Nisin and nanoparticle delivery to improve the antimicrobial potential of the compounds against Listeria monocytogenes (L.m.), Salmonella Typhimurium (S.T.), and Escherichia coli O157:H7 (E.c.), in brain …