Aminoglucoside/Imidazole in the Treatment of Acanthamoeba Keratitis

doi:10.33140/jocr/02/02/00002

Aminoglucoside/Imidazole in the Treatment of Acanthamoeba Keratitis

Journal of Ophthalmology & Clinical Research ◽

10.33140/jocr/02/02/00002 ◽

2018 ◽

Vol 2 (2) ◽

Keyword(s):

Visual Acuity ◽

Acanthamoeba Keratitis ◽

Final Visual Acuity ◽

Free Living ◽

Corneal Infection ◽

Free Living Amoeba

Acanthamoeba Keratitis (AK) is an infrequent corneal infection caused by free living amoeba, it is frequently misdiagnosed and medically/surgical treated with low or no response in advanced cases. In this paper we present five cases of AK with early diagnoses and good response to aminoglucoside/imidazole treatment and achieving acceptable final visual acuity in each case.

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Isoniazid Conjugated Magnetic Nanoparticles Loaded with Amphotericin B as a Potent Antiamoebic Agent against Acanthamoeba castellanii

Antibiotics ◽

10.3390/antibiotics9050276 ◽

2020 ◽

Vol 9 (5) ◽

pp. 276

Author(s):

Kawish Iqbal ◽

Sumayah Abdelnasir Osman Abdalla ◽

Ayaz Anwar ◽

Kanwal Muhammad Iqbal ◽

Muhammad Raza Shah ◽

...

Keyword(s):

Magnetic Nanoparticles ◽

Amphotericin B ◽

Central Nervous System Infection ◽

Acanthamoeba Castellanii ◽

Acanthamoeba Keratitis ◽

Free Living ◽

Granulomatous Amoebic Encephalitis ◽

Nano Drug Delivery ◽

Free Living Amoeba ◽

Acanthamoeba Species

The pathogenic free-living amoeba, Acanthamoeba castellanii, is responsible for a rare but deadly central nervous system infection, granulomatous amoebic encephalitis and a blinding eye disease called Acanthamoeba keratitis. Currently, a combination of biguanides, amidine, azoles and antibiotics are used to manage these infections; however, the host cell cytotoxicity of these drugs remains a challenge. Furthermore, Acanthamoeba species are capable of transforming to the cyst form to resist chemotherapy. Herein, we have developed a nano drug delivery system based on iron oxide nanoparticles conjugated with isoniazid, which were further loaded with amphotericin B (ISO-NPs-AMP) to cause potent antiamoebic effects against Acanthamoeba castellanii. The IC50 of isoniazid conjugated with magnetic nanoparticles and loaded with amphotericin B was found to be 45 μg/mL against Acanthamoeba castellanii trophozoites and 50 μg/mL against cysts. The results obtained in this study have promising implications in drug discovery as these nanomaterials exhibited high trophicidal and cysticidal effects, as well as limited cytotoxicity against rat and human cells.

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Encystment Induces Down-Regulation of an Acetyltransferase-Like Gene in Acanthamoeba castellanii

Pathogens ◽

10.3390/pathogens9050321 ◽

2020 ◽

Vol 9 (5) ◽

pp. 321 ◽

Cited By ~ 1

Author(s):

Steven Rolland ◽

Luce Mengue ◽

Cyril Noël ◽

Stéphanie Crapart ◽

Anne Mercier ◽

...

Keyword(s):

Bioinformatics Analysis ◽

Acanthamoeba Castellanii ◽

Acanthamoeba Keratitis ◽

Free Living ◽

Adverse Conditions ◽

Genetic Modifications ◽

Granulomatous Amoebic Encephalitis ◽

Free Living Amoeba ◽

Causative Agents

Acanthamoeba castellanii is a ubiquitous free-living amoeba. Pathogenic strains are causative agents of Acanthamoeba keratitis and granulomatous amoebic encephalitis. In response to adverse conditions, A. castellanii differentiate into cysts, which are metabolically inactive and resistant cells. This process, also named encystment, involves biochemical and genetic modifications that remain largely unknown. This study characterizes the role of the ACA1_384820 Acanthamoeba gene during encystment. This gene encodes a putative N-acetyltransferase, belonging to the Gcn5-related N-acetyltransferase (GNAT) family. We showed that expression of the ACA1_384820 gene was down-regulated as early as two hours after induction of encystment in A. castellanii. Interestingly, overexpression of the ACA1_384820 gene affects formation of cysts. Unexpectedly, the search of homologs of ACA1_384820 in the Eukaryota gene datasets failed, except for some species in the Acanthamoeba genus. Bioinformatics analysis suggested a possible lateral acquisition of this gene from prokaryotic cells. This study enabled us to describe a new Acanthamoeba gene that is down-regulated during encystment.

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Enhanced Killing of Acanthamoeba Cysts with a Plant Peroxidase-Hydrogen Peroxide-Halide Antimicrobial System

Applied and Environmental Microbiology ◽

10.1128/aem.69.5.2563-2567.2003 ◽

2003 ◽

Vol 69 (5) ◽

pp. 2563-2567 ◽

Cited By ~ 13

Author(s):

Reanne Hughes ◽

Peter W. Andrew ◽

Simon Kilvington

Keyword(s):

Hydrogen Peroxide ◽

Horseradish Peroxidase ◽

Contact Lens ◽

Acanthamoeba Keratitis ◽

Free Living ◽

Soybean Peroxidase ◽

Plant Peroxidase ◽

Time Points ◽

Free Living Amoeba ◽

Care Systems

ABSTRACT The activity of H2O2 against the resistant cyst stage of the pathogenic free-living amoeba Acanthamoeba was enhanced by the addition of KI and either horseradish peroxidase or soybean peroxidase or, to a lesser degree, lactoperoxidase. This resulted in an increase in the cysticidal activity of 3% (wt/vol) H2O2, and there was >3-log killing in 2 h, compared with the 6 h required for comparable results with the peroxide solution alone (P < 0.05). With 2% H2O2, enhancement was observed at all time points (P < 0.05), and total killing of the cyst inoculum occurred at 4 h, compared with 6 h for the peroxide alone. The activity of sublethal 1% H2O2 was enhanced to give 3-log killing after 8 h of exposure (P < 0.05). No enhancement was obtained when KCl or catalase was used as a substitute in the reaction mixtures. The H2O2 was not neutralized in the enhanced system during the experiments. However, in the presence of a platinum disk used to neutralize H2O2 in contact lens care systems, the enhanced 2% H2O2 system gave 2.8-log killing after 6 h or total cyst killing by 8 h, and total neutralization of the H2O2 occurred by 4 h. In contrast, 2% H2O2 alone resulted in <0.8-log killing of cysts in the presence of the platinum disk due to rapid (<1 h) neutralization of the peroxide. Our observations could result in significant improvement in the efficacy of H2O2 contact lens disinfection systems against Acanthamoeba cysts and prevention of acanthamoeba keratitis.

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Acanthamoeba spp. in river water samples from the Black Sea region, Turkey

Journal of Water and Health ◽

10.2166/wh.2020.170 ◽

2020 ◽

Vol 18 (2) ◽

pp. 186-199 ◽

Cited By ~ 1

Author(s):

İlknur Koyun ◽

Zeynep Kolören ◽

Ülkü Karaman ◽

Amalia Tsiami ◽

Panagiotis Karanis

Keyword(s):

Black Sea ◽

Water Samples ◽

Tap Water ◽

Acanthamoeba Keratitis ◽

The Black Sea ◽

Free Living ◽

Black Sea Region ◽

River Waters ◽

Free Living Amoeba ◽

Acanthamoeba Species

Abstract The present study aims to investigate the occurrence of free living amoeba (FLA) in water resources (rivers and tap water) in Samsun in the Black Sea. The presence of Acanthamoeba spp. was confirmed in 98 of 192 water samples collected from 32 sites of Samsun province (Samsun centre, Terme, Carsamba, Tekkekoy, Bafra) by PCR. Acanthamoeba spp. were found in 15/36 river samples from Samsun, in 58/90 from Terme, in 12/30 from Carsamba, in 7/18 from Tekkekoy and in 6/18 from Bafra. No Acanthamoeba species were detected in tap water samples. The highest rate in river waters contaminated with Acanthamoeba species was in Terme followed by Samsun centre (41.7%), Carsamba (40%), Tekkekoy (38.9%) and Bafra districts (33.3%), respectively. The result of the subsequent sequence analysis showed Haplotype I (A. triangularis) in 5%, Haplotype II (A. polyphaga) in 29.6%, Haplotype III (Acanthamoeba spp.) in 62% and Haplotype IV (A. lenticulata) in 3%. The most common genotype was Acanthamoeba T4 (Acanthamoeba spp., A. polyphaga, A. triangularis) and T5 genotype was also found in 3%. The T4 genotype is the most common genotype associated with Acanthamoeba keratitis (AK) worldwide; therefore, humans and animals living in the area are at risk after contact with such waters.

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Ophthalmology hospital wards contamination to pathogenic free living Amoebae in Iran

Acta Parasitologica ◽

10.1515/ap-2015-0057 ◽

2015 ◽

Vol 60 (3) ◽

Cited By ~ 9

Author(s):

Zohreh Lasjerdi ◽

Maryam Niyyati ◽

Jacob Lorenzo-Morales ◽

Ali Haghighi ◽

Niloofar Taghipour

Keyword(s):

Acanthamoeba Keratitis ◽

Slit Lamp ◽

Free Living ◽

Eye Surgery ◽

Disinfection Methods ◽

Eye Trauma ◽

Morphological Criteria ◽

Free Living Amoeba ◽

Hospital Wards ◽

Good Hygiene

AbstractThe present study was conducted to determine the occurrence of potentially pathogenic free-living amoeba in ophthalmology wards in reference hospitals in Iran. Since an increasing number of Acanthamoeba Keratitis cases after eye surgery and eye trauma have been recently observed in this country, it could be possible that the disinfection procedures undertaken in the clinical setting may not have a good hygiene and disinfection procedures, hence the aim of this study. Therefore, 42 dust and biofilm samples were collected from different areas of ophthalmology wards and checked for the presence of FLA using morphological criteria, PCR based analysis and DNA sequencing. Of the 42 samples from dust and biofilm sources, 18(42.86%) isolates were found to contain FLA and 12(92.3%) isolates belonged to Acanthamoeba T4 genotype. Isolation of the pathogenic genotype T4 from medical instruments, including slit lamp in corneal wards, may be a threat for patients undergoing eye surgery in these wards. Other FLA isolated in this study included Acanthamoeba genotype T5, Vahlkampfia sp, Naegleria australiensis, Vermamoeba vermiformis and Echinamoeba exudans. To our knowledge, this is the first report of the presence of potentially pathogenic FLA in ophthalmology wards in Iran. Improved disinfection methods and monitoring of hospitals ward are thus necessary in this area in order to minimize the risk of infection in patients.

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Effect of a Commercial Disinfectant CLORICAN® on Acanthamoeba spp. and Naegleria fowleri Viability

Parasitologia ◽

10.3390/parasitologia1030013 ◽

2021 ◽

Vol 1 (3) ◽

pp. 119-129

Author(s):

Ines Sifaoui ◽

Aitor Rizo-Liendo ◽

María Reyes-Batlle ◽

Iñigo Arberas-Jiménez ◽

Rubén L. Rodríguez-Expósito ◽

...

Keyword(s):

Chlorine Dioxide ◽

Acanthamoeba Keratitis ◽

Naegleria Fowleri ◽

Free Living ◽

Short Period ◽

Free Living Amoeba ◽

Swimming Pool Water ◽

Microbial Proliferation ◽

Nægleria Fowleri ◽

Primary Amebic Meningoencephalitis

Swimming pool water treatment by chemicals is an essential step to avoid microbial proliferation and infections namely caused by free living amoeba such as, for example, primary amebic meningoencephalitis and Acanthamoeba keratitis. In the present study, a commercial reactive, CLORICAN, based on chlorine dioxide, was evaluated against Acanthamoeba spp. and Naegleria fowleri. We observed that CLORICAN could eliminate in a short period of incubation time both amoebae. Furthermore, Naegleria fowleri’s trophozoites were more sensitive than those of Acanthamoeba spp. By means of inverted microscopy, the chlorine dioxide was found to greatly affect morphology shape by increasing the cell size shrinkage.

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Description of Virulent Factors and Horizontal Gene Transfers of Keratitis-Associated Amoeba Acanthamoeba Triangularis by Genome Analysis

Pathogens ◽

10.3390/pathogens9030217 ◽

2020 ◽

Vol 9 (3) ◽

pp. 217 ◽

Cited By ~ 4

Author(s):

Issam Hasni ◽

Julien Andréani ◽

Philippe Colson ◽

Bernard La Scola

Keyword(s):

Core Genome ◽

Severe Infection ◽

Acanthamoeba Keratitis ◽

Orthologous Group ◽

Human Cornea ◽

Genomic Comparison ◽

Free Living ◽

Homologous Genes ◽

Free Living Amoeba ◽

Medical Interest

Acanthamoeba triangularis strain SH 621 is a free-living amoeba belonging to Acanthamoeba ribo-genotype T4. This ubiquitous protist is among the free-living amoebas responsible for Acanthamoeba keratitis, a severe infection of human cornea. Genome sequencing and genomic comparison were carried out to explore the biological functions and to better understand the virulence mechanism related to the pathogenicity of Acanthamoeba keratitis. The genome assembly harbored a length of 66.43 Mb encompassing 13,849 scaffolds. The analysis of predicted proteins reported the presence of 37,062 ORFs. A complete annotation revealed 33,168 and 16,605 genes that matched with NCBI non-redundant protein sequence (nr) and Cluster of Orthologous Group of proteins (COG) databases, respectively. The Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG) annotation reported a great number of genes related to carbohydrate, amino acid and lipid metabolic pathways. The pangenome performed with 8 available amoeba genomes belonging to genus Acanthamoeba revealed a core genome containing 843 clusters of orthologous genes with a ratio core genome/pangenome of less than 0.02. We detected 48 genes related to virulent factors of Acanthamoeba keratitis. Best hit analyses in nr database identified 99 homologous genes shared with amoeba-resisting microorganisms. This study allows the deciphering the genome of a free-living amoeba with medical interest and provides genomic data to better understand virulence-related Acanthamoeba keratitis.

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Molecular Identification of Pathogenic Free-Living Amoeba from Household Biofilm Samples in Iran: A Risk Factor for Acanthamoeba Keratitis

Microorganisms ◽

10.3390/microorganisms9102098 ◽

2021 ◽

Vol 9 (10) ◽

pp. 2098

Author(s):

Maryam Norouzi ◽

Reza Saberi ◽

Maryam Niyyati ◽

Jacob Lorenzo-Morales ◽

Hamed Mirjalali ◽

...

Keyword(s):

Contact Lenses ◽

Opportunistic Infections ◽

Acanthamoeba Keratitis ◽

Free Living ◽

Pathogenic Potential ◽

Ability Test ◽

Soft Contact Lenses ◽

Increased Risk ◽

Free Living Amoeba ◽

Causative Agents

Free-living amoeba (FLA) are ubiquitously distributed in the environment. However, they are also the causative agents of opportunistic infections in humans and other animals. A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. Moreover, FLA have been detected in various biofilms around the world. Therefore, the present study aimed to check for presence of FLA in samples from household biofilms in Iran and to characterize them at the molecular level. A total of 69 biofilm samples collected from showerheads, kitchen areas, and bathroom sinks were analyzed. Positive samples for FLA were characterized at the morphological and molecular levels. Furthermore, the results of morphology analysis indicated that 26.08% (18/69) of biofilm samples were positive for Acanthamoeba spp., Vermamoeba genus, and Vahlkampfiids. According to sequence analysis, five strains of Acanthamoeba isolates related to the T4 genotype and two strains belonged to the T2 genotype. In addition, the pathogenic potential of Acanthamoeba-positive isolates was conducted using the tolerance ability test. The results of BLASTn of Vermamoeba sequences were similar to what was expected for Vermamoeba vermiformis. The above-mentioned reasons revealed that the relative high contamination of household biofilm samples with FLA may pose a risk for people using soft contact lenses and for patients with traumatic cataract. Our finding proposes that filtration should be performed in shower heads and indicates the need to monitor people at increased risk of Acanthamoeba keratitis.

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