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PloS One 2023As the number of contact lens users increases, contact lens induced corneal infection is becoming more common. Acanthamoeba keratitis (AK) is a type of those which is...
As the number of contact lens users increases, contact lens induced corneal infection is becoming more common. Acanthamoeba keratitis (AK) is a type of those which is caused by Acanthamoeba species, and may cause severe ocular inflammation and visual loss. We evaluated whether Torreya nucifera (T. nucifera) extract has an anti-amoebic effect and studied its mechanism of action on Acanthamoeba lugdunensis (A. lugdunensis). Cell viability was tested using the alamarBlue™ method, and the cell death mechanism was confirmed using the Tali® Apoptosis Kit. The SYTOX® Green assay was performed to check the plasma membrane permeability. The JC-1 dye was used to measure the mitochondrial membrane potential. A CellTiter-Glo® Luminescent Assay was used to measure the adenosine-triphosphate (ATP) level. Morphological changes in the mitochondria were examined by transmission electron microscopy (TEM). Cystic changes and a decrease in cell viability after treatment with T. nucifera were observed. Both apoptotic and necrotic cells were found in the Tali® Apoptosis assay. There was no significant difference in plasma membrane permeability between the control and T. nucifera treated groups. The collapse of the mitochondrial membrane potential and reduced ATP level in A. lugdunensis was confirmed in the groups treated with T. nucifera. Structural damage to the mitochondria was observed on TEM in the groups treated with T. nucifera. T. nucifera showed an anti-amoebic effect on A. lugdunensis, by inducing the loss of mitochondrial membrane potential. Thus, it could be a future therapeutic agent for AK.
Topics: Humans; Acanthamoeba; Amebicides; Acanthamoeba Keratitis; Adenosine Triphosphate; Plant Extracts
PubMed: 36745609
DOI: 10.1371/journal.pone.0281141 -
PloS One 2023[This corrects the article DOI: 10.1371/journal.pone.0281141.].
[This corrects the article DOI: 10.1371/journal.pone.0281141.].
PubMed: 37922291
DOI: 10.1371/journal.pone.0294194 -
Journal of Korean Medical Science Jan 2018This study aimed to evaluate the adhesion of Acanthamoeba trophozoites on cosmetic contact lenses (CLs) with and without CL care multipurpose solution (MPS) treatment.
BACKGROUND
This study aimed to evaluate the adhesion of Acanthamoeba trophozoites on cosmetic contact lenses (CLs) with and without CL care multipurpose solution (MPS) treatment.
METHODS
Acanthamoeba lugdunensis L3a trophozoites were inoculated onto disks trimmed from CLs: 1-day Acuvue moist, 1-day Acuvue define, Acuvue 2, and Acuvue 2 define. After 18-hour inoculation, the number of adherent trophozoites was counted under phase contrast microscopy. The effects of MPS, Opti-Free Express, soaking CLs for 6 hours, on Acanthamoeba adhesion were analyzed. Scanning electron microscopic examination was performed for assessment of Acanthamoeba attached on the lens surface.
RESULTS
Acanthamoeba trophozoites showed greater adhesion to cosmetic CL (P = 0.017 for 1-day CL and P = 0.009 for 2-week CL) although there was no significant difference between the types of cosmetic CL. On all lenses, the number of adherent Acanthamoeba was significantly reduced after treatment with MPS (P < 0.001 for 1-day Acuvue moist, P = 0.046 for 1-day Acuvue define, P < 0.001 for Acuvue 2, and P = 0.015 for Acuvue 2 define), but there was still significant difference between conventional and cosmetic CLs (P = 0.003 for 1-day CL and P < 0.001 for 2-week CL, respectively). More attachment of Acanthamoeba was observed on colored area and the acanthopodia of Acanthamoeba was placed on the rough surface of colored area.
CONCLUSION
Acanthamoeba showed a greater affinity for cosmetic CL and mostly attached on colored area. Although MPS that contained myristamidopropyl dimethylamine reduced the adhesion rate, there was a significant difference between conventional and cosmetic CLs.
Topics: Acanthamoeba; Contact Lenses; Disinfectants; Humans; Microscopy, Electron, Scanning; Trophozoites
PubMed: 29318793
DOI: 10.3346/jkms.2018.33.e26 -
Investigative Ophthalmology & Visual... May 2004Species of four Acanthamoeba isolates (KA/E2, KA/E12, KA/E15, and KA/E16) from the cornea of patients with keratitis were identified and their molecular characteristics...
PURPOSE
Species of four Acanthamoeba isolates (KA/E2, KA/E12, KA/E15, and KA/E16) from the cornea of patients with keratitis were identified and their molecular characteristics compared with those of other strains.
METHODS
Morphologic features of amebic cysts were evaluated with a microscope with differential interference contrast (DIC) optics. Restriction fragment length polymorphisms (RFLP) of mitochondrial DNA (mtDNA), riboprinting of small subunit ribosomal RNA gene (18S rDNA), and DNA sequences of 18S rDNA were analyzed. mtDNA and PCR-amplified 18S rDNA of the ocular isolates were digested with restriction enzymes, and the restriction patterns were compared with those of reference strains purchased from American Type Culture Collection (ATCC, Manassas, VA). PCR products of 18S rDNA were cloned and subjected to sequencing. The complete sequence of approximately 2300 bp obtained from the isolates and reference strains were compared with each other and those registered in GenBank.
RESULTS
Three ocular isolates (KA/E2, KA/E12, and KA/E16) of Acanthamoeba revealed the identical mtDNA RFLPs and riboprint patterns with Acanthamoeba L3a, the type strain of A. lugdunensis. The other isolate (KA/E15) had riboprint patterns very similar to A. lugdunensis L3a but quite different mtDNA RFLP patterns from those of all the other strains. A dendrogram based on the riboprint data showed that three ocular isolates were identified as A. lugdunensis and the other isolate was very closely related to this species. Identification of the isolates as A. lugdunensis was confirmed by 18S rDNA sequence analysis. The sequence differences of the four isolates from A. lugdunensis L3a was 0.1% to 0.4% (3 to 8/2284 bp) and 1.2% to 1.5% from A. castellanii Castellani.
CONCLUSIONS
This is the first report of Acanthamoeba keratitis in Korea caused by A. lugdunensis, which was originally isolated from a freshwater pool in France. Riboprinting can be used as a simple and rapid tool for putative identification of unknown Acanthamoeba ocular isolates.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Adolescent; Adult; Animals; Base Sequence; Contact Lenses, Hydrophilic; Cornea; DNA, Mitochondrial; DNA, Protozoan; DNA, Ribosomal; Disposable Equipment; Female; Humans; Male; Molecular Sequence Data; Parasitic Sensitivity Tests; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; RNA, Ribosomal, 18S; Sequence Homology, Nucleic Acid
PubMed: 15111597
DOI: 10.1167/iovs.03-0433 -
Cornea May 2016To evaluate adhesion of Acanthamoeba trophozoites to different silicone hydrogel contact lens (SHCL) generations with and without multipurpose contact lens care solution... (Comparative Study)
Comparative Study
PURPOSE
To evaluate adhesion of Acanthamoeba trophozoites to different silicone hydrogel contact lens (SHCL) generations with and without multipurpose contact lens care solution (MPS) treatment.
METHODS
Acanthamoeba lugdunensis L3a trophozoites were inoculated onto discs trimmed from SHCLs: first generation, Air Optix (Lotrafilcon B) with a plasma surface treatment, second generation, Acuvue Oasys (Senofilcon A), which contains an internal wetting agent (Hydraclear), and third generation, Biofinity (Comfilcon A) with no surface treatment. After 18-hour inoculation, the number of adherent trophozoites on SHCLs was counted as the control under phase contrast microscopy. The effects of the 3 different MPSs, Opti-Free Express, ReNu Fresh, and Biotrue, soaking SHCLs for 6 hours, on Acanthamoeba adhesion were analyzed. Scanning electron microscopic examination was performed for assessment of Acanthamoeba attached on the lens surface.
RESULTS
Acanthamoeba trophozoites showed greater adhesion to Air Optix than to Acuvue Oasys and Biofinity (P < 0.05). On Air Optix and Acuvue Oasys, the number of adherent Acanthamoeba was significantly reduced compared with the control after treatment with Opti-Free Express (P < 0.05), but not significantly reduced by treatment with ReNu Fresh and Biotrue (P > 0.05). Acanthamoeba did not adhere to Biofinity regardless of MPSs treatment. Attachment of the acanthopodia of Acanthamoeba on the curved ridge of the Air Optix lens surface was observed.
CONCLUSIONS
Acanthamoeba showed greater affinity for the first-generation SHCL and seemed to be more attached on SHCLs with more ridges. MPS with myristamidopropyl dimethylamine reduced the adhesion rate.
Topics: Acanthamoeba; Contact Lens Solutions; Contact Lenses, Hydrophilic; Hydrogel, Polyethylene Glycol Dimethacrylate; Hydrogels; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Microscopy, Phase-Contrast; Parasite Load; Silicone Elastomers; Silicones
PubMed: 26938330
DOI: 10.1097/ICO.0000000000000788 -
The Journal of Parasitology Jun 2011Hexadecylphosphocholine (miltefosine) is an anticancer drug active in vitro against various protozoan parasites, and recently used for the treatment of disseminated...
Hexadecylphosphocholine (miltefosine) is an anticancer drug active in vitro against various protozoan parasites, and recently used for the treatment of disseminated Acanthamoeba infection. In the present study, we present results of weak cytotoxic activity of this potential amoebicidal agent for 2 of 3 clinical isolates of Acanthamoeba spp. Although the inhibition effect for all tested concentrations was apparent, and showed 100% eradication of trophozoites of Acanthamoeba castellanii strain at a concentration of 62.5 µM after 24 hr, the strains Acanthamoeba sp. and Acanthamoeba lugdunensis exhibited low sensitivity to hexadecylphosphocholine, even in high concentrations. The determined minimal trophocidal concentrations were 250 µM for Acanthamoeba sp. and 500 µM for A. lugdunensis after 24 hr of exposure. Although hexadecylphosphocholine is a potential agent for treatment of Acanthamoeba keratitis and systemic infections, in clinical practice the possible insusceptibility of the amoebic strain should be considered for optimizing therapy.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Acanthamoeba castellanii; Antiprotozoal Agents; Cornea; Dose-Response Relationship, Drug; Humans; Phosphorylcholine; Trophozoites
PubMed: 21506779
DOI: 10.1645/GE-2669.1 -
Acta Tropica Apr 2021Amoebae of the genus Acanthamoeba are worldwide distributed causative agents of serious human infections such as granulomatous amoebic encephalitis (GAE) and...
Amoebae of the genus Acanthamoeba are worldwide distributed causative agents of serious human infections such as granulomatous amoebic encephalitis (GAE) and Acanthamoeba keratitis (AK). To date, treatment of these infections is non-uniform and frequently unsuccessful. Recently, the phosphonium salts were studied for their high levels of antimicrobial activity. This work was aimed to investigate the cytotoxic effect of metronidazole and two phosphonium salts (PS1, PS2) on two clinical Acanthamoeba isolates. The isolates showed distinctly higher susceptibility to both phosphonium salts than to metronidazole. The highest susceptibility was noted to PS1 after 48 h of incubation. Metronidazole derivate PS2 showed higher susceptibility than metronidazole. The values of EC of PS2 were approximately twenty times lower than EC of metronidazole for Acanthamoeba lugdunensis strain and sixteen times lower for Acanthamoeba quina strain after 48 h. Although the therapeutic effect of metronidazole in Acanthamoeba infections is usually insufficient, its derivatisation can result in a significantly higher amoebicidal effect. Cytomorphological changes of trophozoites after exposure to tested compounds included rounding up of the cells, damage of membrane integrity, presence of pathological protrusions, elongation of the cells or pseudocyst-like stages. Obtained results indicate possible therapeutic potential of studied phosphonium salts.
Topics: Acanthamoeba; Amebicides; Animals; Genotype; Humans; Metronidazole; Trophozoites
PubMed: 33465352
DOI: 10.1016/j.actatropica.2021.105830 -
The Korean Journal of Parasitology Aug 2022The high percentage of Vermamoeba was found in tap water in Korea. This study investigated whether Vermamoeba induced allergic airway inflammation in mice. We selected 2...
The high percentage of Vermamoeba was found in tap water in Korea. This study investigated whether Vermamoeba induced allergic airway inflammation in mice. We selected 2 free-living amoebas (FLAs) isolated from tap water, which included Korean FLA 5 (KFA5; Vermamoeba vermiformis) and 21 (an homolog of Acanthamoeba lugdunensis KA/ E2). We axenically cultured KFA5 and KFA21. We applied approximately 1 × 106 to mice's nasal passages 6 times and investigated their pathogenicity. The airway resistance value was significantly increased after KFA5 and KFA21 treatments. The eosinophil recruitment and goblet cell hyperplasia were concomitantly observed in bronchial alveolar lavage (BAL) fluid and lung tissue in mice infected with KFA5 and KFA21. These infections also activated the Th2-related interleukin 25, thymic stromal lymphopoietin, and thymus and activation-regulated chemokines gene expression in mouse lung epithelial cells. The CD4+ interleukin 4+ cell population was increased in the lung, and the secretion of Th2-, Th17-, and Th1-associated cytokines were upregulated during KFA5 and KFA21 infection in the spleen, lung-draining lymph nodes, and BAL fluid. The pathogenicity (allergenicity) of KFA5 and KFA21 might not have drastically changed during the long-term in vitro culture. Our results suggested that Vermamoeba could elicit allergic airway inflammation and may be an airway allergen.
Topics: Acanthamoeba; Amoeba; Animals; Bronchoalveolar Lavage Fluid; Eosinophils; Inflammation; Mice; Water
PubMed: 36041484
DOI: 10.3347/kjp.2022.60.4.229 -
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 -
Bioorganic & Medicinal Chemistry Letters Nov 2009A series of dialkylphosphocholines were prepared and evaluated for their biological activity. The antiprotozoal activity was determined against Acanthamoeba lugdunensis....
A series of dialkylphosphocholines were prepared and evaluated for their biological activity. The antiprotozoal activity was determined against Acanthamoeba lugdunensis. Compound 15 exhibited excellent trophocidal activity. None of the tested dialkylphosphocholines exhibited better fungicidal activity against Candida albicans than miltefosine. The antineoplastic activity was determined against HeLa. The most cytotoxic was compound 10, which was more active against tumor cells as against normal cells.
Topics: Acanthamoeba; Anti-Bacterial Agents; Antifungal Agents; Antineoplastic Agents; Antiprotozoal Agents; Candida albicans; Drug Screening Assays, Antitumor; Inhibitory Concentration 50; Microbial Sensitivity Tests; Molecular Structure; Phosphorylcholine; Plant Extracts; Structure-Activity Relationship
PubMed: 19818608
DOI: 10.1016/j.bmcl.2009.09.079