Novel intermicrobial molecular interaction: Pseudomonas aeruginosa Quinolone Signal (PQS) modulates Aspergillus fumigatus response to iron.

Novel intermicrobial molecular interaction: Pseudomonas aeruginosa Quinolone Signal (PQS) modulates Aspergillus fumigatus response to iron. Microbiology. 2019 Nov 28;: Authors: Nazik H, Sass G, Ansari SR, Ertekin R, Haas H, Déziel E, Stevens DA Abstract Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af), the commonest bacterium and fungus in compromised host airways, compete for iron (Fe). The Pseudomonas quinolone signal (PQS), a Pa quorum sensing molecule, also chelates Fe, and delivers Fe to the Pa cell membrane using Pa siderophores. In models of Af biofilm formation or preformed biofilms, PQS inhibited Af in a low Fe environment. AfΔsidA (mutant unable to produce siderophores) biofilm was more sensitive to PQS inhibition than wild-type (WT), as was planktonic AfΔsidA growth. PQS decreased WT Af growth on agar. All these inhibitory actions were reversed by Fe. The Pa siderophore pyoverdin, or Af siderophore inhibitor celastrol, act cooperatively with PQS in Af inhibition. These findings all indicate PQS inhibition is owing to Fe chelation. Remarkably, in high Fe environments, PQS enhanced Af biofilm at 1/100 to 1/2000 Fe concentration required for Fe alone to enhance. Planktonic Af growth, and on agar, Af conidiation, were also enhanced by PQS+Fe compared to Fe alone. In contrast, neither AfΔsidA biofilm, nor planktonic AfΔsidA, were enhanced by PQS-Fe compared to Fe. When Af siderophore ferricrocin (FC),+PQS, were a...
Source: Microbiology - Category: Microbiology Authors: Tags: Microbiology Source Type: research