03.10.2022The Kümmerli group shows that loss-of-function and regulon modulation drives diversification in quorum sensing activity patterns in P. aeruginosa

See Jayakumar, Figueiredo & Kümmerli, mSystems

Pseudomonas aeruginosa uses quorum sensing (QS) to coordinate expression of traits required for growth and virulence in the context of infections. Despite its importance for bacterial fitness, the QS regulon appears to be a common mutational target during long-term adaptation of P. aeruginosa in the host, natural environments, and experimental evolutions. By examining mutation types in the three QS regulons of 61 experimentally evolved QS mutants, the Kümmerli group found that mutations involving the master regulator, LasR, resulted in an almost complete breakdown of QS, whereas mutations in RhlR and PqsR resulted in changes in regulon structure and the QS-regulated trait profile. Beyond affecting the plasticity and diversity of evolved populations, these mutations might also impact bacterial fitness and virulence during infections.