Reassessment of the Listeria monocytogenes pan-genome reveals dynamic integration hotspots and mobile genetic elements as major components of the accessory genome

摘要: Background: Listeria monocytogenes is an important food-borne pathogen and model organism for host-pathogen interaction, thus representing invaluable target considering research on the forces governing evolution of such microbes. The diversity this species has not been exhaustively explored yet, as previous efforts have focused analyses serotypes primarily implicated in human listeriosis. We conducted complete genome sequencing 11 strains employing 454 GS FLX technology, thereby achieving full coverage all including first 1/2b, 3c, 3b, 4c, 4d, 4e. These were comparatively analyzed conjunction with publicly available data assessed pathogenicity Galleria mellonella insect model. Results: pan-genome L. highly stable but open, suggesting ability to adapt new niches by generating or genetic information. majority gene-scale differences represented accessory resulted from nine hyper variable hotspots, a similar number different prophages, three transposons (Tn916, Tn554, IS3-like), two mobilizable islands. Only subset showed CRISPR/Cas bacteriophage resistance systems subtypes, supplementary function maintenance chromosomal stability. Multiple phylogenetic branches genus imply long common histories each lineage revealed SNP-based core tree highlighting impact small mutations monocytogenes. Frequent loss truncation genes described be vital virulence was confirmed recurring pattern, especially belonging lineages III II. New candidate predicted based functional domains distribution. A comparative analysis regulatory RNA candidates supports observations differential distribution trans-encoded RNA, hinting at diverse range adaptations impact. Conclusions: This study determined commonly occurring hotspots mobile elements primary effectors quantitative monocytogenes, while gene decay SNPs seem represent major factors influencing long-term evolution. discovery disparately distributed lineages, serogroups, will assist diagnostic, research, supported genomic GECO-LisDB server (http://bioinfo.mikrobio.med.uni-giessen.de/geco2lisdb).