An engineered antimicrobial peptide as an alternative bioreceptor for the detection of pathogenic Escherichia coli O157:H7

초록

Escherichia coli O157:H7, which can cause acute infections even in extremely small numbers, is the most common pathogen responsible for foodborne illnesses. Both the development of antimicrobial agents and establishment of a sensitive and rapid detection method are essential to prevent foodborne illnesses. In this study, three antimicrobial peptides (AMPs) were derived from magainin 1 and clavanin A through peptide engineering. Subsequently, AMP 3, which showed the highest antimicrobial activity against E. coli O157:H7 in antibacterial activity assays, was screened as a potential candidate bioreceptor. To achieve sensitive and selective detection, a hydrophilic tannic acid (TA)-polyethyleneimine (PEI) hydrogel was modified on a gold electrode, and AMP 3 was immobilized to develop an AMP-based electrochemical sensor. The electrochemical performance of the Au/TA-PEI/AMP 3-based electrochemical biosensor was monitored using cyclic voltammetry and differential pulse voltammetry. The limit of detection of the Au/TA-PEI/AMP 3 biosensor was determined to be 3.4 colony-forming units (CFU)/mL, with a linear detection range of 101–105 CFU/mL. In addition, the biosensor was applied to quantitatively detect E. coli O157:H7 in milk samples, achieving excellent recovery rates ranging from 89.1 to 122.0 %. Overall, the developed AMP-based biosensor exhibits a good selectivity and sensitivity in the detection of E. coli O157:H7; these features render it a potential tool for detecting bacteria that pose a threat to public health and safety. © 2023 Elsevier B.V.

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