N’Goran Parfait N’Zi^{1, 2}, Hadja Djénéba Ouattara³, Yao Paul Attien¹, Valérie Carole Gbonon², Nathalie Kouadio Guessennd², Djédoux Maxime Angaman^1,

Ready-to-eat salads have become highly demanded foods in the city of Abidjan (Côte d’ivoire) because of their considerable benefits both nutritionally and therapeutically. However, these foods are considered products that are very vulnerable to microbial contamination. In order to contribute to food safety in Côte d'Ivoire, in particular among the Abidjan population, we have set the objective of inventorying psychrophilic pathogenic species in ready-to-eat salads sold in supermarkets. Thus, a total of 60 samples were analyzed using the techniques of classical microbiology, molecular biology, bioinformatics and statistics. For the search for psychrophilic pathogens, the selective culture medium (Oxford agar) of the pathogens frequently isolated (L. monocytogenes) was used. Microbiological analyzes revealed the presence of similar germs in 6 samples based on growth characters with Oxford’s selective medium. However, molecular sequencing allowed to identify six (6) different pathogens, Lysinibacillus fusiformis in spinach salads (EP), Listeria monocytogenes in mixed salads (SCOM), Staphylococcus saprophyticus in lamb's lettuce and arugula, Staphylococcus fleurettii in carrots (SCA), Staphylococcus nepalensis in young shoots (JP) and Bacillus cereus in cabbage (SCH). The growth kinetics showed the characterized species grow significantly in the different lettuces under domestic storage conditions after opening the packaging except for S. fleurettii. However, the growth of L. fusiformis and B. cereus was found to be more significant. In conclusion, S. saprophyticus, S. nepalensis, B. cereus, L. fusiformis and B. cereus grow easily on oxford agar presenting similar culture characters like L. monocytogenes. In addition, the presence of unknown pathogenic species in ready-to-eat salads and their significant growth during the domestic storage period is a real public health problem. It would therefore be wise for the health authorities to set up a monitoring program for these species in the ready-to-eat sold in supermarkets in Côte d'Ivoire.

ready-to-eat salads, psychrophilic pathogens, Abidjan (Côte d’Ivoire)