Occurrence and Antimicrobial Resistance of Enterococcus spp. Isolated from Lettuce and Irrigation Water in Abidjan, Côte d\'Ivoire

Background: Enterococcus spp., belonging to the group of lactic acid bacteria, are Gram-positive ubiquitous commensals of the intestines of human beings as well as warm-blooded animals. The main objective of this study was to determine the occurrence and antimicrobial resistance of Enterococcus spp. isolated from lettuce and irrigation water in Abidjan, Côte d'Ivoire. Methods: A total of 72 samples, including leaves of lettuce (n=36) and irrigation water (n=36) were randomly collected from three different agricultural sites located in Abidjan city, Côte d'Ivoire. After microbial analysis and identification of Enterococcus spp. by culturing and biochemical methods, antimicrobial susceptibility tests were carried out using disk diffusion method. Data were analyzed by statistical processing software R (R 3.0 for Windows). Results: E. faecalis was recognized as the most prevalent strain which was found in 27 out of 36 (75%) lettuce as well as 29 out of 36 (80.5%) irrigation water samples. The mean Enterococcus load of lettuces and irrigation water samples were 2.3±0.7 and 3.6±2 log Colony Forming Unit per g lettuce, respectively. Among 45 studied enterococci isolates, the most antibiotic-resistance rates were related to erythromycin (54%) and also co-trimoxazole (49%). Conclusion: There is a considerable public health concern regarding raw consumption of lettuce cultivated in Abidjan city which can cause gastroenteritis diseases in consumers.