Poster Presentation Australian Microbial Ecology 2022

Metabolic diversity of the Klebsiella pnuemoniae Species Complex (#150)

Ben Vezina 1 , Helena B Cooper 1 , Sylvain Brisse 2 , Jonathan M Monk 3 4 , Kathryn E Holt 5 , Kelly L Wyres 1
  1. Infectious Diseases, Monash University, Melbourne, VIC, Australia
  2. Biodiversity and Epidemiology of Bacterial Pathogens, Institut Pasteur, Paris, Franc
  3. Department of Medicine, University of California, San Diego School of Medicine, San Diego, United States of America
  4. The Mitochondrial and Metabolic Disease Centre, San Diego School of Medicine, University of California, San Diego, United States of America
  5. London School of Hygiene & Tropical Medicine, London, UK

The Klebsiella pneumoniae Species Complex (KpSC) is a group of highly related species with a diverse gene pool. Many KpSC lineages are problematic, carrying antimicrobial resistance genes, virulence factors, or both, representing a significant global health burden. The diverse gene pool of the KpSC may help explain their cosmopolitan distribution, as they are found across a wide variety of environments and hosts. Understanding the metabolic genes and requirements of the KpSC at the population level could help explain this global distribution and provide insight into speciation and infection pathways.

7882 publicly available genomes from the KpSC were utilised. These were isolated from a wide variety of sources (human, animal, environmental) to evaluate the distribution and diversity of metabolism. We performed novel analyses including quantitative Clusters of Orthologous Genes (qCOG), and quantitative Gene Ontology (qGO), as well as KEGG pathway analysis. Strain-specific genome scale metabolic models were generated, then growth was simulated across 946 conditions, using substrates as sole carbon, nitrogen, phosphorus and sulfur sources. Species- and lineage- specific core and accessory metabolic traits were identified. Notably, qCOG analysis highlighted previously undescribed differing macromolecule metabolic strategies between KpSC species. Significant differences were found between species and the proportion of metabolic genes associated with macromolecules: K. pneumoniae devotes more of its genome to carbohydrate metabolism, while K. quasipneumoniae dedicates more to lipid metabolism, and K. variicola devotes a greater proportion to amino acid metabolism. qGO results showed K. pneumoniae, K. quasivariicola and K. africana can also be distinguished from the remainder of the KpSC by the absence of nitrogen fixation and nitrogenase enzymes among their sets of core metabolic traits.

Our data support the hypothesis that reduction in nutrient overlap reduces inter-species competition and allows wider dissemination of KpSC across environments.