Efficient detection of Escherichia coli O157:H7 using a reusable microfluidic chip embedded with antimicrobial peptide-labeled beads

Abstract

The ability of antimicrobial peptides (AMPs) for effective binding to multiple target microbes has drawn lots of attention as an alternative to antibodies for detecting whole bacteria. We investigated pathogenic Escherichia coli (E. coli) detection by applying a microfluidic based biosensing device embedded with AMP-labeled beads. According to a new channel design, our device is reusable by the repeated operation of detection and regeneration modes, and the binding rate is more enhanced due to even distribution of the bacterial suspension inside the chamber by implementing influx side channels. We observed higher binding affinity of pathogenic E. coli O157:H7 for AMP-labeled beads than nonpathogenic E. coli DH5α, and the fluorescence intensity of pathogenic E. coli was about 3.4 times higher than the nonpathogenic one. The flow rate of bacterial suspension should be applied above a certain level for stronger binding and rapid detection by attaining a saturation level of detection within a short time of less than 20 min. A possible improvement in the limit of detection in the level of 10 cells per mL for E. coli O157:H7 implies that the AMP-labeled beads have high potential for the sensitive detection of pathogenic E. coli at an appropriate flow rate.

Bacteria Detection: From Powerful SERS to Its Advanced Compatible Techniques

“…[62] Even at low concentrations, good bacterial capture efficiency and fast antibacterial rate are the main advantages of antimicrobial peptides over other capture methods. [63] However, bacterial detection using antimicrobial peptides as capture and recognition elements is based on electrochemical method, [63][64][65] and fluorescence method, [66,67] antimicrobial peptides applied in SERS detection have rarely been reported. The advantages and disadvantages of these capture and recognition methods are summarized in Table 2, with the aim of providing readers with a reference when selecting the appropriate bacterial capture method in order to optimize SERS detection.…”

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

“…Uses where peptides play an auxiliary role to detection, such as capture prior to label mediated-detection of pathogens by spectroscopy [63][64][65] or with PCR [66] were ruled out. Only biosensors where the analysis chain is fully integrated are considered, which excludes applications based on the combined use of AMPs and labels with subsequent analysis techniques such as fluorescence or microscopy [48,[66][67][68][69][70][71]. In other words, this means that the result must be interpretable by the operator without any additional handling step other than that of bringing the sample into contact with the biosensor.…”

Clearance of ESKAPE Pathogens from Blood Using Bacterially Activated Macrophage Membrane‐Coated Silicon Nanowires

“…[17] Bendable nanowires have been described to capture Salmonella from human blood by forming "nanoclaws" with an efficiency of 97% at 50 mL min −1 . [18] Surfaces in capture devices have also been coated with a variety of monoclonal antibodies, [19][20][21] aptamers, [22,23] and peptides that increase capture of specific pathogens, [24][25][26] but this is only useful when the pathogen is known. To the best of our knowledge, no extracorporeal capture device has ever been developed with demonstrated broad-spectrum capture efficiency of all six members of the clinically important ESKAPE panel of pathogens.…”