Presence of Listeria monocytogenes in Chilean food matrices

ObjectivesTo compare Listeria monocytogenes strains obtained from food matrices with those from environmental samples in the same food processing plant.Methods and resultsBetween 2008 and 2012 the presence of L. monocytogenes was evaluated in 2647 food samples. A total of 448 work surfaces and 92 equipment's were also evaluated from 6 plants which produce ready-to-eat (RTE) foods in Santiago, Chile. An additional selected sample of hand and nails samples was also obtained from 13 food handlers working in a sausage elaboration plant.As a whole L. monocytogenes was present in 265 (10%) food samples and 22 (4%) environmental samples. The foods with highest recovery were red meats 14/60 (23%), poultry 223/1196 (19%), the remaining samples accounted a total of 27/1391 (2%). The environmental samples positive for L. monocytogenes were obtained from two food plants both the cheese 8/8 (100%) and from a fresh peaches exporter 3/3 (100%). Finally L. monocytogenes was isolated from 5/13 (38%) food handlers studied.ConclusionsThe study confirms the presence of L. monocytogenes in different matrices, especially in meat and RTE products. Analyses conducted on work surfaces revealed that contamination comes mostly from both raw materials and surfaces in indirect contact with foods.Significance and impact of studyThe study reinforces the need for companies to apply regulations related to food quality and safety systems (HACCP, Hazard Analysis & Critical Control Points) to prevent L. monocytogenes contamination from food processing plants.