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Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction
05:31

Purification and Visualization of Lipopolysaccharide from Gram-negative Bacteria by Hot Aqueous-phenol Extraction

Published on: May 28, 2012

Haemophilus parainfluenzae expresses diverse lipopolysaccharide O-antigens using ABC transporter and Wzy

Rosanna E B Young1, Brigitte Twelkmeyer, Varvara Vitiazeva

  • 1Department of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London WC1E 6BT, United Kingdom; Department of Paediatrics, University of Oxford, United Kingdom(1).

International Journal of Medical Microbiology : IJMM
|September 17, 2013
PubMed

Insights

Lipopolysaccharide O-antigens were discovered in Haemophilus parainfluenzae, a common human commensal. These O-antigens enhance bacterial resistance to human serum, unlike its relative Haemophilus influenzae.

Area of Science:

  • Microbiology
  • Bacterial Pathogenesis
  • Genomics

Background:

  • Lipopolysaccharide (LPS) O-antigens are crucial for Gram-negative bacterial serotyping and host-pathogen interactions.
  • Haemophilus parainfluenzae is a human commensal that can act as an opportunistic pathogen.

Purpose of the Study:

  • To investigate the prevalence, diversity, and biosynthesis of O-antigens in Haemophilus parainfluenzae for the first time.
  • To understand the genetic basis and functional implications of O-antigen presence in this species.

Main Methods:

  • Analysis of O-antigen biosynthesis gene clusters in 18 commensal H. parainfluenzae isolates.
  • Restriction digest pattern analysis to group O-antigen loci.
  • Genomic location analysis of O-antigen ligase in isolates using the ABC transporter system.
  • In vitro assessment of bacterial resistance to human serum.

Main Results:

  • All 18 commensal H. parainfluenzae isolates possessed an O-antigen biosynthesis gene cluster.
  • Two main O-antigen biosynthesis groups were identified: one involving FucNAc4N and Wzy-dependent transport, the other galactofuranose and an ABC transporter.
  • Three isolates showed unique O-antigen predictions (ribitol phosphate or deoxytalose).
  • Isolates with ABC transporters had a separate O-antigen ligase gene.
  • O-antigen presence significantly increased resistance to human serum killing.

Conclusions:

  • Haemophilus parainfluenzae synthesizes diverse O-antigens, a feature absent in Haemophilus influenzae.
  • O-antigen expression is linked to enhanced resistance against human serum, suggesting a role in virulence or survival.
  • The genetic organization and diversity of O-antigens in H. parainfluenzae provide new insights into bacterial surface structures and host interactions.
Keywords:
Cell surfaceHost–bacterial interactionLipopolysaccharideO-antigenPasteurellaceae

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