Paper informativo

Turk J Vet Anim Sci 30 (2006) 229-234 © TÜB‹TAK

Research Article

Comparison of Polymerase Chain Reaction and Conventional Methods for the Diagnosis of Listeria monocytogenes in Stuffed Mussels
Ergün Ö. GÖKSOY1,*, fiükrü KIRKAN2, Osman KAYA2
1

Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, Adnan Menderes University, 09016 Ifl›kl›, Ayd›n - TURKEY

2Department of Microbiology, Faculty of Veterinary Medicine, Adnan Menderes University, 09016 Ifl›kl›, Ayd›n - TURKEY

Received: 29.06.2005

Abstract: The aim of this study was to evaluate the role of stuffed mussel as a source of Listeria monocytogenes. Polymerase chain reaction is a rapid procedure with both sensitivity and specificity for quick detection and identification of L. monocytogenes. Atotal of 50 mussel samples were investigated for L. monocytogenes. L. monocytogenes was not identified by the conventional method. However, PCR amplification products demonstrated that 5 out of 50 samples showed positive reactions with L. monocytogenes. The PCR positive samples showed specific amplification at approximately 343 bp for L. monocytogenes. Key Words: Listeria monocytogenes, stuffedmussel, conventional methods, PCR

Midye Dolmalarda Listeria monocytogenes Tan›s› için Polimeraz Zincir Reaksiyonu ve Konvensiyonel Metotlar›n›n Karfl›laflt›r›lmas›
Özet: Bu araflt›rman›n amac›, Listeria monocytogenes kayna¤› olarak midye dolmalar›n rolünün varl›¤›n› ortaya ç›karmakt›r. Polimeraz Zincir Reaksiyonu (PZR), L. monocytogenes’in identifikasyonu ve h›zl› tan›s›nda spesifite ve sensitivitesiyüksek bir metottur. Çal›flmada, toplam 50 adet midye dolma örne¤i L. monocytogenes yönünden incelendi. Konvensiyonel metotlar ile L. monocytogenes identifiye edilemedi. Ancak, PZR’nda, L. monocytogenes yönünden 50 örne¤in 5’inde pozitif amplifikasyon ürünleri görüldü. PZR pozitif ürünlerde, L. monocytogenes için spesifik, yaklafl›k olarak 343 bp aral›¤›ndaki bant görüntüsü elde edildi. AnahtarSözcükler: Listeria monocytogenes, midye dolma, konvensiyonel metotlar, PZR

Introduction

Listeria monocytogenes is a foodborne pathogen capable of causing sporadic and epidemic out-breaks of listeriosis (1). In addition to the very young and elderly, immuno-suppressed individuals such as those with cancer, AIDS and diabetes are also at high risk (2). Disease symptoms vary from flu-like symptomssuch as fever, fatigue, vomiting, malaise, nausea and diarrhoea, to more serious illness resulting in meningitis or encephalitis (1). Listeria infections can result in stillbirth, meningitis, meningoencephalitis, septicaemia, and death (3).

Listeria organisms are widely disseminated in the rural environment and, consequently, contaminate the raw materials used in the preparation of industriallyprocessed foods and the production plants as well (4). They have been isolated from soil, decaying vegetable matter, silage, sewage, water, animal feed, fresh and processed meats, raw milk, cheese, slaughterhouse waste, seafood and asymptomatic human and animal carriers.

L. monocytogenes has been isolated from both domestic and imported, fresh, frozen, and processed seafood products, includingcrustaceans, molluscan shellfish, and finfish (5). Contaminated seafoods, such as

* E-mail: egoksoy@ hotmail.com

229

Comparison of Polymerase Chain Reaction and Conventional Methods for the Diagnosis of Listeria monocytogenes in Stuffed Mussels

smoked cod roe, mussels, and undercooked fish, have been assumed to be the sources for sporadic cases of listeriosis (6-8). L. monocytogenes issporadically isolated from a range of seafoods, including ready-to-eat products like cold and hot smoked salmon, gravad salmon, shrimp, fermented fish, and fish salads (9). Colburn et al. (10) reported that Listeria innocua was identified in oyster samples. Because of their widespread occurrence, Listeria species have many opportunities to enter food production and processing environments...