title: Human intestinal cells modulate conjugational transfer of multidrug resistance plasmids between clinical Escherichia coli isolates.
abstract: Bacterial conjugation in the human gut microbiota is believed to play a major role in the dissemination of antibiotic resistance genes and virulence plasmids. However, the modulation of bacterial conjugation by the human host remains poorly understood and there is a need for controlled systems to study this process. We established an in vitro co-culture system to study the interaction between human intestinal cells and bacteria. We show that the conjugation efficiency of a plasmid encoding an extended spectrum beta-lactamase is reduced when clinical isolates of Escherichia coli are co-cultured with human intestinal cells. We show that filtered media from co-cultures contain a factor that reduces conjugation efficiency. Protease treatment of the filtered media eliminates this inhibition of conjugation. This data suggests that a peptide or protein based factor is secreted on the apical side of the intestinal cells exposed to bacteria leading to a two-fold reduction in conjugation efficiency. These results show that human gut epithelial cells can modulate bacterial conjugation and may have relevance to gene exchange in the gut.
authors: Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark.
authors: Ana Manuel Dantas
authors: AM
authors: Machado
authors: Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark; Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Hørsholm, Denmark.
authors: Morten O A
authors: MO
authors: Sommer
mesh_terms: D018938:Caco-2 Cells; D018920:Coculture Techniques; D003227:Conjugation, Genetic; D024901:Drug Resistance, Multiple, Bacterial; D004847:Epithelial Cells / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007422:Intestines / Q000166:cytology*; D010455:Peptides / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism*
chemical_list: D010455:Peptides