Bacterial Polysaccharide Research

Dr Johanna Kenyon, bacterial polysaccharide capsule researcher

Dr Johanna Kenyon leads the Bacterial Polysaccharide Research group at QUT. The group’s work focuses on:

  1. Understanding the role of bacterial cell surface polysaccharides in the virulence and the success of bacterial pathogens in clinical environments,
  2. Examining the genetics that govern bacterial polysaccharide synthesis, and the effects of genetic variation on polysaccharide structure,
  3. Examining the use of polysaccharide loci as epidemiological markers,
  4. Maintaining and sharing an open access database of capsular polysaccharide sequences and structures for the clinically significant pathogen, Acinetobacter baumannii.

Dr Kenyon’s work focuses largely on the clinically-significant bacterial pathogen, Acinetobacter baumannii, which is the World Health Organisation’s top critical priority pathogen for therapeutics research due to increased prevalence of strains resistant to multiple classes of antibiotics.

Genomic-structure approach to characterizing bacterial polysaccharides

One of the primary focuses for Dr Kenyon’s team is the examination of the genetics that drive polysaccharide production in Gram-negative pathogens, including critical priority pathogens such as A. baumannii. In particular, her group identifies how polysaccharide synthesis genes affect the structure on the cell surface by examining genomic data, and how these genetic differences correlate with bacteria survival in clinical environments. They collaborate with researchers at the University of Sydney, Australia, and the Russian Academy of Sciences, Moscow, Russia, to combine genome sequencing data with the resulting chemical structures for polysaccharide types identified. This enables the classification of the precise roles of enzymes required for polysaccharide synthesis.

By combining genome sequences and structural data, Dr Kenyon’s work with her collaborators has identified two novel sugars in A. baumannii capsular polysaccharides, which belong to the non-2-ulosonic acid family of complex sugars. Her team is continuing to elucidate the complex biosynthesis pathways for these rare sugars, in collaboration with Griffith University to better understand non-2-ulosonic acid synthesis for potential therapeutics and/or industrial applications.

Bacterial polysaccharides as epidemiological markers

Dr Kenyon and her team have characterized the genomic loci responsible for cell-surface polysaccharide synthesis in Acinetobacter baumannii, and developed the standard nomenclature and typing scheme for these polysaccharides. Her team continue to type the various clusters of genes at these loci, and have shown their use as effective epidemiological markers to track A. baumannii both locally and globally.

Develop an open access database of polysaccharide gene sequences

The annotated sequence data generated by Dr Kenyon and her team is currently being incorporated into an online database that will be openly accessible to the community. Her team is expanding this work to include other clinically-significant bacterial pathogens in order to enable rapid typing of genomic data.

Researchers, clinicians, public health professionals, and hospital infection control units seeking to type bacterial strains using the genomic loci involved in the synthesis of polysaccharides such as the capsule or O antigen are welcome to access the database or contact Dr Kenyon’s team for assistance.

Provide bacteria strains to the research community

The group is currently establishing a strain bank that will hold A. baumannii strains representative of each identified capsule polysaccharide type. Researchers wanting to examine specific strains, test pharmaceutical targets, or evaluate potential phage therapies can request strains by contacting Dr Kenyon. We encourage researchers to contribute to our open access strain bank.