Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2022

Co-culture and cross-feeding dynamics of co-isolated clinical strains of Acinetobacter baumannii and Klebsiella pneumoniae (#123)

Catherine J Dawson 1 , Prof. Peter Lewis 2 , Dr. Lucie Semenec 3 , Prof. Ian Paulsen 3 , Dr. Amy Cain 3 , Dr. Karl Hassan 1
  1. University of Newcastle, Callaghan, New South Wales, Australia
  2. University of Wollongong, Wollongong, New South Wales, Australia
  3. Macquarie University, Macquarie Park, New South Wales, Australia

Acinetobacter baumannii (Ab) and Klebsiella pneumoniae (Kp) are, in their own right, nosocomial pathogens of great concern. Both are classified as ESKAPE pathogens due to their ability to ‘escape’ antimicrobial treatment and the increasing difficulty in treating infections caused by these species. Polymicrobial infections of Ab and Kp have been reported at rates of up to 40% of infections involving either species1. Furthermore, co-transmission between patients has been demonstrated in an Australian hospital setting2. Polymicrobial infections are associated with increased infection persistence and poorer patient outcomes. While co-infections of Ab and Kp are increasingly reported, little is known about how they may be interacting in an infection setting. Utilising a strain pair of Ab and Kp co-isolated from a single lung infection, we investigated the co-culture dynamics and potential for cross-feeding between these species. While the ratio of Ab:Kp fluctuated over time, both were stably maintained in the population3. Kp has a broader range of carbon source utilisation than Ab and it was found that Kp could cross-feed excreted metabolites of sugar fermentation to Ab3. This has implications for their co-persistence in infection and environmental settings. Developing a greater understanding of the conditions under which Ab and Kp may be dependent upon one another could allow the development of strategies that target and destabilise this interaction, potentially decreasing persistence and allowing eradication of both strains.

  1. Mammina, C. et al. Co-colonization with carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii in intensive care unit patients. Scand. J. Infect. Dis. 45, 629–634 (2013).
  2. Roberts, L. W. et al. Genomic surveillance, characterization and intervention of a polymicrobial multidrug-resistant outbreak in critical care. Microb. Genomics 7, 000530 (2021).
  3. Semenec, L. et al. Cross-protection and cross-feeding between ESKAPE pathogens Klebsiella pneumoniae and Acinetobacter baumannii promotes their co-existence. https://www.researchsquare.com (2022) doi:10.21203/rs.3.rs-1184776/v1.