Toroidal displacement of Klebsiella pneumoniae by Pseudomonas aeruginosa is a unique mechanism to avoid competition for iron

TY - JOUR

T1 - Toroidal displacement of Klebsiella pneumoniae by Pseudomonas aeruginosa is a unique mechanism to avoid competition for iron

AU - Pradhan, Diana

AU - Tanwar, Ajay

AU - Wong, Joshua

AU - Parthasarathi, Srividhya

AU - Frankel, Gad

AU - Singh, Varsha

N1 - © 2025 Pradhan et al

PY - 2025/6/11

Y1 - 2025/6/11

N2 - Competition for resources is one of the major drivers for evolution and retention of new traits in microbial communities. Quorum sensing-dependent traits of the opportunistic human pathogen Pseudomonas aeruginosa allow it to survive and thrive in the presence of other microbes. Here, we report a unique mechanism that P. aeruginosa employs specifically against Klebsiella pneumoniae to displace it on solid surfaces. Interestingly, P. aeruginosa employs neither proteases nor toxic secondary metabolites against K. pneumoniae. Rhamnolipid biosurfactant under the control of the RhlR quorum sensing system appears to be the primary factor required to displace Klebsiella effectively. Under conditions of iron limitation, both bacteria produce iron-scavenging molecules, while P. aeruginosa also produces rhamnolipid biosurfactant, allowing it to push Klebsiella cells away from the substratum. Our study describes a unique quorum and iron-responsive mechanism in P. aeruginosa to support its own growth during resource competition on a solid surface.

AB - Competition for resources is one of the major drivers for evolution and retention of new traits in microbial communities. Quorum sensing-dependent traits of the opportunistic human pathogen Pseudomonas aeruginosa allow it to survive and thrive in the presence of other microbes. Here, we report a unique mechanism that P. aeruginosa employs specifically against Klebsiella pneumoniae to displace it on solid surfaces. Interestingly, P. aeruginosa employs neither proteases nor toxic secondary metabolites against K. pneumoniae. Rhamnolipid biosurfactant under the control of the RhlR quorum sensing system appears to be the primary factor required to displace Klebsiella effectively. Under conditions of iron limitation, both bacteria produce iron-scavenging molecules, while P. aeruginosa also produces rhamnolipid biosurfactant, allowing it to push Klebsiella cells away from the substratum. Our study describes a unique quorum and iron-responsive mechanism in P. aeruginosa to support its own growth during resource competition on a solid surface.

KW - Pseudomonas aeruginosa

KW - Klebsiella pneumoniae

KW - competition

KW - iron

KW - rhamnolipid

UR - https://www.scopus.com/pages/publications/105010940958

U2 - 10.1128/mbio.01149-25

DO - 10.1128/mbio.01149-25

M3 - Article

C2 - 40497729

SN - 2150-7511

VL - 16

JO - MBio

JF - MBio

IS - 7

M1 - e01149-25

ER -