Comparison between Listeria sensu stricto and Listeria sensu lato strains identifies novel determinants involved in infection

• Published in: Scientific reports 2017-12, Vol.7 (1), p.17821-14, Article 17821
• Main Authors: Schardt, Jakob, Jones, Grant, Müller-Herbst, Stefanie, Schauer, Kristina, D’Orazio, Sarah E. F., Fuchs, Thilo M.
• Format: Article
• Language: English
• Subjects: 38; 38/91; 631/326/325/2482; 631/326/421; 64; 64/60; Animals; ATP-Binding Cassette Transporters - genetics; Biodegradation; Caco-2 Cells; Cell Line, Tumor; Colonization; Energy sources; Female; Foodborne diseases; Foodborne Diseases - genetics; Foodborne Diseases - microbiology; Genomes; Humanities and Social Sciences; Humans; Infections; Listeria; Listeria monocytogenes; Listeria monocytogenes - genetics; Listeriosis; Listeriosis - genetics; Listeriosis - microbiology; Liver; Mice; Mice, Inbred BALB C; multidisciplinary; Pathogens; Science; Science (multidisciplinary); Small intestine; Virulence - genetics
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-17570-0

The human pathogen L . monocytogenes and the animal pathogen L. ivanovii , together with four other species isolated from symptom-free animals, form the “ Listeria sensu stricto ” clade. The members of the second clade, “ Listeria sensu lato ”, are believed to be solely environmental bacteria without the ability to colonize mammalian hosts. To identify novel determinants that contribute to infection by L. monocytogenes , the causative agent of the foodborne disease listeriosis, we performed a genome comparison of the two clades and found 151 candidate genes that are conserved in the Listeria sensu stricto species. Two factors were investigated further in vitro and in vivo . A mutant lacking an ATP-binding cassette transporter exhibited defective adhesion and invasion of human Caco-2 cells. Using a mouse model of foodborne L. monocytogenes infection, a reduced number of the mutant strain compared to the parental strain was observed in the small intestine and the liver. Another mutant with a defective 1,2-propanediol degradation pathway showed reduced persistence in the stool of infected mice, suggesting a role of 1,2-propanediol as a carbon and energy source of listeriae during infection. These findings reveal the relevance of novel factors for the colonization process of L. monocytogenes .