Prevalence of in Ready-to-Eat Foods Sampled from the Point of Sale in Wales, United Kingdom

Abstract

A survey of Listeria in ready-to-eat food took place in Wales, United Kingdom, between February 2008 and January 2009. In total, 5,840 samples were taken and examined for the presence of Listeria species, including L. monocytogenes. Samples were tested using detection and enumeration methods, and the results were compared with current United Kingdom guidelines for the microbiological quality of ready-to-eat foods. The majority of samples were negative for Listeria by both direct plating and enriched culture. Seventeen samples (0.29%) had countable levels of Listeria species (other than L. monocytogenes), and another 11 samples (0.19%) had countable levels of L. monocytogenes. Nine samples (0.15%) were unsatisfactory or potentially hazardous when compared with United Kingdom guideline limits; six (0.10%) were in the unsatisfactory category (>100 CFU/g) for Listeria species (other than L. monocytogenes), and three (0.05%) were in the unacceptable or potentially hazardous category (>100 CFU/g) for L. monocytogenes. All three of these samples were from sandwiches (two chicken sandwiches and one ham-and-cheese sandwich). The most commonly isolated serotype of L. monocytogenes was 1/2a. This survey was used to determine the current prevalence of Listeria species and L. monocytogenes in ready-to-eat foods sampled from the point of sale in Wales.

Viability of Salmonella and Listeria monocytogenes in Delicatessen Salads and Hummus as Affected by Sodium Content and Storage Temperature

“…The same trend was observed in the United Kingdom for prepacked meats and sandwiches containing salad vegetables as an ingredient (30). L. monocytogenes was detected in 3.1% of 404 pasta-and rice-based salads obtained at points of sale or service to the customer in Wales (37). In a study to determine the prevalence of L. monocytogenes in RTE foods in Belgium, Uyttendaele et al (52) detected this pathogen in 80 (6.7%) of 1,187 25-g samples.…”

Highly specific fiber optic immunosensor coupled with immunomagnetic separation for detection of low levels of Listeria monocytogenes and L. ivanovii

“…However, when an enrichment step is used, the non-pathogenic species may overgrow and outcompete L. monocytogenes [17-19], leading to false-negative results. L. innocua is the most frequently found bacteria in Listeria -contaminated foods [17,20], thus presenting a challenge for the specific capture and detection of pathogenic Listeria [21]. Hence, it is essential to develop methods that are capable of detecting pathogenic species in the presence of non-pathogenic species.…”

Identification of the significant factors in food quality using global sensitivity analysis and the accept-and-reject algorithm. Part II: Application to the cold chain of cooked ham

“…The data of y 0 in products (cooked ham after slicing) was given by a survey undertaken from January 1997 to December 1998 in a big supermarket in Belgium (Uyttendaele et al, 1999). Among 879 products, L. monocytogenes was detected in 54 products (sample of 25 g) and 8 of them were detected in sample of 0.1 g. According to our literature review, only 3 studies reported the statistical data on the initial contamination in ham: Uyttendaele et al (1999), Garrido et al (2009) and Meldrum et al (2010). In our case, only the data of Uyttendaele et al (1999) were used because of the low number of products tested by Garrido et al (2009) and the lack of knowledge of the type of product tested by Meldrum et al (2010).…”

“…However, this task requires an accurate knowledge of the different sources of variability (product characteristics, prevalence, time temperature profiles...) of products along the cold chain which can be obtained by surveys. For this purpose, several surveys have been carried out on the contamination of food products by L. monocytogenes (Garrido et al, 2009;Gombas et al, 2003;Meldrum et al, 2010;Uyttendaele et al, 1999;Van Kessel et al, 2004) or on product temperature in the cold chain (Derens-Bertheau et al, 2014;Laguerre et al, 2002;Rediers et al, 2009) are expensive and time consuming. Few studies used such survey data to describe the logistics of the cold chain (Afchain et al, 2005;Couvert et al, 2010;De Cesare et al, 2013;Ellouze et al, 2010;Koutsoumanis et al, 2010;Pouillot et al, 2007).…”