IntroductionListeria monocytogenes is a gram-positive foodborne pathogen that causes listeriosis, leading to septicemia, encephalitis, meningitis, and gastroenteritis, particularly in pregnant women, newborns, the elderly, and immunosuppressed individuals (1).L. monocytogenes is widely distributed in nature. The organism is commonly found in silage, soil, sewage, fertilizer, vegetable matter, and many foods including cabbage, coleslaw, raw milk and dairy products, meat, poultry, and their products (2). The other important source of L. monocytogenes infection is consumption of ready-to-eat (RTE) foods such as cooked meats, desserts, sandwiches, cheese from either raw or pasteurized milk, and fish products. These foods are not cooked or reheated before serving. Therefore L. monocytogenes can survive and grow under refrigerated conditions in packaged RTE foods (3,4). Several outbreaks of listeriosis in the United States in 1998-2008 as indicated by the Centers for Disease Control and Prevention were associated with the consumption of RTE foods. It was reported that 359 people were affected in 24 confirmed listeriosis outbreaks, resulting in 215 hospitalizations and 38 deaths (5).There is little information on the prevalence and contamination levels of L. monocytogenes in RTE foods in Turkey. RTE foods such as Turkish-style tomato dip/ condiment (ezme), stuffed mussels, fried spiced liver, and mayonnaise-based salads are frequently consumed in Turkey. Ingredients and preparation methods of these RTE foods are summarized in Table 1.Conventional bacteriological methods used for the identification of L. monocytogenes are not always reliable and are often time-consuming and laborious. Thus, more reliable, rapid, and cost-effective molecular techniques such as polymerase chain reaction (PCR)-based methods have been developed for the detection of these pathogens in food (6). The hly gene encoding hemolysin listeriolysin O (LLO), a pore-forming exotoxin with hemolytic activity, is an important virulence factor for the specific detection of L. monocytogenes (7).The increased use of antibiotics for therapeutic purposes in animals and humans has led to the development of antibiotic resistance, an important public health concern (8). Studies have shown the existence of L. monocytogenes strains that are resistant to one or more antibiotics such as nalidixic acid, oxacillin, tetracycline, gentamicin,