RT Journal Article SR Electronic(1) A1 La Rosa, Sabina Leanti A1 Montealegre, Maria Camila A1 Singh, Kavindra V. A1 Murray, Barbara E.YR 2016 T1 Enterococcus faecalis Ebp pili are important for cell-cell aggregation and intraspecies gene transfer JF Microbiology, VO 162 IS 5 SP 798 OP 802 DO https://doi.org/10.1099/mic.0.000276 PB Microbiology Society, SN 1465-2080, AB Enterococcus faecalis is an opportunistic pathogen that ranks among the leading causes of biofilm-associated infections. We previously demonstrated that the endocarditis- and biofilm-associated pili (Ebp) of E. faecalis play a major role in biofilm formation, adherence to abiotic surfaces and experimental infections. In this study, derivatives of E. faecalis strain OG1 were engineered to further characterize functions of Ebp pili. Loss of pili resulted in a 36-fold decrease in the number of closely associated cells when OG1RFΔebpABC was mixed with OG1SSpΔebpABC, compared with mixing the Ebp+ parental strains. In addition, using the Ebp+ parental strains as donor and recipient, we found a statistically significant increase (280–360 %, P < 0.05) in the frequency of plasmid transfer versus using Ebp−  mutants in the conjugation experiments. These results demonstrate a previously unrecognized role of Ebp pili, namely, as important contributors to microscale cell aggregation and horizontal spread of genetic material., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.000276