# Visual Screening of Genetic Polymorphisms in eae Gene of Escherichia coli O157:H7 with Single-Nucleotide Resolution by ARMS-PCR-Mediated Lateral Flow Strip

## TL;DR

This paper introduces a visual method to detect genetic variations in E. coli O157:H7 using a simple test strip, enabling rapid and accurate field testing for food safety.

## Contribution

A novel ARMS-PCR-mediated lateral flow strip for SNP detection with single-nucleotide resolution and visual readout.

## Key findings

- The method can visually distinguish SNPs in the eae gene with 0.1% differentiation accuracy.
- The assay provides a simple yes/no readout without requiring specialized equipment.
- It shows high sensitivity and specificity for practical field applications.

## Abstract

Development of rapid, precise and fieldable detection methods for foodborne pathogens is one of the essential requirements in food safety and public health. In this research, the single-nucleotide polymorphisms (SNPs) in the eae gene of Escherichia coli O157:H7 are well visually identified with the designed amplification refractory mutation system–polymerase chain reaction (ARMS-PCR) mediated lateral flow strip (LFS). Allele-specific primers were designed and optimized to discriminate the mutant-type genes from wild-type genes with single-nucleotide resolution in a simple visual format. The single-nucleotide variation in the eae gene could be easily differentiated by the observation of an optical signal on the T line of the LFS without any devices. Assay performance results show that it has a high sensitivity and specificity with the single-nucleotide differentiation ratio as low as 0.1%. This genetic polymorphisms screening performance could enumerate complex genetic variation into a simple and direct yes/no readout, highlighting the ultra-easy SNP screening mode and the simplicity of the result output for practical applications. This ARMS-PCR mediated LFS offers a straightforward, swift, and economical strategy for SNP identification with great potential for use in evolution of bacterial resistance genes and viral evolution under different environmental stresses.