Miss Hannah Agnew

Streptococcus pneumoniae is a commensal Gram-positive bacterium that is commonly found in the normal human microflora. However, the pneumococci can switch to cause both local (otitis media) and invasive diseases (meningitis) leading to high rates of morbidity and mortality. 

In the last 2 years, our lab has received clinical isolates of Streptococcus pneumoniae from the German National Reference Center for Streptococci (Aachen) collected in Germany over 17 years, from 2002 to 2019. These isolates were acquired from children, aged 4 months to over 6 years old, admitted to hospital with otitis media, pneumonia, sepsis and meningitis. Specifically, children with otitis media had both ear and nasopharynx isolates collected, whilst children with sepsis or meningitis had both blood and cerebral spinal fluid (CSF) isolates collected. 

These new isolates are being grouped based on clonal lineage and phenotypically characterised to determine any differences. In particular, the metabolic capabilities of the isolates are being closely examined due to research undertaken previously in the Paton lab that identified genetic differences in metabolic genes within closely related isolates from different niches, which influenced disease tropism. 

My research aims to identify metabolic differences, in vitro and in vivo, between clinical isolates of the same clonal lineage collected from different anatomical niches. Identification of these differences will elucidate the molecular mechanisms that contribute to tissue tropism, which may lead to improved vaccines and therapeutic strategies.