MICROBIOLOGY

• Free-living amoebae are ubiquitous in the environment and can be isolated worldwide from soil, air, and fresh- and saltwater.
  • Eukaryotic protozoan that shares homologies with mammalian cells.[12]
  • Other free-living amoebae include N. fowleri.
• Life cycle consists of 2 stages: the infective stage, which is a mobile trophozoite that ranges from 14-40 um in diameter, and the dormant stage, which is a double-walled, wrinkled cyst.
  • The cyst is resistant to chlorine and antibiotics. Encystation occurs under stress.
    • The minimal metabolic activity of cysts contributes to persistent infections; cysts can remain viable for decades.
  • The transition from cyst to trophozoite occurs optimally in vitro at 30°C or 86°F.[8]
• Acanthamoeba are described as “Trojan horses” because they can harbor intracellular bacteria.[14][4]
  • Treatment of intracellular bacterial endosymbionts may attenuate inflammation associated with acanthamoebae infection.[10]