Whole Genome Analysis of Three Multi-Drug Resistant Listeria innocua and Genomic Insights Into Their Relatedness With Resistant Listeria monocytogenes

Abstract

Listeria innocua are Gram-positive rod-shaped bacteria, which are not generally infectious as opposed to Listeria monocytogenes. However, the comparatively high genomic similarity between both along with on occasion, their coexistence in similar ecological niches may present the opportunity for resistance or virulence gene transfer. In this study, three multi-drug resistant L. innocua originally cultured from food were put forward for long-read genome sequencing. Chromosome and plasmid genomes were assembled and annotated. Analysis demonstrated that the resistant phenotypes correlated well with genotypes. Three plasmids pLI42, pLI203, and pLI47-1 were identified which harbor resistance islands. Sequence alignments suggested that plasmids pLI42 and pLI203 were highly similar to a previously sequenced L. monocytogenes plasmid pLR1. Similarly, another three types of resistance gene islands were observed on chromosome, including tet(M) gene islands (transposon Tn916 orthologs), dfrG gene islands and optrA-erm(A) gene islands. All three L. innocua isolates possessed listeria pathogenicity island-4 (LIPI-4) which is linked to cases of mengitis. Further genome environment and phylogenic analysis of regions flanking LIPI-4 of L. innocua and L. monocytogenes showed that these may have common origins and with the potential to transmit from the former. Our findings raise the possible need to include both L. monocytogenes and L. innocua in food surveillance programs so as to further understand of the origins of antimicrobial resistance and virulence markers of public health importance in L. monocytogenes.

Change in antimicrobial susceptibility of Listeria spp. in response to stress conditions

“…We could argue that the pathogenic species of Listeria (L. monocytogenes) shares similar morphological, biochemical, and genetic characteristics with other non-pathogenic species of Listeria (Li et al, 2021). In this regard, previous studies have reported the close genetic relationships between L. monocytogenes and L. innocua coexisted in similar ecological niches, these species shared similar Frontiers in Sustainable Systems 08 frontiersin.org plasmids and resistance/virulence genes and may horizontally transfer common genetic elements (Li et al, 2021).…”

“…Moreover, previous studies have demonstrated the ability of L. monocytogenes to resist stress during food processing and storage (Bucur et al, 2018), including tolerance to heat stress (60°C for 10 min) (Shen et al, 2014), acidic pH (pH = 3), alkaline pH (pH = 12), and saturated NaCl (Liu et al, 2005), and exposition to UV (Gayán et al, 2015). We could argue that the pathogenic species of Listeria (L. monocytogenes) shares similar morphological, biochemical, and genetic characteristics with other non-pathogenic species of Listeria (Li et al, 2021). In this regard, previous studies have reported the close genetic relationships between L. monocytogenes and L. innocua coexisted in similar ecological niches, these species shared similar Frontiers in Sustainable Systems 08 frontiersin.org plasmids and resistance/virulence genes and may horizontally transfer common genetic elements (Li et al, 2021).…”

Nanopore sequencing of human associated methicillin-resistant Staphylococcus aureus RWP1 genome for inferring antibiotic resistant gene, plasmid and prophage information

“…In a survey comprising data from 13 years from Holland, this gene, along with blaZ plasmid was present in majority of the SCCmec subtype IVc(2B) (Witteveen et al, 2022). It has also been reported from Listeria innocua (Li et al, 2021a). tet(M) with variety of integrative conjugative elements has been reported in several species other than S. aureus (Chalker et al, 2021, Marathe et al, 2021, Li et al, 2021b.…”