Free-living amoebae: what part do they play in healthcare-associated infections?

J Hosp Infect. 2014 Jul;87(3):131-40. doi: 10.1016/j.jhin.2014.05.001. Epub 2014 May 19.


Free-living amoebae (FLA) are ubiquitous protozoa that do not require a host organism for survival. They are found in natural environments such as water or soil, and man-made environments including tap water or swimming pools, where they may interact with other micro-organisms, including bacteria, fungi and viruses. FLA can harbour micro-organisms including those found in hospital water systems, offering them protection against hostile conditions, providing a vehicle of dissemination, and enabling them to prepare for subsequent survival in macrophages. The interaction between Legionella pneumophila and FLA has been studied extensively; subsequent investigations have shown that FLA may serve as a reservoir for other bacteria including mycobacteria, Pseudomonas aeruginosa, Acinetobacter baumannii, or even fungi and viruses. Amoebae found in hospital water systems can serve as a reservoir of potential pathogens and thus be indirectly related to healthcare-associated infections.

Keywords: Free-living amoebae; Healthcare-associated infections; Interactions; Micro-organisms; Water.

Publication types

  • Review

MeSH terms

  • Acinetobacter baumannii / isolation & purification
  • Amoeba / isolation & purification*
  • Amoeba / microbiology*
  • Bacterial Infections / epidemiology*
  • Bacterial Infections / microbiology*
  • Cross Infection / epidemiology*
  • Cross Infection / microbiology*
  • Humans
  • Legionella pneumophila / isolation & purification
  • Mycobacterium / isolation & purification
  • Pseudomonas aeruginosa / isolation & purification
  • Water Microbiology