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Full-Text Articles in Organisms

Antimicrobial Activity Screening Of Recombinant And Synthetic Varasin A Defensin From The Hard Tick Dermacentor Variabilis Against Various Bacteria, Julia A. Sharp Oct 2007

Antimicrobial Activity Screening Of Recombinant And Synthetic Varasin A Defensin From The Hard Tick Dermacentor Variabilis Against Various Bacteria, Julia A. Sharp

Biological Sciences Theses & Dissertations

Hematophagous arthropods, such as ticks and mosquitoes, rely on their innate immune system for defense against pathogens ingested in a blood meal as well as those acquired through injury. In response to pathogen recognition, the production of antimicrobial peptides, such as defensin, is typically upregulated. Varisin, a defensin, is thought to be a key component in the immunocompetence of the hard tick D. variabilis against Borrelia burgdorferi, the causative agent of Lyme disease. To study the antimicrobial effects of varisin, recombinant varisin was expressed by both insect cells and E coli. Purification of the protein followed by enterokinase treatment yielded …


The Effect Of Mtad On Eight Strains Of E. Faecalis In Contaminated Root Canals, Bradley M. Newberry Aug 2007

The Effect Of Mtad On Eight Strains Of E. Faecalis In Contaminated Root Canals, Bradley M. Newberry

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this investigation was to determine the antimicrobial effect of Biopure MTAD (a mixture of a tetracycline isomer, an acid, and a detergent) as a final irrigant on eight strains of Enterococcus faecalis (E. faecalis) in contaminated root canals of extracted human teeth. In addition, the Minimum Inhibitory Concentration (MIC) and Minimum Lethal Concentration (MLC) of MTAD were also measured on the same strains of bacteria. Two-hundred and forty extracted human teeth were instrumented using 1.3% NaOCl followed by 17% EDTA to remove the smear layer. The teeth were randomly contaminated with one of eight strains of E. …


Downstream Pathway Activation In Cultured Hepatocytes Following Treatment With Francisella Tularensis, Nicole Wakefield Apr 2007

Downstream Pathway Activation In Cultured Hepatocytes Following Treatment With Francisella Tularensis, Nicole Wakefield

Undergraduate Theses and Capstone Projects

Francisella tularensis, the intracellular pathogen that causes tularemia, was investigated to determine how it infects and replicates within mammalian hepatocytes. To date, it has been shown that hepatocytes can be infected by F. tularensis and that this causes considerable change in the protein phosphorylation state of several vital signaling molecules within the host cell. Protein kinase pathways can be mapped as signatures of infection. Hepatocytes tend to be susceptible to infection by F. tularensis, thus stimulating internal signaling. The Francisella strains used were selected with the goal of producing a model that can be used to elucidate the cell signaling …


Investigation Of Environmental Microorganisms Associated With The Intrinsic Microbial Contamination Of An Alcohol-Free Mouthwash, Michelle D. Trickett Jan 2007

Investigation Of Environmental Microorganisms Associated With The Intrinsic Microbial Contamination Of An Alcohol-Free Mouthwash, Michelle D. Trickett

Theses, Dissertations and Capstones

The United States Pharmacopoeia (USP) Microbial Limits Test and Preservative Effectiveness Test were validated and completed on an alcohol-free mouthwash using standard USP recommended microorganisms and selected organisms isolated from the manufacturing environment. The microbial limits test using environmental isolates was found equivalent to the USP Microbial Limits Test currently used for release of the product. The preservative effectiveness test was performed to determine the efficacy of the parabens system against environmental isolates compared to those recommended in the USP test. In both tests Pseudomonas aeruginosa isolates exhibited resistance to the preservative system. All other isolates failed to grow after …