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The Korean Journal of Parasitology Jun 1998Subgenus classification of Acanthamoeba remains uncertain. Twenty-three reference strains of Acanthamoeba including 18 (neo)type-strains were subjected for...
Subgenus classification of Acanthamoeba remains uncertain. Twenty-three reference strains of Acanthamoeba including 18 (neo)type-strains were subjected for classification at the subgenus level by riboprinting. PCR/RFLP analysis of 18S rRNA gene (rDNA). On the dendrogram reconstructed on the basis of riboprint analyses, two type-strains (A. astronyxis and A. tubiashi) of morphological group 1 diverged early from the other strains and were quite distinct from each other. Four type-strains of morphological group 3, A. culbertsoni, A. palestinensis, A. healyi were considered taxonomically valid, but A. pustulosa was regarded as an invalid synonym of A. palestinensis. Strains of morphological group 2 were classified into 6 subgroups. Among them, A. griffini which has an intron in its 18S rDNA was the most divergent from the remaining strains. Acanthamoeba castellanii Castellani, A. quina Vil3, A. lugdunensis L3a, A. polyphaga Jones, A. triangularis SH621, and A. castellanii Ma strains belonged to a subgroup, A. castellanii complex. However, A. quina and A. lugdunensis were regarded as synonyms of A. castellanii. The Chang strain could be regarded as A. hatchetti. Acanthamoeba mauritaniensis, A. divionensis, A. paradivionensis could be considered as synonyms of A. rhysodes. Neff strain was regarded as A. polyphaga rather than as A. castellanii. It is likely that riboprinting can be applied for rapid identification of Acanthamoeba isolated from the clinical specimens and environments.
Topics: Acanthamoeba; Animals; DNA, Protozoan; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; RNA, Protozoan; RNA, Ribosomal, 18S
PubMed: 9637824
DOI: 10.3347/kjp.1998.36.2.69 -
The British Journal of Ophthalmology Feb 2002Contact lens cases contaminated with Acanthamoeba are a major risk factor for an infection of the eye. In this study the anti-Acanthamoeba activity of three different... (Comparative Study)
Comparative Study
BACKGROUND/AIM
Contact lens cases contaminated with Acanthamoeba are a major risk factor for an infection of the eye. In this study the anti-Acanthamoeba activity of three different contact lens storage solutions was tested.
METHODS
A new multipurpose contact lens storage solution (Meni Care Plus) and a two step (Titmus H(2)O(2)) and one step (Oxysept Comfort) hydrogen peroxide system were tested for their effects on trophozoites and cysts of three different Acanthamoeba species: A castellanii, A hatchetti, and A lenticulata.
RESULTS
After a soaking time of 8 hours (overnight soaking of contact lenses) the Titmus H(2)O(2) 0.6% solution showed very good amoebicidal effects, while Oxysept Comfort 3% H(2)O(2) could not effectively destroy the cysts of any of the three tested species. Viable cysts of the species A lenticulata and A hatchetti were still present after exposure to Meni Care Plus (0.0005% PHMB) for 8 hours.
CONCLUSION
Not all of the three tested contact lens storage solutions have sufficient amoebicidal effects. The two step peroxide system Titmus H(2)O(2) is a very effective disinfectant contact lens solution in order to avoid a possible Acanthamoeba infection of the eye.
Topics: Acanthamoeba; Animals; Biguanides; Contact Lens Solutions; Disinfectants; Disinfection; Equipment Contamination; Humans; Hydrogen Peroxide
PubMed: 11815336
DOI: 10.1136/bjo.86.2.144 -
The Korean Journal of Parasitology Sep 1999We investigated the value of mitochondrial small subunit rRNA gene (mt SSU rDNA) PCR-RFLP as a taxonomic tool for Acanthamoeba isolates with close inter-relationships....
We investigated the value of mitochondrial small subunit rRNA gene (mt SSU rDNA) PCR-RFLP as a taxonomic tool for Acanthamoeba isolates with close inter-relationships. Twenty-five isolates representing 20 species were included in the analysis. As in nuclear 18S rDNA analysis, two type strains (A. astronyxis and A. tubiashi) of morphological group 1 diverged earliest from the other strains, but the divergence between them was less than in 18S riboprinting. Acanthamoeba griffini of morphological group 2 branched between pathogenic (A. culbertsoni A-1 and A. healyi OC-3A) and nonpathogenic (A. palestinensis Reich, A. pustulosa GE-3a, A. royreba Oak Ridge, and A lenticulata PD2S) strains of morphological group 3. Among the remaining isolates of morphological group 2, the Chang strain had the identical mitochondrial riboprints as the type strain of A. hatchetti. AA2 and AA1, the type strains of A. divionensis and A. paradivionensis, respectively, had the identical riboprints as A. quina Vil3 and A. castellanii Ma. Although the branching orders of A. castellanii Neff, A. polyphaga P23, A. triangularis SH621, and A. lugdunensis L3a were different from those in 18S riboprinting analysis, the results obtained from this study generally coincided well with those from 18S riboprinting. Mitochondrial riboprinting may have an advantage over nuclear 18S rDNA riboprinting because the mt SSU rDNAs do not seem to have introns that are found in the 18S genes of Acanthamoeba and that distort phylogenetic analyses.
Topics: Acanthamoeba; Animals; DNA, Mitochondrial; DNA, Protozoan; DNA, Ribosomal; Phylogeny; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length
PubMed: 10507226
DOI: 10.3347/kjp.1999.37.3.181 -
The Korean Journal of Parasitology Jun 1999To determine the pathogenicity of Acanthamoeba spp. isolated in Korea and to develop a isoenzymatic maker, the mortality rate of infected mice, in vitro cytotoxicity...
To determine the pathogenicity of Acanthamoeba spp. isolated in Korea and to develop a isoenzymatic maker, the mortality rate of infected mice, in vitro cytotoxicity against target cells and isoenzyme band patterns were observed. Five isolates of Acanthamoeba spp. (YM-2, YM-3, YM-4, YM-5, and YM-7) were used in this study as well as three reference Acanthamoeba spp. (A. culbertsoni, A. hatchetti, and A. royreba). According to the mortality rate of infected mice, Korean isolates could be categorized into three groups high virulent (YM-4), low virulent (YM-2, YM-5, YM-7) and the nonpathogenic group (YM-3). In addition, the virulence of Acanthamoeba spp. was enhanced by brain passage in mice. In the cytotoxicity assay against chinese hamster ovary cells, especially, the cytotoxicity of brain-passaged amoebae was relatively higher than the long-term cultivated ones. The zymodeme patterns of glucose-6-phosphate dehydrogenase (G6PD), malate dehydrogenase (MDH), hexokinase (HK), glutamate oxaloacetate transaminase (GOT) and malic enzyme (ME) of Acanthamoeba spp. were different among each isolate, and also between long-term cultured amoebae and brain passaged ones. In spite of the polymorphic zymodemes, a slow band of G6PD and HK, and an intermediate band of MDH were only observed in pathogenic Acanthamoeba spp., which should be used as isoenzymatic makers.
Topics: Acanthamoeba; Amebiasis; Animals; Aspartate Aminotransferases; CHO Cells; Cricetinae; Glucosephosphate Dehydrogenase; Hexokinase; Isoenzymes; Korea; Malate Dehydrogenase; Mice; Mice, Inbred ICR; Virulence
PubMed: 10388266
DOI: 10.3347/kjp.1999.37.2.85 -
Journal of Clinical Microbiology Nov 2000Eighteen cases of Acanthamoeba-associated keratitis among contact lens wearers seen at the Department of Ophthalmology, Karl-Franzens-University, Graz, Austria, between...
Eighteen cases of Acanthamoeba-associated keratitis among contact lens wearers seen at the Department of Ophthalmology, Karl-Franzens-University, Graz, Austria, between 1996 and 1999 are reviewed. The amoebae were proven to be the causative agents in three patients. The aim of our study was to discriminate between clinically relevant and nonrelevant isolates and to assess the relatedness of the isolates to published strains. Altogether, 20 strains of free-living amoebae, including 15 Acanthamoeba strains, 3 Vahlkampfia strains, and 2 Hartmannella strains, were isolated from clinical specimens. The virulent Acanthamoeba strains were identified as A. polyphaga and two strains of A. hatchetti. To our knowledge this is the first determination of keratitis-causing Acanthamoeba strains in Austria. Clinically relevant isolates differed markedly from nonrelevant isolates with respect to their physiological properties. 18S ribosomal DNA sequence types were determined for the three physiologically most-divergent strains including one of the keratitis-causing strains. This highly virulent strain exhibited sequence type T6, a sequence type not previously associated with keratitis. Sequence data indicate that Acanthamoeba strains causing keratitis as well as nonpathogenic strains of Acanthamoeba in Austria are most closely related to published strains from other parts of the world. Moreover, the results of our study support the assumption that pathogenicity in Acanthamoeba is a distinct capability of certain strains and not dependent on appropriate conditions for the establishment of an infection.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Adolescent; Adult; Animals; Contact Lenses; DNA, Protozoan; DNA, Ribosomal; Female; Humans; Male; Middle Aged; Molecular Sequence Data; Polymerase Chain Reaction; RNA, Ribosomal, 18S; Sequence Analysis, DNA; Virulence
PubMed: 11060047
DOI: 10.1128/JCM.38.11.3932-3936.2000 -
The Korean Journal of Parasitology Jun 2000In order to observe the cytotoxicity of Acanthamoeba spp., which were isolated from contact lens containers as ethiological agents for the probable amoebic keratitis in...
In order to observe the cytotoxicity of Acanthamoeba spp., which were isolated from contact lens containers as ethiological agents for the probable amoebic keratitis in Korea, the crystal violet staining method and LDH release assay were carried out. In the crystal violet staining method, among eight contact lens container isolates, isolate 3 (Acanthamoeba KA/LS5) showed 83.6% and 81.8% of cytotoxicity, and isolate 7 (Acanthamoeba KA/LS37) showed 28.2% and 25.1% of cytotoxicity, in 1 mg/ml and 0.5 mg/ml lysate treatments, respectively. Acanthamoeba culbertsoni and A. healyi showed 84.0% and 82.8% of cytotoxicity. Similar results were observed in A. castellanii and A. hatchetti which showed 83.6% and 75.5% of cytotoxicity. Acanthamoeba royreba and A. polyphaga showed 9.0% and 1.7% of cytotoxicity. In the LDH release assay, isolate 3 (20.4%) showed higher cytotoxicity than other isolates in 1 mg/ml lysate treatment. The results provide that at least isolate 3 has the cytotoxic effect against CHO cells and seems to be the pathogenic strain.
Topics: Acanthamoeba; Animals; CHO Cells; Cell Survival; Contact Lenses; Cricetinae; Equipment Contamination; Gentian Violet; Humans; Korea; L-Lactate Dehydrogenase; Staining and Labeling
PubMed: 10905072
DOI: 10.3347/kjp.2000.38.2.99 -
Journal of Clinical Microbiology Aug 2014A case of amoebic placentitis in a mare from eastern Australia was diagnosed postpartum by histopathological examination of the placenta. The identity of the etiological...
A case of amoebic placentitis in a mare from eastern Australia was diagnosed postpartum by histopathological examination of the placenta. The identity of the etiological agent was confirmed as Acanthamoeba hatchetti by use of diversity profiling based on a next-generation sequencing approach.
Topics: Acanthamoeba; Amebiasis; Animals; Australia; DNA, Protozoan; Female; High-Throughput Nucleotide Sequencing; Horse Diseases; Horses; Molecular Sequence Data; Placenta Diseases; Pregnancy; Pregnancy Complications, Parasitic
PubMed: 24829227
DOI: 10.1128/JCM.01071-14 -
Applied and Environmental Microbiology Oct 1993Two species of amoebae were isolated from the cooling tower of an air-conditioning system and examined for effects of exposure to four cooling tower biocides, a...
Two species of amoebae were isolated from the cooling tower of an air-conditioning system and examined for effects of exposure to four cooling tower biocides, a thiocarbamate compound, tributyltin neodecanoate mixed with quaternary ammonium compounds, another quaternary ammonium compound alone, and an isothiazolin derivative. The amoebae isolated were Acanthamoeba hatchetti and a Cochliopodium species. Two other amoeba cultures, an A. hatchetti culture and Cochliopodium bilimbosum, were obtained from the American Type Culture Collection (ATCC) and were also tested. The cooling tower isolates were more resistant to most of the biocides than the ATCC isolates were. The isothiazolin derivative was the least inhibitory to all four amoeba isolates, and tributyltin neodecanoate mixed with quaternary ammonium compounds was the most inhibitory to three of the four isolates. After exposure to lower concentrations of the biocides, including for one strain the manufacturer's recommended concentration of one biocide, the cooling tower amoeba populations increased significantly compared with unexposed controls, whereas the ATCC isolates were not stimulated at any of the concentrations tested. In some cases, concentrations which stimulated cooling tower amoebae inhibited the growth of the ATCC isolates. These results suggest that cooling tower amoebae may adapt to biocides, underscoring the need to use freshly isolated cooling tower organisms rather than organisms from culture collections for testing the efficacy of such biocides. The stimulatory effect of biocides on amoeba populations is an alarming observation, since these organisms may be reservoirs for legionellae. Biocides used to control microbial growth may actually enhance populations of host organisms for pathogenic bacteria.
Topics: Acanthamoeba; Air Conditioning; Amoeba; Animals; Dimethyldithiocarbamate; Disinfectants; Legionella; Quaternary Ammonium Compounds; Thiazoles; Trialkyltin Compounds; Water; Water Microbiology
PubMed: 8250551
DOI: 10.1128/aem.59.10.3245-3249.1993 -
The Korean Journal of Parasitology Jun 2006Genetic diversity of 18 Acanthamoeba isolates from ocean sediments was evaluated by comparing mitochondrial (mt) DNA RFLP, 18S rDNA sequences and by examining their...
Genetic diversity of 18 Acanthamoeba isolates from ocean sediments was evaluated by comparing mitochondrial (mt) DNA RFLP, 18S rDNA sequences and by examining their cytopathic effects on human corneal epithelial cells versus reference strains. All isolates belonged to morphologic group II. Total of 16 restriction phenotypes of mtDNA from 18 isolates demonstrated the genetic diversity of Acanthamoeba in ocean sediments. Phylogenetic analysis using 18s rDNA sequences revealed that the 18 isolates were distinct from morphological groups I and III. Fifteen isolates showed close relatedness with 17 clinical isolates and A. castellanii Castellani and formed a lineage equivalent to T4 genotype of Byers group. Two reference strains from ocean sediment, A. hatchetti BH-2 and A. griffini S-7 clustered unequivocally with these 15 isolates. Diversity among isolates was also evident from their cytopathic effects on human corneal cells. This is the first time describing Acanthamoeba diversity in ocean sediments in Korea.
Topics: Acanthamoeba; Animals; DNA, Mitochondrial; Epithelial Cells; Epithelium, Corneal; Genetic Variation; Geologic Sediments; Humans; Oceans and Seas; Phylogeny; RNA, Ribosomal, 18S
PubMed: 16809959
DOI: 10.3347/kjp.2006.44.2.117 -
Applied and Environmental Microbiology Jun 1992Some protozoans isolated from aquatic habitats, including domestic water supplies, can support the intracellular replication of autochthonous legionellae in vitro. We...
Some protozoans isolated from aquatic habitats, including domestic water supplies, can support the intracellular replication of autochthonous legionellae in vitro. We studied the effect of incubating water samples containing amoebae on the sensitivity of culture for legionellae. Samples collected during investigations of legionellosis epidemics and shown by conventional culture procedures to contain amoebae, but not legionellae, were incubated at 35 degrees C and replated. Legionellae were recovered from 59 of 144 such samples. Species isolated included L. pneumophila, L. anisa, L. bozemanii, L. gormanii, L. micdadei, L. rubrilucens, L. sainthelensi, L. steigerwaltii, and an unnamed species. Acanthamoeba polyphaga, Acanthamoeba hatchetti, a Rosculus sp., Hartmannella vermiformis, and Vahlkampfia spp. were among the autochthonous amoebae identified. Legionellae were recovered by this procedure from only 3 of 63 samples that were negative for amoebae by conventional culture procedures. These results show that water samples negative for legionellae, but positive for amoebae, by standard culture techniques should be incubated and replated to maximize the sensitivity of culture for legionellae.
Topics: Amoeba; Animals; Bacteriological Techniques; Cell Division; Ecology; Legionella; Sensitivity and Specificity; Species Specificity; Water Microbiology
PubMed: 1622278
DOI: 10.1128/aem.58.6.2001-2004.1992