INDIGO Home University of Illinois at Urbana-Champaign logo uic building uic pavilion uic student center

MS Imaging of Antibiotics within Staph. epidermidis Bacterial Biofilms by Laser Desorption Postionization

Show simple item record

Bookmark or cite this item: http://hdl.handle.net/10027/8831

Files in this item

File Description Format
PDF THESIS_GasperGerald070911.pdf (13MB) (no description provided) PDF
Title: MS Imaging of Antibiotics within Staph. epidermidis Bacterial Biofilms by Laser Desorption Postionization
Author(s): Gasper, Gerald L.
Advisor(s): Shippy, Scott
Contributor(s): Trenary, Michael; Keiderling, Tim; Shippy, Scott; Moore, Jerry F.
Department / Program: Chemistry
Graduate Major: Analytical Chemistry
Degree Granting Institution: University of Illinois at Chicago
Degree: PhD, Doctor of Philosophy
Genre: Doctoral
Subject(s): antibiotics biofilm depth profiling desorption matrix laser desorption MS imaging postionization vacuum ultraviolet
Abstract: Biofilms can cause persistent and antibiotic-resistant infections, whose treatment is of major medical concern. Microbial biofilms composed of S. epidermidis are a major source of hospital infections. To address the many questions surrounding bacterial biofilms, MS imaging is needed. MS imaging allowed correlation of chemical information with biologically relevant structures, while maintaining spatial and chemical integrity. Vacuum ultraviolet single photon ionization laser desorption postionization mass spectrometry (LDPI-MS) was used to postionize the abundant gas-phase neutral molecules ejected by laser desorption from bacterial biofilms. LDPI-MS was chemically selective for low ionization energy species, such as antibiotics. Sensitivity was also improved by increasing the neutral desorption yields via addition of a matrix, analogous to the improvement in ion yields observed in MALDI-MS. LDPI-MS with vacuum and extreme ultraviolet radiation from 8 to 24 eV generated at a synchrotron was used to postionize laser desorbed neutrals of antibiotic-treated biofilms and a modified fullerene. LDPI-MS imaging characterized the distribution of antibiotics within intact S. epidermidis bacterial biofilms and displayed heterogeneous features of its microstructure. Spatial resolution of MS imaging experiments of doped biofilms was ~30 microns. Cross sectioning was used to depth profile antibiotics within biofilm slices with depth resolution of ~30 microns. Matrix addition provided nearly a ten fold enhancement of LDPI-MS signal producing limits of detection near 20 fmol.
Issue Date: 2012-12-07
Genre: thesis
URI: http://hdl.handle.net/10027/8831
Rights Information: Copyright 2011 Gerald L. Gasper
Date Available in INDIGO: 2012-12-07
Date Deposited: 2011-08
 

This item appears in the following Collection(s)

Show simple item record

Statistics

Country Code Views
United States of America 167
China 37
United Kingdom 10
Iraq 3
Netherlands 3

Browse

My Account

Information

Access Key