Free-living amoebae have gained attention for their role in pathogenicity and as reservoirs for amoeba-resistant microorganisms. These amoebae have two developmental stages: the trophozoite, a feeding and metabolically active form, and the cyst, a resting form. Some amoebae, like Naegleria spp., have an additional flagellate stage. Free-living amoebae are found worldwide and are present in soil, water, air, and the nasal mucosa of humans. Their abundance and diversity depend on environmental factors such as temperature, moisture, and nutrient availability.
Free-living amoebae feed on bacteria, fungi, and algae through phagocytosis, and some microorganisms have evolved to resist destruction by these amoebae. These "amoeba-resistant microorganisms" include bacteria, viruses, and fungi. Among the amoeba-resistant bacteria (ARB), some were recovered by amoebal coculture, while others were identified within free-living amoebae isolated by amoebal enrichment. Some ARB are obligate intracellular bacteria, while others are facultative intracellular or extracellular bacteria. Some are established human pathogens, while others are emerging pathogens or nonpathogenic species.
The study of parasites and symbionts of free-living amoebae is relatively new. The term "symbiosis" was first used in the late 18th century, but it was only in 1956 that Drozanski described the presence of an intracellular microorganism that lysed amoebae. Since then, the role of free-living amoebae in the transmission and selection of virulence traits has been studied. Free-living amoebae are important reservoirs for amoeba-resistant microorganisms and may act as Trojan horses in the transmission of these microorganisms.
Free-living amoebae are used as a tool for isolating amoeba-resistant intracellular microorganisms. The two-step strategy allows the identification and culture of several ARB, such as Odyssella thessalonicensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens (LLAP). Amoebal coculture is useful for the recovery of L. pneumophila, L. anisa, and numerous α-proteobacteria. Amoebal coculture may help in selectively growing new ARB of unknown pathogenicity.
The practical use of amoebae for ARB culture involves growing amoebae in cell culture flasks with specific media and using them to culture ARB. The amoebae are harvested, washed, and resuspended in a suitable medium. The amoebal suspension is then placed in microplates, and the sample is inoculated. The amoebae and ARB are incubated under specific conditions to promote growth and detection.
Adaptation to macrophages is important for theFree-living amoebae have gained attention for their role in pathogenicity and as reservoirs for amoeba-resistant microorganisms. These amoebae have two developmental stages: the trophozoite, a feeding and metabolically active form, and the cyst, a resting form. Some amoebae, like Naegleria spp., have an additional flagellate stage. Free-living amoebae are found worldwide and are present in soil, water, air, and the nasal mucosa of humans. Their abundance and diversity depend on environmental factors such as temperature, moisture, and nutrient availability.
Free-living amoebae feed on bacteria, fungi, and algae through phagocytosis, and some microorganisms have evolved to resist destruction by these amoebae. These "amoeba-resistant microorganisms" include bacteria, viruses, and fungi. Among the amoeba-resistant bacteria (ARB), some were recovered by amoebal coculture, while others were identified within free-living amoebae isolated by amoebal enrichment. Some ARB are obligate intracellular bacteria, while others are facultative intracellular or extracellular bacteria. Some are established human pathogens, while others are emerging pathogens or nonpathogenic species.
The study of parasites and symbionts of free-living amoebae is relatively new. The term "symbiosis" was first used in the late 18th century, but it was only in 1956 that Drozanski described the presence of an intracellular microorganism that lysed amoebae. Since then, the role of free-living amoebae in the transmission and selection of virulence traits has been studied. Free-living amoebae are important reservoirs for amoeba-resistant microorganisms and may act as Trojan horses in the transmission of these microorganisms.
Free-living amoebae are used as a tool for isolating amoeba-resistant intracellular microorganisms. The two-step strategy allows the identification and culture of several ARB, such as Odyssella thessalonicensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens (LLAP). Amoebal coculture is useful for the recovery of L. pneumophila, L. anisa, and numerous α-proteobacteria. Amoebal coculture may help in selectively growing new ARB of unknown pathogenicity.
The practical use of amoebae for ARB culture involves growing amoebae in cell culture flasks with specific media and using them to culture ARB. The amoebae are harvested, washed, and resuspended in a suitable medium. The amoebal suspension is then placed in microplates, and the sample is inoculated. The amoebae and ARB are incubated under specific conditions to promote growth and detection.
Adaptation to macrophages is important for the