Quorum Sensing

Chapter 9

Rapid Electrochemical Detection ofPseudomonas

aeruginosaSignaling Molecules by Boron-Doped

Diamond Electrode

Alyah Buzid, John H.T. Luong, F. Jerry Reen, Fergal O’Gara,

Jeremy D. Glennon, and Gerard P. McGlacken

Abstract

As the leading cause of morbidity and mortality of cystic fibrosis (CF) patients, early detection ofPseudo-
monas aeruginosa(PA) is critical in the clinical management of this pathogen. Herein, we describe rapid and
sensitive electroanalytical methods using differential pulse voltammetry (DPV) at a boron-doped diamond
(BDD) electrode for the detection of PA signaling biomolecules. Monitoring the production of key
signaling molecules in bacterial cultures ofP. aeruginosaPA14 over 8 h is described, involving sample
pretreatment by liquid-liquid and solid-phase extraction. In addition, direct electrochemical detection
approach of PA signaling molecules is also reported in conjunction with hexadecyltrimethylammonium
bromide (CTAB) to disrupt the bacterial membrane.

Key wordsPseudomonas aeruginosa, Signaling molecules, Cystic fibrosis, Electrochemical detection,

Extraction, Cationic surfactants, Boron-doped diamond electrode

1 Introduction

As an intrinsically antibiotic-resistant human pathogen, the Gram-

negative bacteriumPseudomonas aeruginosa(PA) is associated with

hospital-acquired infections and causes acute and chronic lung

infections in cystic fibrosis (CF) patients [1, 2]. The ability of PA

to form biofilms, with their associated resistance to antibiotic pen-

etration in nosocomial infections, underpins its classification as a

life-threatening infection [3, 4]. PA also causes bovine mastitis in

cows which in turn poses a serious health risk for the consumption

of infected dairy products [5–7].

Quorum sensing (QS) allows bacteria to coordinate gene

expression at a multicellular level in response to changes in popula-

tion density and/or the environment. Therefore, bacteria can

behave as a community and express phenotypes that are beneficial

Livia Leoni and Giordano Rampioni (eds.),Quorum Sensing: Methods and Protocols, Methods in Molecular Biology,
vol. 1673,https://doi.org/10.1007/978-1-4939-7309-5_9,©Springer Science+Business Media LLC 2018

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