-
Middle East African Journal of... 2019Natural honey in spite of its usefulness is known to contain certain microorganisms. In the present study, we describe a case of after using topical honey administered...
Natural honey in spite of its usefulness is known to contain certain microorganisms. In the present study, we describe a case of after using topical honey administered by a traditional medicine therapist. A 32-year-old male came with red eye and blurred vision. The pain and other symptoms became more severe after the 1st week, with appearance of radial perineuritis at the cornea. A repeated interview revealed that 1 week before appearance of ocular symptoms, the patient had instilled a drop of natural honey in his left eye. Confocal microscopic cornea imaging demonstrated cyst and trophozoite of in the corneal stroma.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Adult; Honey; Humans; Male; Vision Disorders
PubMed: 32153338
DOI: 10.4103/meajo.MEAJO_56_18 -
The Journal of Eukaryotic Microbiology 2015Acanthamoebae are the causative agents of an often seriously progressing keratitis (AK) occurring predominantly in contact lens wearers and can cause several... (Review)
Review
Acanthamoebae are the causative agents of an often seriously progressing keratitis (AK) occurring predominantly in contact lens wearers and can cause several disseminating infections potentially resulting in granulomatous amoebic encephalitis (GAE) in the immunocompromised host. Our institution is the Austrian reference laboratory for Acanthamoeba diagnostics and the aim of this study was to give an overview of proven cases of Acanthamoeba infections in Austria during the past 20 yr. All samples of patients with suspected AK or GAE were screened for Acanthamoeba spp. by culture and/or PCR and the detected amoebae were genotyped. Altogether, 154 cases of AK and three cases of GAE were diagnosed. Age of the AK patients ranged from 8 to 82 yr (mean 37.8) and 58% of the patients were female. Approximately 89% of the AK patients were contact lens wearers, almost all cases were unilateral and 19% of the patients required a keratoplasty. Age of the GAE patients ranged from 2 to 25 yr (mean 14.7), all were HIV-negative, but two were severely immunosuppressed at the time of diagnosis. The predominant genotype in the AK cases was T4, other genotypes found were T3, T5, T6, T10 and T11. The three GAE cases involved genotypes T2, T4 and T5.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Adolescent; Adult; Aged; Aged, 80 and over; Amebiasis; Child; Child, Preschool; Contact Lenses; Corneal Transplantation; Encephalitis; Female; Genotype; Humans; Immunocompromised Host; Male; Middle Aged
PubMed: 25047131
DOI: 10.1111/jeu.12149 -
Journal of Clinical Microbiology Jan 2021is a free-living amoeba of extensive genetic diversity. It may cause infectious keratitis (IK), which can also be caused by bacteria, fungi, and viruses. High...
Detection and Identification of and Other Nonviral Causes of Infectious Keratitis in Corneal Scrapings by Real-Time PCR and Next-Generation Sequencing-Based 16S-18S Gene Analysis.
is a free-living amoeba of extensive genetic diversity. It may cause infectious keratitis (IK), which can also be caused by bacteria, fungi, and viruses. High diagnostic sensitivity is essential to establish an early diagnosis of -associated keratitis. Here, we investigated the applicability of next-generation sequencing (NGS)-based ribosomal gene detection and differentiation (16S-18S) compared with specific real-time PCR for the detection of Two hundred DNAs extracted from corneal scrapings and screened by -specific real-time PCR were analyzed using an in-house 16S-18S NGS assay. Of these, 24 were positive by specific real-time PCR, of which 21 were positive by the NGS assay. Compared with real-time PCR; the specificity and sensitivity of the NGS assay were 100% and 88%, respectively. Genotypes identified by the NGS assay included T4 ( = 19) and T6 ( = 2). Fungal and bacterial species of potential clinical relevance were identified in 31 of the samples negative for , exemplified by ( = 11), spp. ( = 6), ( = 2), spp. ( = 4), and ( = 1). In conclusion, the 16S-18S assay was slightly less sensitive than real-time PCR in detecting -specific DNA in corneal scrapings. Robust information on genotypes was provided by the NGS assay, and other pathogens of potential clinical relevance were identified in 16% of the samples negative for NGS-based detection of ribosomal genes in corneal scrapings could be an efficient screening method for detecting nonviral causes of IK, including .
Topics: Acanthamoeba; Acanthamoeba Keratitis; High-Throughput Nucleotide Sequencing; Humans; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 33239372
DOI: 10.1128/JCM.02224-20 -
Parasitology Jun 2020Free-living amoebae (FLA) are widely dispersed in the environment, can cause opportunistic and non-opportunistic infections in humans and other animals. The aim of the...
Free-living amoebae (FLA) are widely dispersed in the environment, can cause opportunistic and non-opportunistic infections in humans and other animals. The aim of the present study was characterize FLA obtained from air-conditioners of a public hospital in the city of Florianópolis, SC, Brazil. Fifty-four dust samples were collected of air conditioners, and were inoculated on 1.5% non-nutrient agar, overlaid with layers of Escherichia coli. Subsequently the isolates were axenised in PYG growth medium. The morphological and molecular characterization of the isolates was performed, as well as the tolerance (physiological) assays were used to evaluate the pathogenic potential. The results revealed the presence of FLA in 42 (77.8%) of the collected samples. Of these, 39 (92.9%) axenic isolates of FLA were obtained for morphological and genotypic studies. All the isolates characterized belong to the genus Acanthamoeba. Nineteen (48.7%) isolates belong to the genotype T4, 16 (41.0%) to the T5 genotype and 4 (10.3%) to genotype T11. Seven (18.0%) isolates were considered potentially pathogenic in tolerance assays. These findings require attention, considering the isolation environment and immunocompromised characteristics of many hospitalized patients.
Topics: Acanthamoeba; Air; Air Conditioning; Air Pollution; Brazil; Genotype; Hospitals
PubMed: 32183918
DOI: 10.1017/S0031182020000487 -
FEMS Microbiology Reviews Jul 2006Acanthamoeba is an opportunistic protozoan that is widely distributed in the environment and is well recognized to produce serious human infections, including a blinding... (Review)
Review
Acanthamoeba is an opportunistic protozoan that is widely distributed in the environment and is well recognized to produce serious human infections, including a blinding keratitis and a fatal encephalitis. This review presents our current understanding of the burden of Acanthamoeba infections on human health, their pathogenesis and pathophysiology, and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be targets for therapeutic interventions and/or the development of preventative measures.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Amebiasis; Animals; Central Nervous System Protozoal Infections; Disease Vectors; Host-Parasite Interactions; Humans; Skin Diseases, Parasitic; Virulence
PubMed: 16774587
DOI: 10.1111/j.1574-6976.2006.00023.x -
Parasitology Research Sep 2021Acanthamoeba spp. are among the most worldwide prevalent protozoa. It is the causative agent of a disease known as Acanthamoeba keratitis, a painful and severe... (Review)
Review
Acanthamoeba spp. are among the most worldwide prevalent protozoa. It is the causative agent of a disease known as Acanthamoeba keratitis, a painful and severe sight-threatening corneal infection that can lead to blindness. In recent years, the prevalence of Acanthamoeba keratitis has rapidly increased, growing its importance to human health. This systematic review aims to assess the distribution of Acanthamoeba sp. genotypes causing keratitis around the world, considering the sample collected type and the used identification method. Most of the cases were found in Asia and Europe. Not surprisingly, the T4 genotype was the most prevalent worldwide, followed by T3, T15, T11, and T5. Furthermore, the T4 genotype contains a higher number of species. Given the differences in pathology, susceptibility to treatment, and clinical outcome between distinct genotypes, it is essential to genotype isolates from Acanthamoeba keratitis cases to help to establish a better correlation between in vitro and in vivo activities, resulting in better drug therapies and successful treatment in cases of this important ocular infection.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Cornea; Genotype; Humans
PubMed: 34351492
DOI: 10.1007/s00436-021-07261-1 -
Annals of Parasitology 2018Acanthamoeba, an opportunistic protozoan parasite, is distributed in the environment globally, causes serious human infections, including a fatal encephalitis and... (Meta-Analysis)
Meta-Analysis
Acanthamoeba, an opportunistic protozoan parasite, is distributed in the environment globally, causes serious human infections, including a fatal encephalitis and keratitis. The purpose of this study was to evaluate the prevalence and genotyping of Acanthamoeba spp. from different water and soil sources in Iran. Six English language and four Persian language databases were searched to identify studies published from March 2005 to October 2016. Random effect model and Stats Direct statistical software was used for the meta-analysis. This review resulted in a total 34 articles meeting the including criteria. The overall prevalence rate of Acanthamoeba spp. among the 1850 water and soil samples in Iran with using random-effect model was estimated 42.7%. The genotyping results of the Acanthamoeba isolates showed that T4 (81.2%) was a predominant strain in Iran. In addition, other genotypes, T2, T3, T4, T5, T6, T11, T13, T15, mixed T3/T4 and mixed T2/T6, were obtained in the environmental samples of Iran. This study may be the first systematic review and meta-analysis of Acanthamoeba prevalence and genotyping in different environmental sources of Iran. Knowledge about wide distribution of Acanthamoeba T4 in the environmental sources may help physicians to manage the patients and susceptible persons in Iran.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Genotype; Humans; Iran; Soil; Water
PubMed: 30710471
DOI: 10.17420/ap6404.163 -
The Korean Journal of Parasitology Sep 2004Acanthamoeba and Naegleria are widely distributed in fresh water, soil and dust throughout the world, and cause meningoencephalitis or keratoconjunctivitis in humans and... (Review)
Review
Acanthamoeba and Naegleria are widely distributed in fresh water, soil and dust throughout the world, and cause meningoencephalitis or keratoconjunctivitis in humans and other mammals. Korean isolates, namely, Naegleria sp. YM-1 and Acanthamoeba sp. YM-2, YM-3, YM-4, YM-5, YM-6 and YM-7, were collected from sewage, water puddles, a storage reservoir, the gills of a fresh water fish, and by corneal washing. These isolates were categorized into three groups based on the mortalities of infected mice namely, highly virulent (YM-4), moderately virulent (YM-2, YM-5 and YM-7) and nonpathogenic (YM-3). In addition, a new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Korean isolate YM-4. The morphologic characters of its cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Based on experimentally infected mouse mortality, Acanthamoeba YM-4 was highly virulent. The isoenzymes profile of Acanthamoeba YM-4 was similar to that of A. royreba. Moreover, an anti-Acanthamoeba YM-4 monoclonal antibody reacted only with Acanthamoeba YM-4, and not with A. culbertsoni. Random amplified polymorphic DNA marker analysis and RFLP analysis of mitochondrial DNA and of a 18S small subunit ribosomal RNA, placed Acanthamoeba YM-4 in a separate cluster based on phylogenic distances. Thus Acanthamoeba YM-4 was identified as a new species, and assigned Acanthamoeba sohi. Up to the year 2002 in Korea, two clinical cases were found to be infected with Acanthamoeba spp. These patients died of meningoencephalitis. In addition, one case of Acanthamoeba pneumonia with an immunodeficient status was reported and Acanthamoeba was detected in several cases of chronic relapsing corneal ulcer, chronic conjunctivitis, and keratitis.
Topics: Acanthamoeba; Amebiasis; Animals; Antigens, Protozoan; DNA, Mitochondrial; DNA, Protozoan; Korea; Life Cycle Stages; Naegleria; Phylogeny; Polymorphism, Restriction Fragment Length; Random Amplified Polymorphic DNA Technique; Virulence
PubMed: 15381859
DOI: 10.3347/kjp.2004.42.3.93 -
Parasites & Vectors Jan 2018Acanthamoeba spp. are protist pathogens and causative agents of serious infections including keratitis and granulomatous amoebic encephalitis. Its ability to convert... (Review)
Review
Acanthamoeba spp. are protist pathogens and causative agents of serious infections including keratitis and granulomatous amoebic encephalitis. Its ability to convert into dormant and highly resistant cysts form limits effectiveness of available therapeutic agents and presents a pivotal challenge for drug development. During the cyst stage, Acanthamoeba is protected by the presence of hardy cyst walls, comprised primarily of carbohydrates and cyst-specific proteins, hence synthesis inhibition and/or degradation of cyst walls is of major interest. This review focuses on targeting of Acanthamoeba cysts by identifying viable therapeutic targets.
Topics: Acanthamoeba; Amebiasis; Antiprotozoal Agents; Drug Discovery; Humans; Spores, Protozoan
PubMed: 29316961
DOI: 10.1186/s13071-017-2572-z -
Scientific Reports Oct 2022Humans and Acanthamoeba polyphaga mimivirus share numerous homologous genes, including collagens and collagen-modifying enzymes. To explore this homology, we performed a... (Comparative Study)
Comparative Study
Humans and Acanthamoeba polyphaga mimivirus share numerous homologous genes, including collagens and collagen-modifying enzymes. To explore this homology, we performed a genome-wide comparison between human and mimivirus using DELTA-BLAST (Domain Enhanced Lookup Time Accelerated BLAST) and identified 52 new putative mimiviral proteins that are homologous with human proteins. To gain functional insights into mimiviral proteins, their human protein homologs were organized into Gene Ontology (GO) and REACTOME pathways to build a functional network. Collagen and collagen-modifying enzymes form the largest subnetwork with most nodes. Further analysis of this subnetwork identified a putative collagen glycosyltransferase R699. Protein expression test suggested that R699 is highly expressed in Escherichia coli, unlike the human collagen-modifying enzymes. Enzymatic activity assay and mass spectrometric analyses showed that R699 catalyzes the glucosylation of galactosylhydroxylysine to glucosylgalactosylhydroxylysine on collagen using uridine diphosphate glucose (UDP-glucose) but no other UDP-sugars as a sugar donor, suggesting R699 is a mimiviral collagen galactosylhydroxylysyl glucosyltransferase (GGT). To facilitate further analysis of human and mimiviral homologous proteins, we presented an interactive and searchable genome-wide comparison website for quickly browsing human and Acanthamoeba polyphaga mimivirus homologs, which is available at RRID Resource ID: SCR_022140 or https://guolab.shinyapps.io/app-mimivirus-publication/ .
Topics: Acanthamoeba; Collagen; Genomics; Glucose; Glucosyltransferases; Glycosyltransferases; Humans; Mimiviridae; Sugars; Uridine Diphosphate Glucose; Viral Proteins
PubMed: 36207453
DOI: 10.1038/s41598-022-21197-1