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Biological Chemistry Aug 2012Although countless genomes have now been sequenced, the glycomes of the vast majority of eukaryotes still present a series of unmapped frontiers. However, strides are... (Review)
Review
Although countless genomes have now been sequenced, the glycomes of the vast majority of eukaryotes still present a series of unmapped frontiers. However, strides are being made in a few groups of invertebrate and unicellular organisms as regards their N-glycans and N-glycosylation pathways. Thereby, the traditional classification of glycan structures inevitably approaches its boundaries. Indeed, the glycomes of these organisms are rich in surprises, including a multitude of modifications of the core regions of N-glycans and unusual antennae. From the actually rather limited glycomic information we have, it is nevertheless obvious that the biotechnological, developmental and immunological relevance of these modifications, especially in insect cell lines, model organisms and parasites means that deciphering unusual glycomes is of more than just academic interest.
Topics: Amoebozoa; Animals; Carbohydrate Sequence; Chlorophyta; Glycosylation; Invertebrates; Molecular Sequence Data; Polysaccharides
PubMed: 22944671
DOI: 10.1515/hsz-2012-0150 -
Pathogens and Global Health Sep 2023FLA-related conditions are a rare medical occurrence. Despite their rarity, they are considered a public health concern for two reasons: the absence of a regular... (Review)
Review
FLA-related conditions are a rare medical occurrence. Despite their rarity, they are considered a public health concern for two reasons: the absence of a regular treatment regimen in the case of central nervous system infections and the fast progression of the symptoms leading to fatal outcomes. A total of 358 articles were retrieved from different databases (91 from PubMed, 26 from NCBI, 138 from Academia, 102 from Science Direct, and one from IJMED). 7 (46.6%) clinical cases came from Egypt, 2 (13.3%) cases of FLA infection came from Nigeria, 3 (20%) cases came from the Gambia, and 1 (6.6%) case was reported from African countries like Algeria, Tunisia, South Africa, and Zambia. Medical conditions caused by free-living amoeba are considered significant public health concerns. These ubiquitous organisms can cause both fatal and debilitating health conditions. Immediate diagnosis of cases and proper hygienic practices are necessary to provide direct medical intervention. They may be the key to reducing the morbidity and mortality rates from FLA-acquired infections. Although several government-led initiatives have been implemented to mitigate a plethora of parasitic diseases, the case of FLA-related conditions in African countries has yet to be realized.
Topics: Humans; Acanthamoeba; Amebiasis; Amoeba; Public Health; Nigeria
PubMed: 36562083
DOI: 10.1080/20477724.2022.2160890 -
Research in Microbiology Sep 2001Free-living amoebae are a diverse group of ubiquitous unicellular organisms, some of which cause severe central nervous system infections and keratitis. However, the... (Review)
Review
Free-living amoebae are a diverse group of ubiquitous unicellular organisms, some of which cause severe central nervous system infections and keratitis. However, the focus of research has shifted from the direct pathogenic effects of free-living amoebae towards their role as carriers of pathogenic bacteria. Large outbreaks of legionellosis with numerous fatal cases, both in hospitals and in the community, appear to be the visible tip of the iceberg of complex relationships between amoebae and bacteria in biofilms. The recognition of amoebae as reservoirs and vehicles for bacterial spread leads us to public health issues such as the development of pathogenicity, antibiotic resistance, quality of public water supplies, housing standards, sanitation and decontamination measures. In this review we discuss bacterial infections of free-living amoebae from both a "biological" and general "infection control" point of view.
Topics: Acanthamoeba; Amoeba; Animals; Bacteria; Symbiosis
PubMed: 11605981
DOI: 10.1016/s0923-2508(01)01240-2 -
Protist Feb 2019Plants, fungi, and some protists possess a more branched electron transport chain in their mitochondria compared to canonical one. In these organisms, the electron... (Review)
Review
Plants, fungi, and some protists possess a more branched electron transport chain in their mitochondria compared to canonical one. In these organisms, the electron transport chain contains several rotenone-insensitive NAD(P)H dehydrogenases. Some are located on the outer surface, and others are located on the inner surface of the inner mitochondrial membrane. The putative role of these enzymes still remains elusive, but they may prevent the overreduction of the electron transport chain components and decrease the production of reaction oxygen species as a consequence. The last two decades resulted in the discovery of alternative rotenone-insensitive NAD(P)H dehydrogenases present in representatives of fungi and protozoa. The aim of this review is to gather and focus on current information concerning molecular and functional properties, regulation, and the physiological role of fungal and protozoan alternative NAD(P)H dehydrogenases.
Topics: Amoebozoa; Apicomplexa; Fungal Proteins; Fungi; Mitochondrial Proteins; NADPH Dehydrogenase; Protozoan Proteins; Trypanosoma
PubMed: 30553126
DOI: 10.1016/j.protis.2018.11.001 -
Small GTPases Jan 2022Rab GTPase is a paralog-rich gene family that controls the maintenance of the eukaryotic cell compartmentalization system. Diverse eukaryotes have varying numbers of Rab...
Rab GTPase is a paralog-rich gene family that controls the maintenance of the eukaryotic cell compartmentalization system. Diverse eukaryotes have varying numbers of Rab paralogs. Currently, little is known about the evolutionary pattern of Rab GTPase in most major eukaryotic 'supergroups'. Here, we present a comprehensive phylogenetic reconstruction of the Rab GTPase gene family in the eukaryotic 'supergroup' Amoebozoa, a diverse lineage represented by unicellular and multicellular organisms. We demonstrate that Amoebozoa conserved 20 of the 23 ancestral Rab GTPases predicted to be present in the last eukaryotic common ancestor and massively expanded several 'novel' in-paralogs. Due to these 'novel' in-paralogs, the Rab family composition dramatically varies between the members of Amoebozoa; as a consequence, 'supergroup'-based studies may significantly change our current understanding of the evolution and diversity of this gene family. The high diversity of the Rab GTPase gene family in Amoebozoa makes this 'supergroup' a key lineage to study and advance our knowledge of the evolution of Rab in Eukaryotes.
Topics: Phylogeny; rab GTP-Binding Proteins; Evolution, Molecular; Amoebozoa; Eukaryota
PubMed: 33779495
DOI: 10.1080/21541248.2021.1903794 -
MBio Oct 2018Within the human host, replicates within alveolar macrophages, leading to pneumonia. However, is an aquatic generalist pathogen that replicates within a wide variety... (Review)
Review
Within the human host, replicates within alveolar macrophages, leading to pneumonia. However, is an aquatic generalist pathogen that replicates within a wide variety of protist hosts, including amoebozoa, percolozoa, and ciliophora. The intracellular lifestyles of within the two evolutionarily distant hosts macrophages and protists are remarkably similar. Coevolution with numerous protist hosts has shaped plasticity of the genome of , which harbors numerous proteins encoded by genes acquired from primitive eukaryotic hosts through interkingdom horizontal gene transfer. The Dot/Icm type IVb translocation system translocates ∼6,000 effectors among species and >320 effector proteins in into host cells to modulate a plethora of cellular processes to create proliferative niches. Since many of the effectors have likely evolved to modulate cellular processes of primitive eukaryotic hosts, it is not surprising that most of the effectors do not contribute to intracellular growth within human macrophages. Some of the effectors may modulate highly conserved eukaryotic processes, while others may target protist-specific processes that are absent in mammals. The lack of studies to determine the role of the effectors in adaptation of to various protists has hampered the progress to determine the function of most of these effectors, which are routinely studied in mouse or human macrophages. Since many protists restrict , utilization of such hosts can also be instrumental in deciphering the mechanisms of failure of to overcome restriction of certain protist hosts. Here, we review the interaction of with its permissive and restrictive protist environmental hosts and outline the accomplishments as well as gaps in our knowledge of -protist host interaction and 's evolution to become a human pathogen.
Topics: Amoebozoa; Biological Coevolution; Ciliophora; Cytoplasm; Genome, Bacterial; Host-Pathogen Interactions; Humans; Legionella pneumophila; Macrophages
PubMed: 30301851
DOI: 10.1128/mBio.01313-18 -
Genes Mar 2021Multicellularity evolved repeatedly in the history of life, but how it unfolded varies greatly between different lineages. Dictyostelid social amoebas offer a good... (Comparative Study)
Comparative Study Review
Multicellularity evolved repeatedly in the history of life, but how it unfolded varies greatly between different lineages. Dictyostelid social amoebas offer a good system to study the evolution of multicellular complexity, with a well-resolved phylogeny and molecular genetic tools being available. We compare the life cycles of the Dictyostelids with closely related amoebozoans to show that complex life cycles were already present in the unicellular common ancestor of Dictyostelids. We propose frost resistance as an early driver of multicellular evolution in Dictyostelids and show that the cell signalling pathways for differentiating spore and stalk cells evolved from that for encystation. The stalk cell differentiation program was further modified, possibly through gene duplication, to evolve a new cell type, cup cells, in Group 4 Dictyostelids. Studies in various multicellular organisms, including Dictyostelids, volvocine algae, and metazoans, suggest as a common principle in the evolution of multicellular complexity that unicellular regulatory programs for adapting to environmental change serve as "proto-cell types" for subsequent evolution of multicellular organisms. Later, new cell types could further evolve by duplicating and diversifying the "proto-cell type" gene regulatory networks.
Topics: Amoeba; Biological Evolution; Cold Temperature; Dictyostelium; Evolution, Molecular; Life Cycle Stages; Phylogeny; Signal Transduction; Stress, Physiological
PubMed: 33801615
DOI: 10.3390/genes12040487 -
The Korean Journal of Parasitology Sep 2004Acanthamoeba and Naegleria are widely distributed in fresh water, soil and dust throughout the world, and cause meningoencephalitis or keratoconjunctivitis in humans and... (Review)
Review
Acanthamoeba and Naegleria are widely distributed in fresh water, soil and dust throughout the world, and cause meningoencephalitis or keratoconjunctivitis in humans and other mammals. Korean isolates, namely, Naegleria sp. YM-1 and Acanthamoeba sp. YM-2, YM-3, YM-4, YM-5, YM-6 and YM-7, were collected from sewage, water puddles, a storage reservoir, the gills of a fresh water fish, and by corneal washing. These isolates were categorized into three groups based on the mortalities of infected mice namely, highly virulent (YM-4), moderately virulent (YM-2, YM-5 and YM-7) and nonpathogenic (YM-3). In addition, a new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Korean isolate YM-4. The morphologic characters of its cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Based on experimentally infected mouse mortality, Acanthamoeba YM-4 was highly virulent. The isoenzymes profile of Acanthamoeba YM-4 was similar to that of A. royreba. Moreover, an anti-Acanthamoeba YM-4 monoclonal antibody reacted only with Acanthamoeba YM-4, and not with A. culbertsoni. Random amplified polymorphic DNA marker analysis and RFLP analysis of mitochondrial DNA and of a 18S small subunit ribosomal RNA, placed Acanthamoeba YM-4 in a separate cluster based on phylogenic distances. Thus Acanthamoeba YM-4 was identified as a new species, and assigned Acanthamoeba sohi. Up to the year 2002 in Korea, two clinical cases were found to be infected with Acanthamoeba spp. These patients died of meningoencephalitis. In addition, one case of Acanthamoeba pneumonia with an immunodeficient status was reported and Acanthamoeba was detected in several cases of chronic relapsing corneal ulcer, chronic conjunctivitis, and keratitis.
Topics: Acanthamoeba; Amebiasis; Animals; Antigens, Protozoan; DNA, Mitochondrial; DNA, Protozoan; Korea; Life Cycle Stages; Naegleria; Phylogeny; Polymorphism, Restriction Fragment Length; Random Amplified Polymorphic DNA Technique; Virulence
PubMed: 15381859
DOI: 10.3347/kjp.2004.42.3.93 -
FEMS Microbiology Ecology Dec 2020Naegleria fowleri is a free-living protozoan that resides in soil and freshwater. Human intranasal amoebae exposure through water or potentially dust particles can... (Review)
Review
Naegleria fowleri is a free-living protozoan that resides in soil and freshwater. Human intranasal amoebae exposure through water or potentially dust particles can culminate in primary amoebic meningoencephalitis, which generally causes death. While many questions remain regarding pathogenesis, the microbial ecology of N. fowleri is even less understood. This review outlines current knowledge of the environmental abiotic and biotic factors that affect the distribution and abundance of N. fowleri. Although the impacts of some abiotic factors remain poorly investigated or inconclusive, N. fowleri appears to have a wide pH range, low salinity tolerance and thermophilic preference. From what is known about biotic factors, the amoebae preferentially feed upon bacteria and are preyed upon by other free-living amoebae. Additional laboratory and environmental studies are needed to fill in knowledge gaps, which are crucial for surveillance and management of N. fowleri in freshwaters. As surface water temperatures increase with climate change, it is likely that this amoeba will pose a greater threat to human health, suggesting that identifying its abiotic and biotic preferences is critical to mitigating this risk.
Topics: Amoeba; Central Nervous System Protozoal Infections; Fresh Water; Humans; Naegleria fowleri; Water
PubMed: 33242082
DOI: 10.1093/femsec/fiaa238 -
BMC Microbiology Dec 2022Myxomycetes are a group of eukaryotes belonging to Amoebozoa, which are characterized by a distinctive life cycle, including the plasmodium stage and fruit body stage....
BACKGROUND
Myxomycetes are a group of eukaryotes belonging to Amoebozoa, which are characterized by a distinctive life cycle, including the plasmodium stage and fruit body stage. Plasmodia are all found to be associated with bacteria. However, the information about bacteria diversity and composition in different plasmodia was limited. Therefore, this study aimed to investigate the bacterial diversity of plasmodia from different myxomycetes species and reveal the potential function of plasmodia-associated bacterial communities.
RESULTS
The bacterial communities associated with the plasmodia of six myxomycetes (Didymium iridis, Didymium squamulosum, Diderma hemisphaericum, Lepidoderma tigrinum, Fuligo leviderma, and Physarum melleum) were identified by 16S rRNA amplicon sequencing. The six plasmodia harbored 38 to 52 bacterial operational taxonomic units (OTUs) that belonged to 7 phyla, 16 classes, 23 orders, 40 families, and 53 genera. The dominant phyla were Bacteroidetes, Firmicutes, and Proteobacteria. Most OTUs were shared among the six myxomycetes, while unique bacteria in each species only accounted for a tiny proportion of the total OTUs.
CONCLUSIONS
Although each of the six myxomycetes plasmodia had different bacterial community compositions, a high similarity was observed in the plasmodia-associated bacterial communities' functional composition. The high enrichment for gram-negative (> 90%) and aerobic (> 99%) bacteria in plasmodia suggest that myxomycetes may positively recruit certain kinds of bacteria from the surrounding environment.
Topics: Humans; Myxomycetes; RNA, Ribosomal, 16S; Physarum; Bacteria; Plasmodium
PubMed: 36544088
DOI: 10.1186/s12866-022-02725-5