RT Journal Article SR Electronic T1 RecA levels modulate biofilm development in Acinetobacter baumannii JF bioRxiv FD Cold Spring Harbor Laboratory SP 809392 DO 10.1101/809392 A1 Carly Ching A1 Paul Muller A1 Merlin Brychcy A1 Alicyn Reverdy A1 Brian Nguyen A1 Margaret Downs A1 Samuel Regan A1 Breanna Isley A1 William Fowle A1 Yunrong Chai A1 Veronica G. Godoy YR 2020 UL http://biorxiv.org/content/early/2020/09/05/809392.abstract AB Infections caused by Acinetobacter baumannii, a Gram-negative opportunistic pathogen, are difficult to eradicate due to the bacterium’s propensity to quickly gain antibiotic resistances and form protective bacterial multicellular communities known as biofilms. The A. baumannii DNA damage response (DDR) mediates antibiotic resistance acquisition and regulates RecA in an atypical fashion; both RecALow and RecAHigh cell types are formed in response to DNA damage. In this study, we show that RecA levels modulate biofilm development, formation and dispersal, through bfmR, the global biofilm regulator. RecA loss results in surface attachment and prominent biofilms while elevated RecA leads to diminished attachment and dispersal. Recalcitrance to treatment may be explained by DDR induction, common during infection, and the balance between biofilm maintenance in low RecA cells, and increased mutagenesis and dispersal to reach new niches in high RecA cells. These data highlight the importance of understanding fundamental biology to better treat bacterial infections.Impact The mechanism of biofilm formation and dispersal in A. baumannii, shown here to depend on RecA levels, contributes to the understanding of recalcitrant infections caused by this important pathogen.Competing Interest StatementThe authors have declared no competing interest.