International Journal of Food Microbiology 49 (1999) 151–159 The development of a combined surface adhesion and polymerase chain reaction technique in the rapid detection of Listeria monocytogenes in meat and poultry a a, a b b * Geraldine Duffy , Orla M. Cloak , J.J. Sheridan , I.S. Blair , D.A. McDowell a The National Food Centre, Teagasc, Dunsinea, Castleknock, Dublin 15, Ireland b University of Ulster, Jordanstown, Newtownabbey, Co. Antrim BT37 OQB, Northern Ireland, UK Received 26 August 1998; received in revised form 8 December 1998; accepted 13 June 1999 Abstract A procedure combining enrichment surface adhesion and polymerase chain detection (SA-PCR) was developed and applied in the detection of Listeria monocytogenes in meat products. Minced beef samples were inoculated with L. 21 monocytogenes (log 3 cfu g ) and incubated for 10 h at 308C in buffered peptone water. L. monocytogenes was recovered 10 from the culture by attachment to a polycarbonate membrane immersed for 15 min in the enriched meat culture. The membrane and attached bacteria were removed from the culture and the membrane dissolved in phenol:chloroform. The DNA was extracted from the bacteria and a PCR assay was carried out using primers directed against the listerolysin O gene 21 of L. monocytogenes. The combined (SA-PCR) technique had a detection limit of log 4.0 cfu ml in enriched meat 10 cultures.The rapid technique was applied to a small number of retail samples ( n 5 100) and was found to compare favourably to the standard cultural method. A total of 12 samples were confirmed positive for L. monocytogenes using the standard cultural method and the SA-PCR assay. No false positives or negatives were recorded by either method.  1999 Elsevier Science B.V. All rights reserved. Keywords: Surface adhesion; Listeria; PCR 1. Introduction Fleming et al., 1985; Brackett, 1988; Linnan et al., 1988; Kaczmarski and Jones, 1989, McLauchlin et Listeria monocytogenes is a pathogen which has al., 1991). It has also been detected on a range of been linked to outbreaks of food poisoning involving food products including raw and ready to eat prod- a wide range of foods including coleslaw, milk, ucts at retail level (Gilbert et al., 1989; Carosella, cheese, chicken and pate (Schlech et al., 1983; 1990; Sheridan et al., 1994), at concentrations of 21 10–1000 cfu g (Sheridan et al., 1994; Jay, 1996; Walsh et al., 1998). The minimum infective dose has *Corresponding author. Tel.: 1 353-1-805-9500; fax: 1 353-1- not been reliably established, however, published 805-9550. E-mail address: o.cloak@nfc.teagasc.ie (O.M. Cloak) information on the numbers of L. monocytogenes in 0168-1605 / 99 / $ – see front matter  1999 Elsevier Science B.V. All rights reserved. PII: S0168-1605(99)00091-4