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The Korean Journal of Parasitology Jun 1996Twelve isolates of Acanthamoeba spp. assigned to either A. castellanii or A. polyphaga, and type strains of A. culbertsoni, A. healyi, A. palestinensis, and A....
Twelve isolates of Acanthamoeba spp. assigned to either A. castellanii or A. polyphaga, and type strains of A. culbertsoni, A. healyi, A. palestinensis, and A. astronyxis were examined by restriction fragment length polymorphism (RFLP) of a conserved region of small subunit ribosomal RNA gene (ssu rDNA) amplified by polymerase chain reaction (PCR). The PCR products of the isolates measured approximately 910-930 bp, except for that of A. astronyxis which was extraordinarily long, approximately 1,170 bp. Average of estimated sequence divergence of the amplified DNA among the isolates assigned to A. castellaii was 9.8% whereas that among the isolates assigned to A. polyphaga 9.6%. The maximum intraspecific sequence divergence among the isolates assigned to A. castellanii was observed between the Chang and Ma strains (17.3%) while that among the isolates assigned to A. polyphaga was observed between KA/S3 and KA/S7 strains (16.1%). The both maximum sequence divergences were much greater than the minimum interspecific sequence divergence between A. castellanii and A. polyphaga (2.6%) which appeared between the Castellani (or CCAP 1501/2 g) and KA/S3 strains. The PCR-RFLP patterns of A. culbertsoni, A. healyi, A. palestinensis, and A. astronyxis were quite diverse from one another and from those of isolates assigned to either A. castellanii or A. polyphaga. It is suggested that taxonomic validity of the isolates assigned to either A. castellanii or A. polyphaga should be reevaluated.
Topics: Acanthamoeba; Animals; DNA, Protozoan; DNA, Ribosomal; Phylogeny; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length
PubMed: 8925245
DOI: 10.3347/kjp.1996.34.2.127 -
Clinical and Diagnostic Laboratory... May 2000To determine whether trophozoites and lysates of pathogenic Acanthamoeba spp. induce apoptosis in primary-culture microglial cells, transmission electron microscopic...
To determine whether trophozoites and lysates of pathogenic Acanthamoeba spp. induce apoptosis in primary-culture microglial cells, transmission electron microscopic (TEM) examinations, assessment of DNA fragmentation by agarose gel electrophoresis, and the TdT-mediated dUTP nick-end labeling assay were performed. When a trophozoite of pathogenic Acanthamoeba culbertsoni came in contact with a microglial cell, the digipodium was observed by TEM. Nuclear chromatin condensation was observed in 10% of microglial cells, while it was not revealed when they were cocultured with weakly pathogenic Acanthamoeba royreba trophozoites. DNA fragmentation in microglial cells cocultured with the A. culbertsoni lysate was detected by electrophoresis, showing DNA ladder formation, whereas it was hardly observed in microglial cells cocultured with A. royreba. DNA fragmentation of microglial cells was also confirmed by flow cytometry analysis. The fluorescence of TdT-stained apoptotic bodies became intensely visible with microglial cells cocultured with the A. culbertsoni lysate. In contrast, with microglial cells cocultured with the A. royreba lysate, only a background level of fluorescence of TdT-stained apoptotic bodies was detected. These results suggest that some rat microglial cells cocultured with pathogenic A. culbertsoni undergo cytopathic changes which show the characteristics of the apoptotic process, such as nuclear condensation and DNA fragmentation.
Topics: Acanthamoeba; Amebiasis; Animals; Animals, Newborn; Apoptosis; Cells, Cultured; Cerebral Cortex; DNA, Protozoan; Flow Cytometry; In Situ Nick-End Labeling; Microglia; Microscopy, Electron; Rats; Rats, Sprague-Dawley
PubMed: 10799471
DOI: 10.1128/CDLI.7.3.510-514.2000 -
Antimicrobial Agents and Chemotherapy Jan 1984The phenothiazine compounds trifluoperazine dihydrochloride and chlorpromazine hydrochloride have in vitro activity against the pathogenic free-living amoebae Naegleria...
The phenothiazine compounds trifluoperazine dihydrochloride and chlorpromazine hydrochloride have in vitro activity against the pathogenic free-living amoebae Naegleria fowleri, Acanthamoeba culbertsoni, and Acanthamoeba polyphaga. Drug concentrations of 10 microM were amoebastatic; concentrations of 50 microM were either amoebastatic or amoebicidal. Concentrations of 100 microM were generally amoebicidal. The mechanism of drug action is unclear. It may reflect sensitivity of amoeba calcium regulatory protein to the phenothiazine compounds or may be due to the lipophilic action of the drugs on the amoeba plasma membrane. Accumulation of these drugs in the central nervous system makes them potentially useful chemotherapeutic agents in humans for treatment of amoebic meningoencephalitis caused by N. fowleri and Acanthamoeba spp.
Topics: Amebicides; Amoeba; Animals; Chlorpromazine; Germ-Free Life; Rats; Trifluoperazine
PubMed: 6703673
DOI: 10.1128/AAC.25.1.109 -
The Korean Journal of Parasitology Mar 1998The pathogenic potential of Acanthamoeba strains was evaluated by experimental infection of murine AIDS (MAIDS) model. C57BL/6 mice were induced to immunocompromized... (Comparative Study)
Comparative Study
The pathogenic potential of Acanthamoeba strains was evaluated by experimental infection of murine AIDS (MAIDS) model. C57BL/6 mice were induced to immunocompromized state by intraperitoneal injection of LP-BM5 MuLV and revealed the typical splenomegaly and lymphatic enlargement of axillar and inguinal regions on necropsy 4 weeks after viral infection. Although there was no significant difference in the mortality rate of MAIDS mouse according to the culture temperature, it was very different in the mortality rate from strain to strain of Acanthamoeba. A. healyi OC-3A strain isolated from the brain of a GAE patient showed the highest mortality rate and A. culbertsoni A-1 strain from tissue culture was the second. KA/S3 and KA/S2 strains isolated from soil revealed very low virulence. The mice infected by intranasal inoculation of Acanthamoeba showed relatively chronic course than intravenous inoculation. The gross findings of lungs and brains from infected mice were variable among mice. On the microscopic observations, the lungs showed much more severe inflammation and necrosis than the brains microscopically. This MAIDS model would be useful to study the opportunistic protozoan infections of AIDS patients. In the light of these results, the pathogenic potential and the virulence of Acanthamoeba may be determined genetically.
Topics: AIDS-Related Opportunistic Infections; Acanthamoeba; Amebiasis; Animals; Disease Models, Animal; Immunocompromised Host; Male; Mice; Mice, Inbred C57BL; Murine Acquired Immunodeficiency Syndrome; Virulence
PubMed: 9529860
DOI: 10.3347/kjp.1998.36.1.23 -
Infection and Immunity Feb 1986Human neutrophils in the presence of serum containing anti-amoeba antibody either lacked amoebicidal activity or were poorly amoebicidal for Acanthamoeba culbertsoni. In...
Human neutrophils in the presence of serum containing anti-amoeba antibody either lacked amoebicidal activity or were poorly amoebicidal for Acanthamoeba culbertsoni. In contrast, neutrophils preexposed for 1 h to supernatants from human peripheral blood mononuclear leukocytes (MNLs) stimulated with phytohemagglutinin demonstrated significant amoeba killing in the presence of serum containing anti-acanthamoeba antibodies. Supernatant from MNL cultured in the absence of phytohemagglutinin were not effective in stimulating significant activity in the neutrophils. Serum containing antibody promoted the adherence of many neutrophils to one amoeba. There was no significant difference between the ability of neutrophils treated with supernatants from stimulated MNLs (stimulated conditioned medium [sCM]) and supernatants from nonstimulated MNLs (nonstimulated conditioned medium [nsCM]) in their binding to acanthamoeba. The effects of sCM on neutrophils was a general phenomenon. For example, the sCM but not the nsCM enhanced the antibody-dependent neutrophil-mediated cytotoxicity against three tumor targets (K562 erythroid myeloid leukemia cell line, B16 melanoma, and P815 (DBA/2 mastocytoma). Furthermore, the sCM but not the nsCM increased the bactericidal (against Staphylococcus aureus and Streptococcus pneumoniae) and fungicidal (against Torulopsis glabrata) activity of the neutrophil. The sCM but not the nsCM contained activities which inhibited neutrophil migration and stimulated a respiratory burst in these leukocytes. These results suggest that the neutrophil antimicrobial power can be increased by exposing the leukocytes to MNL mediators.
Topics: Amoeba; Animals; Blood Physiological Phenomena; Cell Movement; Culture Media; Cytotoxicity, Immunologic; Humans; Leukocytes; Mice; Neoplasms; Neutrophils; Phagocytosis; Phytohemagglutinins; Rabbits; Virulence
PubMed: 3943902
DOI: 10.1128/iai.51.2.607-617.1986 -
Archives of Pathology & Laboratory... Sep 2004
Pathologic quiz case. Progressive fatal encephalopathy in an immunosuppressed patient with a history of discoid lupus erythematosus. Subacute granulomatous meningoencephalitis (Acanthamoeba culbertsoni).
Topics: Acanthamoeba; Aged; Amebiasis; Animals; Brain; Fatal Outcome; Female; Granuloma; Humans; Immunocompromised Host; Lupus Erythematosus, Discoid; Meningoencephalitis; Myelodysplastic Syndromes; Necrosis
PubMed: 15335263
DOI: 10.5858/2004-128-e109-PQC -
The Korean Journal of Parasitology Dec 1994The role of macrophages was observed in intranasally infected C3H/HeJ mice with trophozoites (3 x 10(5)) of Acanthamoeba culbertsoni which was a kind of free-living...
The role of macrophages was observed in intranasally infected C3H/HeJ mice with trophozoites (3 x 10(5)) of Acanthamoeba culbertsoni which was a kind of free-living amoebae inducing meningoencephalitis in human and experimental animals. The mortality was 60% in the group of intraperitoneally injected mice with silica (0.5 mg/0.5 ml). It was much higher than that of 10% in the group of amoeba infected mice without silica administration. The phagocytic index of peritoneal macrophages co-cultured with Toxoplasma gondii was estimated daily. In contrast to the control and amoeba infected group which didn't show significant fluctuation of the phagocytic indices, the silica administrated group revealed under 3% until day 3, and gradual increase up to 24.7% in day 5 which was same level of amoeba infected group without silica administration. The level of interleukin-1b (IL-1b) measured by ELISA was the highest in the amoeba infected group without silica injection and the lowest in the amoeba infected group with silica administration. In the test of the amoebicidal activity of mice peritoneal macrophages in vitro, silica administration revealed reducing effect on amoebicidal activity of macrophages. In conclusion, macrophages were proven to play a significant role in defense mechanism against the development of experimentally induced Acanthamoeba meningoencephalitis.
Topics: Acanthamoeba; Amebiasis; Animals; Macrophages; Meningoencephalitis; Mice; Mice, Inbred C3H; Silicon Dioxide
PubMed: 7834243
DOI: 10.3347/kjp.1994.32.4.259 -
Immunology Mar 1984The whole-killed pathogenic free-living amoeba, Naegleria fowleri, contained mitogenic activity (NFM) for mouse spleen cells. Similar preparations from the...
The whole-killed pathogenic free-living amoeba, Naegleria fowleri, contained mitogenic activity (NFM) for mouse spleen cells. Similar preparations from the non-pathogenic amoeba N. gruberi and the pathogenic Acanthamoeba culbertsoni lacked mitogenic activity. Fluids from N. fowleri cultures, containing amoeba antigens, also failed to cause proliferation of mouse spleen lymphocytes. Spleen cells from athymic nude mice failed to respond to NFM. In addition, nylon wool non-adherent, but not the adherent, spleen cell subpopulation proliferated in the presence of NFM. These results show that the factor(s) is mitogenic for T lymphocytes. The spleen cells from mice treated with cyclophosphamide doses known to deplete T suppressor cell activity from this organ failed to respond to NFM, indicating that NFM may be mitogenic for T suppressor cells.
Topics: Amoeba; Animals; B-Lymphocytes; Cell Adhesion; Cells, Cultured; Cyclophosphamide; Dose-Response Relationship, Immunologic; Leukocyte Count; Mice; Mice, Inbred BALB C; Mice, Nude; Mitogens; Mitosis; Spleen; T-Lymphocytes
PubMed: 6607875
DOI: No ID Found