Short communication Microdroplet-based multiplex PCR on chip to detect foodborne bacteria producing biogenic amines Anna Giovanna Sciancalepore a, * , Elisa Mele a,1 , Valentina Arcadio b, c , Francesco Reddavide b, d , Francesco Grieco e , Giuseppe Spano f , Patrick Lucas g , Giovanni Mita e , Dario Pisignano b, h, ** a Center for Biomolecular Nanotechnologies, Fondazione Istituto Italiano di Tecnologia @UniLe, via Barsanti 1, I-73010 Arnesano, Lecce, Italy b National Nanotechnology Laboratory (NNL) of Istituto Nanoscienze-CNR, via Arnesano, I-73100 Lecce, Italy c Facoltà di Scienze Matematiche Fisiche e Naturali, Università del Salento, via Prov. Lecce-Monteroni, I-73100 Lecce, Italy d Facoltà di Scienze Biotecnologiche, Università degli Studi di Bari, via G. Fanelli 204, I-70125 Bari, Italy e CNR e Istituto di Scienze delle Produzioni Alimentari, via Prov. Lecce-Monteroni, I-73100 Lecce, Italy f Dipartimento di Scienze Agrarie, degli Alimenti e dell’Ambiente, via Napoli 25, I-71100 Foggia, Italy g UMR Œnologie, INRA, ISVV, Université de Bordeaux, 210 chemin de Leysotte, CS50008, 33882 Villenave d’Ornon, France h Dipartimento di Matematica e Fisica “Ennio De Giorgi”, Università del Salento, via Arnesano, I-73100 Lecce, Italy article info Article history: Received 19 October 2012 Received in revised form 6 February 2013 Accepted 14 February 2013 Available online 1 March 2013 Keywords: Biogenic amines Microfluidics Multiplex-PCR Food safety abstract The development of fast, reliable and culture-independent molecular tools to detect bacteria producing biogenic amines deserves the attention of research and ultimately of the food industry in order to protect consumers’ health. Here we present the application of a simple, low-cost, fast and sensitive method to perform microdroplet-based multiplex PCR, directly on a food matrix, for the simultaneous detection of bacterial genes involved in biogenic amine biosynthesis. After inoculating wine with Lactobacillus brevis IOEB 9809, cell lysis and DNA amplification are performed in one single step, without preliminary nucleic acid extraction or purification treatments. The assay is performed in about 30 min, requiring 150 nL of starting sample and it enables the detection of down to 15 bacterial cells. With respect to traditional culture techniques, the speed, the simplicity and the cheapness of this procedure allow an effective monitoring of microbial cells during food-making and processing. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Controlling food quality and safety, from primary production through processing and storage, to transportation and marketing, is crucial to reduce the risk of illness and guarantee the protection of consumers’ health. Special attention is required for fermented foods or for food undergone inappropriate processing and storage conditions. Wine, cheese, beer, sausages and yeast extracts can contain bacteria responsible for the production and accumulation of biogenic amines (BAs) (Russo et al., 2010; Beneduce et al., 2010). BAs are basic nitrogenous compounds with low molecular weight, usually produced by lactic acid bacteria (LAB) through amino acids decarboxylation or deimination (Silla-Santos, 1996; Spano et al., 2010). However, in food such as fermented sausages, BA are also produced by genera of the family Enterobacteriaceae, such as Citrobacter , Klebsiella, Escherichia, Proteus, Salmonella and Shigella (Suzzi and Garnini, 2003). The main BA found in food and fer- mented beverages are histamine, tyramine, putrescine and cadav- erine (Landete et al., 2007). In higher animals these compounds are involved in many biological and physiological processes, such as synaptic transmission, blood pressure control, regulation of body temperature and allergic response (Russo et al., 2010). Neverthe- less, the ingestion of food containing high amounts of BAs can induce several toxicological effects. For example, histamine causes headache, edema, diarrhea, allergy, respiratory difficulties; tyra- mine can induce hypertension, migraine and neurological disor- ders, while putrescine and cadaverine may have carcinogenic effects (Shalaby, 1996; Ladero et al., 2010). In alcoholic beverages such as wine and beer the toxic effects of BAs are aggravated by the presence of ethyl alcohol, which inhibits the detoxification activity of diamine oxidase in human gut, causing gastric acid secretion, tachycardia and high blood pressure (Shalaby, 1996). Overall, the potential toxicity of BAs and their use as indicators of microbiological contamination have driven the development of analytical methods for their rapid determination in food matrices * Corresponding author. Tel.: þ39 0832 298119; fax: þ39 0832 298146. ** Corresponding author. National Nanotechnology Laboratory (NNL) of Istituto Nanoscienze-CNR, via Arnesano, I-73100 Lecce, Italy. Tel./fax: þ39 0832 298146. E-mailaddresses: anna.sciancalepore@iit.it (A.G. Sciancalepore), dario.pisignano@ unisalento.it (D. Pisignano). 1 Present address: Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genoa, Italy. Contents lists available at SciVerse ScienceDirect Food Microbiology journal homepage: www.elsevier.com/locate/fm 0740-0020/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.fm.2013.02.010 Food Microbiology 35 (2013) 10e14