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The Korean Journal of Parasitology Dec 1996The taxonomic validity of morphological group III Acanthamoeba spp. is uncertain. In the present study, six type strains of group III Acanthamoeba spp., A. culbertsoni,...
The taxonomic validity of morphological group III Acanthamoeba spp. is uncertain. In the present study, six type strains of group III Acanthamoeba spp., A. culbertsoni, A. healyi, A. pustulosa, A. palestinensis, A. royreba and A. lenticulata were subjected for the evaluation of their taxonomic validity by comparison of the isoenzyme patterns by isoelectic focusing on polyacrylamide gels, mitochondrial DNA (Mt DNA) restriction fragment length polymorphism (RFLP), and small subunit ribosomal DNA (ssu rDNA) PCR-RFLP patterns. The Mt DNA RFLP patterns were heterogeneous between the species. The type strains of A. palestinensis and A. pustulosa showed almost identical patterns of isoenzymes and rDNA PCR RFLP with an estimated sequence divergence of 2.6%. The other species showed heterogeneous patterns of isoenzymes and rDNA PCR-RFLP. It is likely that A. pustulosa is closely related with A. palestinensis and that the former may be regarded as a junior synonym of the latter.
Topics: Acanthamoeba; Animals; DNA, Mitochondrial; DNA, Protozoan; DNA, Ribosomal; Isoelectric Focusing; Isoenzymes; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length
PubMed: 9017912
DOI: 10.3347/kjp.1996.34.4.259 -
Iranian Journal of Parasitology Mar 2010Acanthamoeba keratitis develops by pathogenic Acanthamoeba such as A. palestinensis. Indeed this species is one of the known causative agents of amoebic keratitis in...
BACKGROUND
Acanthamoeba keratitis develops by pathogenic Acanthamoeba such as A. palestinensis. Indeed this species is one of the known causative agents of amoebic keratitis in Iran. Mannose Binding Protein (MBP) is the main pathogenicity factors for developing this sight threatening disease. We aimed to characterize MBP gene in pathogenic Acanthamoeba isolates such as A. palestinensis.
METHODS
This experimental research was performed in the School of Public Health, Tehran University of Medical Sciences, Tehran, Iran during 2007-2008. A. palestinensis was grown on 2% non-nutrient agar overlaid with Escherichia coli. DNA extraction was performed using phenol-chloroform method. PCR reaction and amplification were done using specific primer pairs of MBP. The amplified fragment were purified and sequenced. Finally, the obtained fragment was deposited in the gene data bank.
RESULTS
A 900 bp PCR-product was recovered after PCR reaction. Sequence analysis of the purified PCR product revealed a gene with 943 nucleotides. Homology analysis of the obtained sequence showed 81% similarity with the available MBP gene in the gene data bank. The fragment was deposited in the gene data bank under accession number EU678895,
CONCLUSION
MBP is known as the most important factor in Acanthamoeba pathogenesis cascade. Therefore, characterization of this gene can aid in developing better therapeutic agents and even immunization of high-risk people.
PubMed: 22347229
DOI: No ID Found -
The Journal of Hygiene Oct 1983Co-cultivation of Legionella pneumophila serogroup I and Acanthamoeba palestinensis in Neff's medium at 35 degrees C resulted in the intracellular multiplication of the...
Co-cultivation of Legionella pneumophila serogroup I and Acanthamoeba palestinensis in Neff's medium at 35 degrees C resulted in the intracellular multiplication of the bacteria as demonstrated by electron microscopy and immunofluorescence. In the closed experimental system used, the number of legionellae rose from 10(7) colony forming units (c.f.u.)/ml initially to a maximum of 10(10) c.f.u./ml on day 5. Legionellae were seen in expelled phagosomes, in some amoebae filling the cytoplasm and in others in which the process of encystment appeared to have commenced. At 20 degrees C the acanthamoebae phagocytosed and digested the legionellae. The bacteria disappeared from the co-cultivation flask by day 2 but reappeared in low numbers (10(2) c.f.u./ml) by day 6 suggesting that even at this temperature some intra-amoebal multiplication occurred.
Topics: Amoeba; Fluorescent Antibody Technique; Legionella; Microscopy, Electron
PubMed: 6358342
DOI: 10.1017/s0022172400060174 -
PloS One 2020The microbiological content of drinking water traditionally is determined by employing culture-dependent methods that are unable to detect all microorganisms, especially... (Comparative Study)
Comparative Study
The microbiological content of drinking water traditionally is determined by employing culture-dependent methods that are unable to detect all microorganisms, especially those that are not culturable. High-throughput sequencing now makes it possible to determine the microbiome of drinking water. Thus, the natural microbiota of water and water distribution systems can now be determined more accurately and analyzed in significantly greater detail, providing comprehensive understanding of the microbial community of drinking water applicable to public health. In this study, shotgun metagenomic analysis was performed to determine the microbiological content of drinking water and to provide a preliminary assessment of tap, drinking fountain, sparkling natural mineral, and non-mineral bottled water. Predominant bacterial species detected were members of the phyla Actinobacteria and Proteobacteria, notably the genera Alishewanella, Salmonella, and Propionibacterium in non-carbonated non-mineral bottled water, Methyloversatilis and Methylibium in sparkling natural mineral water, and Mycobacterium and Afipia in tap and drinking fountain water. Fecal indicator bacteria, i.e., Escherichia coli or enterococci, were not detected in any samples examined in this study. Bacteriophages and DNA encoding a few virulence-associated factors were detected but determined to be present only at low abundance. Antibiotic resistance markers were detected only at abundance values below our threshold of confidence. DNA of opportunistic plant and animal pathogens was identified in some samples and these included bacteria (Mycobacterium spp.), protozoa (Acanthamoeba mauritaniensis and Acanthamoeba palestinensis), and fungi (Melampsora pinitorqua and Chryosporium queenslandicum). Archaeal DNA (Candidatus Nitrosoarchaeum) was detected only in sparkling natural mineral water. This preliminary study reports the complete microbiome (bacteria, viruses, fungi, and protists) of selected types of drinking water employing whole-genome high-throughput sequencing and bioinformatics. Investigation into activity and function of the organisms detected is in progress.
Topics: Bacteria; Colony Count, Microbial; DNA; Drinking Water; Genes, Bacterial; Metagenomics; Microbiota; Principal Component Analysis; Virulence
PubMed: 32271799
DOI: 10.1371/journal.pone.0231210 -
Journal of Applied Microbiology Nov 2009To advance our understanding of the mechanisms involved in the RLP068 phthalocyanine-photosensitized inactivation of Acanthamoeba palestinensis trophozoites through a...
AIMS
To advance our understanding of the mechanisms involved in the RLP068 phthalocyanine-photosensitized inactivation of Acanthamoeba palestinensis trophozoites through a precise identification of the targets of the photoprocess in both the cytosolic and mitochondrial compartments.
METHODS AND RESULTS
We followed the activities of selected marker enzymes as well as we performed fluorescence and transmission electron microscopy investigations of the alterations induced by the photoprocess in the fine structure of subcellular compartments. RLP068 is preferentially located in the contractile vacuole: the fluorescence in that site is particularly evident in the unirradiated cells and becomes more diffused after irradiation. Electron microscopic analysis of photosensitized A. palestinensis cells clearly shows that the swelling of trophozoites and the appearance of vacuoles spread throughout the cytoplasm after phototreatment. The activity of a typical cytoplasmic enzyme, such as lactate dehydrogenase, underwent a 35% decrease as a consequence of the photoprocess, reflecting the photodamage induced by migrating phthalocyanine molecules in their micro-environment.
CONCLUSIONS
The presence of multiple targets for the phthalocyanine-photosensitized process is of utmost importance because this pattern of cell damage makes it unlikely that photoresistant A. palestinensis strains are gradually selected or mutagenic phenomena are developed as a consequence of the photoinduced damage.
SIGNIFICANCE AND IMPACT OF THE STUDY
Photosensitization via phthalocyanines appears to represent an efficient and safe approach for achieving a close control of the population of a potentially pathogenic protozoan such as A. palestinensis, opening new perspectives for the disinfection of microbiologically polluted waters.
Topics: Acanthamoeba; Caspase 3; Indoles; L-Lactate Dehydrogenase; Lactic Acid; Microscopy, Electron, Transmission; Microscopy, Fluorescence; Mitochondria; Organometallic Compounds; Photochemotherapy; Photosensitizing Agents; Spectrophotometry; Succinic Acid; Trophozoites
PubMed: 19457022
DOI: 10.1111/j.1365-2672.2009.04348.x -
The Journal of Cell Biology Sep 1971The membranes of Acanthamoeba palestinensis were studied by examination in fixed cells, and then by following the movements of glycerol-(3)H-labeled phospholipids by...
The membranes of Acanthamoeba palestinensis were studied by examination in fixed cells, and then by following the movements of glycerol-(3)H-labeled phospholipids by cell fractionation. Two previously undescribed structures were observed: collapsed cytoplasmic vesicles of cup shape, and plaques in food vacuole and plasma membrane similar in size to the collapsed vesicles. It appeared that the plaques formed by insertion of collapsed vesicles into membranes and/or that collapsed vesicles formed by pinching off of plaques. Fractions were isolated, enriched with nuclei, rough endoplasmic reticulum (RER), plasma membrane, Golgi-like membranes, and collapsed vesicles. The changes in specific activity of glycerol-(3)H-labeled phospholipids in these membranes during incorporation, turnover, and after pulse-labeling indicated an ordered sequence of appearances of newly synthesized phospholipids, first in nuclei and RER, then successively in Golgi membranes, collapsed vesicles, and finally, plasma membrane. In previous work we had found no large nonmembranous phospholipid pool in A. palestinensis. These observations are consistent with the hypothesis that membrane phospholipids are synthesized, perhaps as integral parts of membranes, in RER and nuclei. Subsequently, some of the newly synthesized phospholipids are transported to the Golgi complex to become integrated into the membranes of collapsed vesicles, which are precursors of the plasma membrane. Collapsed vesicles from the plasma membrane by inserting into it as plaques. When portions of the plasmalemma from food vacuoles, collapsed vesicles pinch off from their membranes and are recycled back to the cell surface.
Topics: Amoeba; Animals; Cell Fractionation; Cell Membrane; Cell Nucleus; Centrifugation, Zonal; Endoplasmic Reticulum; Glycerol; Golgi Apparatus; Histocytochemistry; Inclusion Bodies; Kinetics; Microscopy, Electron; Microscopy, Phase-Contrast; Microsomes; Phospholipids; Time Factors; Tritium
PubMed: 4329152
DOI: 10.1083/jcb.50.3.634 -
The Journal of Cell Biology Sep 1971In order to determine the feasibility of using radioactive precursors as markers for membrane phospholipids in Acanthamoeba palestinensis, the characteristics of...
Assembly of lipids into membranes in Acanthamoeba palestinensis. I. Observations on the specificity and stability of choline- 14 C and glycerol- 3 H as labels for membrane phospholipids.
In order to determine the feasibility of using radioactive precursors as markers for membrane phospholipids in Acanthamoeba palestinensis, the characteristics of phospholipids labeled with choline-(14)C and glycerol-(3)H were examined. Choline-(14)C was found to be a specific label for phosphatidyl choline. There was a turnover of the radioactive moiety of phosphatidyl choline at a rate that varied with the concentration of nonradioactive choline added to the growth medium. Radioactivity was lost from labeled phosphatidyl choline into the acid-soluble intracellular pool and from the pool into the extracellular medium. This loss of radioactivity from cells leveled off and an equilibrium was reached between the label in the cells and in the medium. Radioactive choline was incorporated into phosphatidyl choline by cell-free microsomal suspensions. This incorporation leveled off with the attainment of an equilibrium between the choline-(14)C in the reaction mixture and the choline-(14)C moiety of phosphatidyl choline in the microsomal membranes. Therefore, a choline exchange reaction may occur in cell-free membranes, as well as living A. palestinensis. In contrast to choline-(14)C, the apparent turnover of glycerol-(3)H-labeled phospholipids was not affected by large concentrations of nonradioactive choline or glycerol in the medium. The radioactivity in lipids labeled with glycerol-(3)H consisted of 33% neutral lipids and 67% phospholipids. Phospholipids labeled with glycerol-(3)H turned over slowly, with a concomitant increase in the percentage of label in neutral lipids, indicating a conversion of phospholipids to neutral lipids. Because most ( approximately 96%) of the glycerol-(3)H recovered from microsomal membranes was in phospholipids, whereas only a minor component ( approximately 2%) of the glycerol-(3)H was in the phospholipids isolated from nonmembrane lipids, glycerol-(3)H was judged to be a specific marker for membrane phospholipids.
Topics: Amoeba; Animals; Carbon Isotopes; Cell Fractionation; Cell Membrane; Cell-Free System; Choline; Culture Media; Germ-Free Life; Glycerides; Glycerol; Lipids; Microsomes; Phosphatidylcholines; Phospholipids; Postural Balance; Time Factors; Tritium
PubMed: 5098863
DOI: 10.1083/jcb.50.3.625 -
BioMed Research International 2013This study evaluated the presence of Acanthamoeba species in the Puzih River watershed, which features typical subtropical monsoon climate and is located just above the...
This study evaluated the presence of Acanthamoeba species in the Puzih River watershed, which features typical subtropical monsoon climate and is located just above the Tropic of Cancer in Taiwan. The relationship between the seasonal and geographical distributions of Acanthamoeba species in this rivershed was also investigated. Acanthamoeba species were detected in water samples using the amoebal enrichment culture method and confirmed by PCR. A total of 136 water samples were included in this study, 16 (11.7%) of which contained Acanthamoeba species. Samples with the highest percentage of Acanthamoeba (32.4%) were obtained during the summer season, mainly from upstream areas. The identified species in the four seasons included Acanthamoeba palestinensis (T2), Acanthamoeba sp. IS2/T4 (T4), Acanthamoeba lenticulata (T5), Acanthamoeba hatchetti (T11), Acanthamoeba healyi (T12), and Acanthamoeba jacobsi (T15). The most frequently identified Acanthamoeba genotype was T4 (68.7%). Acanthamoeba genotype T4 is responsible for Acanthamoeba keratitis and should be considered for associated human health risk potential in the rivershed.
Topics: Acanthamoeba; Genetic Variation; Genotype; Humans; Phylogeny; Seasons; Sequence Analysis, DNA; Taiwan
PubMed: 24490160
DOI: 10.1155/2013/405794 -
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 -
Applied and Environmental Microbiology Mar 1977Cyst walls of Acanthamoeba rhysodes, A. palestinensis, A. castellanii, and one other strain of Acanthamoeba contain 36 to 45% protein and 20 to 34% carbohydrate. More...
Cyst walls of Acanthamoeba rhysodes, A. palestinensis, A. castellanii, and one other strain of Acanthamoeba contain 36 to 45% protein and 20 to 34% carbohydrate. More than half of the protein in the walls of A. palestinensis, A. castellanii and Acanthamoeba sp. is accessible to and hydrolyzed by protease, and 67 to 69% of the carbohydrate of A. palestinensis and A. rhysodes walls is hydrolyzed by cellulase. The extent of hydrolysis of walls of the other amoebae by these enzymes is appreciably less, and chitinase and beta-1,3-glucanase have no detectable effect. Protease solubilizes 10% or less of the weight of intact cysts, and no solubilization is observed with cellulase. Walls of A. palestinensis are extensively degraded in soil, the activity is less with A. rhysodes, and little attack on the other amoebae occurs. When added to soil, the protozoa excyst and grow for short periods, the trophozoites then die, and chiefly cysts persist thereafter.
PubMed: 16345225
DOI: 10.1128/aem.33.3.670-674.1977