Gut inflammation can boost horizontal gene transfer between pathogenic and commensal Enterobacteriaceae.

TitleGut inflammation can boost horizontal gene transfer between pathogenic and commensal Enterobacteriaceae.
Publication TypeJournal Article
Year of Publication2012
AuthorsStecher, B, Denzler, R, Maier, L, Bernet, F, Sanders, MJ, Pickard, DJ, Barthel, M, Westendorf, AM, Krogfelt, KA, Walker, AW, Ackermann, M, Dobrindt, U, Thomson, NR, Hardt, W-D
JournalProc Natl Acad Sci U S A
Date Published2012 Jan 24
KeywordsAnimals, Bacteriocin Plasmids, Base Sequence, Biological Evolution, Colitis, Computational Biology, DNA Primers, Enterobacteriaceae, Escherichia coli, Gene Transfer, Horizontal, Mice, Molecular Sequence Data, Oligonucleotide Array Sequence Analysis, Phylogeny, RNA, Ribosomal, 16S, Salmonella typhimurium, Sequence Alignment, Sequence Analysis, DNA

The mammalian gut harbors a dense microbial community interacting in multiple ways, including horizontal gene transfer (HGT). Pangenome analyses established particularly high levels of genetic flux between Gram-negative Enterobacteriaceae. However, the mechanisms fostering intraenterobacterial HGT are incompletely understood. Using a mouse colitis model, we found that Salmonella-inflicted enteropathy elicits parallel blooms of the pathogen and of resident commensal Escherichia coli. These blooms boosted conjugative HGT of the colicin-plasmid p2 from Salmonella enterica serovar Typhimurium to E. coli. Transconjugation efficiencies of ~100% in vivo were attributable to high intrinsic p2-transfer rates. Plasmid-encoded fitness benefits contributed little. Under normal conditions, HGT was blocked by the commensal microbiota inhibiting contact-dependent conjugation between Enterobacteriaceae. Our data show that pathogen-driven inflammatory responses in the gut can generate transient enterobacterial blooms in which conjugative transfer occurs at unprecedented rates. These blooms may favor reassortment of plasmid-encoded genes between pathogens and commensals fostering the spread of fitness-, virulence-, and antibiotic-resistance determinants.

Alternate JournalProc. Natl. Acad. Sci. U.S.A.