Small molecules targeting LapB protein prevent Listeria attachment to catfish muscle

Abstract

Listeria monocytogenes is a Gram-positive foodborne pathogen and the causative agent of listeriosis. L. monocytogenes lapB gene encodes a cell wall surface anchor protein, and mutation of this gene causes Listeria attenuation in mice. In this work, the potential role of Listeria LapB protein in catfish fillet attachment was investigated. To achieve this, boron-based small molecules designed to interfere with the active site of the L. monocytogenes LapB protein were developed, and their ability to prevent L. monocytogenes attachment to fish fillet was tested. Results indicated that seven out of nine different small molecules were effective in reducing the Listeria attachment to catfish fillets. Of these, three small molecules (SM3, SM5, and SM7) were highly effective in blocking Listeria attachment to catfish fillets. This study suggests an alternative strategy for reduction of L. monocytogenes contamination in fresh and frozen fish products.

Garcinia mangostana extract inhibits the attachment of chicken isolates of Listeria monocytogenes to cultured colorectal cells potentially due to a high proanthocyanidin content

“…Therefore, proanthocyanidins may have induced changes in biological factors specific to L. monocytogenes that play a role in their attachment to mammalian tissues. For instance, surface adhesins internalin A and B, pore‐forming toxin listeriolysin O, cell wall‐anchored biofilm‐associated protein BapL, cellulose‐binding protein LCP, and actin‐binding protein ActA have been found to facilitate the attachment of Listeria monocytogenes to various surfaces (Akgul, Al‐Janabi, Das, Lawrence, & Karsi, 2017; Bae et al, 2013; Jordan et al, 2008; Phelps et al, 2018). The type strain attached in a lower number to the cell line and responded differently to mangosteen extract treatments as compared to the wild‐type strains, suggesting that these wild‐type chicken isolates may carry surface adhesins that have a high affinity for biotic surfaces (especially meat products) and can be blocked by polyphenolic compounds, such as cell wall surface adhesin LapB (Akgul et al, 2017; Oloketuyi & Khan, 2017).…”