Mathipa, Moloko GloriaThantsha, Mapitsi SilvesterBhunia, Arun K.2020-08-052020-08-052019-07Mathipa, M.G., Thantsha, M.S. & Bhunia, A.K. 2019, 'Lactobacillus casei expressing Internalins A and B reduces Listeria monocytogenes interaction with Caco-2 cells in vitro', Microbial Biotechnology, vol. 12, no. 4, pp. 715–729.1751-7915 (online)10.1111/1751-7915.13407http://hdl.handle.net/2263/75589Listeria monocytogenes has been implicated in a number of outbreaks including the recent largest outbreak in South Africa. Current methods for prevention of foodborne L. monocytogenes infection are inadequate, thus raising a need for an alternative strategy. Probiotic bioengineering is considered a prevailing approach to enhance the efficacy of probiotics for targeted control of pathogens. Here, the ability of Lactobacillus casei expressing the L. monocytogenes invasion proteins Internalins A and B (inlAB) to prevent infection was investigated. The inlAB operon was cloned and surface-expressed on L. casei resulting in a recombinant strain, LbcInl AB , and subsequently, its ability to inhibit adhesion, invasion and translocation of L. monocytogenes through enterocyte-like Caco-2 cells was examined. Cell surface expression of InlAB on the LbcInl AB was confirmed by Western blotting and immunofluorescence staining. The LbcInl AB strain showed significantly higher (P < 0.0001) adherence, invasion and translocation of Caco-2 cells than the wild-type L. casei strain (LbcWT ), as well as reduced L. monocytogenes adhesion, invasion and transcellular passage through the cell monolayer than LbcWT . Furthermore, pre-exposure of Caco-2 cells to LbcInl AB significantly reduced L. monocytogenes-induced cell cytotoxicity and epithelial barrier dysfunction. These results suggest that InlAB-expressing L. casei could be a potential practical approach for prevention of listeriosis.en© 2019 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology. This is an open access article under the terms of the Creative Commons Attribution License.Lactobacillus caseiHumanBacterial adhesionBacterial proteinsCaco-2 cellsArticle