Genome Modification in Enterococcus faecalis OG1RF Assessed by Bisulfite Sequencing and Single-Molecule Real-Time Sequencing.

The horizontal transfer of antibiotic resistance genes among bacteria is a critical public health concern. Enterococcus faecalis is an opportunistic pathogen that causes life-threatening infections in humans. Multidrug resistance acquired by horizontal gene transfer limits treatment options for these infections. In this study, we used innovative DNA sequencing methodologies to investigate how a model strain of E. faecalis discriminates its own DNA from foreign DNA, i.e., self versus nonself discrimination. We also assess the role of an E. faecalis genome modification system in modulating conjugative transfer of an antibiotic resistance plasmid. These results are significant because they demonstrate that differential genome modification impacts horizontal gene transfer frequencies in E. faecalis.