Come Inside

A conman’s crafty sob story might have you opening your arms, inviting him for an unwise hug, before he picks your pocket. This is the trick of Bordetella atropi, a bacteria related to whooping cough’s B. pertussis. Researchers observed the bacteria invading intestinal lining cells of nematode worms, a much-studied model system, and revealed specialised machinery called ‘type III secretion system’. It manipulates host cells to form protrusions (green in the nematode intestine pictured) that wrap around and engulf the invading bacteria (pink), welcoming it in where it can exploit the host’s hospitality. Similar systems aid invasion of Salmonella or Shigella infections, and the researchers identified a key bacterial gene essential for successful invasion, providing both new information and a new platform for future investigation on bacterial misbehaviour.

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 Tuan D. Tran and colleagues
• Department of Biology, San Diego State University, San Diego, CA, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in PLOS Pathogens, February 2026