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Akbar N, Khan AS, Siddiqui R, Ibrahim TH, Khamis MI, Alawfi BS, Al-Ahmadi BM, Khan NA. Phosphonium chloride-based deep eutectic solvents inhibit pathogenic Acanthamoeba castellanii belonging to the T4 genotype. Folia Microbiol (Praha) 2024:10.1007/s12223-024-01180-1. [PMID: 38869777 DOI: 10.1007/s12223-024-01180-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 05/26/2024] [Indexed: 06/14/2024]
Abstract
Herein, we investigated the anti-amoebic activity of phosphonium-chloride-based deep eutectic solvents against pathogenic Acanthamoeba castellanii of the T4 genotype. Deep eutectic solvents are ionic fluids composed of two or three substances, capable of self-association to form a eutectic mixture with a melting point lower than each substance. In this study, three distinct hydrophobic deep eutectic solvents were formulated, employing trihexyltetradecylphosphonium chloride as the hydrogen bond acceptor and aspirin, dodecanoic acid, and 4-tert-butylbenzoic acid as the hydrogen bond donors. Subsequently, all three deep eutectic solvents, denoted as DES1, DES2, DES3 formulations, underwent investigations comprising amoebicidal, adhesion, excystation, cytotoxicity, and cytopathogenicity assays. The findings revealed that DES2 was the most potent anti-amoebic agent, with a 94% elimination rate against the amoebae within 24 h at 30 °C. Adhesion assays revealed that deep eutectic solvents hindered amoebae adhesion to human brain endothelial cells, with DES2 exhibiting 88% reduction of adhesion. Notably, DES3 exhibited remarkable anti-excystation properties, preventing 94% of cysts from reverting to trophozoites. In cytopathogenicity experiments, deep eutectic solvent formulations and dodecanoic acid alone reduced amoebae-induced human brain endothelial cell death, with DES2 showing the highest effects. Lactate dehydrogenase assays revealed the minimal cytotoxicity of the tested deep eutectic solvents, with the exception of trihexyltetradecylphosphonium chloride, which exhibited 35% endothelial cell damage. These findings underscore the potential of specific deep eutectic solvents in combating pathogenic Acanthamoeba, presenting promising avenues for further research and development against free-living amoebae.
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Affiliation(s)
- Noor Akbar
- Research Institute of Medical and Health Sciences, University of Sharjah, 27272, Sharjah, United Arab Emirates.
- Department of Chemical Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates.
| | - Amir Sada Khan
- Department of Chemical Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates
- Department of Chemistry, University of Science and Technology Bannu, Bannu, 28100, Khyber Pakhtunkhwa, Pakistan
| | - Ruqaiyyah Siddiqui
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University Edinburgh, Edinburgh, EH14 4AS, UK
- Microbiota Research Center, Istinye University, Istanbul, 34010, Turkey
| | - Taleb Hassan Ibrahim
- Department of Chemical Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates
| | - Mustafa I Khamis
- College of Arts and Sciences, American University of Sharjah, 26666, Sharjah, United Arab Emirates
| | - Bader S Alawfi
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taibah University, Medina, Saudi Arabia
| | - Bassam M Al-Ahmadi
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taibah University, Medina, Saudi Arabia
| | - Naveed Ahmed Khan
- Microbiota Research Center, Istinye University, Istanbul, 34010, Turkey.
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Pezeshki A, Tajic S, Farahmandian P, Haniloo A, Mahmmodzadeh A, Niyyati M, Behniafar H. Phylogenetic analysis of Acanthamoeba isolated from soil samples and nasal cavities of patients with malignancy: a public health concern in the northwest of Iran. Trans R Soc Trop Med Hyg 2024; 118:367-375. [PMID: 38240056 DOI: 10.1093/trstmh/trad100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/28/2023] [Accepted: 12/22/2023] [Indexed: 06/05/2024] Open
Abstract
BACKGROUND The genus Acanthamoeba is reported from various environmental sources and can cause multiple complications, including chronic amoebic aeratitis and amoebic granulomatous encephalitis. This study investigated the presence and genotyping of Acanthamoeba in the soil of parks and patients with malignancies referred to health centers in Zanjan city, Iran. METHODS In this cross-sectional study, 200 soil samples were collected from amusement parks in Zanjan city from September 2017 to May 2018. Samples were cultured on 1.5% non-nutrient agar, and the Acanthamoeba genus was identified using the morphological method. PCR was performed on all positive environmental samples, and six microscopically positive clinical samples belonged to our previous study. DNA sequencing of 18S rRNA was performed to analyze the genetic pattern of some PCR-positive isolates. RESULTS Microscopic results showed that 96 (48%) soil samples were positive. PCR confirmed all positive cases of clinical samples and 84 soil samples. Out of the PCR-positive samples, 20 soil samples and five clinical samples were sequenced successfully. All soil isolates belonged to the T4 genotype, and three and two clinical samples belonged to T4 and T5 genotypes, respectively. CONCLUSION : The presence of Acanthamoeba in both the environment and clinical samples of Zanjan city suggests paying greater attention to the infections caused by it.
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Affiliation(s)
- Ali Pezeshki
- Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, 45331 Zanjan, Iran
| | - Shadi Tajic
- Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, 45331 Zanjan, Iran
| | - Parvin Farahmandian
- Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, 45331 Zanjan, Iran
| | - Ali Haniloo
- Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, 45331 Zanjan, Iran
| | - Abbas Mahmmodzadeh
- Department of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, 45331 Zanjan, Iran
| | - Maryam Niyyati
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, 1701706 Tehran, Iran
| | - Hamed Behniafar
- Department of Medical Parasitology, Sarab Faculty of Medical Sciences, 54731 Sarab, East Azerbaijan, Iran
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Ali M, Rice CA, Byrne AW, Paré PE, Beauvais W. Modelling dynamics between free-living amoebae and bacteria. Environ Microbiol 2024; 26:e16623. [PMID: 38715450 DOI: 10.1111/1462-2920.16623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 04/04/2024] [Indexed: 05/23/2024]
Abstract
Free-living amoebae (FLA) serve as hosts for a variety of endosymbionts, which are microorganisms that reside and multiply within the FLA. Some of these endosymbionts pose a pathogenic threat to humans, animals, or both. The symbiotic relationship with FLA not only offers these microorganisms protection but also enhances their survival outside their hosts and assists in their dispersal across diverse habitats, thereby escalating disease transmission. This review is intended to offer an exhaustive overview of the existing mathematical models that have been applied to understand the dynamics of FLA, especially concerning their interactions with bacteria. An extensive literature review was conducted across Google Scholar, PubMed, and Scopus databases to identify mathematical models that describe the dynamics of interactions between FLA and bacteria, as published in peer-reviewed scientific journals. The literature search revealed several FLA-bacteria model systems, including Pseudomonas aeruginosa, Pasteurella multocida, and Legionella spp. Although the published mathematical models account for significant system dynamics such as predator-prey relationships and non-linear growth rates, they generally overlook spatial and temporal heterogeneity in environmental conditions, such as temperature, and population diversity. Future mathematical models will need to incorporate these factors to enhance our understanding of FLA-bacteria dynamics and to provide valuable insights for future risk assessment and disease control measures.
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Affiliation(s)
- Marwa Ali
- Comparative Pathobiology Department, Purdue Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
| | - Christopher A Rice
- Comparative Pathobiology Department, Purdue Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute for Drug Discovery (PIDD), Purdue University, West Lafayette, Indiana, USA
- Purdue Institute of Inflammation, Immunology and Infectious Disease (PI4D), Purdue University, West Lafayette, Indiana, USA
- Regenstrief Center for Healthcare Engineering (RHCE), Purdue University, West Lafayette, Indiana, USA
| | - Andrew W Byrne
- One Health Scientific Support Unit, National Disease Control Centre, Agriculture House, Dublin, Ireland
| | - Philip E Paré
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana, USA
| | - Wendy Beauvais
- Comparative Pathobiology Department, Purdue Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute of Inflammation, Immunology and Infectious Disease (PI4D), Purdue University, West Lafayette, Indiana, USA
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Rao K, Abdullah M, Ahmed U, Wehelie HI, Shah MR, Siddiqui R, Khan NA, Alawfi BS, Anwar A. Self-assembled micelles loaded with itraconazole as anti-Acanthamoeba nano-formulation. Arch Microbiol 2024; 206:134. [PMID: 38433145 DOI: 10.1007/s00203-024-03854-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 01/13/2024] [Accepted: 01/17/2024] [Indexed: 03/05/2024]
Abstract
Acanthamoeba castellanii are opportunistic pathogens known to cause infection of the central nervous system termed: granulomatous amoebic encephalitis, that mostly effects immunocompromised individuals, and a sight threatening keratitis, known as Acanthamoeba keratitis, which mostly affects contact lens wearers. The current treatment available is problematic, and is toxic. Herein, an amphiphilic star polymer with AB2 miktoarms [A = hydrophobic poly(ℇ-Caprolacton) and B = hydrophilic poly (ethylene glycol)] was synthesized by ring opening polymerization and CuI catalyzed azide-alkyne cycloaddition. Characterization by 1H and 13C NMR spectroscopy, size-exclusion chromatography and fluorescence spectroscopy was accomplished. The hydrophobic drug itraconazole (ITZ) was incorporated in self-assembled micellar structure of AB2 miktoarms through co-solvent evaporation. The properties of ITZ loaded (ITZ-PCL-PEG2) and blank micelles (PCL-PEG2) were investigated through zeta sizer, scanning electron microscopy and Fourier-transform infrared spectroscopy. Itraconazole alone (ITZ), polymer (DPB-PCL), empty polymeric micelles (PCL-PEG2) alone, and itraconazole loaded in polymeric micelles (ITZ-PCL-PEG2) were tested for anti-amoebic potential against Acanthamoeba, and the cytotoxicity on human cells were determined. The polymer was able to self-assemble in aqueous conditions and exhibited low value for critical micelle concentration (CMC) 0.05-0.06 µg/mL. The maximum entrapment efficiency of ITZ was 68%. Of note, ITZ, DPB, PCL-PEG2 and ITZ-PCL-PEG2 inhibited amoebae trophozoites by 37.34%, 36.30%, 35.77%, and 68.24%, respectively, as compared to controls. Moreover, ITZ-PCL-PEG2 revealed limited cytotoxicity against human keratinocyte cells. These results are indicative that ITZ-PCL-PEG2 micelle show significantly better anti-amoebic effects as compared to ITZ alone and thus should be investigated further in vivo to determine its clinical potential.
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Affiliation(s)
- Komal Rao
- International Center for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, Karachi University, Karachi, 75270, Pakistan
| | - Muhammad Abdullah
- International Center for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, Karachi University, Karachi, 75270, Pakistan
| | - Usman Ahmed
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Hashi Isse Wehelie
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Muhammad Raza Shah
- International Center for Chemical and Biological Sciences, HEJ Research Institute of Chemistry, Karachi University, Karachi, 75270, Pakistan
| | - Ruqaiyyah Siddiqui
- Institute of Biological Chemistry, Biophysics and Bioengineering, Heriot-Watt University Edinburgh, Edinburgh, EH14 4AS, UK
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey
| | - Naveed A Khan
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey.
| | - Bader S Alawfi
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taibah University, 42353, Madinah, Saudi Arabia
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia.
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Latifi A, Esmaeili F, Mohebali M, Yasami-Khiabani S, Rezaeian M, Soleimani M, Kazemirad E, Amani A. Chitosan nanoparticles improve the effectivity of miltefosine against Acanthamoeba. PLoS Negl Trop Dis 2024; 18:e0011976. [PMID: 38527059 PMCID: PMC10962830 DOI: 10.1371/journal.pntd.0011976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 02/07/2024] [Indexed: 03/27/2024] Open
Abstract
BACKGROUND Acanthamoeba keratitis (AK) is a corneal sight-threatening infection caused by the free-living amoebae of the genus Acanthamoeba. Early and appropriate treatment significantly impacts visual outcomes. Mucoadhesive polymers such as chitosan are a potential strategy to prolong the residence time and bioavailability of the encapsulated drugs in the cornea. Regarding the recent administration of miltefosine (MF) for treating resistant AK, in the present study, we synthesized miltefosine-loaded chitosan nanoparticles (MF-CS-NPs) and evaluated them against Acanthamoeba. METHODOLOGY/PRINCIPAL FINDINGS Chitosan nanoparticles (CNPs) were prepared using the ionic gelation method with negatively charged tripolyphosphate (TPP). The zeta-potential (ZP) and the particle size of MF-CS-NPs were 21.8±3.2 mV and 46.61±18.16 nm, respectively. The release profile of MF-CS-NPs indicated linearity with sustained drug release. The cytotoxicity of MF-CS-NPs on the Vero cell line was 2.67 and 1.64 times lower than free MF at 24 and 48 hours. This formulation exhibited no hemolytic activity in vitro and ocular irritation in rabbit eyes. The IC50 of MF-CS-NPs showed a significant reduction by 2.06 and 1.69-fold in trophozoites at 24 and 48 hours compared to free MF. Also, the MF-CS-NPs IC50 in the cysts form was slightly decreased by 1.26 and 1.21-fold at 24 and 48 hours compared to free MF. CONCLUSIONS The MF-CS-NPs were more effective against the trophozoites and cysts than free MF. The nano-chitosan formulation was more effective on trophozoites than the cysts form. MF-CS-NPs reduced toxicity and improved the amoebicidal effect of MF. Nano-chitosan could be an ideal carrier that decreases the cytotoxicity of miltefosine. Further analysis in animal settings is needed to evaluate this nano-formulation for clinical ocular drug delivery.
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Affiliation(s)
- Alireza Latifi
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Fariba Esmaeili
- Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Mohebali
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Center for Research of Endemic Parasites of Iran (CREPI), Tehran University of Medical Sciences, Tehran, Iran
| | | | - Mostafa Rezaeian
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Soleimani
- Department of Ocular Trauma and Emergency, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Elham Kazemirad
- Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Amir Amani
- Natural products and medicinal plants Research center, North Khorasan University of Medical Sciences, Bojnurd, Iran
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Ilyas M, Stapleton F, Willcox MDP, Henriquez F, Peguda HK, Rayamajhee B, Zahid T, Petsoglou C, Carnt NA. Epidemiology of and Genetic Factors Associated with Acanthamoeba Keratitis. Pathogens 2024; 13:142. [PMID: 38392880 PMCID: PMC10892102 DOI: 10.3390/pathogens13020142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/14/2024] [Accepted: 01/31/2024] [Indexed: 02/25/2024] Open
Abstract
Acanthamoeba keratitis (AK) is a severe, rare protozoal infection of the cornea. Acanthamoeba can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens wearers whose lenses have become contaminated or who have a history of water exposure, and in those without contact lens wear who have experienced recent eye trauma involving contaminated soil or water. Infection usually results in severe eye pain, photophobia, inflammation, and corneal epithelial defects. The pathophysiology of this infection is multifactorial, including the production of cytotoxic proteases by Acanthamoeba that degrades the corneal epithelial basement membrane and induces the death of ocular surface cells, resulting in degradation of the collagen-rich corneal stroma. AK can be prevented by avoiding risk factors, which includes avoiding water contact, such as swimming or showering in contact lenses, and wearing protective goggles when working on the land. AK is mostly treated with an antimicrobial therapy of biguanides alone or in combination with diaminidines, although the commercial availability of these medicines is variable. Other than anti-amoeba therapies, targeting host immune pathways in Acanthamoeba disease may lead to the development of vaccines or antibody therapeutics which could transform the management of AK.
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Affiliation(s)
- Muhammad Ilyas
- Primary & Secondary Healthcare Department, Punjab 54000, Pakistan; (M.I.)
| | - Fiona Stapleton
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Mark D. P. Willcox
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Fiona Henriquez
- School of Health and Life Sciences, The University of the West of Scotland, Glasgow G72 0LH, UK
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Binod Rayamajhee
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Tasbiha Zahid
- Primary & Secondary Healthcare Department, Punjab 54000, Pakistan; (M.I.)
| | | | - Nicole A. Carnt
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
- Centre for Vision Research, Westmead Institute for Medical Research, Sydney, NSW 2145, Australia
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Pang J, Wei Z, Wang L, Guo X, Chen Q, Wei Y, Peng Y, Zhang Z, Zhang Y, Liu J, Cheng Z, Wang Z, Zhang Y, Chen K, Xu X, Lu X, Liang Q. Acanthamoeba Keratitis in China: Genotypic and Clinical Correlations. Transl Vis Sci Technol 2024; 13:5. [PMID: 38329750 PMCID: PMC10860683 DOI: 10.1167/tvst.13.2.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/31/2023] [Indexed: 02/09/2024] Open
Abstract
Purpose To investigate the relationship between Acanthamoeba genotypes, clinical manifestations, and outcomes in Acanthamoeba keratitis (AK) patients. Methods This retrospective study included 159 culture-confirmed AK patients. Patients' data were collected, including demographics, initial diagnosis, treatments, and clinical features. The genotype of Acanthamoeba was identified through sequencing the Diagnostic Fragment 3 (DF3) region in the small ribosomal subunit RNA genes. The phylogenetic tree was constructed using the ClustalW model and maximum likelihood method. Cases with "poor outcome" were defined based on specific clinical criteria, including corneal perforation, keratoplasty, other eye surgery, duration of anti-amoebic therapy ≥8.0 months, and final visual acuity ≤20/80. "Better outcome" cases were the remainder. The correlation between T4 subtypes, clinical phenotypes, and clinical prognosis were further analyzed. Results In this study, AK was primarily attributed to the T4A genotype, with a positive correlation between geographical and genetic distances. The primary clinical associated with T4 subtypes was deep stromal infiltration. Results was also showed a significant association between T4 subtypes and clinical outcomes (P = 0.021). Further analysis revealed that T4C was closely associated with a better prognosis (P = 0.040) and T4D with worse outcomes (P = 0.013). Conclusions In China, AK was predominantly caused by the T4A subtype. Geographical distance positively correlated with genetic distance. Clinical prognosis varied among different subtypes, notably in T4C and T4D. Translational Relevance This study demonstrated the association between T4 subtypes and clinical phenotypes, as well as the effects of T4 subtypes on clinical prognosis.
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Affiliation(s)
- Jinding Pang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhenyu Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Leying Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiaoyan Guo
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qiankun Chen
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuan Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yan Peng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zijun Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuheng Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Jiamin Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhen Cheng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhiqun Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yang Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Kexin Chen
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xizhan Xu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xinxin Lu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qingfeng Liang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
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Pourabbasi Ardekan A, Niyyati M, Saberi R, Zanjirani Farahani L, Fatemi M. Isolation and genotyping of Acanthamoeba species and Vahlkampfiidae in the harsh environmental conditions in the centre of Iran. JOURNAL OF WATER AND HEALTH 2023; 21:1572-1579. [PMID: 37902210 PMCID: wh_2023_203 DOI: 10.2166/wh.2023.203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
Different species of free-living amoeba (FLA) have been abundantly isolated in harsh environmental conditions such as hot springs and brackish water. The present study aimed to isolate, genotype, and evaluate the pathogenicity of FLAs in Qom Roud, a large river, in the centre of Iran. About 500 mL of water samples (n = 30) were collected from each sampling site and were investigated for the presence of FLAs using morphological and molecular characters. Genotype identification was performed using DNA sequencing and a phylogenetic tree was constructed with the MEGA X software. The pathogenic potential of all positive isolates was evaluated using the tolerance ability test. Morphological and molecular analysis indicated that 14 (46.66%) and two (6.66%) water samples were positive for Acanthamoeba species and Vahlkampfiidae, respectively. According to sequence analysis, Acanthamoeba isolates related to the T4 genotype and Vahlkampfiidae sequences were similar to Naegleria philippinensis. In the next step, thermo- and osmotolerance tests indicated four Acanthamoeba strains are extremely pathogenic. Our data showed the presence of potentially pathogenic Acanthamoeba T4 genotype and N. philippinensis in the super harsh Qom Roud. Contamination of water with virulent T4 genotype of Acanthamoeba may pose risk factors for contact lens users, children, and immunocompromised people.
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Affiliation(s)
- Azam Pourabbasi Ardekan
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran E-mail:
| | - Maryam Niyyati
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Saberi
- Toxoplasmosis Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Mazandaran, Iran
| | - Leyli Zanjirani Farahani
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Marziye Fatemi
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Abdul Halim R, Mohd Hussain RH, Aazmi S, Halim H, Ahmed Khan N, Siddiqui R, Shahrul Anuar T. Molecular characterisation and potential pathogenicity analysis of Acanthamoeba isolated from recreational lakes in Peninsular Malaysia. JOURNAL OF WATER AND HEALTH 2023; 21:1342-1356. [PMID: 37756200 PMCID: wh_2023_186 DOI: 10.2166/wh.2023.186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
The present study aims to identify the Acanthamoeba genotypes and their pathogenic potential in three recreational lakes in Malaysia. Thirty water samples were collected by purposive sampling between June and July 2022. Physical parameters of water quality were measured in situ while chemical and microbiological analyses were performed in the laboratory. The samples were vacuum filtered through nitrate filter, cultured onto non-nutrient agar and observed microscopically for amoebic growth. DNAs from positive samples were extracted and made to react with polymerase chain reaction using specific primers. Physiological tolerance tests were performed for all Acanthamoeba-positive samples. The presence of Acanthamoeba was found in 26 of 30 water samples by PCR. The highest rate in lake waters contaminated with amoeba was in Biru Lake (100%), followed by Titiwangsa Lake (80%) and Shah Alam Lake (80%). ORP, water temperature, pH and DO were found to be significantly correlated with the presence of Acanthamoeba. The most common genotype was T4. Temperature- and osmo-tolerance tests showed that 8 (30.8%) of the genotypes T4, T9 and T11 were highly pathogenic. The presence of genotype T4 in habitats related to human activities supports the relevance of this amoeba as a potential public health concern.
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Affiliation(s)
- Rohaya Abdul Halim
- Centre for Medical Laboratory Technology Studies, Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam Campus, Puncak Alam, Selangor, Malaysia E-mail:
| | - Rosnani Hanim Mohd Hussain
- Centre for Medical Laboratory Technology Studies, Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam Campus, Puncak Alam, Selangor, Malaysia
| | - Shafiq Aazmi
- School of Biology, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor, Malaysia; Microbiome Health and Environment (MiHeaRT), Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor, Malaysia
| | - Hasseri Halim
- Faculty of Pharmacy, Universiti Teknologi MARA, Puncak Alam Campus, Puncak Alam, Selangor, Malaysia; Integrative Pharmacogenomics Institute, Universiti Teknologi MARA, Puncak Alam Campus, Puncak Alam, Selangor, Malaysia
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates; Department of Medical Biology, Faculty of Medicine, Istinye University, Istanbul, Turkey
| | - Ruqaiyyah Siddiqui
- Department of Medical Biology, Faculty of Medicine, Istinye University, Istanbul, Turkey; College of Arts and Sciences, American University of Sharjah, Sharjah, United Arab Emirates
| | - Tengku Shahrul Anuar
- Centre for Medical Laboratory Technology Studies, Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam Campus, Puncak Alam, Selangor, Malaysia; Microbiome Health and Environment (MiHeaRT), Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor, Malaysia
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10
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Connelly L, Anijeet D, Tole D, Alexander CL. Acanthamoeba keratitis: Molecular typing of Acanthamoeba species directly from ocular tissue. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2023; 4:100141. [PMID: 37680763 PMCID: PMC10480524 DOI: 10.1016/j.crpvbd.2023.100141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/11/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023]
Abstract
This report explores the molecular profiling of Acanthamoeba spp. from individuals in the UK suffering from a debilitating, sight-threatening disease of the cornea known as Acanthamoeba keratitis (AK). Seventy ocular samples from individuals undergoing investigations for AK were sent to the Scottish Microbiology Reference Laboratories (SMiRL), Glasgow during 2017-2019, and subjected to DNA extraction followed by in-depth molecular typing using a nested PCR/bi-directional sequencing approach. Of the 70 samples tested, 40 were PCR-positive. Of these, 32 were successfully sequenced and assigned to two of 23 existing genotypes termed T1 to T23. Molecular profiling of the 32 samples highlighted two genotypes, namely T3 (n = 3) and T4 (n = 29). For those 29 samples identified as the T4 genotype, a sub-genotype (T4A-T4H) was recorded: T4A (n = 18); T4B (n = 5); T4C (n = 1); T4E (n = 4); and T4F (n = 1). This study highlights that the T4 genotype and T4A subtype are the predominant molecular variants to cause ocular disease in the UK. Gaining in-depth information on the molecular profiling of Acanthamoeba spp. is essential to increase our understanding of the source(s) of infection, transmission pathways, and potential associations with clinical outcomes for this rare, yet potentially debilitating ocular disease.
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Affiliation(s)
- Lisa Connelly
- Scottish Microbiology Reference Laboratories, Glasgow (SMiRL), Glasgow, UK
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11
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Loufouma Mbouaka A, Lesiak-Markowicz I, Heredero-Bermejo I, Mazumdar R, Walochnik J, Martín-Pérez T. Assessing Acanthamoeba cytotoxicity: comparison of common cell viability assays. Front Microbiol 2023; 14:1175469. [PMID: 37180263 PMCID: PMC10167018 DOI: 10.3389/fmicb.2023.1175469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/03/2023] [Indexed: 05/16/2023] Open
Abstract
Background In vitro models for studying interactions between Acanthamoeba and host cells are crucial for understanding the pathomechanism of Acanthamoeba and assessing differences between strains and cell types. The virulence of Acanthamoeba strains is usually assessed and monitored by using cell cytotoxicity assays. The aim of the present study was to evaluate and compare the most widely used cytotoxicity assays for their suitability to assess Acanthamoeba cytopathogenicity. Methods The viability of human corneal epithelial cells (HCECs) after co-culture with Acanthamoeba was evaluated in phase contrast microscopy. Results It was shown that Acanthamoeba is unable to considerably reduce the tetrazolium salt and the NanoLuc® Luciferase prosubstrate to formazan and the luciferase substrate, respectively. This incapacity helped to generate a cell density-dependent signal allowing to accurately quantify Acanthamoeba cytotoxicity. The lactate dehydrogenase (LDH) assay led to an underestimation of the cytotoxic effect of Acanthamoeba on HCECs since their co-incubation negatively affected the lactate dehydrogenase activity. Discussion Our findings demonstrate that cell-based assays using the aqueous soluble tetrazolium-formazan, and the NanoLuc® Luciferase prosubstrate products, in contrast to LDH, are excellent markers to monitor the interaction of Acanthamoeba with human cell lines and to determine and quantify effectively the cytotoxic effect induced by the amoebae. Furthermore, our data indicate that protease activity may have an impact on the outcome and thus the reliability of these tests.
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Affiliation(s)
- Alvie Loufouma Mbouaka
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Iwona Lesiak-Markowicz
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Irene Heredero-Bermejo
- Department of Biomedicine and Biotechnology, Faculty of Pharmacy, University of Alcalá, Madrid, Spain
| | - Rounik Mazumdar
- Max Perutz Labs Vienna, Department of Medical Biochemistry, Medical University of Vienna, Vienna, Austria
| | - Julia Walochnik
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Tania Martín-Pérez
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
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12
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Corsaro D, Venditti D. Molecular evidence for a new lineage within the Acanthamoeba T4 genotype. Parasitol Res 2023; 122:1445-1450. [PMID: 37046026 DOI: 10.1007/s00436-023-07844-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/05/2023] [Indexed: 04/14/2023]
Abstract
Acanthamoeba is a widespread free-living amoeba capable of causing serious infections in humans and other animals, such as amoebic keratitis, disseminated infections, and fatal encephalitis. Strain identification is usually based on 18S rDNA sequencing, which allows the distinction of over twenty genotypes. Most sequences from environmental and clinical samples belong to the T4 genotype, which can be divided into seven subtypes, T4A to T4G, and by a nearly similar grouping of mitochondrial sequences into T4a to T4j subtypes. The co-clustering of nuclear and mitochondrial groups can be very useful for a better identification of lineages within the very rich T4 genotype. In this study, we provided molecular phylogenetic evidence for the delineation of a new nuclear subtype, hereafter labelled T4H, and its co-clustering with the mitochondrial T4j subtype. At least three cases of amoebic keratitis are due to strains belonging to this new group, present mainly in fresh water and detected in various countries (France, Iran, India and China).
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Affiliation(s)
- Daniele Corsaro
- CHLAREAS, 12, rue du Maconnais, F-54500, Vandœuvre-lès-Nancy, France.
| | - Danielle Venditti
- CHLAREAS, 12, rue du Maconnais, F-54500, Vandœuvre-lès-Nancy, France
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13
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de Souza Fernandes N, Caliari MV, Oliveira FMS, Neto ABC, Rodrigues IA, Furst C, Costa AO. Experimental keratitis induced in rat by Acanthamoeba from distinct morphological groups/genotypes: a histological and immunohistochemical evaluation. Parasitol Res 2023; 122:1167-1175. [PMID: 36922408 DOI: 10.1007/s00436-023-07817-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 03/02/2023] [Indexed: 03/18/2023]
Abstract
Species of the genus Acanthamoeba are free-living protozoans that occasionally act as parasites, causing a severe, progressive corneal infection termed Acanthamoeba keratitis (AK). The variable pathogenic potential among Acanthamoeba lineages has been shown by in vitro assays, but little is known about the behavior of different strains in animal models of AK. This work aimed to evaluate the infectivity of Acanthamoeba from distinct morphological groups and genotypes in a rat model of AK and apply an immunohistochemical technique for histological characterization of the lesions. Only a strain classified as group I/genotype T17, isolated from a soil source, caused ulcerated corneal lesions in two Wistar rats (n = 9) subjected to intrastromal inoculation. Two strains derived from AK human cases (group II/genotype T4 and group III/genotype T5) did not induce corneal lesions in the rats. A previous association of group II/genotype T4 trophozoites with lethally irradiated Escherichia coli did not influence the infectivity. A hyperimmune serum produced in Wistar rats was validated by an immunocytochemical technique using the three distinct strains and then applied for immunohistochemistry. The abundance of antigenic residues was observed in both corneas with keratitis, suggesting that the infectious process tended to resolve. Despite the low infection rate of the AK Wistar rat model, we produced an immunochemical tool with a potential diagnostic application. We also showed for the first time the ability of Acanthamoeba from T17 genotype to cause AK in experimental conditions.
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Affiliation(s)
- Norberto de Souza Fernandes
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais (UFMG), Minas Gerais, Belo Horizonte, Brazil
| | - Marcelo Vidigal Caliari
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Fabricio Marcos Silva Oliveira
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | | | - Isabela Aurora Rodrigues
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais (UFMG), Minas Gerais, Belo Horizonte, Brazil
| | - Cinthia Furst
- Santa Casa de Misericórdia, Belo Horizonte, Minas Gerais, Brazil
| | - Adriana Oliveira Costa
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais (UFMG), Minas Gerais, Belo Horizonte, Brazil.
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14
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Abdelnasir S, Mungroo MR, Chew J, Siddiqui R, Khan NA, Ahmad I, Shahabuddin S, Anwar A. Applications of Polyaniline-Based Molybdenum Disulfide Nanoparticles against Brain-Eating Amoebae. ACS OMEGA 2023; 8:8237-8247. [PMID: 36910978 PMCID: PMC9996588 DOI: 10.1021/acsomega.2c06050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 12/16/2022] [Indexed: 06/18/2023]
Abstract
Primary amoebic meningoencephalitis and granulomatous amoebic encephalitis are distressing infections of the central nervous system caused by brain-eating amoebae, namely, Naegleria fowleri and Acanthamoeba spp., respectively, and present mortality rates of over 90%. No single drug has been approved for use against these infections, and current therapy is met with an array of obstacles including high toxicity and limited specificity. Thus, the development of alternative effective chemotherapeutic agents for the management of infections due to brain-eating amoebae is a crucial requirement to avert future mortalities. In this paper, we synthesized a conducting polymer-based nanocomposite entailing polyaniline (PANI) and molybdenum disulfide (MoS2) and explored its anti-trophozoite and anti-cyst potentials against Acanthamoeba castellanii and Naegleria fowleri. The intracellular generation of reactive oxygen species (ROS) and ultrastructural appearances of amoeba were also evaluated with treatment. Throughout, treatment with the 1:2 and 1:5 ratios of PANI/MoS2 at 100 μg/mL demonstrated significant anti-amoebic effects toward A. castellanii as well as N. fowleri, appraised to be ROS mediated and effectuate physical alterations to amoeba morphology. Further, cytocompatibility toward human keratinocyte skin cells (HaCaT) and primary human corneal epithelial cells (pHCEC) was noted. For the first time, polymer-based nanocomposites such as PANI/MoS2 are reported in this study as appealing options in the drug discovery for brain-eating amoebae infections.
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Affiliation(s)
- Sumayah Abdelnasir
- Department
of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya 47500, Selangor, Malaysia
| | - Mohammad Ridwane Mungroo
- Department
of Medical Biology, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Centre, Amsterdam 1105 AZ, The Netherlands
| | - Jactty Chew
- Department
of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya 47500, Selangor, Malaysia
| | - Ruqaiyyah Siddiqui
- Department
of Biology, Chemistry and Environmental Sciences, College of Arts
and Sciences, American University of Sharjah, Sharjah 26666, United Arab Emirates
- Faculty
of Medicine, Istinye University, Istanbul, 34010, Turkey
| | - Naveed Ahmed Khan
- Department
of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah 27272, United Arab Emirates
- Department
of Medical Biology, Faculty of Medicine, Istinye University, Istanbul, 34010, Turkey
| | - Irfan Ahmad
- Department
of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Abha 62529, Saudi
Arabia
| | - Syed Shahabuddin
- Department
of Chemistry, School of Energy Technology, Pandit Deendayal Energy University, Raisan, Gandhinagar 382426, India
- Faculty of
Applied Sciences, Universiti Teknologi MARA, Cawangan Negeri Sembilan, Kampus
Kuala Pilah, Shah Alam 40450, Malaysia
| | - Ayaz Anwar
- Department
of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya 47500, Selangor, Malaysia
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15
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Haston JC, O’Laughlin K, Matteson K, Roy S, Qvarnstrom Y, Ali IKM, Cope JR. The Epidemiology and Clinical Features of Non-Keratitis Acanthamoeba Infections in the United States, 1956-2020. Open Forum Infect Dis 2023; 10:ofac682. [PMID: 36655187 PMCID: PMC9835757 DOI: 10.1093/ofid/ofac682] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Indexed: 01/15/2023] Open
Abstract
Background Acanthamoeba is a free-living ameba that can cause severe disease affecting the central nervous system, skin, sinuses, and other organs, particularly in immunocompromised individuals. These rare but severe infections are often fatal, yet incompletely described. Methods Cases included were either reported to the Centers for Disease Control and Prevention (CDC) Free-Living Ameba program or published in scientific literature. Characteristics of all patients in the United States with laboratory-confirmed non-keratitis Acanthamoeba infections were described using descriptive statistics, and associations with survival were determined using χ2 and Fisher exact tests. Results Of 173 patients identified, 71% were male and the median age was 44 years (range, 0-87 years). Of these, 26 (15%) survived. Most patients (88%) had at least 1 immunocompromising condition, most commonly human immunodeficiency virus (39%), cancer (28%), and solid organ or hematopoietic stem cell transplant (28%). Granulomatous amebic encephalitis (GAE) was the most common disease presentation (71%). Skin (46%), sinuses (29%), lungs (13%), and bone (6%) were also involved. Nearly half of patients (47%) had involvement of >1 organ system. Survival was less frequent among those with GAE (3%, P < .001) compared with cutaneous disease, rhinosinusitis, or multiorgan disease not including GAE. Of 7 who received the currently recommended treatment regimen, 5 (71%) survived. Conclusions Non-keratitis Acanthamoeba infections occur primarily in immunocompromised individuals and are usually fatal. Survival may be associated with disease presentation and treatment. Providers who care for at-risk patients should be aware of the various disease manifestations to improve early recognition and treatment.
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Affiliation(s)
- Julia C Haston
- Correspondence: Julia C. Haston, MD, MSc, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, USA ()
| | - Kevin O’Laughlin
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Kelsey Matteson
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA,Epidemiology Elective Program, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Shantanu Roy
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Yvonne Qvarnstrom
- Parasitic Diseases Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Ibne K M Ali
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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16
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Wang Y, Jiang L, Zhao Y, Ju X, Wang L, Jin L, Fine RD, Li M. Biological characteristics and pathogenicity of Acanthamoeba. Front Microbiol 2023; 14:1147077. [PMID: 37089530 PMCID: PMC10113681 DOI: 10.3389/fmicb.2023.1147077] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/21/2023] [Indexed: 04/25/2023] Open
Abstract
Acanthamoeba is an opportunistic protozoa, which exists widely in nature and is mainly distributed in soil and water. Acanthamoeba usually exists in two forms, trophozoites and cysts. The trophozoite stage is one of growth and reproduction while the cyst stage is characterized by cellular quiescence, commonly resulting in human infection, and the lack of effective monotherapy after initial infection leads to chronic disease. Acanthamoeba can infect several human body tissues such as the skin, cornea, conjunctiva, respiratory tract, and reproductive tract, especially when the tissue barriers are damaged. Furthermore, serious infections can cause Acanthamoeba keratitis, granulomatous amoebic encephalitis, skin, and lung infections. With an increasing number of Acanthamoeba infections in recent years, the pathogenicity of Acanthamoeba is becoming more relevant to mainstream clinical care. This review article will describe the etiological characteristics of Acanthamoeba infection in detail from the aspects of biological characteristic, classification, disease, and pathogenic mechanism in order to provide scientific basis for the diagnosis, treatment, and prevention of Acanthamoeba infection.
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Affiliation(s)
- Yuehua Wang
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
| | - Linzhe Jiang
- General Surgery, Jilin People’s Hospital, Jilin City, China
| | - Yitong Zhao
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
| | - Xiaohong Ju
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
| | - Le Wang
- Department of Laboratory Medicine, Jilin Hospital of Integrated Chinese and Western Medicine, Jilin City, China
| | - Liang Jin
- Department of Laboratory Medicine, Jilin Hospital of Integrated Chinese and Western Medicine, Jilin City, China
| | - Ryan D. Fine
- Center for Human Genetics and Genomics, New York University Grossman School of Medicine, New York City, NY, United States
| | - Mingguang Li
- College of Laboratory Medicine, Jilin Medical University, Jilin City, China
- *Correspondence: Mingguang Li,
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17
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In Vitro Cytopathogenic Activities of Acanthamoeba T3 and T4 Genotypes on HeLa Cell Monolayer. Pathogens 2022; 11:pathogens11121474. [PMID: 36558808 PMCID: PMC9782662 DOI: 10.3390/pathogens11121474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/28/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
Amoebic keratitis and encephalitis are mainly caused by free-living amoebae of the genus Acanthamoeba, which consists of both pathogenic and nonpathogenic species. The global distribution, amphizoic properties and the severity of the disease caused by Acanthamoeba species have inspired the scientific community to put more effort into the isolation of Acanthamoeba, besides exploring the direct and indirect parameters that could signify a pathogenic potential. Therefore, this study was performed to characterize the pathogenic potential of Acanthamoeba isolated from contact lens paraphernalia and water sources in Malaysia. Various methodologies were utilized to analyze the thermotolerance and osmotolerance, the secretion level of proteases and the cytopathic effect of trophozoites on the cell monolayer. In addition, the in vitro cytopathogenicity of these isolates was assessed using the LDH-release assay. A total of 14 Acanthamoeba isolates were classified as thermo- and osmotolerant and had presence of serine proteases with a molecular weight of 45-230 kDa. Four T4 genotypes isolated from contact lens paraphernalia recorded the presence of serine-type proteases of 107 kDa and 133 kDa. In contrast, all T3 genotypes isolated from environmental samples showed the presence of a 56 kDa proteolytic enzyme. Remarkably, eight T4 and a single T3 genotype isolates demonstrated a high adhesion percentage of greater than 90%. Moreover, the use of the HeLa cell monolayer showed that four T4 isolates and one T3 isolate achieved a cytopathic effect in the range of 44.9-59.4%, indicating an intermediate-to-high cytotoxicity level. Apart from that, the LDH-release assay revealed that three T4 isolates (CL5, CL54 and CL149) and one T3 isolate (SKA5-SK35) measured an exceptional toxicity level of higher than 40% compared to other isolates. In short, the presence of Acanthamoeba T3 and T4 genotypes with significant pathogenic potential in this study reiterates the essential need to reassess the functionality of other genotypes that were previously classified as nonpathogenic isolates in past research.
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18
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Pastrana C, Guerreiro JRL, Elumalai M, Carpena-Torres C, Crooke A, Carracedo G, Prado M, Huete-Toral F. Dual-Mode Gold Nanoparticle-Based Method for Early Detection of Acanthamoeba. Int J Mol Sci 2022; 23:ijms232314877. [PMID: 36499204 PMCID: PMC9740238 DOI: 10.3390/ijms232314877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 11/29/2022] Open
Abstract
Acanthamoeba keratitis is an aggressive and rapidly progressing ocular pathology whose main risk factor is the use of contact lenses. An early and differential diagnosis is considered the main factor to prevent the progression and improve the prognosis of the pathology. However, current diagnosis techniques require time, complex and costly materials making an early diagnosis challenging. Thus, there is a need for fast, accessible, and accurate methods for Acanthamoeba detection by practitioners for timely and suitable treatment and even for contact lens user as preventive diagnosis. Here, we developed a dual-mode colorimetric-based method for fast, visual, and accurate detection of Acanthamoeba using gold nanoparticles (AuNPs). For this strategy, AuNPs were functionalized with thiolated probes and the presence of target Acanthamoeba genomic sequences, produce a colorimetric change from red to purple. This approach allows the detection of 0.02 and 0.009 μM of the unamplified Acanthamoeba genome by the naked eye in less than 20 min and by color analysis using a smartphone. Additionally, real samples were successfully analyzed showing the potential of the technology considering the lack of point-of-care tools that are mostly needed.
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Affiliation(s)
- Cristina Pastrana
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, C/Arcos de Jalón 118, 28037 Madrid, Spain
- Correspondence: (C.P.); (J.R.L.G.)
| | - J. Rafaela L. Guerreiro
- Food Quality and Safety Group, International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330 Braga, Portugal
- BioMark@ISEP, School of Engineering of the Polytechnic Institute of Porto, Rua Dr. António Bernardino de Almeida 431, 4249-015 Porto, Portugal
- CEB/LABBELS, Center of Biological Engineering, Minho University, Campus de Gualtar, Rua da Universidade, 4710-057 Braga, Portugal
- Correspondence: (C.P.); (J.R.L.G.)
| | - Monisha Elumalai
- Food Quality and Safety Group, International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330 Braga, Portugal
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Carlos Carpena-Torres
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, C/Arcos de Jalón 118, 28037 Madrid, Spain
| | - Almudena Crooke
- Department of Biochemistry and Molecular Biology, Faculty of Optics and Optometry, Complutense University of Madrid, C/Arcos de Jalón 118, 28037 Madrid, Spain
| | - Gonzalo Carracedo
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, C/Arcos de Jalón 118, 28037 Madrid, Spain
| | - Marta Prado
- Food Quality and Safety Group, International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330 Braga, Portugal
| | - Fernando Huete-Toral
- Ocupharm Research Group, Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, C/Arcos de Jalón 118, 28037 Madrid, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Optics and Optometry, Complutense University of Madrid, C/Arcos de Jalón 118, 28037 Madrid, Spain
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Sepulveda-Beltran PA, Levine H, Altamirano DS, Martinez JD, Durkee H, Mintz K, Leblanc R, Tóthová JD, Miller D, Parel JM, Amescua G. Rose Bengal Photodynamic Antimicrobial Therapy: A review of the intermediate term clinical and surgical outcomes. Am J Ophthalmol 2022; 243:125-134. [PMID: 35952754 DOI: 10.1016/j.ajo.2022.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 11/01/2022]
Abstract
PURPOSE To evaluate the intermediate term clinical outcomes of Rose Bengal Photodynamic Antimicrobial Therapy (RB-PDAT) for infectious keratitis. Secondarily, to evaluate the surgical outcomes of individuals that underwent optical keratoplasty after RB-PDAT. DESIGN Retrospective cohort study. METHODS Retrospective chart review of 31 eyes from 30 consecutive individuals with infectious keratitis refractory to standard medical therapy who underwent RB-PDAT at the Bascom Palmer Eye Institute between January 2016 and July 2020. Data collected included demographics, risk factors for infectious keratitis, microbiological diagnosis, Best Spectacle-Corrected Visual Acuity (BCVA), clinical outcomes after RB-PDAT and complication rates post-keratoplasty. RB-PDAT was performed as described in previous studies. Graft survival was evaluated using Kaplan Meier curves with log-ranks in individuals that underwent keratoplasty after RB-PDAT. RESULTS Mean age of the study population was 53±18.0 years. 70% were female; 53.3% self-identified as non-Hispanic White; 43.3% as Hispanic. Mean follow-up time was 28.0±14.4 months. Risk factors included contact lens use (80.6%), history of infectious keratitis (19.3%), and ocular surface disease (16.1%). Cultures were positive for Acanthamoeba (51.6%), Fusarium (12.9%), and Pseudomonas (6.5%). 22.5% of individuals with Acanthamoeba infection were treated with concomitant Miltefosine. Clinical resolution was achieved in 77.4% of individuals on average 2.72±1.85 months after RB-PDAT with 22.5% requiring therapeutic penetrating keratoplasties and 54.8% subsequently requiring optical penetrating keratoplasties. At 2 years, the overall probability of graft survival was 78.7% and the graft failure rate was 21.3%. CONCLUSION RB-PDAT is a potential adjunct therapy for infectious keratitis that may reduce the need for a therapeutic penetrating keratoplasty. Cases that undergo keratoplasty after RB-PDAT may have a higher probability of graft survival at one year postoperatively.
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Affiliation(s)
- Paula A Sepulveda-Beltran
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA; Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Harry Levine
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Diego S Altamirano
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jaime D Martinez
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Heather Durkee
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Keenan Mintz
- Department of Chemistry, University of Miami, Coral Gables, FL, USA
| | - Roger Leblanc
- Department of Chemistry, University of Miami, Coral Gables, FL, USA
| | - Jana D'Amato Tóthová
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Darlene Miller
- Ocular Microbiology Laboratory, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jean-Marie Parel
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA; Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Guillermo Amescua
- Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA; Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA.
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Saberi R, Nakhaei M, Fakhar M, Zarrinfar H, Sharifpour A, Hezarjaribi HZ. Molecular identification and genotyping of Acanthamoeba spp., in bronchoalveolar lavage fluid from immunocompetent patients with chronic respiratory disorders (CRD). Parasitol Res 2022; 121:3013-3017. [PMID: 35930044 PMCID: PMC9362591 DOI: 10.1007/s00436-022-07609-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 07/24/2022] [Indexed: 10/26/2022]
Abstract
This study aimed to investigate the presence and genotyping of Acanthamoeba spp., in the bronchoalveolar lavage fluid (BALF) of immunocompetent patients with chronic respiratory disorders (CRD). In this study, 211 BALF samples were collected from patients with CRD during the COVID-19 pandemic who were candidates for fiberoptic bronchoscopy (FOB) at Imam Khomeini Hospital, Sari, Mazandaran Province, northern Iran and investigated for Acanthamoeba spp., by PCR. A total of 211 FBAL samples were examined; 5 (5/211; 2.36%) were positive by using the PCR test for Acanthamoeba spp. According to sequence analysis, three strains belonged to the T4 genotype and one strain to the T2 genotype. Our data demonstrate that the presence of Acanthamoeba (T4 and T2) in BALF specimens of patients with respiratory infections. However, it is important to note that these findings may be merely accidental. Our findings suggest further investigation to fully understand the role of Acanthamoeba spp. in the pathogenesis of lung infections.
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Affiliation(s)
- Reza Saberi
- Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, School of Medicine, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, P.O Box: 48471-91971, Sari, Iran
| | - Maryam Nakhaei
- Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, School of Medicine, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, P.O Box: 48471-91971, Sari, Iran
| | - Mahdi Fakhar
- Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, School of Medicine, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, P.O Box: 48471-91971, Sari, Iran.
| | - Hossein Zarrinfar
- Department of Medical Mycology and Parasitology, Faculty of Medicine, Allergy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Sharifpour
- Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, School of Medicine, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, P.O Box: 48471-91971, Sari, Iran.,Pulmonary and Critical Care Division, Imam Khomeini Hospital, Iranian National Registry Center for Lophomoniasis (INRCL), Mazandaran University of Medical Sciences, Sari, Iran
| | - Hajar Ziaei Hezarjaribi
- Iranian National Registry Center for Lophomoniasis and Toxoplasmosis, School of Medicine, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, P.O Box: 48471-91971, Sari, Iran
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21
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Nageeb MM, Eldeek HEM, Attia RAH, Sakla AA, Alkhalil SS, Farrag HMM. Isolation and morphological and molecular characterization of waterborne free-living amoebae: Evidence of potentially pathogenic Acanthamoeba and Vahlkampfiidae in Assiut, Upper Egypt. PLoS One 2022; 17:e0267591. [PMID: 35802617 PMCID: PMC9269480 DOI: 10.1371/journal.pone.0267591] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 04/12/2022] [Indexed: 12/15/2022] Open
Abstract
Free-living amoebae (FLA) are gaining attention due to the increasing number of related grave central nervous system (CNS) and sight-threatening eye infections and their role as Trojan horses for many bacteria and viruses. This study was conducted in Assiut City, Egypt to detect the presence of FLA in different water sources using morphological and molecular approaches and determine their potential pathogenicity. A total of 188 water samples (100 tap, 80 tank, and 8 swimming pool samples) were collected, cultivated on non-nutrient agar seeded with Escherichia coli, and inspected for FLA. Thermo- and osmo-tolerance assays were performed to determine their pathogenicity. Polymerase chain reaction and sequence analysis were performed to confirm the identification and analyze the genotype. Overall, 52 samples (27.7%) were positive for FLA. Of these, 20.7% were identified as Acanthamoeba, 1.6% as Vahlkampfiidae, and 5.3% as mixed Acanthamoeba and Vahlkampfiidae. Seven species of Acanthamoeba were recognized, of which A. triangularis, A. polyphaga, A. lenticulata, and A. culbertsoni are thermo- and osmo-tolerant, and A. astronyxis, A. comandoni, and A. echinulata are non-thermo- and non-osmo-tolerant. The phylogeny analysis revealed T4 and T7 genotypes. Among Vahlkampfiids, 61.5% were identified as thermo- and osmo-tolerant Vahlkampfia, and 30.8% were identified as non-pathogenic Naegleria. One isolate (7.7%) was identified as potentially pathogenic Allovahlkampfia, as confirmed by sequencing. This is the first report documenting the occurrence and phylogeny of waterborne FLA (Acanthamoeba/Vahlkampfiidae) in Assiut, Egypt. The presence of potentially pathogenic FLA highlights the possible health hazards and the need for preventive measures.
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Affiliation(s)
- Martina M. Nageeb
- Medical Parasitology Department, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Hanan E. M. Eldeek
- Medical Parasitology Department, Faculty of Medicine, Assiut University, Assiut, Egypt
- * E-mail: ,
| | - Rasha A. H. Attia
- Medical Parasitology Department, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Atef A. Sakla
- Medical Parasitology Department, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Samia S. Alkhalil
- Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Shaqra University, Shaqra, Saudi Arabia
| | - Haiam Mohamed Mahmoud Farrag
- Medical Parasitology Department, Faculty of Medicine, Assiut University, Assiut, Egypt
- Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Shaqra University, Shaqra, Saudi Arabia
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22
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Lamien-Meda A, Köhsler M, Walochnik J. Real-Time PCR for the Diagnosis of Acanthamoeba Genotype T4. Microorganisms 2022; 10:microorganisms10071307. [PMID: 35889026 PMCID: PMC9325200 DOI: 10.3390/microorganisms10071307] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/14/2022] [Accepted: 06/25/2022] [Indexed: 02/04/2023] Open
Abstract
Acanthamoeba spp. are ubiquitous and opportunistic free-living amoebae (FLA) that can cause Acanthamoeba keratitis and other infections in the human host. A quick and efficient diagnosis is often challenging. Our study aimed to establish a qPCR assay to detect and, at the same time, quantify the predominant Acanthamoeba genotype T4. DNA from clinical corneal scrapings and Acanthamoeba reference strains, including genotypes T3, T4, T5, T6, T10, T11, and T12, were used to develop the new T4 assay and it was compared to published protocols and one commercial kit for evaluation. The T4 assay showed no amplification with Acanthamoeba genotypes T3, T5, T6, T10, T11, and T12. The efficiencies ranged from 92.01 to 97.59% (R2 of 0.9768 to 0.9951). The calculated LOD range was 3.63 to 33.27 cells/µL. The protocol published by Qvarnstrom and colleagues was more sensitive compared to the other assays, and an overall good agreement was observed between the new T4 and the Qvarnstrom assays. We successfully developed and validated a genotype T4 assay that could be run in duplex with the Qvarnstrom assay to reliably and simultaneously diagnose Acanthamoeba genotype T4 and other genotypes from clinical samples.
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Karsenti N, Purssell A, Lau R, Ralevski F, Bhasker S, Raheel H, Boggild AK. Surveillance of Amoebic Keratitis-Causing Acanthamoebae for Potential Bacterial Endosymbionts in Ontario, Canada. Pathogens 2022; 11:pathogens11060661. [PMID: 35745515 PMCID: PMC9230791 DOI: 10.3390/pathogens11060661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/02/2022] [Accepted: 06/07/2022] [Indexed: 02/04/2023] Open
Abstract
Acanthamoeba spp. are the causative pathogens of several infections, including amoebic keratitis (AK), a vision-threatening infection. Acanthamoebae from corneal specimens of patients with AK harbor bacterial endosymbionts, which may increase virulence. We sought to understand the spectrum of bacterial endosymbionts present in clinical isolates of Acanthamoeba spp. identified in our reference parasitology laboratory. Isolates of Acanthamoeba spp. obtained from our biobank of anonymized corneal scrapings were screened for potential endosymbionts by PCR using primer pairs detecting bacteria belonging to orders Chlamydiales, Rickettsiales, or Legionellales and pan16S primers. Three primer pairs specific to the 18s rRNA gene of Acanthamoeba spp. were used for the amplification of Acanthamoeba DNA used for sequencing. Sanger sequencing of all PCR products was performed, followed by BLAST analysis for species identification. We screened 26 clinical isolates of Acanthamoeba spp. for potential endosymbionts. Five isolates (19%) were found to contain bacterial DNA belonging to Legionellales. Three (11%) contained members of the Rickettsiales and Pseudomonas genticulata was detected in a Rickettsia-positive sample. One strain (4%) contained Neochlamydia hartmannellae, a member of the Chlamydiales order. Bacterial endosymbionts are prevalent in clinical strains of Acanthamoeba causing AK isolated from corneal scrapings. The demonstration of these organisms in clinical Acanthamoeba isolates supports a potential exploration of anti-endosymbiont therapeutics as an adjuvant therapy in the treatment of AK.
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Affiliation(s)
- Nessika Karsenti
- Schulich School of Medicine & Dentistry, London, ON N6A 5C1, Canada; (N.K.); (H.R.)
| | - Andrew Purssell
- Faculty of Medicine, University of Ottawa, Ottawa, ON K1N 6N5, Canada;
| | - Rachel Lau
- Public Health Ontario Laboratories, Public Health Ontario, Toronto, ON M5G 1M1, Canada; (R.L.); (F.R.)
| | - Filip Ralevski
- Public Health Ontario Laboratories, Public Health Ontario, Toronto, ON M5G 1M1, Canada; (R.L.); (F.R.)
| | - Shveta Bhasker
- Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5S 1A1, Canada;
| | - Hira Raheel
- Schulich School of Medicine & Dentistry, London, ON N6A 5C1, Canada; (N.K.); (H.R.)
| | - Andrea K. Boggild
- Tropical Disease Unit, Division of Infectious Diseases, UHN-Toronto General Hospital, Toronto, ON M5G 2C4, Canada
- Department of Medicine, University of Toronto, Toronto, ON M5S 1A1, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON M5S 1A1, Canada
- Correspondence: ; Tel.: +1-416-340-3675
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Abdelnasir S, Mungroo MR, Shahabuddin S, Siddiqui R, Khan NA, Ahmad I, Anwar A. Polyaniline (PANI)-conjugated tungsten disulphide (WS 2) nanoparticles as potential therapeutics against brain-eating amoebae. Appl Microbiol Biotechnol 2022; 106:3279-3291. [PMID: 35403857 DOI: 10.1007/s00253-022-11899-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/16/2022] [Accepted: 03/26/2022] [Indexed: 11/02/2022]
Abstract
Brain-eating amoebae, including Acanthamoeba castellanii and Naegleria fowleri, are the causative agents of devastating central nervous system infections with extreme mortality rates. There is an indisputable urgency for the development of effective chemotherapeutic agents for the control of these diseases that are increasing in incidence. Here, we evaluated the anti-amoebic potential of polyaniline:tungsten disulphide (PANI:WS2) nanocomposite against the infective trophozoite and cyst stages of N. fowleri and A. castellanii. Throughout these evaluations, significant viability inhibition was noted when 100 µg/mL of PANI:WS2 was employed at its 1:5 formulation. These effects were studied to be due to increased levels of reactive oxygen species (ROS) as visualised through fluorescence microscopy. Furthermore, field emission scanning electron microscopy (FE-SEM) analysis pictured disruption to amoeba morphology. The host-cell cytotoxicity of the nanocomposite (PANI:WS2) was studied to be negligible, making it an attractive avenue in the pursuit for effective treatments for brain-eating amoeba infections. KEY POINTS: • Synthesis of polyaniline:tungsten disulphide (PANI:WS2) nanocomposite. • Anti-amoebic potential of PANI:WS2 nanocomposite. • PANI:WS2 nanocomposites are promising anti-amoebic agents in vitro.
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Affiliation(s)
- Sumayah Abdelnasir
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Mohammad Ridwane Mungroo
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Syed Shahabuddin
- Department of Chemistry, School of Technology, Pandit Deendayal Energy University, Gandhinagar, 382007, Gujarat, India. .,Faculty of Applied Sciences, Universiti Teknologi MARA, Kampus Kuala Pilah, 72000, Kuala Pilah, Cawangan Negeri Sembilan, Malaysia.
| | - Ruqaiyyah Siddiqui
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, 26666, Sharjah, United Arab Emirates
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, 27272, Sharjah, United Arab Emirates
| | - Irfan Ahmad
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Abha, Saudi Arabia
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, 47500, Subang Jaya, Selangor, Malaysia.
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Potgieter N, van der Loo C, Barnard TG. Co-Existence of Free-Living Amoebae and Potential Human Pathogenic Bacteria Isolated from Rural Household Water Storage Containers. BIOLOGY 2021; 10:biology10121228. [PMID: 34943143 PMCID: PMC8698325 DOI: 10.3390/biology10121228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/07/2021] [Accepted: 11/08/2021] [Indexed: 12/24/2022]
Abstract
Simple Summary In many households in rural communities, water needed for drinking and cooking is fetched from rivers, fountains, or boreholes shared by the community. The water is then stored in various storage containers for several days without treatment and exposed to several conditions that could potentially contaminate the water and cause diseases. If the storage containers are not regularly and properly cleaned, biofilms can form inside the containers. Several microorganisms can be found inside the biofilm that can potentially cause diseases in humans. One such group of organisms is called free-living amoebae, which graze on the bacteria found inside the biofilm. Several of these potentially harmful bacteria have adapted and can survive inside these free-living amoebae and potentially cause diseases when ingested by humans. Abstract This study investigated the co-existence of potential human pathogenic bacteria and free-living amoebae in samples collected from stored water in rural households in South Africa using borehole water as a primary water source. Over a period of 5 months, a total of 398 stored water and 392 biofilm samples were collected and assessed. Free-living amoebae were identified microscopically in 92.0% of the water samples and 89.8% of the biofilm samples. A further molecular identification using 18S rRNA sequencing identified Vermamoeba vermiformis, Entamoeba spp., Stenamoeba spp., Flamella spp., and Acanthamoeba spp. including Acanthamoeba genotype T4, which is known to be potentially harmful to humans. Targeted potential pathogenic bacteria were isolated from the water samples using standard culture methods and identified using 16S rRNA sequencing. Mycobacterium spp., Pseudomonas spp., Enterobacter spp., and other emerging opportunistic pathogens such as Stenotrophomonas maltophilia were identified. The results showed the importance of further studies to assess the health risk of free-living amoebae and potential human pathogenic bacteria to people living in rural communities who have no other option than to store water in their homes due to water shortages.
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Affiliation(s)
- Natasha Potgieter
- One Health Research Group, Department of Biochemistry and Microbiology, Faculty of Science, Engineering and Agriculture, University of Venda, Thohoyandou 0950, Limpopo Province, South Africa
- Correspondence:
| | - Clarissa van der Loo
- Water and Health Research Centre, Doornfontein Campus, University of Johannesburg, Johannesburg 2112, Gauteng, South Africa; (T.G.B.); (C.v.d.L.)
| | - Tobias George Barnard
- Water and Health Research Centre, Doornfontein Campus, University of Johannesburg, Johannesburg 2112, Gauteng, South Africa; (T.G.B.); (C.v.d.L.)
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Contact lenses contamination by Acanthamoeba spp. in Upper Egypt. PLoS One 2021; 16:e0259847. [PMID: 34780533 PMCID: PMC8592476 DOI: 10.1371/journal.pone.0259847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 10/28/2021] [Indexed: 12/01/2022] Open
Abstract
Background Acanthamoeba spp. are one of the free-living amoeba that spread worldwide causing keratitis. Owing to the increase in the use of lenses, whether for medical or cosmetic purposes, the incidence of disease increases every year. Contamination of the lenses with the Acanthamoeba trophozoites or cysts may lead to eye infection and cause sight-threatening keratitis in human. We isolated Acanthamoeba spp. from new lenses, used lenses, and contact lens disinfecting solutions and identified them based on morphological characteristics and molecular test. Methods New and used lenses and contact lens disinfecting solutions were cultured on monogenic media. Light and scanning electron microscope was used to identify Acanthamoeba spp. morphological features. Genotype identification was also evaluated using PCR sequencing of 18S rRNA gene specific primer pair JDP1 and JDP2. Results A hundred samples were examined, 29 (29%) were infected with Acanthamoeba spp. That belonged to two strains of Acanthamoeba (Acanthamoeba 41 and Acanthamoeba 68). 18S rRNA of the Acanthamoeba 41 had 99.69% sequence identity to Acanthamoeba castellanii clone HDU-JUMS-2, whereas Acanthamoeba 68 had 99.74% similar pattern to that of Acanthamoeba sp. isolate T4 clone ac2t4 that are morphologically identified as Acanthamoeba polyphaga. The obtained data revealed that the isolated strains belong to T4 genotype that was evolutionarily similar to strains isolated in Iran. Conclusions Cosmetic lenses and disinfectant solutions are a major transmissible mode for infection. This genotype is common as the cause of Acanthamoeba keratitis. To avoid infection, care must be taken to clean the lenses and their preservative solutions and prevent contamination with the parasite.
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Efficient nested-PCR-based method development for detection and genotype identification of Acanthamoeba from a small volume of aquatic environmental sample. Sci Rep 2021; 11:21740. [PMID: 34741041 PMCID: PMC8571327 DOI: 10.1038/s41598-021-00968-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 10/15/2021] [Indexed: 12/17/2022] Open
Abstract
Acanthamoeba spp. are opportunistic human pathogens that cause granulomatous amoebic encephalitis and keratitis, and their accurate detection and enumeration in environmental samples is a challenge. In addition, information regarding the genotyping of Acanthamoeba spp. using various PCR methods is equally critical. Therefore, considering the diverse niches of habitats, it is necessary to develop an even more efficient genotyping method for Acanthamoeba spp. detection. This study improved the sensitivity of detection to avoid underestimation of Acanthamoeba spp. occurrence in aquatic environmental samples, and to accurately define the pathogenic risk by developing an efficient PCR method. In this study, a new nested genotyping method was established and compared with various PCR-based methods using in silico, lab, and empirical tests. The in silico test showed that many PCR-based methods could not successfully align specific genotypes of Acanthamoeba, except for the newly designed nested PCR and real-time PCR method. Furthermore, 52 water samples from rivers, reservoirs, and a river basin in Taiwan were analysed by six different PCR methods and compared for genotyping and detection efficiency of Acanthamoeba. The newly developed nested-PCR-based method of genotyping was found to be significantly sensitive as it could effectively detect the occurrence of Acanthamoeba spp., which was underestimated by the JDP-PCR method. Additionally, the present results are consistent with previous studies indicating that the high prevalence of Acanthamoeba in the aquatic environment of Taiwan is attributed to the commonly found T4 genotype. Ultimately, we report the development of a small volume procedure, which is a combination of recent genotyping PCR and conventional real-time PCR for enumeration of aquatic Acanthamoeba and acquirement of biologically meaningful genotyping information. We anticipate that the newly developed detection method will contribute to the precise estimation, evaluation, and reduction of the contamination risk of pathogenic Acanthamoeba spp., which is regularly found in the water resources utilised for domestic purposes.
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Abdelnasir S, Mungroo MR, Shahabuddin S, Siddiqui R, Khan NA, Anwar A. Polyaniline-Conjugated Boron Nitride Nanoparticles Exhibiting Potent Effects against Pathogenic Brain-Eating Amoebae. ACS Chem Neurosci 2021; 12:3579-3587. [PMID: 34545742 DOI: 10.1021/acschemneuro.1c00179] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Free-living amoebae include Acanthamoeba castellanii and Naegleria fowleri that are opportunistic protozoa responsible for life-threatening central nervous system infections with mortality rates over 90%. The rising number of cases and high mortality rates are indicative of the critical unmet need for the development of efficient drugs in order to avert future deaths. In this study, we assess the anti-amoebic capacity of a conducting polymer nanocomposite comprising polyaniline (PANI) and hexagonal boron nitride (hBN) against A. castellanii and N. fowleri. We observed significant amoebicidal and cysticidal effects using 100 μg/mL PANI/hBN (P < 0.05). Further, the nanocomposite demonstrated negligible cytotoxicity toward HaCaT and primary human corneal epithelial cells (pHCECs). In evaluating the mode of inhibition of A. castellanii due to treatment with PANI/hBN, increased intracellular reactive oxygen species (ROS) was measured and scanning microscopy visualized the formation of pores in the amoebae. Overall, this study is suggestive of the potential of the PANI/hBN nanocomposite as a promising therapy for amoeba infections.
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Affiliation(s)
- Sumayah Abdelnasir
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya 47500, Selangor, Malaysia
| | - Mohammad Ridwane Mungroo
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya 47500, Selangor, Malaysia
| | - Syed Shahabuddin
- Department of Chemistry, School of Technology, Pandit Deendayal Energy University, Gandhinagar 382007, Gujarat, India
| | - Ruqaiyyah Siddiqui
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, Sharjah 26666, United Arab Emirates
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University City, Sharjah 27272, United Arab Emirates
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya 47500, Selangor, Malaysia
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Mungroo MR, Khan NA, Maciver S, Siddiqui R. Opportunistic free-living amoebal pathogens. Pathog Glob Health 2021; 116:70-84. [PMID: 34602025 DOI: 10.1080/20477724.2021.1985892] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Pathogenic free-living amoebae affecting the central nervous system are known to cause granulomatous amoebic encephalitis (GAE) or primary amoebic meningoencephalitis (PAM). Although hosts with impaired immunity are generally at a higher risk of severe disease, amoebae such as Naegleria fowleri and Balamuthia mandrillaris can instigate disease in otherwise immunocompetent individuals, whereas Acanthamoeba species mostly infect immunocompromised people. Acanthamoeba also cause a sight-threatening eye infection, mostly in contact lens wearers. Although infections due to pathogenic amoebae are considered rare, recently, these deadly amoebae were detected in water supplies in the USA. This is of particular concern, especially with global warming further exacerbating the problem. Herein, we describe the epidemiology, presentation, diagnosis, and management of free-living amoeba infections.
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Affiliation(s)
- Mohammad Ridwane Mungroo
- Department of Clinical Sciences, College of Medicine, University City, Sharjah, United Arab Emirates
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University City, Sharjah, United Arab Emirates.,Research Institute of Health and Medical Sciences, University of Sharjah, Sharjah, UAE
| | - Sutherland Maciver
- Centre for Discovery Brain Sciences, Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh, UK
| | - Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, Sharjah, UAE
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Analysis of Acanthamoeba genotypes from public freshwater sources in Thailand reveals a new genotype, T23 Acanthamoeba bangkokensis sp. nov. Sci Rep 2021; 11:17290. [PMID: 34453084 PMCID: PMC8397737 DOI: 10.1038/s41598-021-96690-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/11/2021] [Indexed: 02/07/2023] Open
Abstract
A survey of Acanthamoeba in 100 public freshwater sources in 28 provinces across Thailand has identified 9 genotypes comprising T2/6, T3-T5, T9, T11, T12, T18 and a novel ‘T23’ among 131 isolates. Sequencing of the near complete 18S rRNA gene of Acanthamoeba of all isolates has shown that the most predominant genotype T4 found in 87 isolates (66.4%) contained 4 subtypes, i.e. T4A, T4B, T4C and T4F, while all isolates assigned to genotype T2/6 belonged to subtype B. Among intron-bearing genotypes, most isolates harbouring genotype T3 contained S516 introns, characterised by 3 distinct variants whilst all genotypes T4A and T5 were intronless. Identical 18S rRNA sequences of Acanthamoeba were identified across regions of the country and four isolates in this study shared the same sequences with those from remote nations, suggesting that some strains have reproductive success in diverse ecological niche. Nucleotide diversity of genotypes T2/6B, T3, T4, T9 and T11 in this study was significantly less than that among global isolates outside Thailand, implying that limited sequence diversity occurred within local populations. A remarkably higher level of nucleotide diversity in genotype T11 than those of other genotypes (0.041 vs. 0.012–0.024) could be due to cryptic subtypes. Recombination breakpoints have been detected within genotypes and subtypes as well as within isolates despite no evidence for sexual and parasexual cycles in the genus Acanthamoeba. Tajima’s D, Fu & Li’s D* and F* statistics revealed significantly negative deviation from neutrality across genotypes and subtypes, implying purifying selection in this locus. The 18S rRNA gene of the novel genotype ‘T23’ displayed 7.82% to 28.44% sequence differences in comparison with all known genotypes. Both Bayesian and maximum likelihood phylogenetic trees have placed genotype T23 as sister to the clade comprising genotypes T10, T12 and T14, all of these possess cyst structure belonging to morphological group III. Hence, Acanthamoeba bangkokensis sp. nov. is proposed for this novel genotype. It is likely that more genotypes of Acanthamoeba remain to be discovered while the evolution of the 18S rRNA gene of this pathogenic-free living amoeba seems to be ongoing.
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van der Loo C, Bartie C, Barnard TG, Potgieter N. Detection of Free-Living Amoebae and Their Intracellular Bacteria in Borehole Water before and after a Ceramic Pot Filter Point-of-Use Intervention in Rural Communities in South Africa. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:3912. [PMID: 33917870 PMCID: PMC8068299 DOI: 10.3390/ijerph18083912] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/26/2021] [Accepted: 04/02/2021] [Indexed: 11/21/2022]
Abstract
Free-living amoebae (FLA) are ubiquitous in nature, whereas amoeba-resistant bacteria (ARB) have evolved virulent mechanisms that allow them to resist FLA digestion mechanisms and survive inside the amoeba during hostile environmental conditions. This study assessed the prevalence of FLA and ARB species in borehole water before and after a ceramic point-of-use intervention in rural households. A total of 529 water samples were collected over a five-month period from 82 households. All water samples were subjected to amoebal enrichment, bacterial isolation on selective media, and molecular identification using 16S PCR/sequencing to determine ARB species and 18S rRNA PCR/sequencing to determine FLA species present in the water samples before and after the ceramic pot intervention. Several FLA species including Acanthamoeba spp. and Mycobacterium spp. were isolated. The ceramic pot filter removed many of these microorganisms from the borehole water. However, design flaws could have been responsible for some FLA and ARB detected in the filtered water. FLA and their associated ARB are ubiquitous in borehole water, and some of these species might be potentially harmful and a health risk to vulnerable individuals. There is a need to do more investigations into the health risk of these organisms after point-of-use treatment.
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Affiliation(s)
- Clarissa van der Loo
- Water and Health Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2094, South Africa; (C.v.d.L.); (T.G.B.)
| | | | - Tobias George Barnard
- Water and Health Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg 2094, South Africa; (C.v.d.L.); (T.G.B.)
| | - Natasha Potgieter
- Environmental Health, Domestic Hygiene and Microbial Pathogens Research Group, Department of Microbiology, University of Venda, Thohoyandou 1950, South Africa
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Costa AO, Chagas IAR, de Menezes-Neto A, Rêgo FD, Nogueira PM, Torrecilhas AC, Furst C, Fux B, Soares RP. Distinct immunomodulatory properties of extracellular vesicles released by different strains of Acanthamoeba. Cell Biol Int 2021; 45:1060-1071. [PMID: 33448518 DOI: 10.1002/cbin.11551] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 12/08/2020] [Accepted: 01/09/2021] [Indexed: 01/07/2023]
Abstract
Free living amoeba of the genus Acanthamoeba are opportunist protozoan involved in corneal, systemic, and encephalic infections in humans. Most of the mechanisms underlying intraspecies variations and pathogenicity are still unknown. Recently, the release of extracellular vesicles (EVs) by Acanthamoeba was reported. However, comparative characterization of EVs from distinct strains is not available. The aim of this study was to evaluate EVs produced by Acanthamoeba from different genotypes, comparing their proteases profile and immunomodulatory properties. EVs from four environmental or clinical strains (genotypes T1, T2, T4, and T11) were obtained by ultracentrifugation, quantitated by nanoparticle tracking analysis and analyzed by scanning and transmission electron microscopy. Proteases profile was determined by zymography and functional properties of EVs (measure of nitrite and cytokine production) were determined after peritoneal macrophage stimulation. Despite their genotype, all strains released EVs and no differences in size and/or concentration were detected. EVs exhibited a predominant activity of serine proteases (pH 7.4 and 3.5), with higher intensity in T4 and T1 strains. EVs from the environmental, nonpathogenic T11 strain exhibited a more proinflammatory profile, inducing higher levels of Nitrite, tumor necrosis factor alpha and interleukin-6 via TLR4/TLR2 than those strains with pathogenic traits (T4, T1, and T2). Preincubation with EVs treated with protease inhibitors or heating drastically decreased nitrite concentration production in macrophages. Those data suggest that immunomodulatory effects of EVs may reflect their pathogenic potential depending on the Acanthamoeba strains and are dependent on protease integrity.
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Affiliation(s)
- Adriana Oliveira Costa
- Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Armando de Menezes-Neto
- Instituto René Rachou, FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil.,Departamento de Patologia, Universidade Federal do Espírito Santo, Vitória, Espírito Santo, Brazil
| | - Felipe Dutra Rêgo
- Instituto René Rachou, FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | | | - Ana Claudia Torrecilhas
- Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo, Campus Diadema, Diadema, São Paulo, Brazil
| | - Cinthia Furst
- Departamento de Patologia, Universidade Federal do Espírito Santo, Vitória, Espírito Santo, Brazil
| | - Blima Fux
- Departamento de Patologia, Universidade Federal do Espírito Santo, Vitória, Espírito Santo, Brazil
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Detection and Identification of Acanthamoeba and Other Nonviral Causes of Infectious Keratitis in Corneal Scrapings by Real-Time PCR and Next-Generation Sequencing-Based 16S-18S Gene Analysis. J Clin Microbiol 2021; 59:JCM.02224-20. [PMID: 33239372 PMCID: PMC8111161 DOI: 10.1128/jcm.02224-20] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/16/2020] [Indexed: 01/29/2023] Open
Abstract
Acanthamoeba 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. Acanthamoeba 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 Acanthamoeba-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 Acanthamoeba. Two hundred DNAs extracted from corneal scrapings and screened by Acanthamoeba-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 (n = 19) and T6 (n = 2). Fungal and bacterial species of potential clinical relevance were identified in 31 of the samples negative for Acanthamoeba, exemplified by Pseudomonas aeruginosa (n = 11), Moraxella spp. (n = 6), Staphylococcus aureus (n = 2), Fusarium spp. (n = 4), and Candida albicans (n = 1). In conclusion, the 16S-18S assay was slightly less sensitive than real-time PCR in detecting Acanthamoeba-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 Acanthamoeba. NGS-based detection of ribosomal genes in corneal scrapings could be an efficient screening method for detecting nonviral causes of IK, including Acanthamoeba.
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Carvalho-Silva AC, Coelho CH, Cirelli C, Crepaldi F, Rodrigues-Chagas IA, Furst C, Pimenta DC, Toledo JSD, Fernandes AP, Costa AO. Differential expression of Acanthamoeba castellanii proteins during amoebic keratitis in rats. Exp Parasitol 2020; 221:108060. [PMID: 33338467 DOI: 10.1016/j.exppara.2020.108060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 11/04/2020] [Accepted: 12/13/2020] [Indexed: 11/25/2022]
Abstract
Amoebic keratitis (AK) is a sight-threatening infection characterized by a severe inflammation of the cornea, caused by the free-living protozoan of the genus Acanthamoeba. Identification of amoebic proteins involved in AK pathogenesis may help to elucidate molecular mechanisms of infection and contribute to indicate diagnostic and therapeutic targets. In this study, we evaluated changes in the expression profile of Acanthamoeba proteins triggered by the invasive process, using an approach involving two-dimensional polyacrylamide gel electrophoresis (2DE PAGE), followed by mass spectrometry identification (ESI-IT-TOF LC-MSn). AK was induced by intrastromal inoculation in Wistar rats, using trophozoites from a T4 genotype, human case-derived A. castellanii strain under prolonged axenic culture. Cultures re-isolated from the lesions after two successive passages in the animals were used as biological triplicate for proteomic experiments. Analysis of the protein profile comparing long-term and re-isolated cultures indicated 62 significant spots, from which 27 proteins could be identified in the Acanthamoeba proteome database. Five of them (Serpin, Carboxypeptidase A1, Hypothetical protein, Calponin domain-containing protein, aldo/keto reductase) were exclusively found in the re-isolated trophozoites. Our analysis also revealed that a concerted modulation of several biochemical pathways is triggered when A. castellanii switches from a free-living style to a parasitic mode, including energetic metabolism, proteolytic activity, control of gene expression, protein degradation and methylation of DNA, which may be also involved in gain of virulence in an animal model of AK.
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Affiliation(s)
- Ana Carolina Carvalho-Silva
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Camila H Coelho
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Cecília Cirelli
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Frederico Crepaldi
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Cinthia Furst
- Department of Pathology, Health Sciences Center, Federal University of Espírito Santo, Vitória, ES, Brazil
| | | | - Juliano Simões de Toledo
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ana Paula Fernandes
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Adriana Oliveira Costa
- Department of Clinical and Toxicological Analysis, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
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Niederkorn JY. The biology of Acanthamoeba keratitis. Exp Eye Res 2020; 202:108365. [PMID: 33221372 DOI: 10.1016/j.exer.2020.108365] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/10/2020] [Accepted: 11/13/2020] [Indexed: 12/31/2022]
Abstract
Acanthamoeba keratitis (AK) is a rare protozoal infection of the cornea. At least eight species of Acanthamoeba are known to cause this sight-threatening disease of the ocular surface. Acanthamoeba spp. exist in a wide array of niches ranging from thermal springs to under ice and every conceivable habitat in between. Contact lens wear is the leading risk factor for AK and is practiced by over 30 million individuals in the United States, yet the incidence of AK is less than 33 cases per one million contact lens wearers. Serological studies have reported that 90%-100% of individuals with no history of AK possess antibodies specific for Acanthamoeba antigens indicating that exposure to this organism is commonplace, yet disease is remarkably rare. Animal studies have shed light on the pathobiology and immunobiology of AK and indicate that a constellation of factors including the ocular surface microbiome and the microbiome of Acanthamoeba itself contribute to the pathogenesis of AK. Interesting, secretory antibodies produced by the adaptive immune response can prevent the initiation of corneal infection, but once Acanthamoeba trophozoites breach the corneal epithelium the adaptive immune system is helpless in altering the course of AK. It has been almost 50 years since AK was first described, yet many questions remain unanswered about this curious and enigmatic disease of the ocular surface.
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Affiliation(s)
- Jerry Y Niederkorn
- Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA.
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Acanthamoeba spp. monoclonal antibody against a CPA2 transporter: a promising molecular tool for acanthamoebiasis diagnosis and encystment study. Parasitology 2020; 147:1678-1688. [PMID: 32951614 DOI: 10.1017/s0031182020001778] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Free-living amoeba of the genus Acanthamoeba are ubiquitous protozoa involved in opportunistic and non-opportunistic infection in humans, such as granulomatous amoebic encephalitis and amoebic keratitis. Both infections have challenging characteristics such as the formation of the resistant cysts in infected tissues, hampering the treatment and most usual diagnosis depending on time-consuming and/or low sensitivity techniques. The use of monoclonal antibodies presents itself as an opportunity for the development of more effective alternative diagnostic methods, as well as an important and useful tool in the search for new therapeutic targets. This study investigated the possibility of using a previously produced monoclonal antibody (mAb3), as a diagnostic tool for the detection of Acanthamoeba trophozoites by direct and indirect flow cytometry and immunofluorescence. Immunoprecipitation assay and mass spectrometry allowed the isolation of the antibody's target and suggested it is a transporter part of the CPA (cation: proton antiporter) superfamily. In vitro tests indicate an important role of this target in Acanthamoeba's encystment physiology. Our results support the importance of studying the role of CPA2 transporters in the context of acanthamoebiasis, as this may be a way to identify new therapeutic candidates.
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Cartography of Free-Living Amoebae in Soil in Guadeloupe (French West Indies) Using DNA Metabarcoding. Pathogens 2020; 9:pathogens9060440. [PMID: 32512696 PMCID: PMC7350318 DOI: 10.3390/pathogens9060440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/02/2020] [Accepted: 05/03/2020] [Indexed: 12/20/2022] Open
Abstract
Free-living amoebae (FLA) are ubiquitous protists. Pathogenic FLA such as N. fowleri can be found in hot springs in Guadeloupe, soil being the origin of this contamination. Herein, we analyzed the diversity and distribution of FLA in soil using a targeted metataxonomic analysis. Soil samples (n = 107) were collected from 40 sites. DNA was extracted directly from soil samples or from FLA cultivated at different temperatures (30, 37 and 44 °C). Metabarcoding studies were then conducted through FLA 18SrDNA amplicons sequencing; amplicon sequence variants (ASV) were extracted from each sample and taxonomy assigned against SILVA database using QIIME2 and SHAMAN pipelines. Vermamoeba were detected in DNA extracted directly from the soil, but to detect other FLA an amoebal enrichment step was necessary. V. vermiformis was by far the most represented species of FLA, being detected throughout the islands. Although Naegleria were mainly found in Basse-Terre region, N. fowleri was also detected in Grand Terre and Les Saintes Islands. Acanthamoeba were mainly found in areas where temperature is approx. 30 °C. Vannella and Vahlkampfia were randomly found in Guadeloupe islands. FLA detected in Guadeloupe include both pathogenic genera and genera that can putatively harbor microbial pathogens, therefore posing a potential threat to human health.
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Carnt NA, Subedi D, Lim AW, Lee R, Mistry P, Badenoch PR, Kilvington S, Dutta D. Prevalence and seasonal variation of Acanthamoeba in domestic tap water in greater Sydney, Australia. Clin Exp Optom 2020; 103:782-786. [PMID: 32227362 DOI: 10.1111/cxo.13065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 11/17/2019] [Accepted: 02/28/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND This study examined the prevalence of free-living Acanthamoeba in domestic tap water in the greater Sydney region, Australia, and determined any seasonal variation in prevalence. METHODS Fifty-four participants were included in this study following approval from an institutional human research ethics committee. Each participant self-collected two samples (one in summer and another in winter) from the surface of the drain of the bathroom sink using an instructional kit. The samples were cultured by inoculating onto a non-nutrient agar plate seeded with Escherichia coli and incubation at 32°C for two weeks. The plates were microscopically examined for the presence of free-living amoeba. DNA was isolated from 20 samples and a polymerase chain reaction (PCR) assay was performed for amplification of the partial sequence of the 18S ribosomal RNA gene. The PCR amplified products were sequenced using Sanger sequencing and genotyping was performed based on the variation in nucleotide sequences. RESULTS A total of 97 samples were collected over the two collection periods, with 28.6 per cent of samples morphologically classified as Acanthamoeba. The summer period yielded 16 of 54 (29.6 per cent) samples classified as Acanthamoeba, while the winter period yielded 12 of 43 (27.9 per cent) samples classified as Acanthamoeba. There was no statistically significant difference (p = 0.85) between the prevalence of free-living Acanthamoeba in summer compared to winter. Phylogenetic analysis showed that 15 of 20 (75 per cent) isolates belonged to genotype T4, the most frequent genotype isolated in Acanthamoeba keratitis. CONCLUSION The prevalence of free-living Acanthamoeba characterised morphologically in domestic tap water of the greater Sydney region was higher than expected, especially considering the low incidence of Acanthamoeba keratitis in Australia. However, this study did not find variation between seasons. As the T4 genotype was most common, Sydney-based practitioners must always consider Acanthamoeba as a possible causative organism in cases of microbial keratitis, regardless of the season.
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Affiliation(s)
- Nicole A Carnt
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia.,Centre for Vision Research, Westmead Institute for Medical Research, The University of Sydney, Sydney, Australia.,Institute of Ophthalmology, University College London, London, UK
| | - Dinesh Subedi
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
| | - Ann W Lim
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
| | - Rebecca Lee
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
| | - Priyal Mistry
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
| | - Paul R Badenoch
- Department of Ophthalmology, Flinders Medical Centre, Adelaide, Australia.,College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Simon Kilvington
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
| | - Debarun Dutta
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia.,Optometry and Vision Science, Life and Health Sciences, Aston University, Birmingham, UK
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Isolates from ancient permafrost help to elucidate species boundaries in Acanthamoeba castellanii complex (Amoebozoa: Discosea). Eur J Protistol 2020; 73:125671. [DOI: 10.1016/j.ejop.2020.125671] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 01/03/2020] [Accepted: 01/08/2020] [Indexed: 11/22/2022]
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Alvarado-Ocampo J, Retana-Moreira L, Abrahams-Sandí E. In vitro effects of environmental isolates of Acanthamoeba T4 and T5 over human erythrocytes and platelets. Exp Parasitol 2020; 210:107842. [PMID: 31978393 DOI: 10.1016/j.exppara.2020.107842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/10/2020] [Accepted: 01/18/2020] [Indexed: 01/07/2023]
Abstract
Free-living amoebae of the genus Acanthamoeba have been associated with keratitis and encephalitis. Some factors related to their pathogenic potential have been described, including the release of hydrolytic enzymes, and the adhesion and phagocytosis processes. However, other factors such as their effect over the hemodynamics and microcirculation elements have not been fully investigated. This work determines the in vitro activity of potentially pathogenic environmental isolates of Acanthamoeba genotype T4 and T5 over erythrocytes and platelets. The hemolytic activity (dependent and independent of contact), as well as the production of ADP of ten environmental isolates of Acanthamoeba obtained from dental units, combined emergency showers, dust, and hospital water, were measured. Tests were carried out over erythrocytes in suspension and blood agar plates, incubated at 4 °C, room temperature and 37 °C. Erythrophagocytosis and platelet aggregation assays were also performed. Live trophozoites of all of the isolates tested showed a hemolytic activity that was temperature-dependent. Over erythrocytes in suspension, variable hemolysis percentages were obtained: a maximum of 41% and a minimum of 15%. Regarding hemolysis over agar plates, two patterns of hemolysis were observed: double and simple halos. Conditioned medium and crude extracts of trophozoites did not show hemolytic activity. Erythrophagocytosis by Acanthamoeba was also observed; however, no production of ADP was determined by the employed methodology.
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Affiliation(s)
- Johan Alvarado-Ocampo
- University of Costa Rica, Faculty of Microbiology, Department of Parasitology, San Pedro, San José, Costa Rica; Centro de Investigación en Enfermedades Tropicales, San Pedro, San José, Costa Rica
| | - Lissette Retana-Moreira
- University of Costa Rica, Faculty of Microbiology, Department of Parasitology, San Pedro, San José, Costa Rica; Centro de Investigación en Enfermedades Tropicales, San Pedro, San José, Costa Rica
| | - Elizabeth Abrahams-Sandí
- University of Costa Rica, Faculty of Microbiology, Department of Parasitology, San Pedro, San José, Costa Rica; Centro de Investigación en Enfermedades Tropicales, San Pedro, San José, Costa Rica.
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Cirelli C, Mesquita EIS, Chagas IAR, Furst C, Possamai CO, Abrahão JS, dos Santos Silva LK, Grossi MF, Tagliati CA, Costa AO. Extracellular protease profile of Acanthamoeba after prolonged axenic culture and after interaction with MDCK cells. Parasitol Res 2019; 119:659-666. [DOI: 10.1007/s00436-019-06562-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/19/2019] [Indexed: 12/27/2022]
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Khan NA, Anwar A, Siddiqui R. Acanthamoeba Keratitis: Current Status and Urgent Research Priorities. Curr Med Chem 2019; 26:5711-5726. [DOI: 10.2174/0929867325666180510125633] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 01/10/2018] [Accepted: 05/01/2018] [Indexed: 12/13/2022]
Abstract
Background:First discovered in the early 1970s, Acanthamoeba keratitis has remained a major eye infection and presents a significant threat to the public health, especially in developing countries. The aim is to present a timely review of our current understanding of the advances made in this field in a comprehensible manner and includes novel concepts and provides clear directions for immediate research priorities.Methods:We undertook a search of bibliographic databases for peer-reviewed research literature and also summarized our published results in this field.Results:The present review focuses on novel diagnostic and therapeutic strategies in details which can provide access to management and treatment of Acanthamoeba keratitis. This coupled with the recently available genome sequence information together with high throughput genomics technology and innovative approaches should stimulate interest in the rational design of preventative and therapeutic measures. Current treatment of Acanthamoeba keratitis is problematic and often leads to infection recurrence. Better understanding of diagnosis, pathogenesis, pathophysiology and therapeutic regimens, would lead to novel strategies in treatment and prophylaxis.
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Affiliation(s)
- Naveed Ahmed Khan
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City, Sharjah, United Arab Emirates
| | - Ayaz Anwar
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City, Sharjah, United Arab Emirates
| | - Ruqaiyyah Siddiqui
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City, Sharjah, United Arab Emirates
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Orosz E, Kriskó D, Shi L, Sándor GL, Kiss HJ, Seitz B, Nagy ZZ, Szentmáry N. Clinical course of Acanthamoeba keratitis by genotypes T4 and T8 in Hungary. Acta Microbiol Immunol Hung 2019; 66:289-300. [PMID: 30835133 DOI: 10.1556/030.66.2019.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Genus Acanthamoeba is an opportunistic protozoan that is widely distributed in the environment. Within this genus, numerous species are recognized as human pathogens, potentially causing Acanthamoeba keratitis (AK). AK is a corneal disease, associated predominantly with contact lens (CL) wear; its epidemiology is related to the specific Acanthamoeba genotypes. This study reports seven CL wearer, Acanthamoeba PCR-positive patients with AK, diagnosed between January 2015 and 2018. Patients had the diagnosis of AK 1.36 months after first symptoms. Genotyping allowed the identification of six isolates of the T4 and one of the T8 genotypes. At first presentation, pseudendritiformic epithelopathy/dirty epithelium (four eyes, 57.1%), multifocal stromal infiltrates (five eyes, 71.4%), ring infiltrate (three eyes, 42.8%), and perineuritis (one eye, 14.3%) were observed. AK was healed without later recurrence in two eyes (28.5%) using triple-topical therapy, in three eyes (42.8%) following additional penetrating keratoplasty. In one patient (14.3%), AK recurred following successful application of triple-therapy and was treated successfully with repeated triple-topical therapy and in one patient (14.3%), no follow-up data were available after diagnosis. We could not observe correlation of genotype and clinical course or the necessity of corneal transplantation in our case series.
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Affiliation(s)
- Erika Orosz
- 1 Department of Parasitology, National Public Health Center, Budapest, Hungary
| | - Dorottya Kriskó
- 2 Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Lei Shi
- 3 Department of Ophthalmology, Saarland University Medical Center, Homburg, Germany
| | - Gábor L. Sándor
- 2 Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Huba J. Kiss
- 2 Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Berthold Seitz
- 3 Department of Ophthalmology, Saarland University Medical Center, Homburg, Germany
| | - Zoltán Zsolt Nagy
- 2 Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Nóra Szentmáry
- 2 Department of Ophthalmology, Semmelweis University, Budapest, Hungary
- 3 Department of Ophthalmology, Saarland University Medical Center, Homburg, Germany
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Cano A, Mattana A, Henriquez FL, Alexander J, Roberts CW. Acanthamoebaproteases contribute to macrophage activation through PAR1, but not PAR2. Parasite Immunol 2019; 41:e12612. [DOI: 10.1111/pim.12612] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/07/2018] [Indexed: 12/28/2022]
Affiliation(s)
- Antonella Cano
- Strathclyde Institute of Pharmacy & Biomedical SciencesUniversity of Strathclyde Glasgow UK
| | - Antonella Mattana
- Department of Biomedical SciencesDivision of Experimental and Clinical MicrobiologyUniversity of Sassari Sassari Italy
| | - Fiona L. Henriquez
- Infection and MicrobiologyInstitute of Biomedical and Environmental HealthSchool of Science & SportUniversity of the West of Scotland Paisley UK
| | - James Alexander
- Strathclyde Institute of Pharmacy & Biomedical SciencesUniversity of Strathclyde Glasgow UK
| | - Craig W. Roberts
- Strathclyde Institute of Pharmacy & Biomedical SciencesUniversity of Strathclyde Glasgow UK
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45
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Koutsogiannis Z, MacLeod ET, Maciver SK. G418 induces programmed cell death in Acanthamoeba through the elevation of intracellular calcium and cytochrome c translocation. Parasitol Res 2019; 118:641-651. [PMID: 30617503 PMCID: PMC6349814 DOI: 10.1007/s00436-018-6192-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 12/19/2018] [Indexed: 11/27/2022]
Abstract
Acanthamoeba is a widely distributed opportunistic parasite which causes a vision-threatening keratitis and a life-threatening encephalitis. The cyst stage of this amoeba is especially resistant to currently used therapeutics and so alternative agents are urgently required. Growing evidence supports the existence of a programmed cell death system (PCD) in Acanthamoeba and while some features are shared by higher eukaryote cells, others differ. It is hoped that by understanding these differences we can exploit them as targets for novel drug intervention to activate PCD pathways in the amoebae but not the invaded human tissue. Here, we use the aminoglycoside G418 to activate PCD in Acanthamoeba. This drug caused a shape change in the treated amoebae. Cells rounded up and contracted, and after 6 h fragments of cells resembling the ‘apoptotic bodies’ of vertebrate cells were observed. G418 causes an increase in intracellular calcium from a resting level of 24 nM to 60 nM after 6 h of treatment. Mitochondrial function as assayed by the ΔΨm reporting dye JC-1 and CTC a redox dye becomes inhibited during treatment and we have found that cytochrome c is released from the mitochondria. Cells stained with Hoechst showed first an alteration in chromatin structure and then a vesiculation of the nucleus with G418 treatment, although we found no obvious breakdown in genomic DNA in the early stages of PCD.
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Affiliation(s)
| | - Ewan T MacLeod
- Division of Infection and Pathway Medicine, Biomedical Sciences, Edinburgh Medical School, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, Scotland, EH8 9XD, UK
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46
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Abd El Wahab WM, El-Badry AA, Hamdy DA. Molecular characterization and phylogenetic analysis of Acanthamoeba isolates in tap water of Beni-Suef, Egypt. Acta Parasitol 2018; 63:826-834. [PMID: 30367777 DOI: 10.1515/ap-2018-0101] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 08/29/2018] [Indexed: 11/15/2022]
Abstract
The genus Acanthamoeba is a free-living amoeba widely distributed in various aquatic environments. It is an etiologic cause of amoebic encephalitis and keratitis particularly for immunocompromised individuals. The purpose of the present study was to investigate Acanthamoeba species prevalence in household and hospital potable water in Beni-Suef governorate, Egypt, and to employ sequencing methods to identify positive Acanthamoeba species isolates and their potential health risks. Sixty tap water samples (30 household and 30 governmental and private hospital settings) collected from Beni-Suef governorate, Egypt were filtered, cultured on non-nutrient agar, identified by morphotyping keys after staining with Giemsa stain and then confirmed by PCR using Acanthamoeba specific primers. Twenty positive samples were successfully genetically characterized and phylogenetically analyzed to identify Acanthamoeba species. The total detection rate for Acanthamoeba was 48/60 (80%); Acanthamoeba contamination in water collected from domestic houses was higher than in hospitals; 27/30 (90%) versus 21/30 (70%) with statistical significant value (P value = 0.05). Sequencing of 20 positive isolates revealed Acanthamoeba T4 in 65% and T2 in 35%. To our knowledge, this is the first research that documents the occurrence and phylogeny of Acanthamoeba species in Beni-Suef, Egypt. The presence of a higher percentage of Acanthamoeba species in tap water, in particular T4, highlights the potential health hazards for immunocompromised individuals and emphasizes the urgent need for the implementation of effective filtration and disinfection measures.
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Affiliation(s)
- Wegdan M Abd El Wahab
- Department of Medical Parasitology, College of Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Ayman A El-Badry
- Department of Microbiology-Medical Parasitology Section, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Doaa A Hamdy
- Department of Medical Parasitology, College of Medicine, Beni-Suef University, Beni-Suef, Egypt
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47
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Contact lens-related polymicrobial keratitis: Acanthamoeba spp. genotype T4 and Candida albicans. Parasitol Res 2018; 117:3431-3436. [PMID: 30094541 DOI: 10.1007/s00436-018-6037-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/30/2018] [Indexed: 10/28/2022]
Abstract
A 31-year-old female daily user of contact lenses sought medical attention, reporting blurred vision and irritation of the left eye. Slit-lamp examination revealed hyperemia and an irregular corneal epithelium surface, and empirical treatment was started. A corneal scrape was obtained and examined for the presence of fungi, bacteria, and Acanthamoeba spp. The results of the microbial culture revealed growth of Acanthamoeba spp. and Candida albicans. The Acanthamoeba isolate was characterized by cyst morphology as belonging to group II according to Pussard and Pons. Sequencing of the diagnostic fragment 3 (DF3) region located on the 18S ribosomal DNA identified the isolate as genotype T4. The patient was treated with chlorhexidine 0.02% and polyhexamethylene biguanide (PHMB) 0.02% drops for 5 months until the infection resolved. Lately, rare cases of polymicrobial keratitis associated with Acanthamoeba and Candida albicans have been reported. Cases of co-infection are more difficult to treat, since the specific treatment depends on precise identification of the agents involved.
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48
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Taher EE, Méabed EM, Abdallah I, Abdel Wahed WY. Acanthamoeba keratitis in noncompliant soft contact lenses users: Genotyping and risk factors, a study from Cairo, Egypt. J Infect Public Health 2018; 11:377-383. [DOI: 10.1016/j.jiph.2017.09.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/09/2017] [Accepted: 09/09/2017] [Indexed: 11/27/2022] Open
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Possamai CO, Loss AC, Costa AO, Falqueto A, Furst C. Acanthamoeba of three morphological groups and distinct genotypes exhibit variable and weakly inter-related physiological properties. Parasitol Res 2018. [PMID: 29532218 DOI: 10.1007/s00436-018-5824-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Free-living amoeba of the genus Acanthamoeba can eventually act as parasites, causing infections in humans. Some physiological characteristics of Acanthamoeba have been related to the grade of pathogenicity, allowing inferences about the pathogenic potential. The main goal of this study was to characterize isolates of Acanthamoeba obtained in Brazil and evaluate properties associated with their pathogenicity. A total of 39 isolates obtained from keratitis cases (n = 16) and environmental sources (n = 23) were classified into morphological groups and genotyped by sequencing the 18S rDNA fragments ASA.S1 and GTSA.B1. Samples were also tested regarding their thermo-tolerance, osmo-tolerance, and cytopathogenicity in MDCK cells. Isolates were identified and classified as follows: group I (T17, T18); group II (T1, T3, T4, T11); and group III (T5, T15), with the predominance of genotype T4 (22/39). Clinical isolates were genotyped as T3 (1/16), T4 (14/16) and T5 (1/16). The majority of isolates (38/39) were able to grow at 37 °C, but tolerance to 40 °C was more frequent among environmental samples. The tolerance to 1 M mannitol was infrequent (4/39), with three of these corresponding to clinical samples. The variable ability to cause cytopathic effects was observed among isolates of distinct genotypes and origins. This study identified, for the first time, T1 and T18 in Brazil. It also indicated a weak association between the clinical origin of the isolates and tolerance to high temperatures, high osmolarity, and cytopathogenicity, demonstrating that some in vitro parameters do not necessarily reflect a higher propensity of Acanthamoeba to cause a disease.
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Affiliation(s)
- Cynara Oliveira Possamai
- Departamento de Patologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Av. Marechal Campos, 1468, Vitória, ES, CEP 29043-900, Brazil
| | - Ana Carolina Loss
- Departamento de Ciências Biológicas, Centro de Ciências Humanas e Naturais, Universidade Federal do Espírito Santo, Av. Fernando Ferrari, 514, Vitória, ES, CEP 29075-900, Brazil
| | - Adriana Oliveira Costa
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Belo Horizonte, MG, CEP 31270-901, Brazil
| | - Aloisio Falqueto
- Departamento de Medicina Social, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Av. Marechal Campos, 1468, Vitória, ES, CEP 29043-900, Brazil
| | - Cinthia Furst
- Departamento de Patologia, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Av. Marechal Campos, 1468, Vitória, ES, CEP 29043-900, Brazil.
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50
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Detection and molecular characterization of Acanthamoeba spp. in stray cats from Madrid, Spain. Exp Parasitol 2018; 188:8-12. [PMID: 29501695 DOI: 10.1016/j.exppara.2018.02.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 02/08/2018] [Accepted: 02/28/2018] [Indexed: 11/23/2022]
Abstract
Acanthamoeba spp. is a widespread protozoan that has been isolated from air, dust, soil, water and biological samples. An opportunistic pathogen of humans and animals, it may cause ocular keratitis, encephalitis, and even multisystem disease. The frequency of Acanthamoeba in animals is unknown. The aim of present study was determine the presence of Acanthamoeba spp. in immunocompromised stray cats - animals possibly more likely to harbour the infection given their immunocompromised status and frequenting of contaminated environments. Of 307 cats examined, 55 were positive for feline immunodeficiency virus and/or feline leukaemia virus and therefore included in the study. Corneal scrapings were obtained to isolate Acanthamoeba spp. by culture and molecular detection by conventional and real time PCR. None of the samples examined directly by molecular methods were positive for Acanthamoeba spp. However, two (3.6%) cases of the cultured samples provided positive results, which were confirmed by subsequent molecular analysis. Sequencing assigned one isolate to genotype T4 and the other to T2. Since Acanthamoeba spp. may also infect animals and humans, the present findings may raise some public health and veterinary concerns.
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