Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Capsule Regulation Shapes Klebsiella pneumoniae Pathogenesis by Balancing Adhesion, Biofilm Formation, and Intracellular Survival

Guerra, Maria Eduarda Souza ; Destro, Giulia ; Cezar, Rafael Venicius ; Ciaparin, Isabelle ; Ferraz, Lúcio Fábio Caldas ; Hakansson, Anders P LU orcid ; Girardello, Raquel ; Darrieux, Michelle LU and Converso, Thiago R (2026) In International Journal of Molecular Sciences 27(5).
Abstract


Klebsiella pneumoniae is a major opportunistic pathogen, where the polysaccharide capsule is traditionally recognized as a critical virulence determinant. However, its role in surface interactions and intracellular adaptation remains incompletely understood. Here, we combined phenotypic assays with physicochemical analyses to dissect the contribution of the capsule. A
wza knockout mutant displayed enhanced biofilm formation, adhesion, and invasion of epithelial cells compared to the encapsulated strain. Zeta potential and hydrodynamic size measurements revealed that capsule absence increased surface negativity and exposure of adhesion structures, thereby promoting host-cell interactions. In contrast, intracellular survival... (More)


Klebsiella pneumoniae is a major opportunistic pathogen, where the polysaccharide capsule is traditionally recognized as a critical virulence determinant. However, its role in surface interactions and intracellular adaptation remains incompletely understood. Here, we combined phenotypic assays with physicochemical analyses to dissect the contribution of the capsule. A
wza knockout mutant displayed enhanced biofilm formation, adhesion, and invasion of epithelial cells compared to the encapsulated strain. Zeta potential and hydrodynamic size measurements revealed that capsule absence increased surface negativity and exposure of adhesion structures, thereby promoting host-cell interactions. In contrast, intracellular survival assays demonstrated that the capsule conferred a clear advantage for persistence and replication. Together, our results support a dynamic model in which capsule expression imposes a trade-off: restricting early adhesion and biofilm development but favoring long-term intracellular survival. This trade-off model expands the understanding of capsule biology and may inform novel strategies to disrupt colonization or persistence in antibiotic-resistant
K. pneumoniae.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Klebsiella pneumoniae/pathogenicity, Biofilms/growth & development, Bacterial Capsules/metabolism, Bacterial Adhesion, Humans, Klebsiella Infections/microbiology, Virulence, Epithelial Cells/microbiology, Bacterial Proteins/genetics
in
International Journal of Molecular Sciences
volume
27
issue
5
article number
2169
pages
15 pages
publisher
MDPI AG
external identifiers
  • scopus:105032707701
  • pmid:41828398
ISSN
1422-0067
DOI
10.3390/ijms27052169
language
English
LU publication?
yes
id
2bb0b401-b802-4f1e-b830-76d79b2cc0ad
date added to LUP
2026-03-16 14:47:26
date last changed
2026-05-07 04:01:08
@article{2bb0b401-b802-4f1e-b830-76d79b2cc0ad,
  abstract     = {{<p><br>
 Klebsiella pneumoniae is a major opportunistic pathogen, where the polysaccharide capsule is traditionally recognized as a critical virulence determinant. However, its role in surface interactions and intracellular adaptation remains incompletely understood. Here, we combined phenotypic assays with physicochemical analyses to dissect the contribution of the capsule. A <br>
 wza knockout mutant displayed enhanced biofilm formation, adhesion, and invasion of epithelial cells compared to the encapsulated strain. Zeta potential and hydrodynamic size measurements revealed that capsule absence increased surface negativity and exposure of adhesion structures, thereby promoting host-cell interactions. In contrast, intracellular survival assays demonstrated that the capsule conferred a clear advantage for persistence and replication. Together, our results support a dynamic model in which capsule expression imposes a trade-off: restricting early adhesion and biofilm development but favoring long-term intracellular survival. This trade-off model expands the understanding of capsule biology and may inform novel strategies to disrupt colonization or persistence in antibiotic-resistant<br>
 K. pneumoniae.<br>
 </p>}},
  author       = {{Guerra, Maria Eduarda Souza and Destro, Giulia and Cezar, Rafael Venicius and Ciaparin, Isabelle and Ferraz, Lúcio Fábio Caldas and Hakansson, Anders P and Girardello, Raquel and Darrieux, Michelle and Converso, Thiago R}},
  issn         = {{1422-0067}},
  keywords     = {{Klebsiella pneumoniae/pathogenicity; Biofilms/growth & development; Bacterial Capsules/metabolism; Bacterial Adhesion; Humans; Klebsiella Infections/microbiology; Virulence; Epithelial Cells/microbiology; Bacterial Proteins/genetics}},
  language     = {{eng}},
  month        = {{02}},
  number       = {{5}},
  publisher    = {{MDPI AG}},
  series       = {{International Journal of Molecular Sciences}},
  title        = {{Capsule Regulation Shapes Klebsiella pneumoniae Pathogenesis by Balancing Adhesion, Biofilm Formation, and Intracellular Survival}},
  url          = {{http://dx.doi.org/10.3390/ijms27052169}},
  doi          = {{10.3390/ijms27052169}},
  volume       = {{27}},
  year         = {{2026}},
}