How does Haemophilus influenzae import sialic acids from the human host?

Despite advances in prevention and treatment, bacterial infections remain a global public health challenge largely due to the emergence of antibiotic resistance. Thus, there is a critical need for the identification, validation and molecular understanding of new targets for antimicrobial design. 

To combat the development of antibiotic resistance, one strategy for antimicrobial design is to specifically target virulence factors that are essential for infection. Pathogenic bacteria rely upon scavenging nutrients from their host. This requires that the nutrients be transported across the bacterial cell membrane, a semi-permeable barrier that separates the bacterial cell from its environment. Transport is a tightly controlled process, mediated by specialised transporter proteins embedded within the membrane.

As a model system, we aim to unravel how a transporter protein embedded in the membrane of Haemophilus influenzae imports a simple sugar (sialic acid) into the cell. Haemophilus influenzae is an antimicrobial resistant pathogenic bacterium responsible for a range of illnesses in Canterbury and New Zealand. An inability to import sialic acid decreases Haemophilus influenzae virulence, but the molecular details of how this transporter works are not known. By addressing this gap in our knowledge, this work delivers a molecular understanding of a bacterial virulence factor.