The impact of environmental conditions on the prevalence and aerosol transmission of Streptococcus pyogenes

This project will focus on genetic strains of S. pyogenes best adapted to airborne survival. This
project will utilise established techniques and develop new approaches to investigate the environmental factors which influence survival in air and use fieldwork to contextualise and inform potential enhanced outbreak control guidelines.

Objectives:
Establish CELEBS instrument in ICL category 3 laboratory and validate stability of S.
pyogenes generation, levitation and capturability
Adapt current Bioaerosol Generation Chamber to allow control of environmental
conditions (T & RH) and compare stability and culture forming potential to CELEBS
Adapt CELEBS and biological aerosol chamber to facilitate co-exposure to gaseous and
aerosol pollution sources
Investigate S. pyogenes survivability with variations in ambient concentrations of oxidising gases (NO2, O3), organic and inorganic aerosols.
Undertake field work with UKHSA to sample bioaerosols, culture and compare to
laboratory strains. Assess environmental conditions prevailing during outbreaks to
contextualise laboratory experiments.

Establishing the CELEBS instrument at Imperial will significantly enhance the
capabilities of the laboratory to assess the environmental factors that influence survivability of S. pyogenes and other airborne infectious diseases.

Furthermore, by comparing this with the established laboratory approach, and enhancing both to investigate the influence of a broader range of atmospheric factors, we hope to gain insight into the established periodicity of S. pyogenes outbreaks. This are not correlated with term times, and instead occur in springtime; this indicates a potential environmental influence.

By relating the conditions in which outbreaks occur to the laboratory investigation, there is an
opportunity to contextualise the environmental conditions and provide insight into updated
guidelines for outbreak management.