title: Norharmane Matrix Enhances Detection of Endotoxin by MALDI-MS for Simultaneous Profiling of Pathogen, Host, and Vector Systems.
abstract: The discovery of novel pathogenic mechanisms engaged during bacterial infections requires the evolution of advanced techniques. Here, we evaluate the dual polarity matrix norharmane (NRM) to improve detection of bacterial lipid A (endotoxin), from host and vector tissues infected with Francisella novicida (Fn). We evaluated NRM for improved detection and characterization of a wide range of lipids in both positive and negative polarities, including lipid A and phospholipids across a range of matrix assisted laser desorption-ionization (MALDI)-coupled applications. NRM matrix improved the limit of detection (LOD) for monophosphoryl lipid A (MPLA) down to picogram-level representing a ten-fold improvement of LOD versus 2,5-dihydroxybenzoic acid (DHB) and 100-fold improvement of LOD versus 9-aminoacridine (9-AA). Improved LOD for lipid A subsequently facilitated detection of the Fn lipid A major ion (m/z 1665) from extracts of infected mouse spleen and the temperature-modified Fn lipid A at m/z 1637 from infected D. variabilis ticks. Finally, we simultaneously mapped bacterial phospholipid signatures within an Fn infected spleen along with exclusively host-derived inositol-based phospholipid (m/z 933) demonstrating co-profiling for the host-pathogen interaction. Expanded use of NRM matrix in other infection models and endotoxin-targeting imaging experiments will improve our understanding of the lipid interactions at the host-pathogen interface.
authors.affiliation: Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, Baltimore, Maryland, USA.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Scott
authors.affiliation: FOM-Institute AMOLF, Amsterdam, The Netherlands Maastricht Multimodal Molecular Imaging Institute (M4I), Maastricht University, Maastricht, The Netherlands.
authors.forename: Bryn
authors.initials: B
authors.lastname: Flinders
authors.affiliation: FOM-Institute AMOLF, Amsterdam, The Netherlands Maastricht Multimodal Molecular Imaging Institute (M4I), Maastricht University, Maastricht, The Netherlands.
authors.forename: Joanna
authors.initials: J
authors.lastname: Cappell
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland Baltimore, Baltimore, Maryland, USA.
authors.forename: Tao
authors.initials: T
authors.lastname: Liang
authors.affiliation: Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, Baltimore, Maryland, USA.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Pelc
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland Baltimore, Baltimore, Maryland, USA.
authors.forename: Bao
authors.initials: B
authors.lastname: Tran
authors.affiliation: Nottingham Trent University, Chemistry and Forensics, Clifton Campus, Rosalind Franklin Building, Nottingham, UK.
authors.forename: David P A
authors.initials: DP
authors.lastname: Kilgour
authors.affiliation: FOM-Institute AMOLF, Amsterdam, The Netherlands Maastricht Multimodal Molecular Imaging Institute (M4I), Maastricht University, Maastricht, The Netherlands.
authors.forename: Ron M A
authors.initials: RM
authors.lastname: Heeren
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland Baltimore, Baltimore, Maryland, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Goodlett
authors.affiliation: Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, Baltimore, Maryland, USA rkernst@umaryland.edu.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Ernst