10 July 10, 2008 Another example: Cooperation and conflict in quorum-sensing bacterial populations, S.P.West et al., Nature 450 (2007) 411 Pseudomonas aeruginosa (QS controls biofilm development, swarming and motility, production of virulence factor, …) Focus on the las QS pathway, which controls the rhl system Mutation in las QS results in a general abolition of QS in P.