Engineering probiotic Escherichia coli Nissle 1917 to block transfer of multiple antibiotic resistance genes by exploiting a type I CRISPR-Cas system

Many multidrug-resistant (MDR) bacteria have evolved through accumulation of antibiotic resistance genes (ARGs). Whereas, rates of plasmid transfer into EcN vary largely, in a range from an undetectable level to 10-1, depending on the type of mobilizable plasmid carrying ARGs, donor strain and experimental systems. We evaluated transfer of ARGs to EcN with the donor strain E. coli WM3064 carrying the RP4 conjugative system, which has an extremely wide host range and can deliver DNA to a variety of microbial organisms, especially gram-negative bacteria.