Summary Pseudomonas aeruginosa is an environmental microorganism and a causative agent of diverse acute and chronic, biofilm‐associated infections. Advancing research‐based knowledge on its adaptation to conditions within the human host is bound to reveal novel strategies and targets for therapeutic intervention. Here, we investigated the traits that P. aeruginosa PA14 as well as a virulence attenuated Δ lasR mutant need to su...

Summary The type VI secretion system (T6SS) is a bacterial nanomachine used to inject effectors into prokaryotic or eukaryotic cells and is thus involved in both host manipulation and interbacterial competition. The T6SS is widespread among Gram‐negative bacteria, mostly within the Proteobacterium Phylum. This secretion system is commonly found in commensal and pathogenic plant‐associated bacteria. Phylogenetic analysis of phy...

Summary The second messenger cyclic di‐ GMP (c‐di‐ GMP ) controls the transition between different lifestyles in bacterial pathogens. Here, we report the identification of D gc P (diguanylate cyclase conserved in P seudomonads), whose activity in the olive tree pathogen P seudomonas savastanoi pv. savastanoi is dependent on the integrity of its GGDEF domain. Furthermore, deletion of the dgc P gene revealed that D gc P negative...

Summary Acute bacterial infections are associated with motility and cytotoxicity via the type III secretion system (T3SS), while chronic infections are linked to biofilm formation and reduced virulence. In Pseudomonas aeruginosa , the transition between motility and sessility involves regulatory networks including the RetS/GacS sensors, as well as the second messenger c‐di‐GMP. The RetS/GacS signalling cascade converges on sma...

Summary Biofilm formation in P. aeruginosa is a highly regulated process that proceeds through a number of distinct stages. This development is controlled by a wide range of factors, of which two‐component systems (TCSs) play a key role. In this review, we focus on some of the TCSs that regulate the switch from a motile to a sessile bacterial lifestyle, either via the production of extracellular appendages or by the production...

Summary The opportunistic pathogen Pseudomonas aeruginosa has redundant molecular systems that contribute to its pathogenicity. Those assembling fimbrial structures promote complex organized community lifestyle. We characterized a new 5.8 kb genetic locus, cupE , that includes the conserved usher‐ and chaperone‐encoding genes. This locus, widely conserved in different bacterial species, contains four additional genes encoding...

Summary We discovered a novel secreted protein by Pseudomonas aeruginosa , PlpD, as a member of the bacterial lipolytic enzyme family of patatin‐like proteins (PLPs). PlpD is synthesized as a single molecule consisting of a secreted domain fused to a transporter domain. The N‐terminus of PlpD includes a classical signal peptide followed by the four PLP conserved blocks that account for its lipase activity. The C‐terminus consi...

Summary Bacterial two‐component regulatory systems (TCSs) sense environmental stimuli to adapt the lifestyle of microbial populations. For many TCSs the stimulus is a ligand of unknown chemical nature. Pseudomonas aeruginosa utilizes the closely related RetS and LadS sensor kinases to switch between acute and chronic infections. These sensor proteins antagonistically mediate biofilm formation through communication with a centr...