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1.
Protist ; 173(3): 125870, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35489252

RESUMO

Heterolobosea is one of the major protist groups in soils. While an increasing number of soil heterolobosean species has been described, we have likely only scratched the surface of heterolobosean diversity in soils. Here, we expand this knowledge by morphologically and molecularly classifying four novel strains. One was identified as Naegleria clarki, while the remaining three strains had no identical Blast hit against GenBank and could only be reliably identified to the genus level: two strains as Allovahlkampfia spp. and one strain as Vahlkampfia sp. One Allovahlkampfia strain was most closely affiliated with Allovahlkampfia sp. Nl64 and the other strain was affiliated with 'Solumitrus' palustris, which is now named Allovahlkampfia palustris comb.nov. As there are only two valid species described within Allovahlkampfia, we combined all published sequences related to Allovahlkampfia and propose five new groups within this genus. The last strain was most closely related, but clearly distinct from, Vahlkampfia orchilla, based on DNA barcoding. As such, we propose this amoeba as a new species named Vahlkampfia bulbosis n.sp. Together, our study extends the described diversity of soil heteroloboseans through the description of a new Vahlkampfia species and by revising the morphologically and phylogenetically diverse genus Allovahlkampfia.


Assuntos
Amoeba , Naegleria , DNA Bacteriano/genética , Naegleria/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo
2.
Curr Biol ; 32(6): R269-R271, 2022 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-35349811

RESUMO

How well do we understand the range of mechanisms used by eukaryotes for mitosis? A new study in a highly divergent eukaryote shows that unusual tubulin isoforms can create a mitotic spindle exclusively out of microtubule bundles.


Assuntos
Naegleria , Microtúbulos , Mitose , Fuso Acromático , Tubulina (Proteína)/genética
3.
Metallomics ; 14(3)2022 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-35150262

RESUMO

Aerobic organisms require oxygen for respiration but must simultaneously cope with oxidative damages inherently linked with this molecule. Unicellular amoeboflagellates of the genus Naegleria, containing both free-living species and opportunistic parasites, thrive in aerobic environments. However, they are also known to maintain typical features of anaerobic organisms. Here, we describe the mechanisms of oxidative damage mitigation in Naegleria gruberi and focus on the molecular characteristics of three noncanonical proteins interacting with oxygen and its derived reactive forms. We show that this protist expresses hemerythrin, protoglobin, and an aerobic-type rubrerythrin, with spectral properties characteristic of the cofactors they bind. We provide evidence that protoglobin and hemerythrin interact with oxygen in vitro and confirm the mitochondrial localization of rubrerythrin by immunolabeling. Our proteomic analysis and immunoblotting following heavy metal treatment revealed upregulation of hemerythrin, while rotenone treatment resulted in an increase in rubrerythrin protein levels together with a vast upregulation of alternative oxidase. Our study provided new insights into the mechanisms employed by N. gruberi to cope with different types of oxidative stress and allowed us to propose specific roles for three unique and understudied proteins: hemerythrin, protoglobin, and rubrerythrin.


Assuntos
Naegleria , Hemeritrina/metabolismo , Naegleria/metabolismo , Estresse Oxidativo , Oxigênio/metabolismo , Proteômica
4.
Curr Biol ; 32(6): 1247-1261.e6, 2022 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-35139359

RESUMO

Naegleria gruberi is a unicellular eukaryote whose evolutionary distance from animals and fungi has made it useful for developing hypotheses about the last common eukaryotic ancestor. Naegleria amoebae lack a cytoplasmic microtubule cytoskeleton and assemble microtubules only during mitosis and thus represent a unique system for studying the evolution and functional specificity of mitotic tubulins and the spindles they assemble. Previous studies show that Naegleria amoebae express a divergent α-tubulin during mitosis, and we now show that Naegleria amoebae express a second mitotic α- and two mitotic ß-tubulins. The mitotic tubulins are evolutionarily divergent relative to typical α- and ß-tubulins and contain residues that suggest distinct microtubule properties. These distinct residues are conserved in mitotic tubulin homologs of the "brain-eating amoeba" Naegleria fowleri, making them potential drug targets. Using quantitative light microscopy, we find that Naegleria's mitotic spindle is a distinctive barrel-like structure built from a ring of microtubule bundles. Similar to those of other species, Naegleria's spindle is twisted, and its length increases during mitosis, suggesting that these aspects of mitosis are ancestral features. Because bundle numbers change during metaphase, we hypothesize that the initial bundles represent kinetochore fibers and secondary bundles function as bridging fibers.


Assuntos
Microtúbulos , Naegleria , Fuso Acromático , Tubulina (Proteína) , Eucariotos , Microtúbulos/química , Microtúbulos/genética , Microtúbulos/fisiologia , Mitose , Naegleria/citologia , Naegleria/genética , Fuso Acromático/química , Fuso Acromático/genética , Tubulina (Proteína)/genética
5.
J Water Health ; 19(4): 563-574, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34371494

RESUMO

The occurrence of potentially pathogenic free-living amoebae (FLA) in natural hot springs is considered a public health concern. FLAs are known to cause serious health outcomes to a wide spectrum of mammalian hosts. The present study aimed to provide the distribution of isolated cases of FLAs in hot springs through a systematic review process of available published articles online. Relevant studies are published between January 2010 and January 2020 involving the isolation of Naegleria spp., Acanthamoeba spp., Balamuthia spp., Sappinia spp., and Vermamoeba spp. in natural hot springs in the United States, South America, North America, Europe, Asia, and Africa. Articles were identified through a search of PubMed and Google Scholar databases. Out of 94 articles screened, a total of 20 articles are included in the study with consideration of established inclusion and exclusion criteria. The most common FLAs isolated in hot springs are Acanthamoeba spp. (134; 48.5%) and Naegleria spp. (127; 46.0%). Other FLAs isolated in hot springs include Balamuthia spp. (2; 0.7%) and Vermamoeba spp. (13; 4.7%). FLA in hot springs used for recreational and medical purposes is a potential source of infection. It is recommended that strict surveillance and maintenance of hot springs be implemented to prevent potential future infection.


Assuntos
Acanthamoeba , Amoeba , Fontes Termais , Naegleria , Animais , Humanos , Prevalência
6.
Nat Commun ; 12(1): 2947, 2021 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-34011950

RESUMO

The type 2 secretion system (T2SS) is present in some Gram-negative eubacteria and used to secrete proteins across the outer membrane. Here we report that certain representative heteroloboseans, jakobids, malawimonads and hemimastigotes unexpectedly possess homologues of core T2SS components. We show that at least some of them are present in mitochondria, and their behaviour in biochemical assays is consistent with the presence of a mitochondrial T2SS-derived system (miT2SS). We additionally identified 23 protein families co-occurring with miT2SS in eukaryotes. Seven of these proteins could be directly linked to the core miT2SS by functional data and/or sequence features, whereas others may represent different parts of a broader functional pathway, possibly also involving the peroxisome. Its distribution in eukaryotes and phylogenetic evidence together indicate that the miT2SS-centred pathway is an ancestral eukaryotic trait. Our findings thus have direct implications for the functional properties of the early mitochondrion.


Assuntos
Evolução Molecular , Mitocôndrias/genética , Mitocôndrias/metabolismo , Sistemas de Secreção Tipo II/genética , Sistemas de Secreção Tipo II/metabolismo , Sequência de Aminoácidos , Sequência Conservada , Eucariotos/classificação , Eucariotos/genética , Eucariotos/metabolismo , Bactérias Gram-Negativas/classificação , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/metabolismo , Proteínas Mitocondriais/classificação , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Modelos Biológicos , Modelos Moleculares , Naegleria/classificação , Naegleria/genética , Naegleria/metabolismo , Peroxissomos/metabolismo , Filogenia , Proteínas de Protozoários/classificação , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Homologia de Sequência de Aminoácidos , Sistemas de Secreção Tipo II/classificação
7.
Mol Biol Evol ; 38(8): 3170-3187, 2021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-33837778

RESUMO

The main bacterial pathway for inserting proteins into the plasma membrane relies on the signal recognition particle (SRP), composed of the Ffh protein and an associated RNA component, and the SRP-docking protein FtsY. Eukaryotes use an equivalent system of archaeal origin to deliver proteins into the endoplasmic reticulum, whereas a bacteria-derived SRP and FtsY function in the plastid. Here we report on the presence of homologs of the bacterial Ffh and FtsY proteins in various unrelated plastid-lacking unicellular eukaryotes, namely Heterolobosea, Alveida, Goniomonas, and Hemimastigophora. The monophyly of novel eukaryotic Ffh and FtsY groups, predicted mitochondrial localization experimentally confirmed for Naegleria gruberi, and a strong alphaproteobacterial affinity of the Ffh group, collectively suggest that they constitute parts of an ancestral mitochondrial signal peptide-based protein-targeting system inherited from the last eukaryotic common ancestor, but lost from the majority of extant eukaryotes. The ability of putative signal peptides, predicted in a subset of mitochondrial-encoded N. gruberi proteins, to target a reporter fluorescent protein into the endoplasmic reticulum of Trypanosoma brucei, likely through their interaction with the cytosolic SRP, provided further support for this notion. We also illustrate that known mitochondrial ribosome-interacting proteins implicated in membrane protein targeting in opisthokonts (Mba1, Mdm38, and Mrx15) are broadly conserved in eukaryotes and nonredundant with the mitochondrial SRP system. Finally, we identified a novel mitochondrial protein (MAP67) present in diverse eukaryotes and related to the signal peptide-binding domain of Ffh, which may well be a hitherto unrecognized component of the mitochondrial membrane protein-targeting machinery.


Assuntos
Proteínas de Bactérias/genética , Evolução Biológica , Proteínas de Escherichia coli/genética , Genoma Mitocondrial , Naegleria/genética , Receptores Citoplasmáticos e Nucleares/genética , Partícula de Reconhecimento de Sinal/genética , Homologia de Sequência do Ácido Nucleico
8.
Plasmid ; 115: 102567, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33617907

RESUMO

There are currently 47 characterized species in the Naegleria genus of free-living amoebae. Each amoeba has thousands of extrachromosomal elements that are closed circular structures comprised of a single ribosomal DNA (rDNA) copy and a large non-rDNA sequence. Despite the presence of putative open reading frames and introns, ribosomal RNA is the only established transcript. A single origin of DNA replication (ori) has been mapped within the non-rDNA sequence for one species (N. gruberi), a finding that strongly indicates that these episomes replicate independently of the cell's chromosomal DNA component. This article reviews that which has been published about these interesting DNA elements and by analyzing available sequence data, discusses the possibility that different phylogenetically related clusters of Naegleria species individually conserve ori structures and suggests where the rRNA promoter and termination sites may be located.


Assuntos
Naegleria , DNA Ribossômico/genética , Íntrons/genética , Naegleria/genética , Fases de Leitura Aberta , Plasmídeos
9.
J Water Health ; 18(6): 1139-1145, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33328382

RESUMO

Free-living amoebae (FLA) are ubiquitous protozoa commonly found in water and soil environments. FLA belonging to various genera, including Acanthamoeba, Balamuthia, Naegleria, and Vermamoeba, can cause opportunistic and non-opportunistic infections in humans and animals such as keratitis or meningoencephalitis. In addition, some of them serve as hosts for a large number of pathogenic bacteria, yeasts, and viruses. The purpose of the present study was to assess the prevalence and molecular characterization of FLA in well water samples in Istanbul. Ten well water samples were collected from the taps and the presence of FLA was monitored both by the culture and polymerase chain reaction methods. FLA were isolated in 8 out of the 10 samples (80%) included in this study. Morphological analysis and partial sequencing of the 18S rDNA revealed the presence of Acanthamoeba genotypes T3 and T4, and Vermamoeba vermiformis in the investigated well water samples. This study reports for the first time the detection of Acanthamoeba genotype T3 in well water samples in Istanbul. The presence of potentially pathogenic amoebae in habitats related to human activities supports the relevance of FLA as a potential public health concern.


Assuntos
Acanthamoeba , Amoeba , Naegleria , Acanthamoeba/genética , Animais , Humanos , Água , Abastecimento de Água
10.
J Cell Biol ; 219(11)2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064835

RESUMO

Arp2/3-nucleated actin filaments drive crawling motility and phagocytosis in animal cells and slime molds. In this issue, Velle and Fritz-Laylin (2020. J. Cell Biol.https://doi.org/10.1083/jcb.202007158) now show that Naegleria gruberi, belonging to a lineage that diverged from opisthokonts around a billion years ago, uses similar mechanisms to crawl and phagocytose bacteria.


Assuntos
Actinas , Naegleria , Citoesqueleto de Actina , Animais , Microtúbulos , Fagocitose
11.
J Mol Biol ; 432(23): 6157-6167, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-33065111

RESUMO

Methylation of cytosine to 5-methylcytosine (mC) is a prevalent reversible epigenetic mark in vertebrates established by DNA methyltransferases (MTases); the methylation mark can be actively erased via a multi-step demethylation mechanism involving oxidation by Ten-eleven translocation (TET) enzyme family dioxygenases, excision of the latter oxidation products by thymine DNA (TDG) or Nei-like 1 (NEIL1) glycosylases followed by base excision repair to restore the unmodified state. Here we probed the activity of the mouse TET1 (mTET1) and Naegleria gruberi TET (nTET) oxygenases with DNA substrates containing extended derivatives of the 5-methylcytosine carrying linear carbon chains and adjacent unsaturated CC bonds. We found that the nTET and mTET1 enzymes were active on modified mC residues in single-stranded and double-stranded DNA in vitro, while the extent of the reactions diminished with the size of the extended group. Iterative rounds of nTET hydroxylations of ssDNA proceeded with high stereo specificity and included not only the natural alpha position but also the adjoining carbon atom in the extended side chain. The regioselectivity of hydroxylation was broken when the reactive carbon was adjoined with an sp1 or sp2 system. We also found that NEIL1 but not TDG was active with bulky TET-oxidation products. These findings provide important insights into the mechanism of these biologically important enzymatic reactions.


Assuntos
DNA Glicosilases/genética , Metilação de DNA/genética , Proteínas de Ligação a DNA/genética , DNA/genética , Proteínas Proto-Oncogênicas/genética , 5-Metilcitosina/metabolismo , Animais , Citosina/metabolismo , DNA/metabolismo , Reparo do DNA/genética , Humanos , Hidroxilação , Camundongos , Naegleria/genética , Oxirredução
12.
EMBO J ; 39(22): e106246, 2020 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-32954513

RESUMO

Centrioles are evolutionarily conserved barrels of microtubule triplets that form the core of the centrosome and the base of the cilium. While the crucial role of the proximal region in centriole biogenesis has been well documented, its native architecture and evolutionary conservation remain relatively unexplored. Here, using cryo-electron tomography of centrioles from four evolutionarily distant species, we report on the architectural diversity of the centriole's proximal cartwheel-bearing region. Our work reveals that the cartwheel central hub is constructed from a stack of paired rings with cartwheel inner densities inside. In both Paramecium and Chlamydomonas, the repeating structural unit of the cartwheel has a periodicity of 25 nm and consists of three ring pairs, with 6 radial spokes emanating and merging into a single bundle that connects to the microtubule triplet via the D2-rod and the pinhead. Finally, we identified that the cartwheel is indirectly connected to the A-C linker through the triplet base structure extending from the pinhead. Together, our work provides unprecedented evolutionary insights into the architecture of the centriole proximal region, which underlies centriole biogenesis.


Assuntos
Centríolos/fisiologia , Centríolos/ultraestrutura , Tomografia com Microscopia Eletrônica/métodos , Centrossomo , Chlamydomonas reinhardtii/fisiologia , Cílios , Humanos , Microtúbulos , Modelos Moleculares , Naegleria/fisiologia , Paramecium tetraurellia/fisiologia
13.
J Cell Biol ; 219(11)2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32960946

RESUMO

Much of our understanding of actin-driven phenotypes in eukaryotes has come from the "yeast-to-human" opisthokont lineage and the related amoebozoa. Outside of these groups lies the genus Naegleria, which shared a common ancestor with humans >1 billion years ago and includes the "brain-eating amoeba." Unlike nearly all other known eukaryotic cells, Naegleria amoebae lack interphase microtubules; this suggests that actin alone drives phenotypes like cell crawling and phagocytosis. Naegleria therefore represents a powerful system to probe actin-driven functions in the absence of microtubules, yet surprisingly little is known about its actin cytoskeleton. Using genomic analysis, microscopy, and molecular perturbations, we show that Naegleria encodes conserved actin nucleators and builds Arp2/3-dependent lamellar protrusions. These protrusions correlate with the capacity to migrate and eat bacteria. Because human cells also use Arp2/3-dependent lamellar protrusions for motility and phagocytosis, this work supports an evolutionarily ancient origin for these processes and establishes Naegleria as a natural model system for studying microtubule-independent cytoskeletal phenotypes.


Assuntos
Citoesqueleto de Actina/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Movimento Celular , Microtúbulos/fisiologia , Naegleria/fisiologia , Fagocitose , Proteínas de Protozoários/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Animais , Proteínas de Protozoários/genética
14.
Artigo em Inglês | MEDLINE | ID: mdl-32513800

RESUMO

Primary amoebic meningoencephalitis (PAM) is a rapidly fatal infection caused by the free-living amoeba Naegleria fowleri The amoeba migrates along the olfactory nerve to the brain, resulting in seizures, coma, and, eventually, death. Previous research has shown that Naegleria gruberi, a close relative of N. fowleri, prefers lipids over glucose as an energy source. Therefore, we tested several already-approved inhibitors of fatty acid oxidation alongside the currently used drugs amphotericin B and miltefosine. Our data demonstrate that etomoxir, orlistat, perhexiline, thioridazine, and valproic acid inhibited growth of N. gruberi We then tested these compounds on N. fowleri and found etomoxir, perhexiline, and thioridazine to be effective growth inhibitors. Hence, not only are lipids the preferred food source for N. gruberi, but also oxidation of fatty acids seems to be essential for growth of N. fowleri Inhibition of fatty acid oxidation could result in new treatment options, as thioridazine inhibits N. fowleri growth in concentrations that can be reached at the site of infection. It could also potentiate currently used therapy, as checkerboard assays revealed synergy between miltefosine and etomoxir. Animal testing should be performed to confirm the added value of these inhibitors. Although the development of new drugs and randomized controlled trials for this rare disease are nearly impossible, inhibition of fatty acid oxidation seems a promising strategy as we showed effectivity of several drugs that are or have been in use and that thus could be repurposed to treat PAM in the future.


Assuntos
Infecções Protozoárias do Sistema Nervoso Central , Meningoencefalite , Naegleria fowleri , Naegleria , Anfotericina B , Animais , Ácidos Graxos
15.
Transbound Emerg Dis ; 67(6): 2389-2402, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32443167

RESUMO

Naegleria species (spp.) is a free-living amoeba whose pathogenic species such as N. fowleri pose a significant health risk to young people, and the most important source of infection is water source. This study aims to perform a systematic review and meta-analysis of the data on the prevalence of Naegleria spp. in water sources in the available literature. Included articles on the prevalence of Naegleria spp. in water sources in PubMed, Google Scholar, ProQuest, ScienceDirect, EMBASE, Scopus and Web of Science were systematically searched between January 1977 and September 2019. Regarding meta-analysis, the random-effect model was employed by forest plot with 95% of confidence interval (CI). The meta-analysis considered 103 articles surveying the prevalence of Naegleria spp. in various water sources. The pooled worldwide prevalence of Naegleria spp. across 35 countries was 26.42% (95% CI = 21.52-31.63). The subgroup analysis reported that the pooled worldwide prevalence of N. fowleri is 23.27%, N. australiensis 9.12%, N. lovaniensis 7.68%, N. pagei 5.95, N. polaris 5.17%, N. gruberi 3.95%, N. clarki 3.54%, N. americana 3.19%, N. philippinensis 1.99% and N. dobsoni 1.73%. This is the first systematic review on the prevalence of Naegleria spp. in water sources. Our findings suggest a wide distribution of Naegleria spp., including potential pathogenic species such as N. fowleri, in water sources all over the world. Therefore, it is of paramount importance to provide comprehensive data and systematic analysis regarding the prevalence of Naegleria spp. in water sources. Accordingly, further studies are highly recommended to investigate the presence of pathogenic N. fowleri in other countries.


Assuntos
Naegleria/isolamento & purificação , Água/parasitologia , Animais , Naegleria/classificação , Filogenia , Rios/parasitologia , Instalações Esportivas e Recreacionais , Piscinas , Abastecimento de Água
16.
Nucleic Acids Res ; 48(10): 5603-5615, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32315072

RESUMO

Naegleria gruberi RNA ligase (NgrRnl) exemplifies the Rnl5 family of adenosine triphosphate (ATP)-dependent polynucleotide ligases that seal 3'-OH RNA strands in the context of 3'-OH/5'-PO4 nicked duplexes. Like all classic ligases, NgrRnl forms a covalent lysyl-AMP intermediate. A two-metal mechanism of lysine adenylylation was established via a crystal structure of the NgrRnl•ATP•(Mn2+)2 Michaelis complex. Here we conducted an alanine scan of active site constituents that engage the ATP phosphates and the metal cofactors. We then determined crystal structures of ligase-defective NgrRnl-Ala mutants in complexes with ATP/Mn2+. The unexpected findings were that mutations K170A, E227A, K326A and R149A (none of which impacted overall enzyme structure) triggered adverse secondary changes in the active site entailing dislocations of the ATP phosphates, altered contacts to ATP, and variations in the numbers and positions of the metal ions that perverted the active sites into off-pathway states incompatible with lysine adenylylation. Each alanine mutation elicited a distinctive off-pathway distortion of the ligase active site. Our results illuminate a surprising plasticity of the ligase active site in its interactions with ATP and metals. More broadly, they underscore a valuable caveat when interpreting mutational data in the course of enzyme structure-function studies.


Assuntos
Alanina , Substituição de Aminoácidos , Lisina/química , RNA Ligase (ATP)/química , RNA Ligase (ATP)/genética , Monofosfato de Adenosina/química , Trifosfato de Adenosina/química , Domínio Catalítico , Lisina/metabolismo , Manganês/química , Modelos Moleculares , Naegleria/enzimologia , RNA Ligase (ATP)/metabolismo
17.
Environ Sci Pollut Res Int ; 27(19): 24568-24573, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32342421

RESUMO

Free-living amoebae (FLA) including Acanthamoeba spp., Naegleria fowleri, and Balamuthia mandrillaris are among the many waterborne parasites. There is not much known about the possible FLA contamination of the irrigation resources watering crops and agricultural lands in this country. Forty-five water samples were collected from water canals used for irrigation of farmlands and tested for the presence of pathogenic FLA using morphological and molecular-based methodology. The ITS region of Naegleria species was sequenced and a phylogenetic tree was generated to confirm the genetic associations and taxonomic status of the identified Naegleria spp. A total of seven (15.5%) samples were positive for FLA. Molecular analyses identified two strains as N. philippinensis (isolates: PW1 and PW2) isolated from irrigation treated water. One strain showed high homology with N. americana (isolate: PW3). To the best of our knowledge, the present study is the first study to isolate the two strains of N. philippinensis and N. americana from agricultural waters in Iran. The presence of the FLA in irrigation waters should be considered a potential health threat for exposed farmers and other people.


Assuntos
Naegleria , Solo , Fazendas , Irã (Geográfico) , Filogenia
18.
J Water Health ; 18(2): 244-251, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32300097

RESUMO

Free-living amoeba (FLA), including Acanthamoeba and Naegleria are facultative parasites in humans. The amoeba have widespread distribution in various water sources. The aim of this study was isolation and molecular identification of Acanthamoeba and Naegleria isolated from swimming pools and also hot and cold tub waters in Qazvin province. The samples (166 water samples) were cultured to isolate and identify positive specimens. PCR (polymerase chain reaction) amplification, sequencing and phylogenetic analysis were conducted to confirm the isolated species and genotypes of amoeba. According to morphological characterizations, 18.6% of specimens were identified as FLA, which in 71% were Acanthamoeba by PCR method. Molecular analysis revealed that 36.3%, 18.1% and 4.5% of Acanthamoeba specimens were identified as T3, T4 and T11 Acanthamoeba genotypes, respectively. Protacanthamoeba bohemica (27.2%) and Acanthamoeba sp. (4.5%) were found among the specimens. The results of osmo-tolerance and thermo-tolerance assays demonstrated that 50% of T3 and 25% of T4 genotypes of Acanthamoeba were highly pathogenic parasites. The molecular approach showed the presence of Naegleria lovaniensis (9%) in hot tub water of swimming pools. This study demonstrated that the swimming pools and hot tub water in Qazvin province were contaminated with Acanthamoeba and Naegleria species.


Assuntos
Acanthamoeba/isolamento & purificação , Naegleria/isolamento & purificação , Piscinas , Água/parasitologia , Genótipo , Irã (Geográfico) , Filogenia
19.
J Water Health ; 18(1): 60-66, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32129187

RESUMO

Free-living amoebae (FLA) include many genera which cause serious diseases such as sight-threatening keratitis, cutaneous ulcers and fatal encephalitis. This study was conducted due to the lack of research regarding genotypes Acanthamoeba, Naegleria and Vermamoeba in mineral springs of Guilan Province in northern Iran. Twenty-five water samples were collected from mineral springs in Guilan Province. After filtration through nitrocellulose membrane, samples were cultured on non-nutrient agar plates. The morphological key of Page was used to identify free-living amoebae (FLA) using an inverted microscope. Positive cultures were analyzed by polymerase chain reaction (PCR) and genotypes based on the NCBI database. Eleven (44%) samples were positive for Acanthamoeba, Naegleria and Vermamoeba. By sequencing the positive isolates, the strains were shown to belong to Acanthamoeba castellanii (three case isolates belonged to T4 genotype), three cases of Vermamoeba vermiformis, and two cases of N. australiensis, two cases of N. pagei and one case of N. gruberi. According to our research the occurrence of Acanthamoeba, Naegleria spp. and Vermamoeba spp. in mineral springs could be hazardous for high risk persons. Regular monitoring and posting warning signs of these waters by health planners could prevent free-living amoebae mediated diseases.


Assuntos
Acanthamoeba , Amoeba , Monitoramento Ambiental , Naegleria , Nascentes Naturais/parasitologia , Irã (Geográfico) , Minerais , Poluição da Água
20.
Acta Parasitol ; 65(1): 174-186, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31797194

RESUMO

PURPOSE: The main goal of this study was genotyping of free-living parasites and sub-grouping of pathogenic or non-pathogenic amebae obtained from Turkey's thermal springs. In so doing, distribution and abundance of possible pathogenic or causative strain for humans, which are caused by Acanthamoeba and Naegleria strains, would be elaborated. The number of extensive studies on the general occurrence and distribution of parasitic strains is very high worldwide, but there has been a paucity of information with regard to Turkey. METHODS: From a total of 434 obtained thermal pool samples, free-living amebas were isolated from 148 water samples using the non-nutrient agar (NNA) culture method. Subsequently, the cultivated samples were used for DNA isolation; then 102 obtained DNA samples were subjected to PCR amplification using various primers for samples of genera Acanthamoeba and Naegleria. Ultimately, estimation of genotype or subtype was evaluated by sequencing. RESULTS: About 29 samples that belong to Acanthamoeba and Naegleria were estimated from a total of 102 amplified PCR samples. These eukaryotic PCR products which have Acanthamoeba genus appearance, generated 26 subtypes and 3 Naegleria samples. Among the 26 Acanthamoeba genotypes, 22 aligned sequences were matched with various GenBank reference samples, while the 4 divergent genotypes were not elaborated and marked as ND. Most of the Acanthamoeba genera were determined as likely dominating groups and clustered as T form within totally eight groups. Eight, seven and three subtypes were found as T4A, T15 and T11 genotypes, respectively while the remainings were ultimately found in four groups. Results confirming the predominance of T4A, which is known the most causative form, the presence in the pools. Despite being uncommon, N. fowleri, lovaniensis and australiensis were also observed among the surveyed pools. CONCLUSION: The present study is descriptive and is not unique. However, this is the most comprehensive study of the molecular distribution sampling of thermophilic Acanthamoeba and Naegleria that confirmed and demonstrated their ubiquitous presence throughout Turkey. By this estimation, in some spas, the most and likely causative form Acanthamoeba including T4 and Naegleria fowleri has also been confirmed.


Assuntos
Acanthamoeba/genética , Técnicas de Genotipagem , Fontes Termais/parasitologia , Naegleria/genética , Acanthamoeba/classificação , DNA de Protozoário/genética , Genótipo , Geografia , Naegleria/classificação , Análise de Sequência de DNA , Turquia
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