A collaborative team of scientists, including researchers from Diamond Light Source, has conducted research revealing how Streptococcus pneumoniae selectively captures the host sugar sialic acid as soon as it is released from human cells, providing new insights into how the bacterium establishes itself in the respiratory tract.
Streptococcus pneumoniae (S. pneumoniae) is a bacterium that poses a major public health threat, causing millions of infections worldwide every year. It can cause illnesses ranging from common ear infections to serious, potentially fatal diseases such as pneumonia and meningitis. Young children, older adults and other vulnerable people are especially at risk, making S. pneumoniae a major challenge for healthcare systems, including the NHS.
The bacterium can live in the human nose and throat, but it is the lung, where S. pneumoniae often wreaks havoc. To survive there, S. pneumoniae must obtain nutrients by producing enzymes that release free sugars from the complex sugar chains coating the surface of lung cells.
One of the main sugars released is known as sialic acid, or more formally N-acetylneuraminic acid, making it one of the most important nutrients for S. pneumoniae.
Researchers from Diamond Light Source, the University of St Andrews and Goethe University have been studying a S. pneumoniae protein called SatA, which captures free-floating sialic acid and subsequently shuttles it into the bacterium like a molecular spoon. Using protein crystallography, NMR and other techniques, they have built up a detailed picture of the interaction between SatA and sialic acid.
Read more on the Diamond website
Image: Streptococcus pneumoniae