InlL from Listeria monocytogenes Is Involved in Biofilm Formation and Adhesion to Mucin

Abstract

The bacterial etiological agent of listeriosis, Listeria monocytogenes, is an opportunistic intracellular foodborne pathogen. The infection cycle of L. monocytogenes is well-characterized and involves several key virulence factors, including internalins A and B. While 35 genes encoding internalins have been identified in L. monocytogenes, less than half of them have been characterized as yet. Focusing on lmo2026, it was shown this gene encodes a class I internalin, InlL, exhibiting domains potentially involved in adhesion. Following a functional genetic approach, InlL was demonstrated to be involved in initial bacterial adhesion as well as sessile development in L. monocytogenes. In addition, InlL enables binding to mucin of type 2, i.e., the main secreted mucin making up the mucus layer, rather than to surface-located mucin of type 1. InlL thus appears as a new molecular determinant contributing to the colonization ability of L. monocytogenes.

Listeria monocytogenes Sequence Types 121 and 14 Repeatedly Isolated Within One Year of Sampling in a Rabbit Meat Processing Plant: Persistence and Ecophysiology

“…As far as the ability of biofilm is concerned, 8 genes associated to biofilm formation were included in the dataset. Biofilm formation is essential for survival of L. monocytogenes and further contributes to bacterial persistence in the food processing environment ( Popowska et al, 2017 ).…”

Whole genome sequencing for typing and characterisation of Listeria monocytogenes isolated in a rabbit meat processing plant

“…The gene inlF belong to the internalin family, which includes genes exclusive of the genus Listeria and associated to the adehesion and invasion of host cells (Vázquez-Boland et al, 2001). The gene lmo2026 , was recently identified as an internalin gene, inlL , associated to biofilm formation and adhesion to mucin (Popowska et al, 2017 ). Besides presence/absence of virulence genes the regulation of expression as well as the presence of truncated genes or the presence of mutations leading to truncated versions of their translated proteins might have a crucial role in the virulence potential of ST14 and ST121.…”

Listeria monocytogenes Biofilms in the Wonderland of Food Industry

“…Both extracellular and surface proteins (such as internalin A—inlA, and biofilm associated protein BapL) were found to be part of extracellular matrix [ 59 ]. Very recently, another class of internalin proteins (internalin L—inlL) was found to be involved in both initial bacterial adhesion and sessile development in L. monocytogenes EGD-e [ 60 ].…”