Colorimetric aptasensor for detecting Salmonella spp., Listeria monocytogenes, and Escherichia coli in meat samples

• Sudarat Ledlod ^[1] ; Supatra Areekit ^[2] ; Somchai Santiwatanakul ^[1] ; Kosum Chansiri ^[1]
  1. [1] Srinakharinwirot University

     Srinakharinwirot University

     Tailandia

     
  2. [2] Center of Excellence in Biosensors, Srinakharinwirot University, Panyananthaphikkhu Chonprathan Medical Center, Nonthaburi, Thailand
• Localización: Food science and technology international = Ciencia y tecnología de alimentos internacional, ISSN-e 1532-1738, ISSN 1082-0132, Vol. 26, Nº 5, 2020, págs. 430-443
• Idioma: inglés
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• Resumen

  • In this study, we successfully developed a simple and rapid method for simultaneous detection of Salmonella spp., Listeria monocytogenes, and Escherichia coli using gold nanoparticles and the aptamer aptasensor. We screened 25 specific DNA aptamer candidates against these pathogens using whole-cell Systematic Evolution of Ligands by EXponential enrichment. Among them, Ap6 was selected due to its low energy minimization values of −12.25 and −27.67 kcal/mol derived from MFold and RNAFold analysis, respectively. The assay presented in this study allowed the visual colorimetric detection of labeled colloidal gold nanoparticles as well as determination of UV absorbance at 625 and 525 nm under optimized conditions. The detection limit of this aptasensor was as less as 105 CFU/ml. A random investigation of 50 meat samples, including ham and chicken sausages, collected from the local market revealed 96% accuracy, 96% specificity, and 100% sensitivity of the assay. The colorimetric aptasensor can accomplish one-step detection without pre-culture, DNA extraction, and amplification. Hence, it is an easy, rapid, specific, and qualitative assay that can be used as a point-of-care testing to directly detect multiplex foodborne pathogens.