A molecular beacon-based real-time NASBA assay for detection of Listeria monocytogenes in food products: role of target mRNA secondary structure on NASBA design

A molecular beacon-based real-time NASBA (QNASBA) assay for detection and identification of Listeria monocytogenes has been developed. A correlation between targeting highly accessible mRNA sequences and QNASBA efficiency and sensitivity was demonstrated. The assay targets a sequence from the mRNA t...

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Detalles Bibliográficos
Autores: Nadal i Matamala, Anna, Coll Rius, Anna, Cook, Nigel, Pla i de Solà-Morales, Maria
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2007
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10256/25938
Acceso en línea:http://hdl.handle.net/10256/25938
Access Level:acceso abierto
Palabra clave:Listèria monocitògena
Listeria monocytogenes
RNA
Descripción
Sumario:A molecular beacon-based real-time NASBA (QNASBA) assay for detection and identification of Listeria monocytogenes has been developed. A correlation between targeting highly accessible mRNA sequences and QNASBA efficiency and sensitivity was demonstrated. The assay targets a sequence from the mRNA transcript of the hly gene which is specific for this bacterium; and includes an internal amplification control to disclose failure of the reaction. It was fully selective and consistently detected down to 100 target molecules and 40 L. monocytogenes exponentially growing cells per reaction. In addition, it was capable of accurate quantification of target RNA molecules independently of the presence of DNA in the sample. In combination with a short RNase treatment prior to nucleic acids extraction our QNASBA specifically detected viable L. monocytogenes cells. It was successfully applied to rapid detection of this pathogen in meat and salmon products, and is therefore a useful tool for the study of L. monocytogenes in food samples. We finally discuss considerations of target secondary structure with regard to development of NASBA assays