The incidence and distribution of Listeria monocytogenes in ready-to-eat vegetables in South-Western Nigeria

The study investigated the incidence of Listeria monocytogenes in ready-to-eat (RTE) vegetables: (Cucumber, Cucumis sativas; Cabbage, Brassica olerecea; Carrot, Daucus carota; Tomato, Solanum lycopersicum; Lettuce, Lactuca sativa) in six states in South-Western Nigeria. A total of 555 composite samples were collected from 30 traditional markets within the states and only 244 L.monocytogenes species were isolated by standard methods. The incidence of L.monocytogenes was low and not statistically significant per vegetable type. The percentage distribution of the L.monocytogenes isolates in the RTE vegetables was 28.28, 9.02, 23.36, 19.67, and 19.67 for Cabbage, Carrot, Cucumber, Lettuce, and Tomatoes, respectively. Lagos state had the highest incidence of L.monocytogenes contamination (55%) followed by Ondo (48.89%), Oyo (48.75%), Ogun (44.09%), Osun (34.38%), and Ekiti (33.33%) states, respectively. Although the incidence of L.monocytogenes in the RTE vegetables in South-Western Nigeria is low, its presence should be a source of concern as it could constitute a public health threat for its consumers.