Acanthamoebadifferentiation: a two-faced drama ofDr Jekyll and Mr Hyde

Abstract

<jats:title>SUMMARY</jats:title><jats:p>The ability of cyst-forming protists such as<jats:italic>Acanthamoeba</jats:italic>to escape death by transforming into a cyst form, that is resistant to harsh physiological, environmental and pharmacological conditions, has continued to pose a serious challenge to human and animal health. A complete understanding of the fundamental principles of genome evolution and biochemical pathways of cellular differentiation offers unprecedented opportunities to counter detrimental outcomes.<jats:italic>Acanthamoeba</jats:italic>can elude inhospitable conditions by forming cysts. Here we unravel the processes involved in the phenotypic switching of<jats:italic>Acanthamoeba</jats:italic>, which are critical in our efforts to find potential targets for chemotherapy.</jats:p>

Acanthamoeba and Dictyostelium Use Different Foraging Strategies

“…Dictyostelium is a social organism that can form multicellular aggregates when starved and these aggregates undergo an elaborate developmental program to produce a fruiting body with spores that can remain dormant in the absence of nutrients (Loomis 1982). In contrast, starved Acanthamoeba form solitary cysts that allow survival in nutrient poor conditions (Khan 2006; Siddiqui et al 2012). The formation of dormant spores and cysts are developmental fates for these amoebae if the foraging efforts fail and therefore foraging and dormancy are likely to be tightly regulated with respect to each other.…”

Biological characteristics and pathogenicity of Acanthamoeba

“…In general, the life cycle of Acanthamoeba consists of two stages, trophozoite and cyst ( Marciano-Cabral and Cabral, 2003 ; Siddiqui and Khan, 2012 ; Siddiqui et al, 2012 ), except for Acanthamoeba pyriformis, which is recognized to include facultative sporocarp fruiting in its life cycle ( Tice et al, 2016 ). The trophozoite stage dominates when the growth conditions are suitable, such as abundant food supply, neutral pH, appropriate temperature (i.e., 30°C) and osmolarity between 50 and 80 mOsmol ( Siddiqui et al, 2012 ). The cell cycle of Acanthamoeba consists of growth and replication, which is carried out through mitosis under optimal living conditions ( Band et al, 1970 ; Byers et al, 1991 ; Quinet et al, 2020 ).…”

Applications of medicinal chemistry for drug discovery against Acanthamoeba infections

“…But compound 63 has cysticidal activity against different strains of Acanthamoeba . This activity is due to the inhibition of ergosterol synthesis and it is the most important component in cell membrane of Acanthamoeba 25,132,133 …”

“…This activity is due to the inhibition of ergosterol synthesis and it is the most important component in cell membrane of Acanthamoeba. 25,132,133 5.24 | Thioureidic derivatives Saturnino et al, 96 synthesised a large number of thioureidic derivatives. For evaluating the antiamoebic properties of these compounds, all compounds were tested against three species of Acanthamoeba a causative agent of AK.…”

“…20,21 During the trophozoite stage (Figure 1), Acanthamoeba feeds on small protists, fungi, viruses as well as other microbes and divides mitotically under optimal conditions. [22][23][24] Exposure to the harsh conditions, such as lack of food, hyper-or hypo-osmolarity and extreme pH or temperature, results in the cellular differentiation into a doublewalled cyst form 25 as shown in Figure 1. Acanthamoeba cysts can survive in vitro for more than 20 years.…”