Naegleria
Mostrando 13-24 de 121 artigos, teses e dissertações.
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13. Use of an axenic medium for differentiation between pathogenic and nonpathogenic Naegleria fowleri isolates.
Growth in an axenic medium composed by Chang (3rd Int. Congr. Parasitol. Munich Abstr. ICPIII 1:187-188, 1974) allowed separation of pathogenic from nonpathogenic Naegleria fowleri strains, since only the former show luxuriant growth in this medium. On the basis of these results, this medium was used in early screening for virulent Naegleria isolates. During
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14. Inhibition of Naegleria fowleri by microbial iron-chelating agents: ecological implications.
Deferrioxamine B and rhodotorulic acid, iron-chelating agents of microbial origin, exerted a pronounced inhibitory effect on pathogenic Naegleria fowleri at microgram levels. This inhibition was diminished by adding iron to the chelators before incubation with Naegleria isolates. These and related microbial iron chelators occur naturally in the environment.
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15. Three different group I introns in the nuclear large subunit ribosomal DNA of the amoeboflagellate Naegleria.
We have amplified the large subunit ribosomal DNA (LSUrDNA) of the 12 described Naegleria spp. and of 34 other Naegleria lineages that might be distinct species. Two strains yielded a product that is longer than 3 kb, which is the length of the LSUrDNA of all described Naegleria spp. Sequencing data revealed that the insert in one of these strains is a group
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16. Effect of thermal additions on the density and distribution of thermophilic amoebae and pathogenic Naegleria fowleri in a newly created cooling lake.
Pathogenic Naegleria fowleri is the causative agent of fatal human amoebic meningoencephalitis. The protozoan is ubiquitous in nature, and its presence is enhanced by thermal additions. In this investigation, water and sediments from a newly created cooling lake were quantitatively analyzed for the presence of thermophilic amoebae, thermophilic Naegleria spp
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17. Resistance of highly pathogenic Naegleria fowleri amoebae to complement-mediated lysis.
Weakly pathogenic and nonpathogenic Naegleria spp. are readily lysed by human and guinea pig complement. Highly pathogenic Naegleria fowleri are resistant to complement-mediated lysis. Electrophoretic analysis of normal human serum (NHS) incubated with pathogenic or nonpathogenic Naegleria spp. demonstrates that amoebae activate the complement cascade, resul
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18. Loss of the ORF in the SSUrDNA group I intron of one Naegleria lineage.
We have found a Naegleria lineage in which the SSUrDNA contains a group I intron with a length of 375 nucleotides. This is a unique finding because all group I introns detected until now in Naegleria are 1.3 kilobases long and contain an open reading frame coding for 245 amino acids. Sequence data show that the 375 nucleotide-long intron is at the same place
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19. Hemin Replaces Serum as a Growth Requirement for Naegleria
Four strains of Naegleria gruberi were grown axenically without serum. Serum was replaced by hemin or two selected hemoproteins. Aside from the utility of eliminating serum from the culture medium, the present work shows that Naegleria does not require intact protein, and establishes a specific micronutrient requirement for this amoebo-flagellate.
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20. Thermal ecology of Naegleria fowleri from a power plant cooling reservoir.
The pathogenic, free-living amoeba Naegleria fowleri is the causative agent of human primary amebic meningoencephalitis. N. fowleri has been isolated from thermally elevated aquatic environments worldwide, but temperature factors associated with occurrence of the amoeba remain undefined. In this study, a newly created cooling reservoir (Clinton Lake, Illinoi
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21. In Vitro Susceptibility of Pathogenic Naegleria and Acanthamoeba Species to a Variety of Therapeutic Agents
Six pathogenic strains of Naegleria fowleri, two of Acanthamoeba castellanii, and three of Acanthamoeba polyphaga were tested in vitro for susceptibility to a variety of potentially useful therapeutic agents. Minimal motility inhibitory concentrations and minimal inhibitory concentrations were determined by a technique of subculturing pure clones of amoebae
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22. Isolation and identification of pathogenic Naegleria australiensis (Amoebida, Vahlkampfiidae) from a spa in northern Italy.
Samples from therapeutic swimming pools and mud basins were cultured for free-living amoebae. Seven strains of pathogenic Naegleria species were isolated. Although some of the strains were as virulent as Naegleria fowleri, the etiological agent of primary amoebic meningoencephalitis, they were identified as Naegleria australiensis with the indirect fluoresce
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23. In Vitro Effects of Amphotericin B on Growth and Ultrastructure of the Amoeboflagellates Naegleria gruberi and Naegleria fowleri
In vitro effects of the polyene antibiotic amphotericin B (AmB) on growth, viability, and ultrastructure of amoeboflagellates of the genus Naegleria were examined. The strains studied were the nonpathogenic Naegleria gruberi EGB and the Carter and TY strains of the pathogenic Naegleria fowleri. AmB was amoebicidal at all concentrations used (0.25, 0.50, and
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24. Specificity of antibodies from human sera for Naegleria species.
Serum samples from adult humans in North Carolina and Pennsylvania were assayed for antibodies against four Naegleria species: N. australiensis, N. fowleri, N. gruberi, and N. lovaniensis. Agglutinating activities of serum samples from North Carolina subjects were higher for N. fowleri than were those from Pennsylvania subjects. The distributions of agglutin