Listeria monocytogenes genes supporting growth under standard laboratory cultivation conditions and during macrophage infection

Abstract

The Gram-positive bacterium Listeria monocytogenes occurs widespread in the environment and infects humans when ingested along with contaminated food. Such infections are particularly dangerous for risk group patients, for whom they represent a life-threatening disease. To invent novel strategies to control contamination and disease, it is important to identify those cellular processes that maintain pathogen growth inside and outside the host. Here, we have applied transposon insertion sequencing (Tn-Seq) to L. monocytogenes for the identification of such processes on a genome-wide scale. Our approach identified 394 open reading frames that are required for growth under standard laboratory conditions and 42 further genes, which become necessary during intracellular growth in macrophages. Most of these genes encode components of the translation machinery and act in chromosome-related processes, cell division, and biosynthesis of the cellular envelope. Several cofactor biosynthesis pathways and 29 genes with unknown functions are also required for growth, suggesting novel options for the development of antilisterial drugs. Among the genes specifically required during intracellular growth are known virulence factors, genes compensating intracellular auxotrophies, and several cell division genes. Our experiments also highlight the importance of PASTA kinase signaling for general viability and of glycine metabolism and chromosome segregation for efficient intracellular growth of L. monocytogenes.

Imbalance of peptidoglycan biosynthesis alters the cell surface charge of Listeria monocytogenes

“…In B. subtilis , WalRK also regulates the expression of genes involved in WTA biosynthesis and export ( Howell et al, 2003 ). The regulon of the WalRK system has not yet been determined for L. monocytogenes , however, it was shown that the system is essential ( Fischer et al, 2022 ). Inactivation of WalRK usually leads to cell death of wildtype cells due to loss of peptidoglycan hydrolase activity, however, cell death could be prevented by the inhibition of peptidoglycan biosynthesis ( Salamaga et al, 2021 ).…”

High density genomic surveillance and risk profiling of clinical Listeria monocytogenes subtypes in Germany, 2018-2021

“…We compared the cgMLST and accessory genome MLST (agMLST) allele annotations of the 1,802 isolates with a previously generated list of L. monocytogenes cg/agMLST alleles affected by internal stop codons (44). As the cg/agMLST algorithm annotates frameshifted alleles as "failed" alleles, we also inspected the cg/agMLST alleles for the occurrence of failed alleles that are associated with particular sequence types or even specific cgMLST clusters.…”

ListiWiki: a database for the foodborne pathogenListeria monocytogenes

“…The foundation of data is laid by the genome annotation of L. monocytogenes strain EGD-e (RefSeq accession: NC_003210.1) (Toledo-Arana et al, 2009). Gene essentiality and gene expression data were obtained from published information (Camejo et al, 2009; Fischer et al, 2022). Using specific PubMed queries, 1,285 publications were added as relevant references to the Gene pages.…”

“…Currently, global analyses on protein-protein interactions between L. monocytogenes proteins or even on the interactions of L. monocytogenes proteins with the host proteome are not available. Likewise, the determination of essential gene sets under varying conditions has just started recently (Fischer et al, 2022; Wu et al, 2022). When information on gene essentiality in different mutant backgrounds becomes available one day, implementation and visualization of such synthetic lethal interactions could possibly be a useful extension.…”