Bitter Sugar Capsule

A spoonful of sugar helps the medicine go down, but a tiny capsule of sugar seems to help bacteria infect in the first place. Researchers studying Streptococcus pyogenes, which causes disease around the world, investigated how its sugar coating, made of hyaluronic acid, promotes severe infections. They discovered that when bacteria without the capsule infected mouse nose structures (pictured, red dots - particularly top left) and skin, they were more vulnerable to attack by the immune system. The capsule appeared to initially impede entry to the host cells, but ultimately help them evade the immune system. Unencapsulated bacteria infection was only effective if immune cells called neutrophils were absent or depleted, suggesting the capsule is key to dodging these cells in particular. Understanding the importance of neutrophils, and the role the hyaluronic acid capsule plays in helping bacteria dodge them, could steer the development of new approaches to treatment.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image from work by Jacklyn R. Hurst and colleagues
• Department of Microbiology and Immunology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in PLOS Pathogens, November 2022