Presence of <i>Listeria</i> spp., including pathogenic <i>Listeria monocytogenes</i> and <i>Listeria ivanovii</i>, on fresh vegetables in the markets of Abidjan (Cote d’Ivoire)

Listeria monocytogenes is a pathogenic bacterium that can contaminate various food products and is the causative agent of listeriosis, a severe and life-threatening foodborne illness. This study aimed to assess the occurrence of Listeria species in fresh vegetables and market garden produce from Côte d'Ivoire. Conducted over a 9-week period, this work analyzed 135 samples of fresh vegetables and market garden produce (including lettuces, carrots, cabbage, tomatoes, and cucumbers) collected from 3 major markets in 3 districts of Abidjan. Among the 135 samples, Listeria spp. were found in 11 (8.15%), including Listeria innocua in 8 (5.92%), Listeria ivanovii in 1 (0.74%), and L. monocytogenes in 2 (1.48%). Genetic analysis was performed using restriction fragment length polymorphism targeting the 16S rRNA gene. Further characterization of genetic lineages, serotypes, and virulence genes was achieved through polymerase chain reaction. The two L. monocytogenes isolates belong to the genetic lineage I, associated with serogroups 1/2b, 3b, 4b, 4d, 4e, and 7. They harbored key virulence genes from Listeria pathogenicity island-1, such as actA, hly, prfA, and pclB, as well as internalin genes (inlA, inlJ, and inlC), indicating their potential pathogenicity. This study highlights the presence of Listeria spp., including L. monocytogenes, in fresh vegetables sold in Abidjan markets, underscoring a potential health risk for consumers.