Quantification of Listeria monocytogenes in minimally processed leafy vegetables using a combined method based on enrichment and 16S rRNA real-time PCR

Autor(es)

de Oliveira, Maria Aparecida ^[1] ; Abeid Ribeiro, Eliana Guimaraes ^[1] ; Morato Bergamini, Alzira Maria ^[1] ; Pereira De Martinis, Elaine Cristina ^[2]

Afiliação do(s) autor(es)

^[1] Lab Reg Ribeirao Preto, Inst Adolfo Lutz, BR-14085410 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, BR-14040903 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FOOD MICROBIOLOGY; v. 27, n. 1, p. 19-23, FEB 2010.
• Citações Web of Science: 32

Resumo

Modern lifestyle markedly changed eating habits worldwide, with an increasing demand for ready-to-eat foods, such as minimally processed fruits and leafy greens. Packaging and storage conditions of those products may favor the growth of psychrotrophic bacteria, including the pathogen Listeria monocytogenes. In this work, minimally processed leafy vegetables samples (n = 162) from retail market from Ribeirao Preto, Sao Paulo, Brazil, were tested for the presence or absence of Listeria spp. by the immunoassay Listeria Rapid Test, Oxoid. Two L. monocytogenes positive and six artificially contaminated samples of minimally processed leafy vegetables were evaluated by the Most Probable Number (MPN) with detection by classical culture method and also culture method combined with real-time PCR (RTi-PCR) for 16S rRNA genes of L monocytogenes. Positive MPN enrichment tubes were analyzed by RTi-PCR with primers specific for L. monocytogenes using the commercial preparation ABSOLUTET (TM) QPCR SYBR (R) Green Mix (ABgene, UK). Real-time PCR assay presented good exclusivity and inclusivity results and no statistical significant difference was found in comparison with the conventional culture method (p < 0.05). Moreover, RTi-PCR was fist and easy to perform, with MPN results obtained in ca. 48 h for RTi-PCR in comparison to 7 days for conventional method. (C) 2009 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 06/06401-3 - Enumeração rápida de Listeria monocytogenes em vegetais minimamente processados por PCR em tempo real com detecção de genes de 16S rRNA em comparação com o método clássico
• Beneficiário: Elaine Cristina Pereira de Martinis
• Modalidade de apoio: Auxílio à Pesquisa - Regular