Under Siege

Most antibiotics tackle bacterial infections by interfering with their living processes. But many bacteria are resistant to common antibiotics, including disease-causing Pseudomonas aeruginosa (P. aeruginosa). Here, researchers find a new weakness. Rendered on a computer from an earlier cryo-electron microscopy scan, we see P. aeruginosa‘s cell membrane (shown in shades of blue) which usually protects its fragile machinery. Like siege warfare (but around a billion times smaller) researchers deploy a class of antibiotics called pyocins which can kill bacteria from outside. Pyocins attach to a protein on the surface called BamA, blocking a vital transport channel through the membrane. Without the Bam complex, the cell can’t bring in certain nutrients or expel waste. Despite creating defensive proteins (orange), eventually Pseudomonas aeruginosa dies, suggesting pyocins as a useful weapon in the war against otherwise-resistant bacteria.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

Website

• Video from work by Fabian Munder and colleagues
• Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
• Video originally published with a Creative Commons Attribution – NonCommercial – NoDerivs (CC BY-NC-ND 4.0)
• Published in Nature Communications, July 2026