Staphylococcus aureus strains carrying enterotoxin A gene (sea) causes food poisoning and cannot be distinguished from non-pathogenic strains by the culture method. Here, we developed a rapid, specific and sensitive visual detection of sea using loop-mediated isothermal amplification (LAMP) combined with nanogold probe (AuNP) or styryl dye (STR). LAMP-AuNP and LAMP-STR can detect as low as 9.7 fg (3.2 sea copies) and 7.2 sea copies, respectively, which were lower than PCR (97 fg or 32 sea copies). The excellent performance of these new assays was demonstrated in food samples using crude DNA lysates. While the culture method detected 10 4 CFU/g in ground pork and 10 CFU/mL in milk in 5-7 days, LAMP-AuNP could detect down to 10 CFU/g for both samples in 27 minutes. Analyzing 80 pork and milk samples revealed that the LAMP-AuNP showed 100% sensitivity, 97-100% specificity and 97.5-100% accuracy, which were superior to the culture method, and comparable to PCR but without requirement of a thermal cycler. Furthermore, our LAMP-AuNP detect sea at a range below the food safety control (<100 CFU/g). The LAMP-STR quantitated sea in 10-1,000 CFU (7.2-720 copies). Our crude DNA lysis combined with LAMP-AuNP/STR present effective point-of-care detection and facilitate appropriate control strategies. Staphylococcus aureus strains with the staphylococcal enterotoxin A gene (sea) bacteriophage, are a common cause of foodborne disease and outbreaks worldwide including the United States and countries of the European Union 1-5. In Thailand, one of the largest outbreaks occurred in 2009 reporting 573 illnesses due to consumption of contaminated sticky rice custard 6. S. aureus is commonly found in soil, water, air, as well as human respiratory tract and skin. The sea toxin is relatively heat stable (e.g. up to 100 °C for 30 min) therefore, food contamination generally occurs when cooking is performed without sufficient hygiene. Frequently reported contaminated foods include dairy products (milk, cheese, ice cream, etc.), and meat 7,8. Importantly, contaminated food may not be easily identified by sensory evaluation such as odor or appearance. Clinical symptoms from sea food poisoning include vomiting, abdominal cramps, diarrhea, and dysentery, often within 1-6 h after consumption. Occasional symptoms include sweating, chills, rectal bleeding, and shock 9-11. The severity of illness depends on the concentration of the toxin. Consumption of merely 20-100 ng of sea toxin can cause clinical symptoms and >100 ng may be fatal, therefore a sensitive method of sea detection is important for food safety control. Detection is usually
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