The evolution of short- and long-range weapons for bacterial competition

Sean C. Booth, William Smith, Kevin R. Foster

Research output: Contribution to journalArticlepeer-review


Bacteria possess a diverse range of mechanisms for inhibiting competitors, including bacteriocins, tailocins, type VI secretion systems and contact-dependent inhibition (CDI). Why bacteria have evolved such a wide array of weapon systems remains a mystery. Here we develop an agent-based model to compare short-range weapons that require cell–cell contact, with long-range weapons that rely on diffusion. Our model predicts that contact weapons are useful when an attacking strain is outnumbered, facilitating invasion and establishment. By contrast, ranged weapons tend to be effective only when attackers are abundant. We test our predictions with the opportunistic pathogen Pseudomonas aeruginosa, which naturally carries multiple weapons, including CDI and diffusing tailocins. As predicted, short-range CDI can function at low and high frequencies, while long-range tailocins require high frequency and cell density to function effectively. Head-to-head competition experiments with the two weapon types further support our predictions: a tailocin attacker defeats CDI only when it is numerically dominant, but then we find it can be devastating. Finally, we show that the two weapons work well together when one strain employs both. We conclude that short- and long-range weapons serve different functions and allow bacteria to fight both as individuals and as a group.
Original languageEnglish
Pages (from-to)2080-2091
Number of pages12
JournalNature Ecology & Evolution
Issue number12
Early online date30 Nov 2023
Publication statusPublished - 1 Dec 2023


  • Bacteria/metabolism
  • Bacteriocins/metabolism
  • Humans
  • Pseudomonas aeruginosa


Dive into the research topics of 'The evolution of short- and long-range weapons for bacterial competition'. Together they form a unique fingerprint.

Cite this