• Login
    View Item 
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UMB Digital ArchiveCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    Display statistics

    Structural and molecular interactions of quaternary ammonium compounds with bacteria

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Find Full text
    Author
    Kim, Sang-Nyun
    Advisor
    Nauman, Robert K.
    Date
    1995
    Type
    dissertation
    
    Metadata
    Show full item record
    Abstract
    The molecular interaction of quaternary ammonium compounds (QAC) with bacterial cells was investigated using various techniques to obtain the knowledge on what kinds of damage are done to the cell that results in cell death. Electron microscopy and flow cytometry were used to evaluate direct effects of didecyldimethyl ammonium chloride (DDAC) to Pseudomonas aeruginosa cells. The characteristic effects of DDAC observed on the bacterial structure were the formation and pinching off of blebs from the outer membrane and the formation of multilamellar structures within the nucleoid area. This was followed by coagulation of the entire nucleoid region and cytoplasm. The morphological changes observed in the intact gram-negative bacterium probably accounted for the bactericidal action of DDAC. An extensive theoretical discussion was provided to explain the observed effects of DDAC on the bacterial envelopes and cytoplasm. A flow cytometric approach was evaluated to determine its use for assessing antibacterial activity of a variety of QAC on P. aeruginosa ATCC 15442. LIVE/DEAD BacLight{dollar}\rm \sp{lcub}TM{rcub}{dollar} viability kit and the SYTOX{dollar}\rm \sp{lcub}TM{rcub}{dollar} kit were used as vital fluorescent stains. The DDAC had the greatest activity by converting the most number of bacteria in the population from green to red, followed by tetradecyl benzalkonium chlorides (BKC), hexadecyl BKC and dodecyl BKC. The flow cytometer provided an excellent means to assess the antibacterial activity of individual QAC. In order to decipher the interaction of DDAC with E. coli lipids, a steady-state and time-resolved emission spectra of 2-dimethylamino-6-lauroyinaphthalene (Laurdan), and steady-state anisotropy decay of 1,6-diphenyl-1,3,5,-hexatriene (DPH) were performed. Finally, {dollar}\sp{lcub}31{rcub}{dollar}P NMR spectroscopy allowed for convenient and qualitative measurements of the effects of DDAC on lipid polymorphism which seems relevant in the DDAC effects on membrane perturbation and possibly bactericidal activity. A schematic model for DDAC-membrane interactions that takes into account Laurdan spectral data, and turbidimetric data in conjunction with {dollar}\sp{lcub}31{rcub}{dollar}P NMR results was presented, which attempts to explain the different modes of action of DDAC on lipid supramolecular structures with respect to molar % of DDAC to lipids.
    Description
    University of Maryland, Baltimore. Microbiology. Ph.D. 1995
    Keyword
    Biology, Cell
    Biology, Microbiology
    Bacteria
    Quaternary Ammonium Compounds
    Identifier to cite or link to this item
    http://hdl.handle.net/10713/1546
    Collections
    Theses and Dissertations All Schools
    Theses and Dissertations School of Dentistry

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Policies | Contact Us | UMB Health Sciences & Human Services Library
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.