LPS O antigen plays a key role in Klebsiella pneumoniae capsule retention
Author(s)
Type
Journal Article
Abstract
Despite the importance of encapsulation in bacterial pathogenesis, the biochemical mechanisms and forces that underpin retention of capsule by encapsulated bacteria are poorly understood. In Gram-negative bacteria, there may be interactions between lipopolysaccharide (LPS) core and capsule polymers, between capsule polymers with retained acyl carriers and the outer membrane, and in some bacteria, between the capsule polymers and Wzi, an outer membrane protein lectin. Our transposon studies in Klebsiella pneumoniae B5055 identified additional genes that, when insertionally inactivated, resulted in reduced encapsulation. Inactivation of the gene waaL, which encodes the ligase responsible for attaching the repeated O antigen of LPS to the LPS core, resulted in a significant reduction in capsule retention, measured by atomic force microscopy. This reduction in encapsulation was associated with increased sensitivity to human serum and decreased virulence in a murine model of respiratory infection and, paradoxically, with increased biofilm formation. The capsule in the WaaL mutant was physically smaller than that of the Wzi mutant of K. pneumoniae B5055. These results suggest that interactions between surface carbohydrate polymers may enhance encapsulation, a key phenotype in bacterial virulence, and provide another target for the development of antimicrobials that may avoid resistance issues associated with growth inhibition.
Editor(s)
Rendueles Garcia, Olaya
Date Issued
2022-08-01
Date Acceptance
2022-06-14
Citation
Microbiology Spectrum, 2022, 10 (4)
ISSN
2165-0497
Publisher
American Society for Microbiology
Journal / Book Title
Microbiology Spectrum
Volume
10
Issue
4
Copyright Statement
© 2022 Singh et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/35913154
Subjects
ANTIMICROBIAL RESISTANCE
ATOMIC-FORCE MICROSCOPE
BIOSYNTHESIS
capsule
CORE
encapsulation
ESCHERICHIA-COLI K-12
Klebsiella
Life Sciences & Biomedicine
LPS
Microbiology
MSBB GENE
O antigen
OUTER-MEMBRANE PROTEIN
POLYSACCHARIDES
retention
Science & Technology
VACCINE
virulence
VIRULENCE
Publication Status
Published
Coverage Spatial
United States
Article Number
e01517-21
Date Publish Online
2022-08-01