Poster Presentation BACPATH 2019

Host mobilisation of zinc in response to pneumococcal infection (#113)

Bliss A Cunningham 1 , Bart A Eijkelkamp 2 , Stephanie L Neville 1 , Aimee Tan 1 , Raquel de Vega 3 , Philip A Doble 3 , Christopher A McDevitt 1
  1. Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
  2. Molecular and Biomedical Science, University of Adelaide, Adelaide, VIC, Australia
  3. Elemental Bio-Imaging Facility, University of Technology Sydney, Sydney, VIC, Australia

Zinc deficiency is estimated to affect approximately one third of the global population. Zinc is critical for optimal host defence against infection, and consequently zinc deficiency is associated with increased morbidity and mortality for infectious diseases. Streptococcus pneumoniae (the pneumococcus) is a host-adapted pathogen and the most common cause of bacterial pneumonia in children under the age of 5 years. Bacterial pneumoniae is highly prevalent in regions that also have endemic zinc deficiency. In this study we sought to elucidate how dietary zinc deficiency could compromise host resistance to pneumococcal disease. We investigated how dietary zinc restriction in a murine model of S. pneumoniae infection impacted tissue zinc concentrations and infection kinetics. Here, we generated fluorescently labelled strains of S. pneumoniae for use in combination with elemental bio-imaging, a novel application of laser ablation-inductively coupled plasma-mass spectrometry. By combining fluorescence microscopy with elemental bio-imaging we reveal the spatial redistribution of zinc and show that it co-localised with the invading bacteria. Further, regions that were not enriched for zinc were devoid of bacteria. Taken together, these data show that the host mobilises zinc to sites of pneumococcal infection in lungs. Collectively, this approach shows how changes in the chemistry of the host environment changes can be mapped and will aid in elucidating how dietary zinc contributes to resistance against bacterial infection.