ExlA: A New Contributor to Pseudomonas aeruginosa Virulence

Front Cell Infect Microbiol. 2022 Jun 23:12:929150. doi: 10.3389/fcimb.2022.929150. eCollection 2022.


ExlA (also called exolysin) is a recently discovered virulence factor secreted by a subset of Pseudomonas aeruginosa strains in which a type 3 secretion system is lacking. exlA-positive strains were identified worldwide in the clinic, causing several types of infectious diseases, and were detected in various locations in the environment. ExlA possesses pore-forming activity and is cytolytic for most human cell types. It belongs to a class of poorly characterized bacterial toxins, sharing a similar protein domain organization and a common secretion pathway. This review summarizes the recent findings regarding ExlA synthesis, its secretion pathway, and its toxic behavior for host cells.

Keywords: animal models of infection; bacterial virulence factors; cadherins; inflammasome; pore-forming toxins; two-partner secretion systems.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Bacterial Toxins* / metabolism
  • Humans
  • Pseudomonas Infections* / microbiology
  • Pseudomonas aeruginosa
  • Virulence
  • Virulence Factors* / metabolism


  • Bacterial Proteins
  • Bacterial Toxins
  • Virulence Factors