Antimicrobial peptide arrays for wide spectrum sensing of pathogenic bacteria

Abstract

Fast detection of bacteria in samples presumed to be un-contaminated, such as blood, is of great importance. Indeed, rapid diagnosis allows the setup of appropriate antibiotic treatment. Besides clinical issues, there are many other domains, such as food processing or drug manufacturing, where the strict absence of any bacteria has to be assessed. Because the bacterial load found in most contaminated samples is often below the limit of detection for currently validated assays, a preliminary enrichment step is required to allow bacterial multiplication before proceeding to the analysis step, whatever it might becultural, immunological or molecular methods. In this study, we describe the use of a biosensor for singlestep bacteria detection. The whole analysis is performed in less than 20 hours, during the growth phase of the microorganisms , using an array of antimicrobial peptides (AMPs) coupled with a surface plasmon resonance imager (SPRI). A wide range of bacterial strains are assayed, showing differentiated affinity patterns with the immobilized peptides, which are confirmed by multivariate analysis. This work establishes the evidence that antimicrobial peptides, mostly used so far in the antibiotic drug industry, are suited for the wide-spectrum detection of unknown bacteria in samples, even at very low initial loads. Moreover, the small set of AMPs that were assayed provided a specific affinity profile for each pathogen, as confirmed by multivariate analyses. Furthermore, this work opens up the possibility of applying this method in more complex and relevant samples such as foodstuff, urine or blood.

New Detection Platform for Screening Bacteria in Liquid Samples

“…as models for Gram-negative and Gram-positive bacteria, respectively. The screening potential of our system can be improved by analyzing bacterial motility patterns by using a larger set of AMPs with complementary affinity [ 15 ].…”

“…In particular, pHEMA-AEM (2-hydroxyethylmethacrylate (HEMA) 2-Aminoethyl methacrylate hydrochloride (AEM)) is a polymeric cryogel synthesized through a cryostructuration method characterized by a large inner surface area, resulting in a high capacity for bacteria harvesting, even from complex samples [ 14 ]. Antimicrobial peptides (AMPs) bioreceptors were shown to be an interesting alternative to antibodies due to their broad recognition spectrum [ 15 , 16 , 17 ]. AMPs are a subset of peptides presenting strong bactericidal activity against Gram-positive and Gram-negative bacteria according to specific patterns [ 18 ].…”

Antimicrobial Peptides as Probes in Biosensors Detecting Whole Bacteria: A Review

“…For instance, the electrochemical assay designed by Wilson et al [72] has similar features compared to other electrochemical biosensors operating in food [96]. Alternatively, some systems based on AMPs such as the SPR imaging device we designed [85] do not present faster detection times than previous studies [86][87][88]. However, it is able to detect a broader range of bacteria than devices based on antibodies.…”

“…In a recent study [85], we proposed an approach inspired from a strategy proven to be able to detect pathogens at low concentrations, even in complex matrices [86][87][88]. This assay, based on surface plasmon resonance (SPR) imaging enables the monitoring of growing pathogens, thanks to the "Culture-Capture-Measure" method.…”

Colorimetric Aptasensor for Detecting Bacillus carboniphilus Using Aptamer Isolated with a Non-SELEX-Based Method

“…Recently, AMPs have been used as ligands in biosensors to detect whole-cell bacteria because of their broad-spectrum specificity [14,15]. A microarray chip coupled with multiple AMPs was designed for surface plasmon resonance imaging (SPRI) by Pardoux et al, in which pathogens can be detected using this multiplexing AMP array within 20 h [16]. Kim et al reported a two-stage label-free aptasensing platform for the detection of Cronobacter sakazakii in powdered infant formula [17].…”