Rapid, Sensitive, and Specific Detection of Escherichia coli O157:H7 in Raw Meat Using Loop-Mediated Isothermal Amplification

Abstract

Escherichia coli O157:H7 is a major foodborne pathogen responsible for severe illnesses such as hemorrhagic colitis and hemolytic uremic syndrome, often transmitted through contaminated raw meat. Rapid, sensitive, and specific detection of this pathogen is critical to ensure food safety and protect public health. This study aimed to develop and evaluate a loop-mediated isothermal amplification (LAMP) assay for the detection of E. coli O157:H7 in raw meat samples. Raw meat samples (beef, mutton, and poultry) were collected from local markets, homogenized, and pre-enriched in buffered peptone water. DNA was extracted using both a boiling method and a commercial kit. LAMP primers were designed targeting the virulence genes stx1, stx2, and eae. The reaction was performed at 65°C for 60 minutes, and results were visualized via colorimetric change, turbidity, and agarose gel electrophoresis. The assay demonstrated a detection limit of 10 CFU/mL and exhibited high specificity, with no cross-reactivity with other E. coli serotypes or common foodborne pathogens. Among 60 raw meat samples tested, 12 (20%) were positive for E. coli O157:H7, slightly higher than the 10 samples (16.7%) detected using conventional culture methods. LAMP significantly reduced detection time, providing reliable results within hours. These findings indicate that LAMP is a rapid, sensitive, and practical tool for on-site monitoring of E. coli O157:H7 in meat, supporting timely interventions to prevent outbreaks and enhance food safety.