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Jiang Q, Zhang Z, Cai Y, Chen L, Deng L, Xiong Y. Disseminated Acanthamoeba castellanii infection in a patient with AIDS: a case report and literature review. Front Med (Lausanne) 2024; 11:1377302. [PMID: 38952864 PMCID: PMC11215114 DOI: 10.3389/fmed.2024.1377302] [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: 02/21/2024] [Accepted: 05/27/2024] [Indexed: 07/03/2024] Open
Abstract
Background Acanthamoeba castellanii infection is a rare condition primarily occurring in immunocompromised patients with extremely high mortality. Currently, there is no standard treatment for this condition, and successful treatment reports are scarce. Case presentation We present a case of Acanthamoeba castellanii infection in a 63-year-old female patient with AIDS, who was admitted to our hospital with symptoms of fever, skin ulcers, subcutaneous nodules, and food regurgitation from the nose while eating. After initial empirical treatment failed, a biopsy of the subcutaneous nodule was performed, and metagenomic next-generation sequencing (mNGS) technology was used to detect pathogenic microorganisms in both the biopsy specimen and blood samples. The results revealed Acanthamoeba castellanii infection. Additionally, histopathological examination of the biopsy specimen and cytological examination of the secretions from the ulcer surface also confirmed this pathogenic infection. The patient's symptoms significantly improved upon discharge after adjusting the treatment regimen to a combination of anti-amebic therapy. Conclusion Immunocompromised patients presenting with unexplained fever and skin or sinus lesions should be evaluated for Acanthamoeba castellanii infection. Multi-drug combination therapy is required for this organism infection, and a standard treatment protocol still needs further research. Metagenomic next-generation sequencing is a valuable tool for early diagnosis of unknown pathogen infections.
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Affiliation(s)
- Qunqun Jiang
- Department of Infectious Disease, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Zhongwei Zhang
- Department of Infectious Disease, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yuxiang Cai
- Department of Pathology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Liangjun Chen
- Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Liping Deng
- Department of Infectious Disease, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yong Xiong
- Department of Infectious Disease, Zhongnan Hospital of Wuhan University, Wuhan, China
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Hargrove T, Lamb DC, Wawrzak Z, Hull M, Kelly SL, Guengerich FP, Lepesheva GI. Identification of Potent and Selective Inhibitors of Acanthamoeba: Structural Insights into Sterol 14α-Demethylase as a Key Drug Target. J Med Chem 2024; 67:7443-7457. [PMID: 38683753 PMCID: PMC11089504 DOI: 10.1021/acs.jmedchem.4c00303] [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: 02/02/2024] [Revised: 03/27/2024] [Accepted: 04/22/2024] [Indexed: 05/02/2024]
Abstract
Acanthamoeba are free-living pathogenic protozoa that cause blinding keratitis, disseminated infection, and granulomatous amebic encephalitis, which is generally fatal. The development of efficient and safe drugs is a critical unmet need. Acanthamoeba sterol 14α-demethylase (CYP51) is an essential enzyme of the sterol biosynthetic pathway. Repurposing antifungal azoles for amoebic infections has been reported, but their inhibitory effects on Acanthamoeba CYP51 enzymatic activity have not been studied. Here, we report catalytic properties, inhibition, and structural characterization of CYP51 from Acanthamoeba castellanii. The enzyme displays a 100-fold substrate preference for obtusifoliol over lanosterol, supporting the plant-like cycloartenol-based pathway in the pathogen. The strongest inhibition was observed with voriconazole (1 h IC50 0.45 μM), VT1598 (0.25 μM), and VT1161 (0.20 μM). The crystal structures of A. castellanii CYP51 with bound VT1161 (2.24 Å) and without an inhibitor (1.95 Å), presented here, can be used in the development of azole-based scaffolds to achieve optimal amoebicidal effectiveness.
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Affiliation(s)
- Tatiana
Y. Hargrove
- Department
of Biochemistry, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232, United States
| | - David C. Lamb
- Faculty
of Medicine, Health and Life Science, Swansea
University, Swansea SA2 8PP, U.K.
| | - Zdzislaw Wawrzak
- Synchrotron
Research Center, Life Science Collaborative Access Team, Northwestern University, Argonne, Illinois 60439, United States
| | - Marcus Hull
- Faculty
of Medicine, Health and Life Science, Swansea
University, Swansea SA2 8PP, U.K.
| | - Steven L. Kelly
- Faculty
of Medicine, Health and Life Science, Swansea
University, Swansea SA2 8PP, U.K.
| | - F. Peter Guengerich
- Department
of Biochemistry, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232, United States
| | - Galina I. Lepesheva
- Department
of Biochemistry, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232, United States
- Vanderbilt
Institute of Chemical Biology, Nashville, Tennessee 37232, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
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Ahmed U, Ong SK, Khan KM, Siddiqui R, Khan NA, Shaikh MF, Alawfi BS, Anwar A. Effect of embelin on inhibition of cell growth and induction of apoptosis in Acanthamoeba castellanii. Arch Microbiol 2023; 205:360. [PMID: 37898989 DOI: 10.1007/s00203-023-03698-3] [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: 08/23/2023] [Accepted: 10/02/2023] [Indexed: 10/31/2023]
Abstract
Acanthamoeba castellanii is the causative agent of fatal encephalitis and blinding keratitis. Current therapies remain a challenge, hence there is a need to search for new therapeutics. Here, we tested embelin (EMB) and silver nanoparticles doped with embelin (EMB-AgNPs) against A. castellanii. Using amoebicidal assays, the results revealed that both compounds inhibited the viability of Acanthamoeba, having an IC50 of 27.16 ± 0.63 and 13.63 ± 1.08 μM, respectively, while causing minimal cytotoxicity against HaCaT cells in vitro. The findings suggest that both samples induced apoptosis through the mitochondria-mediated pathway. Differentially expressed genes analysis showed that 652 genes were uniquely expressed in treated versus untreated cells, out of which 191 were significantly regulated in the negative control vs. conjugate. Combining the analysis, seven genes (ARIH1, RAP1, H3, SDR16C5, GST, SRX1, and PFN) were highlighted as the most significant (Log2 (FC) value ± 4) for the molecular mode of action in vitro. The KEGG analysis linked most of the genes to apoptosis, the oxidative stress signaling pathway, cytochrome P450, Rap1, and the oxytocin signaling pathways. In summary, this study provides a thorough framework for developing therapeutic agents against microbial infections using EMB and EMB-AgNPs.
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Affiliation(s)
- Usman Ahmed
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, 47500, Selangor, Malaysia
| | - Seng-Kai Ong
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, 47500, Selangor, Malaysia
| | - Khalid Mohammed Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
- Department of Clinical Pharmacy, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | | | - Naveed Ahmed Khan
- Microbiota Research Center, Istinye University, 34010, Istanbul, Turkey.
| | - Mohd Farooq Shaikh
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, 47500, Bandar Sunway, Malaysia
- School of Dentistry and Medical Sciences, Charles Sturt University, Orange, New South Wales, Australia
| | - Bader Saleem Alawfi
- Department of Medical Laboratories Technology, 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, Subang Jaya, 47500, Selangor, Malaysia.
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Ahmed U, Ho KY, Simon SE, Saad SM, Ong SK, Anwar A, Tan KO, Sridewi N, Khan KM, Khan NA, Anwar A. Potential anti-acanthamoebic effects through inhibition of CYP51 by novel quinazolinones. Acta Trop 2022; 231:106440. [PMID: 35378058 DOI: 10.1016/j.actatropica.2022.106440] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/27/2022] [Accepted: 03/30/2022] [Indexed: 12/01/2022]
Abstract
Acanthamoeba spp. are free living amoebae which can give rise to Acanthamoeba keratitis and granulomatous amoebic encephalitis. The surface of Acanthamoeba contains ergosterol which is an important target for drug development against eukaryotic microorganisms. A library of ten functionally diverse quinazolinone derivatives (Q1-Q10) were synthesised to assess their activity against Acanthamoeba castellanii T4. The in-vitro effectiveness of these quinazolinones were investigated against Acanthamoeba castellanii by amoebicidal, excystation, host cell cytopathogenicity, and NADPH-cytochrome c reductase assays. Furthermore, wound healing capability was assessed at different time durations. Maximum inhibition at 50 μg/mL was recorded for compounds Q5, Q6 and Q8, while the compound Q3 did not exhibit amoebicidal effects at tested concentrations. Moreover, LDH assay was conducted to assess the cytotoxicity of quinazolinones against HaCaT cell line. The results of wound healing assay revealed that all compounds are not cytotoxic and are likely to promote wound healing at 10 μg/mL. The excystation assays revealed that these compounds significantly inhibit the morphological transformation of A. castellanii. Compound Q3, Q7 and Q8 elevated the level of NADPH-cytochrome c reductase up to five folds. Sterol 14alpha-demethylase (CYP51) a reference enzyme in ergosterol pathway was used as a potential target for anti-amoebic drugs. In this study using i-Tasser, the protein structure of Acanthamoeba castellanii (AcCYP51) was developed in comparison with Naegleria fowleri protein (NfCYP51) structure. The sequence alignment of both proteins has shown 42.72% identity. Compounds Q1-Q10 were then molecularly docked with the predicted AcCYP51. Out of ten quinazolinones, three compounds (Q3, Q7 and Q8) showed good binding activity within 3 Å of TYR 114. The in-silico study confirmed that these compounds are the inhibitor of CYP51 target site. This report presents several potential lead compounds belonging to quinazolinone derivatives for drug discovery against Acanthamoeba infections.
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Affiliation(s)
- Usman Ahmed
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Keat-Yie Ho
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Samson Eugin Simon
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | | | - Seng-Kai Ong
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Areeba Anwar
- Faculty of Defence Science and Technology, National Defence University of Malaysia, Kuala Lumpur, Malaysia
| | - Kuan Onn Tan
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, Selangor, Malaysia
| | - Nanthini Sridewi
- Faculty of Defence Science and Technology, National Defence University of Malaysia, Kuala Lumpur, Malaysia
| | - Khalid Mohammed Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan; Department of Clinical Pharmacy, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, University City, United Arab Emirates
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, 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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Lau HL, De Lima Corvino DF, Guerra FM, Malik AM, Lichtenberger PN, Gultekin SH, Ritter JM, Roy S, Ali IKM, Cope JR, Post MJD, Gonzales Zamora JA. Granulomatous amoebic encephalitis caused by Acanthamoeba in a patient with AIDS: a challenging diagnosis. Acta Clin Belg 2021; 76:127-131. [PMID: 31455179 DOI: 10.1080/17843286.2019.1660023] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Acanthamoeba spp. is a ubiquitous free-living amoeba that causes human infections affecting predominantly the cornea and central nervous system. The diagnosis and treatment of Acanthamoeba encephalitis is very challenging. CASE SUMMARY A 53-year-old male with HIV/AIDS was admitted for altered mental status and fever. On initial examination, he had left hemianopia with left-sided weakness and numbness. MRI revealed an inflammatory and enhancing parenchymal mass associated with leptomeningeal enhancement in the occipitoparietal lobe containing multiple punctate hemorrhages. He was treated with empiric antibiotics for presumptive toxoplasmosis, brain abscess, fungal infection and tuberculosis with an unremarkable lymphoma work up. Initial brain biopsy studies were unremarkable except for non-specific granulomas and adjacent necrotic tissue. The patient passed away 2.5 months after initial presentation with no diagnosis. Post-mortem testing by the Centers for Disease Control and Prevention (CDC) confirmed the diagnosis of granulomatous amoebic encephalitis (GAE) by visualization with immunohistochemistry staining and PCR. Recovery is rare from GAE likely due to delay in diagnosis. CONCLUSIONS This case illustrates the importance of including GAE into the differential diagnosis of brain mass. We advocate early molecular testing of tissue specimen by the CDC to achieve an appropriate diagnosis, and a multidisciplinary approach for the management of this condition.
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Affiliation(s)
- Hsien Lee Lau
- Departments of Neurology, Miller School of Medicine University of Miami, Miami, FL, USA
| | | | - Francisco M. Guerra
- Infectious Disease, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Amer M. Malik
- Departments of Neurology, Miller School of Medicine University of Miami, Miami, FL, USA
| | | | - Sakir H. Gultekin
- Pathology, Miller School of Medicine University of Miami, Miami, FL, USA
| | - Jana M. Ritter
- Infectious Diseases Pathology Branch, Division of High Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Shantanu Roy
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Ibne Karim M. Ali
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Jennifer R. Cope
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - M. Judith D. Post
- Pathology and Radiology, Miller School of Medicine University of Miami, Miami, FL, USA
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Alli A, Ortiz JF, Morillo Cox Á, Armas M, Orellana VA. Miltefosine: A Miracle Drug for Meningoencephalitis Caused by Free-Living Amoebas. Cureus 2021; 13:e13698. [PMID: 33833918 PMCID: PMC8020194 DOI: 10.7759/cureus.13698] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2021] [Indexed: 11/05/2022] Open
Abstract
Meningoencephalitis caused by free-living amoebas (FLA) has a high mortality rate, and most treatments are ineffective. FLA includes Naegleria, Fowleri, Acanthamoeba, and Balamuthia mandrillaris (M). We explore the use of miltefosine in the treatment of one of these infections. The concerning mortality of the infection obligates us to look for more effective treatments for meningoencephalitis caused by FLA. During this review, we will consolidate the knowledge of using miltefosine in these three infections. We will investigate the mechanism by which the drug is effective in these infections as well. After this comprehensive review, we should assess if miltefosine improves the mortality and prognosis of the infection with the information collected. We used a Medical Subject Headings (MeSH) search on PubMed. Inclusion criteria included papers written in the English language and human subjects research for the past 25 years. Until today, there are no definitive guidelines to be followed when treating such patients. However, miltefosine has demonstrated promising results. Miltefosine decreases the usual mortality rate in the three infections; however, there are few reports due to the low frequency of these infections. Almost all cases we documented have survived. More information needs to be gathered for the use of miltefosine for these infections.
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Affiliation(s)
- Ammar Alli
- Internal Medicine, Tishreen University Faculty of Medicine, Lattakia, SYR
- Internal Medicine, Universitat de Barcelona, Barcelona, ESP
| | - Juan Fernando Ortiz
- Neurology, Universidad San Francisco de Quito, Quito, ECU
- Neurology, Larkin Community Hospital, Miami, USA
| | | | - Maria Armas
- Surgery, Pontificia Universidad Catolica del Ecuador, Quito, ECU
| | - Victor A Orellana
- Obstetrics and Gynecology, Pontifica Universidad Católica del Ecuador, Quito, ECU
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Thulasi P, Saeed HN, Rapuano CJ, Hou JH, Appenheimer AB, Chodosh J, Kang JJ, Morrill AM, Vyas N, Zegans ME, Zuckerman R, Tu EY. Oral Miltefosine as Salvage Therapy for Refractory Acanthamoeba Keratitis. Am J Ophthalmol 2021; 223:75-82. [PMID: 33045218 DOI: 10.1016/j.ajo.2020.09.048] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 09/25/2020] [Accepted: 09/25/2020] [Indexed: 12/11/2022]
Abstract
PURPOSE To report a case series of patients with treatment-resistant Acanthamoeba keratitis (AK) using oral miltefosine, often as salvage therapy. DESIGN Descriptive, retrospective multicenter case series. METHODS We reviewed 15 patients with AK unresponsive to therapy who were subsequently given adjuvant systemic miltefosine between 2011 and 2017. The main outcome measures were resolution of infection, final visual acuity, tolerance of miltefosine, and clinical course of disease. RESULTS All patients were treated with biguanides and/or diamidines or azoles without resolution of disease before starting miltefosine. Eleven of 15 patients retained count fingers or better vision, and all were considered disease free at last follow-up. Eleven of 15 patients had worsening inflammation with miltefosine, with 10 of them improving with steroids. Six patients received multiple courses of miltefosine. Most tolerated oral miltefosine well, with mild gastrointestinal symptoms as the most common systemic side effect. CONCLUSIONS Oral miltefosine is a generally well-tolerated treatment adjuvant in patients with refractory AK. The clinician should be prepared for a steroid-responsive inflammatory response frequently encountered during the treatment course.
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Kot K, Łanocha-Arendarczyk N, Kosik-Bogacka D. Immunopathogenicity of Acanthamoeba spp. in the Brain and Lungs. Int J Mol Sci 2021; 22:1261. [PMID: 33514026 PMCID: PMC7865479 DOI: 10.3390/ijms22031261] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/24/2021] [Accepted: 01/25/2021] [Indexed: 12/13/2022] Open
Abstract
Free-living amoebas, including Acanthamoeba spp., are widely distributed in soil, water, and air. They are capable of causing granulomatous amebic encephalitis, Acanthamoeba pneumonia, Acanthamoeba keratitis, and disseminated acanthamoebiasis. Despite low occurrence worldwide, the mortality rate of Acanthamoeba spp. infections is very high, especially in immunosuppressed hosts. Acanthamoeba infections are a medical problem, owing to limited improvement in diagnostics and treatment, which is associated with incomplete knowledge of pathophysiology, pathogenesis, and the host immune response against Acanthamoeba spp. infection. The aim of this review is to present the biochemical and molecular mechanisms of Acanthamoeba spp.-host interactions, including the expression of Toll-like receptors, mechanisms of an immune response, the activity of metalloproteinases, the secretion of antioxidant enzymes, and the expression and activity of cyclooxygenases. We show the relationship between Acanthamoeba spp. and the host at the cellular level and host defense reactions that lead to changes in the selected host's organs.
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Affiliation(s)
- Karolina Kot
- Department of Biology and Medical Parasitology, Faculty of Pharmacy, Medical Biotechnology and Laboratory Medicine, Pomeranian Medical University in Szczecin, Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland; (K.K.); (N.Ł.-A.)
| | - Natalia Łanocha-Arendarczyk
- Department of Biology and Medical Parasitology, Faculty of Pharmacy, Medical Biotechnology and Laboratory Medicine, Pomeranian Medical University in Szczecin, Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland; (K.K.); (N.Ł.-A.)
| | - Danuta Kosik-Bogacka
- Independent Laboratory of Pharmaceutical Botany, Faculty of Pharmacy, Medical Biotechnology and Laboratory Medicine, Pomeranian Medical University in Szczecin, Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland
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Walvekar S, Anwar A, Anwar A, Sridewi N, Khalid M, Yow YY, Khan NA. Anti-amoebic potential of azole scaffolds and nanoparticles against pathogenic Acanthamoeba. Acta Trop 2020; 211:105618. [PMID: 32628912 DOI: 10.1016/j.actatropica.2020.105618] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 12/20/2022]
Abstract
Acanthamoeba spp. are free living amoeba (FLA) which are widely distributed in nature. They are opportunistic parasites and can cause severe infections to the eye, skin and central nervous system. The advances in drug discovery and modifications in the chemotherapeutic agents have shown little improvement in morbidity and mortality rates associated with Acanthamoeba infections. The mechanism-based process of drug discovery depends on the molecular drug targets present in the signaling pathways in the genome. Synthetic libraries provide a platform for broad spectrum of activities due to their desired structural modifications. Azoles, originally a class of synthetic anti-fungal drugs, disrupt the fungal cell membrane by inhibiting the biosynthesis of ergosterol through the inhibition of cytochrome P450 dependent 14α-lanosterol, a key step of the sterol pathway. Acanthamoeba and fungi share the presence of similar sterol intermediate, as ergosterol is also the major end-product in the sterol biosynthesis in Acanthamoeba. Sterols present in the eukaryotic cell membrane are one of the most essential lipids and exhibit important structural and signaling functions. Therefore, in this review we highlight the importance of specific targeting of ergosterol present in Acanthamoebic membrane by azole compounds for amoebicidal activity. Previously, azoles have also been repurposed to report antimicrobial, antiparasitic and antibacterial properties. Moreover, by loading the azoles into nanoparticles through advanced techniques in nanotechnology, such as physical encapsulation, adsorption, or chemical conjugation, the pharmacokinetics and therapeutic index of the drugs can be significantly improved. The current review proposes an important strategy to target Acanthamoeba using synthetic libraries of azoles and their conjugated nanoparticles for the first time.
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11
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Keane NA, Lane LM, Canniff E, Hare D, Doran S, Wallace E, Hutchinson S, Healy ML, Hennessy B, Meaney J, Chiodini P, O'Connell B, Beausang A, Vandenberghe E. A Surviving Case of Acanthamoeba Granulomatous Amebic Encephalitis in a Hematopoietic Stem Cell Transplant Recipient. AMERICAN JOURNAL OF CASE REPORTS 2020; 21:e923219. [PMID: 32603318 PMCID: PMC7347033 DOI: 10.12659/ajcr.923219] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Acanthamoeba are free-living amoebae with potential to infect immunocompromised hosts. The mortality rate of granulomatous amebic encephalitis (GAE) due to Acanthamoeba exceeds 90% and there are currently no reports of survival of this infection in recipients of hematopoietic stem cell transplant. CASE REPORT We report herein the case of a 32-year-old man presenting to our service with abrupt neurological deterioration and seizures 5 months after allogeneic stem cell transplantation for Hodgkin lymphoma. Clinical and imaging findings were non-specific at presentation. Multiple circumscribed, heterogenous, mass-like lesions were identified on MRI. Brain biopsy was performed and revealed multiple cysts and trophozoites suggesting a diagnosis of granulomatous amebic encephalitis. PCR testing confirmed Acanthamoeba. Treatment with miltefosine, metronidazole, azithromycin, fluconazole, pentamidine isethionate, and co-trimoxazole was instituted and the patient survived and shows continued improvement with intensive rehabilitation. CONCLUSIONS We report the first successful outcome in this setting. The diagnosis would have been missed on cerebrospinal fluid analysis alone, but was rapidly made by histological analysis of brain biopsy. This diagnostically challenging infection is likely under-recognized. Early brain biopsy and commencement of a prolonged miltefosine-containing anti-ameba regimen can be curative.
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Affiliation(s)
- Niamh A Keane
- Department of Hematology, St. James's Hospital, Dublin, Ireland
| | | | - Emma Canniff
- Department of Radiology, St. James's Hospital, Dublin, Ireland
| | - Daniel Hare
- Department of Microbiology, St. James's Hospital, Dublin, Ireland
| | - Simon Doran
- Department of Radiology, St. James's Hospital, Dublin, Ireland
| | - Eugene Wallace
- Department of Rehabilitation Medicine, St. James's Hospital, Dublin, Ireland
| | | | | | - Brian Hennessy
- Department of Hematology, Waterford University Hospital, Waterford, Ireland
| | - Jim Meaney
- Department of Radiology, St. James's Hospital, Dublin, Ireland
| | - Peter Chiodini
- Hospital for Tropical Diseases, University College London, London, United Kingdom
| | - Brian O'Connell
- Department of Microbiology, St. James's Hospital, Dublin, Ireland
| | - Alan Beausang
- Department of Histopathology, Beaumont Hospital, Dublin, Ireland
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12
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Drug Discovery against Acanthamoeba Infections: Present Knowledge and Unmet Needs. Pathogens 2020; 9:pathogens9050405. [PMID: 32456110 PMCID: PMC7281112 DOI: 10.3390/pathogens9050405] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/09/2020] [Accepted: 05/12/2020] [Indexed: 12/12/2022] Open
Abstract
Although major strides have been made in developing and testing various anti-acanthamoebic drugs, recurrent infections, inadequate treatment outcomes, health complications, and side effects associated with the use of currently available drugs necessitate the development of more effective and safe therapeutic regimens. For any new anti-acanthamoebic drugs to be more effective, they must have either superior potency and safety or at least comparable potency and an improved safety profile compared to the existing drugs. The development of the so-called 'next-generation' anti-acanthamoebic agents to address this challenge is an active area of research. Here, we review the current status of anti-acanthamoebic drugs and discuss recent progress in identifying novel pharmacological targets and new approaches, such as drug repurposing, development of small interfering RNA (siRNA)-based therapies and testing natural products and their derivatives. Some of the discussed approaches have the potential to change the therapeutic landscape of Acanthamoeba infections.
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13
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Anwar A, Yi YP, Fatima I, Khan KM, Siddiqui R, Khan NA, Anwar A. Antiamoebic activity of synthetic tetrazoles against Acanthamoeba castellanii belonging to T4 genotype and effects of conjugation with silver nanoparticles. Parasitol Res 2020; 119:1943-1954. [PMID: 32385711 DOI: 10.1007/s00436-020-06694-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/15/2020] [Indexed: 01/16/2023]
Abstract
Acanthamoeba causes diseases such as Acanthamoeba keratitis (AK) which leads to permanent blindness and granulomatous Acanthamoeba encephalitis (GAE) where there is formation of granulomas in the brain. Current treatments such as chlorhexidine, diamidines, and azoles either exhibit undesirable side effects or require immediate and prolonged treatment for the drug to be effective or prevent relapse. Previously, antifungal drugs amphotericin B, nystatin, and fluconazole-conjugated silver with nanoparticles have shown significantly increased activity against Acanthamoeba castellanii. In this study, two functionally diverse tetrazoles were synthesized, namely 5-(3-4-dimethoxyphenyl)-1H-tetrazole and 1-(3-methoxyphenyl)-5-phenoxy-1H-tetrazole, denoted by T1 and T2 respectively. These compounds were evaluated for anti-Acanthamoeba effects at different concentrations ranging from 5 to 50 μM. Furthermore, these compounds were conjugated with silver nanoparticles (AgNPs) to enhance their efficacy. Particle size analysis showed that T1-AgNPs and T2-AgNPs had an average size of 52 and 70 nm respectively. After the successful synthesis and characterization of tetrazoles and tetrazole-conjugated AgNPs, they were subjected to anti-Acanthamoeba studies. Amoebicidal assay showed that at concentration 10 μM and above, T2 showed promising antiamoebic activities between the two compounds while encystation and excystation assays reveal that both T1 and T2 have inhibited differentiation activity against Acanthamoeba castellanii. Conjugation of T1 and T2 to AgNP also increased efficacy of tetrazoles as anti-Acanthamoeba agents. This may be due to the increased bioavailability as AgNP allows better delivery of treatment compounds to A. castellanii. Human cell cytotoxicity assay revealed that tetrazoles and AgNPs are significantly less toxic towards human cells compared with chlorhexidine which is known to cause undesirable side effects. Cytopathogenicity assay also revealed that T2 conjugated with AgNPs significantly reduced cytopathogenicity of A. castellanii compared with T2 alone, suggesting that T2-conjugated AgNP is an effective and safe anti-Acanthamoeba agent. The use of a synthetic azole compound conjugated with AgNPs can be an alternative strategy for drug development against A. castellanii. However, mechanistic and in vivo studies are needed to explore further translational values.
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Affiliation(s)
- Areeba Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Yim Pei Yi
- Department of Biological Sciences, School of Science and Technology, Sunway University, 47500, Subang Jaya, Selangor, Malaysia
| | - Itrat Fatima
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Khalid Mohammed Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan.,Department of Clinical Pharmacy, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, 31441, Saudi Arabia
| | - 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 Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, Sharjah, 26666, United Arab Emirates
| | - Ayaz Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, 47500, Subang Jaya, Selangor, Malaysia.
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14
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Das S, Gunasekaran K, Ajjampur SSR, Abraham D, George T, Janeela MA, Iyadurai R. Acanthamoeba encephalitis in immunocompetent hosts: A report of two cases. J Family Med Prim Care 2020; 9:1240-1243. [PMID: 32318505 PMCID: PMC7114032 DOI: 10.4103/jfmpc.jfmpc_1010_19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 12/22/2019] [Accepted: 12/27/2019] [Indexed: 12/27/2022] Open
Abstract
Acanthamoeba are ubiquitous free-living amoeba. Acanthamoeba infections cause necrotizing vasculitis, resulting in vessel thrombosis and cerebral infarction. Acanthamoeba CNS infections, though uncommon, are associated with high mortality. Diagnosis is difficult and often delayed. Here, we present two immunocompetent hosts with Acanthamoeba encephalitis with good outcomes.
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Affiliation(s)
- Sohini Das
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Karthik Gunasekaran
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Sitara S R Ajjampur
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Dilip Abraham
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Tina George
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - M Asisha Janeela
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
| | - Ramya Iyadurai
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India
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15
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Kalra SK, Sharma P, Shyam K, Tejan N, Ghoshal U. Acanthamoeba and its pathogenic role in granulomatous amebic encephalitis. Exp Parasitol 2019; 208:107788. [PMID: 31647916 DOI: 10.1016/j.exppara.2019.107788] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 10/11/2019] [Accepted: 10/19/2019] [Indexed: 01/13/2023]
Abstract
Acanthamoeba is a free-living amoeba that is widely distributed in the environment. It is an opportunist protist, which is known to cause rare yet fatal infection of the central nervous system (CNS), granulomatous amebic encephalitis (GAE) in humans. GAE cases are increasingly been reported among immunocompromised patients, with few cases in immunocompetent hosts. Diagnosis of GAE primarily includes neuroimaging, microscopy, cerebrospinal fluid (CSF) culture, histopathology, serology and molecular techniques. Early diagnosis is vital for proper management of infected patients. Combination therapeutic approach has been tried in various GAE cases reported worldwide. We tried to present a comprehensive review, which summarizes on the epidemiology of GAE caused by Acanthamoeba along with the associated clinical symptoms, risk factors, diagnosis and treatment of GAE among infected patients.
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Affiliation(s)
- Sonali K Kalra
- Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Bajhol, Distt. Solan, 173229, HP, India.
| | - Palvi Sharma
- Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Bajhol, Distt. Solan, 173229, HP, India
| | - Kirti Shyam
- Faculty of Applied Sciences and Biotechnology, Shoolini University of Biotechnology and Management Sciences, Bajhol, Distt. Solan, 173229, HP, India
| | - Nidhi Tejan
- Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareili Road, Lucknow, 226014, UP, India
| | - Ujjala Ghoshal
- Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Raebareili Road, Lucknow, 226014, UP, India
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16
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Mungroo MR, Anwar A, Khan NA, Siddiqui R. Brain-eating Amoebae Infection: Challenges and Opportunities in Chemotherapy. Mini Rev Med Chem 2019; 19:980-987. [PMID: 30868950 DOI: 10.2174/1389557519666190313161854] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/01/2019] [Accepted: 03/07/2019] [Indexed: 12/22/2022]
Abstract
Pathogenic free-living amoeba are known to cause a devastating infection of the central nervous system and are often referred to as "brain-eating amoebae". The mortality rate of more than 90% and free-living nature of these amoebae is a cause for concern. It is distressing that the mortality rate has remained the same over the past few decades, highlighting the lack of interest by the pharmaceutical industry. With the threat of global warming and increased outdoor activities of public, there is a need for renewed interest in identifying potential anti-amoebic compounds for successful prognosis. Here, we discuss the available chemotherapeutic options and opportunities for potential strategies in the treatment and diagnosis of these life-threatening infections.
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Affiliation(s)
- Mohammad Ridwane Mungroo
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya 47500, Selangor, Malaysia
| | - Ayaz Anwar
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya 47500, Selangor, Malaysia
| | - Naveed Ahmed Khan
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya 47500, Selangor, Malaysia
| | - Ruqaiyyah Siddiqui
- Department of Biological Sciences, School of Science and Technology, Sunway University, Subang Jaya 47500, Selangor, Malaysia
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17
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Konstantinovic N, Guegan H, Stäjner T, Belaz S, Robert-Gangneux F. Treatment of toxoplasmosis: Current options and future perspectives. Food Waterborne Parasitol 2019; 15:e00036. [PMID: 32095610 PMCID: PMC7033996 DOI: 10.1016/j.fawpar.2019.e00036] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/24/2019] [Accepted: 01/27/2019] [Indexed: 02/08/2023] Open
Abstract
Toxoplasmosis is a worldwide parasitic disease infecting about one third of humans, with possible severe outcomes in neonates and immunocompromised patients. Despite continuous and successful efforts to improve diagnosis, therapeutic schemes have barely evolved since many years. This article aims at reviewing the main clinical trials and current treatment practices, and at addressing future perspectives in the light of ongoing researches.
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Affiliation(s)
- Neda Konstantinovic
- National Reference Laboratory for Toxoplasmosis, Institute for Medical Research, University of Belgrade, 11129 Belgrade, Serbia
| | - Hélène Guegan
- Univ Rennes, CHU Rennes, Inserm, EHESP, Irset - UMR_S 1085, F-35000 Rennes, France
| | - Tijana Stäjner
- National Reference Laboratory for Toxoplasmosis, Institute for Medical Research, University of Belgrade, 11129 Belgrade, Serbia
| | - Sorya Belaz
- Univ Rennes, CHU Rennes, Inserm, EHESP, Irset - UMR_S 1085, F-35000 Rennes, France
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18
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19
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Garajová M, Mrva M, Vaškovicová N, Martinka M, Melicherová J, Valigurová A. Cellulose fibrils formation and organisation of cytoskeleton during encystment are essential for Acanthamoeba cyst wall architecture. Sci Rep 2019; 9:4466. [PMID: 30872791 PMCID: PMC6418277 DOI: 10.1038/s41598-019-41084-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 03/01/2019] [Indexed: 01/26/2023] Open
Abstract
Acanthamoebae success as human pathogens is largely due to the highly resistant cysts which represent a crucial problem in treatment of Acanthamoeba infections. Hence, the study of cyst wall composition and encystment play an important role in finding new therapeutic strategies. For the first time, we detected high activity of cytoskeletal elements - microtubular networks and filamentous actin, in late phases of encystment. Cellulose fibrils - the main components of endocyst were demonstrated in inter-cystic space, and finally in the ectocyst, hereby proving the presence of cellulose in both layers of the cyst wall. We detected clustering of intramembranous particles (IMPs) and their density alterations in cytoplasmic membrane during encystment. We propose a hypothesis that in the phase of endocyst formation, the IMP clusters represent cellulose microfibril terminal complexes involved in cellulose synthesis that after cyst wall completion are reduced. Cyst wall impermeability, due largely to a complex polysaccharide (glycans, mainly cellulose) has been shown to be responsible for Acanthamoeba biocide resistance and cellulose biosynthesis pathway is suggested to be a potential target in treatment of Acanthamoeba infections. Disruption of this pathway would affect the synthesis of cyst wall and reduce considerably the resistance to chemotherapeutic agents.
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Affiliation(s)
- Mária Garajová
- Department of Zoology, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15, Bratislava, Slovak Republic.
| | - Martin Mrva
- Department of Zoology, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15, Bratislava, Slovak Republic
| | - Naděžda Vaškovicová
- Institute of Scientific Instruments, Czech Academy of Sciences, 612 64, Brno, Czech Republic
| | - Michal Martinka
- Department of Plant Physiology, Faculty of Natural Sciences, Comenius University in Bratislava, 842 15, Bratislava, Slovak Republic
| | - Janka Melicherová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, 611 37, Brno, Czech Republic
| | - Andrea Valigurová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, 611 37, Brno, Czech Republic
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20
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Kaya Y, Baldemir A, Karaman Ü, Ildız N, Arıcı YK, Kaçmaz G, Kolören Z, Konca Y. Amebicidal effects of fenugreek ( Trigonella foenum-graecum) against Acanthamoeba cysts. Food Sci Nutr 2019; 7:563-571. [PMID: 30847135 PMCID: PMC6392877 DOI: 10.1002/fsn3.849] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 09/21/2018] [Accepted: 09/26/2018] [Indexed: 11/29/2022] Open
Abstract
Trigonella foenum-graecum L. (TF) is known to the public as a chest emollient, mucous expectorant, laxative and is used to prevent maturation of boils and diabetes since ancient times. In this study, we aimed to determine the amebicidal effects against Acanthamoeba cysts. Plant extracts were prepared at concentrations of 1, 2, 4, 8, 16, and 32 mg/ml and were placed in a hemocytometer with cell counts 22 × 106 cell/ml. The fatty acid profiles of TF seeds were determined. Standard Acanthamoeba cysts were added and incubated at 25°C. The viability of the parasite was checked and recorded at hours 3, 24, 48, 72, 96, and 102. The values of lethal concentration doses (LD50 and LD90) were calculated using probit analysis. This study revealed that T. foenum-graecum prevented proliferation of the parasite at certain times. However, further for in vivo and controlled experimental studies are needed in order to find out how to use this plant as medication.
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Affiliation(s)
- Yasemin Kaya
- Faculty of MedicineDepartment of Internal MedicineOrdu UniversityOrduTurkey
| | - Ayşe Baldemir
- Faculty of PharmacyDepartment of Pharmaceutical BotanyErciyes UniversityKayseriTurkey
| | - Ülkü Karaman
- Faculty of MedicineMedical Parasitology DepartmentOrdu UniversityOrduTurkey
| | - Nilay Ildız
- Faculty of PharmacyDepartment of Pharmaceutical MicrobiologyErciyes UniversityKayseriTurkey
| | - Yeliz Kasko Arıcı
- Faculty of MedicineBiostatistics DepartmentOrdu UniversityOrduTurkey
| | - Gamze Kaçmaz
- Faculty of MedicineMedical Microbiology DepartmentGiresun UniversityGiresunTurkey
| | - Zeynep Kolören
- Department of BiologyOrdu University Faculty of Arts and SciencesOrduTurkey
| | - Yusuf Konca
- Faculty of AgricultureDepartment of Feed and Animal FeedingErciyes UniversityKayseriTurkey
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21
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Hernández-Martínez D, Reyes-Batlle M, Castelan-Ramírez I, Hernández-Olmos P, Vanzzini-Zago V, Ramírez-Flores E, Sifaoui I, Piñero JE, Lorenzo-Morales J, Omaña-Molina M. Evaluation of the sensitivity to chlorhexidine, voriconazole and itraconazole of T4 genotype Acanthamoeba isolated from Mexico. Exp Parasitol 2019; 197:29-35. [DOI: 10.1016/j.exppara.2019.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/12/2018] [Accepted: 01/11/2019] [Indexed: 02/03/2023]
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22
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Lepesheva GI, Friggeri L, Waterman MR. CYP51 as drug targets for fungi and protozoan parasites: past, present and future. Parasitology 2018; 145:1820-1836. [PMID: 29642960 PMCID: PMC6185833 DOI: 10.1017/s0031182018000562] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The efficiency of treatment of human infections with the unicellular eukaryotic pathogens such as fungi and protozoa remains deeply unsatisfactory. For example, the mortality rates from nosocomial fungemia in critically ill, immunosuppressed or post-cancer patients often exceed 50%. A set of six systemic clinical azoles [sterol 14α-demethylase (CYP51) inhibitors] represents the first-line antifungal treatment. All these drugs were discovered empirically, by monitoring their effects on fungal cell growth, though it had been proven that they kill fungal cells by blocking the biosynthesis of ergosterol in fungi at the stage of 14α-demethylation of the sterol nucleus. This review briefs the history of antifungal azoles, outlines the situation with the current clinical azole-based drugs, describes the attempts of their repurposing for treatment of human infections with the protozoan parasites that, similar to fungi, also produce endogenous sterols, and discusses the most recently acquired knowledge on the CYP51 structure/function and inhibition. It is our belief that this information should be helpful in shifting from the traditional phenotypic screening to the actual target-driven drug discovery paradigm, which will rationalize and substantially accelerate the development of new, more efficient and pathogen-oriented CYP51 inhibitors.
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Affiliation(s)
- Galina I. Lepesheva
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
| | - Laura Friggeri
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
| | - Michael R. Waterman
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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23
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Omaña-Molina M, Vanzzini-Zago V, Hernández-Martínez D, Reyes-Batlle M, Castelan-Ramírez I, Hernández-Olmos P, Salazar-Villatoro L, González-Robles A, Ramírez-Flores E, Servín-Flores C, Flores-Alvarado V, Alcántara-Castro M, Lorenzo-Morales J. Acanthamoeba keratitis in Mexico: Report of a clinical case and importance of sensitivity assays for a better outcome. Exp Parasitol 2018; 196:22-27. [PMID: 30472333 DOI: 10.1016/j.exppara.2018.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/08/2018] [Accepted: 11/21/2018] [Indexed: 10/27/2022]
Abstract
Acanthamoeba keratitis (AK) is a sight-threatening corneal infection. The early symptoms include redness, pain, photophobia and intense tearing. Chronic infection usually progresses to stromal inflammation, ring ulcers, corneal opacification and hypopyon. Here we document an AK case in a high myopic 38-year-old woman from Mexico City, with a history of wearing contact lenses while swimming. Corneal scrapes cultures were positive only for amoebae, consequently a treatment including netilmicin 0.3% and oral itraconazole 100 mg/12 h was prescribed. The infection was resolved after 8 months, leaving a slight leucoma outside the visual axis, with a visual acuity of 20/150. In the laboratory, the amoebic isolate was axenized in PYG medium, with an optimal growth at 30 °C, and was identified morphologically as Acanthamoeba polyphaga according to the taxonomic criteria of Page (1988) and placed in the T4 group by genotyping. The virulence of this strain (40%) was determined by intranasal inoculation of 1 × 106/20 μl trophozoites in BALB/c mice recovering from brain, proving their invasion ability and by the interaction with monolayers of epithelial cells of the established MDCK line of canine kidney origin (1:2 ratio of interaction), at 1, 3, 6, 8 and 24 h; trophozoites migrated to cell junctions inducing few lytic zones. In addition to the biological characterization, in vitro drug sensitivity tests were performed using chlorhexidine, itraconazole, netilmicin and voriconazole. Results revealed that voriconazole was the most effective compound. A. polyphaga remains as one of the most frequently isolated species producing AK. The treatment of AK case using netilmicin and oral itraconazole solved the disease, but the healing process was wide-ranging (8 months). The use of voriconazole and chlorhexidine may be an alternative treatment of future AK cases in Mexico.
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Affiliation(s)
- Maritza Omaña-Molina
- Faculty of Superior Studies Iztacala, UNAM. Tlalnepantla, State of Mexico, Mexico.
| | | | | | - María Reyes-Batlle
- University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Tenerife, Canary Island, Spain
| | | | | | - Lizbeth Salazar-Villatoro
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies, Mexico City, Mexico
| | - Arturo González-Robles
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies, Mexico City, Mexico
| | | | | | | | | | - Jacob Lorenzo-Morales
- University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Tenerife, Canary Island, Spain
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24
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Masel JH, Martell DW, Logemann NF, Wilson KE. Nodular Skin Lesions in an Immunocompromised Patient. Clin Infect Dis 2018; 63:1140-1. [PMID: 27672143 DOI: 10.1093/cid/ciw434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - David W Martell
- Dermatology Service, Walter Reed National Military Medical Center, Bethesda, Maryland
| | - Nicholas F Logemann
- Dermatology Service, Walter Reed National Military Medical Center, Bethesda, Maryland
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25
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Nehete LS, Kumar A, Chavali P, A. R. P, Devi BI. Fulminant acanthamoebic meningoencephalitis in immunocompetent patients: an uncommon entity. Br J Neurosurg 2018; 36:98-101. [DOI: 10.1080/02688697.2018.1485873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Lokesh Suresh Nehete
- Department of Neurosurgery, National Institute of Mental Health and Neuro-Sciences, Bangalore, India
| | - Anil Kumar
- Department of Neurosurgery, National Institute of Mental Health and Neuro-Sciences, Bangalore, India
| | - Pooja Chavali
- Department of Neuropathology, National Institute of Mental Health and Neuro-Sciences, Bangalore, India
| | - Prabhuraj A. R.
- Department of Neurosurgery, National Institute of Mental Health and Neuro-Sciences, Bangalore, India
| | - Bhagavatula Indira Devi
- Department of Neurosurgery, National Institute of Mental Health and Neuro-Sciences, Bangalore, India
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26
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Kutner A, Aldrich M, Patel S, Kang JJ, Amin B, Mann R, Ali IKM, Martines RB, Cope JR, De Boccardo GO, Puius YA. Acanthamoeba endophthalmitis during treatment for cutaneous disease in a renal transplant patient. Transpl Infect Dis 2018; 20:e12843. [PMID: 29359845 DOI: 10.1111/tid.12843] [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: 04/17/2017] [Revised: 08/18/2017] [Accepted: 09/08/2017] [Indexed: 11/28/2022]
Abstract
Acanthamoeba infections are difficult to diagnose and treat. We present a renal transplant patient who developed Acanthamoeba endophthalmitis on therapy with posaconazole and miltefosine for cutaneous acanthamobiasis. The patient was maintained on intracameral voriconazole injections, and oral azithromycin, fluconazole, and flucytosine. This case highlights novel presentations and treatments for acanthamoebic infection.
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Affiliation(s)
- Allison Kutner
- Department of Dermatology, Montefiore Medical Center, Bronx, NY, USA
| | - Margaret Aldrich
- Division of Infectious Diseases, Department of Medicine, Montefiore Medical Center, Bronx, NY, USA
| | - Sarju Patel
- Department of Ophthalmology, Weill Cornell Medical Center, New York, NY, USA
| | - Joann J Kang
- Department of Ophthalmology, Montefiore Medical Center, Bronx, NY, USA
| | - Bijal Amin
- Department of Pathology, Montefiore Medical Center, Bronx, NY, USA
| | - Ranon Mann
- Department of Dermatology, Montefiore Medical Center, Bronx, NY, USA
| | - Ibne Karim M Ali
- Waterborne Disease Prevention Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Jennifer Rittenhouse Cope
- Waterborne Disease Prevention Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Yoram A Puius
- Division of Infectious Diseases, Department of Medicine, Montefiore Medical Center, Bronx, NY, USA
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27
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Characterisation of sterol biosynthesis and validation of 14α-demethylase as a drug target in Acanthamoeba. Sci Rep 2017; 7:8247. [PMID: 28811501 PMCID: PMC5557935 DOI: 10.1038/s41598-017-07495-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/29/2017] [Indexed: 11/16/2022] Open
Abstract
The soil amoebae Acanthamoeba causes Acanthamoeba keratitis, a severe sight-threatening infection of the eye and the almost universally fatal granulomatous amoebic encephalitis. More effective treatments are required. Sterol biosynthesis has been effectively targeted in numerous fungi using azole compounds that inhibit the cytochrome P450 enzyme sterol 14α-demethylase. Herein, using Gas Chromatography Mass Spectrometry (GCMS), we demonstrate that the major sterol of Acanthamoeba castellanii is ergosterol and identify novel putative precursors and intermediate sterols in its production. Unlike previously reported, we find no evidence of 7-dehydrostigmasterol or any other phytosterol in Acanthamoeba. Of five azoles tested, we demonstrate that tioconazole and voriconazole have the greatest overall inhibition for all isolates of Acanthamoeba castellanii and Acanthamoeba polyphaga tested. While miconazole and sulconazole have intermediate activity econazole is least effective. Through GCMS, we demonstrate that voriconazole inhibits 14α-demethylase as treatment inhibits the production of ergosterol, but results in the accumulation of the lanosterol substrate. These data provide the most complete description of sterol metabolism in Acanthamoeba, provide a putative framework for their further study and validate 14α-demethylase as the target for azoles in Acanthamoeba.
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Samuels MA, Gonzalez RG, Makadzange AT, Hedley-Whyte ET. Case 3-2017. A 62-Year-Old Man with Cardiac Sarcoidosis and New Diplopia and Weakness. N Engl J Med 2017; 376:368-379. [PMID: 28121502 DOI: 10.1056/nejmcpc1610713] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Martin A Samuels
- From the Department of Neurology (M.A.S.), Brigham and Women's Hospital, the Departments of Radiology (R.G.G.), Medicine (A.T.M.), and Pathology (E.T.H.-W.), Massachusetts General Hospital, and the Departments of Neurology (M.A.S.), Radiology (R.G.G.), Medicine (A.T.M.), and Pathology (E.T.H-W.), Harvard Medical School - all in Boston
| | - R Gilberto Gonzalez
- From the Department of Neurology (M.A.S.), Brigham and Women's Hospital, the Departments of Radiology (R.G.G.), Medicine (A.T.M.), and Pathology (E.T.H.-W.), Massachusetts General Hospital, and the Departments of Neurology (M.A.S.), Radiology (R.G.G.), Medicine (A.T.M.), and Pathology (E.T.H-W.), Harvard Medical School - all in Boston
| | - Azure T Makadzange
- From the Department of Neurology (M.A.S.), Brigham and Women's Hospital, the Departments of Radiology (R.G.G.), Medicine (A.T.M.), and Pathology (E.T.H.-W.), Massachusetts General Hospital, and the Departments of Neurology (M.A.S.), Radiology (R.G.G.), Medicine (A.T.M.), and Pathology (E.T.H-W.), Harvard Medical School - all in Boston
| | - E Tessa Hedley-Whyte
- From the Department of Neurology (M.A.S.), Brigham and Women's Hospital, the Departments of Radiology (R.G.G.), Medicine (A.T.M.), and Pathology (E.T.H.-W.), Massachusetts General Hospital, and the Departments of Neurology (M.A.S.), Radiology (R.G.G.), Medicine (A.T.M.), and Pathology (E.T.H-W.), Harvard Medical School - all in Boston
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Cope JR, Yoder JS, Visvesvara GS. Protozoa. Infect Dis (Lond) 2017. [DOI: 10.1016/b978-0-7020-6285-8.00193-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Abstract
For the past several decades, there has been little improvement in the morbidity and mortality associated with Acanthamoeba keratitis and Acanthamoeba encephalitis, respectively. The discovery of a plethora of antiacanthamoebic compounds has not yielded effective marketed chemotherapeutics. The rate of development of novel antiacanthamoebic chemotherapies of translational value and the lack of interest of the pharmaceutical industry in developing such chemotherapies have been disappointing. On the other hand, the market for contact lenses/contact lens disinfectants is a multi-billion-dollar industry and has been successful and profitable. A better understanding of drugs, their targets, and mechanisms of action will facilitate the development of more-effective chemotherapies. Here, we review the progress toward phenotypic drug discovery, emphasizing the shortcomings of useable therapies.
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Acanthamoeba castellanii Genotype T4 Stimulates the Production of Interleukin-10 as Well as Proinflammatory Cytokines in THP-1 Cells, Human Peripheral Blood Mononuclear Cells, and Human Monocyte-Derived Macrophages. Infect Immun 2016; 84:2953-62. [PMID: 27481240 PMCID: PMC5038060 DOI: 10.1128/iai.00345-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/24/2016] [Indexed: 12/11/2022] Open
Abstract
Free-living amoebae of the genus Acanthamoeba can cause severe and chronic infections in humans, mainly localized in immune privileged sites, such as the brain and the eye. Monocytes/macrophages are thought to be involved in Acanthamoeba infections, but little is known about how these facultative parasites influence their functions. The aim of this work was to investigate the effects of Acanthamoeba on human monocytes/macrophages during the early phase of infection. Here, THP-1 cells, primary human monocytes isolated from peripheral blood, and human monocyte-derived macrophages were either coincubated with trophozoites of a clinical isolate of Acanthamoeba (genotype T4) or stimulated with amoeba-derived cell-free conditioned medium. Production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin-6 [IL-6], and IL-12), anti-inflammatory cytokine (IL-10), and chemokine (IL-8) was evaluated at specific hours poststimulation (ranging from 1.5 h to 23 h). We showed that both Acanthamoeba trophozoites and soluble amoebic products induce an early anti-inflammatory monocyte-macrophage phenotype, characterized by significant production of IL-10; furthermore, challenge with either trophozoites or their soluble metabolites stimulate both proinflammatory cytokines and chemokine production, suggesting that this protozoan infection results from the early induction of coexisting, opposed immune responses. Results reported in this paper confirm that the production of proinflammatory cytokines and chemokines by monocytes and macrophages can play a role in the development of the inflammatory response during Acanthamoeba infections. Furthermore, we demonstrate for the first time that Acanthamoeba stimulates IL-10 production in human innate immune cells, which might both promote the immune evasion of Acanthamoeba and limit the induced inflammatory response.
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Niyyati M, Dodangeh S, Lorenzo-Morales J. A Review of the Current Research Trends in the Application of Medicinal Plants as a Source for Novel Therapeutic Agents Against Acanthamoeba Infections. IRANIAN JOURNAL OF PHARMACEUTICAL RESEARCH : IJPR 2016; 15:893-900. [PMID: 28243287 PMCID: PMC5316269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Acanthamoeba keratitis (AK) is a sight-threating infection of the cornea that mostly affects contact lens wearers. Until now, AK treatment remains very difficult due to the existence of a highly resistant cyst stage in the life cycle of Acanthamoeba which is extremely resistant to most of the available anti-amoebic compounds. Moreover, current treatment of AK is usually based in the combination of various therapeutic agents such as polyhexamethylene biguanide or chlorhexidine and propamidine isethionate. However, all the mentioned compounds have also showed toxic side effects on human keratocytes and presented poor cysticidal effect at the concentrations currently used in the established AK treatments. Nowadays, the elucidation of novel compounds with antimicrobial and anticancer properties from plant and herbs with medicinal properties have encouraged researchers to evaluate plants as a source of new molecules with anti-trophozoite and cysticidal effects. Thus, in recent years, many natural products have been reported to present potent anti-Acanthamoeba properties with good selectivity and minimal toxic effects. Therefore, the chemical drugs currently used for AK treatment, their drawbacks as well as the current research in medicinal plants as a source of potent anti-Acanthamoeba compounds are described in this review.
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Affiliation(s)
- Maryam Niyyati
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Samira Dodangeh
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Jacob Lorenzo-Morales
- University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda. AstrofísicoFco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.
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Jha BK, Jung HJ, Seo I, Suh SI, Suh MH, Baek WK. Juglone induces cell death of Acanthamoeba through increased production of reactive oxygen species. Exp Parasitol 2015; 159:100-6. [PMID: 26358271 DOI: 10.1016/j.exppara.2015.09.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 06/15/2015] [Accepted: 09/03/2015] [Indexed: 12/21/2022]
Abstract
Juglone (5-hydroxy-1,4-naphthoquinone) is a major chemical constituent of Juglans mandshruica Maxim. Recent studies have demonstrated that juglone exhibits anti-cancer, anti-bacterial, anti-viral, and anti-parasitic properties. However, its effect against Acanthamoeba has not been defined yet. The aim of this study was to investigate the effect of juglone on Acanthamoeba. We demonstrate that juglone significantly inhibits the growth of Acanthamoeba castellanii at 3-5 μM concentrations. Juglone increased the production of reactive oxygen species (ROS) and caused cell death of A. castellanii. Inhibition of ROS by antioxidant N-acetyl-l-cysteine (NAC) restored the cell viability. Furthermore, our results show that juglone increased the uptake of mitochondrial specific dye. Collectively, these results indicate that ROS played a significant role in the juglone-induced cell death of Acanthamoeba.
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Affiliation(s)
- Bijay Kumar Jha
- Department of Microbiology, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Hui-Jung Jung
- Department of Microbiology, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Incheol Seo
- Department of Microbiology, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Seong-Il Suh
- Department of Microbiology, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Min-Ho Suh
- Department of Microbiology, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Won-Ki Baek
- Department of Microbiology, Keimyung University School of Medicine, Daegu, Republic of Korea.
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Eissa MM, Barakat AMA, Amer EI, Younis LK. Could miltefosine be used as a therapy for toxoplasmosis? Exp Parasitol 2015; 157:12-22. [PMID: 26112396 DOI: 10.1016/j.exppara.2015.06.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 06/05/2015] [Accepted: 06/14/2015] [Indexed: 02/08/2023]
Abstract
Toxoplasmosis is a zoonotic protozoal disease affecting more than a billion people worldwide. The shortfalls of the current treatment options necessitate the development of non-toxic and well-tolerated, efficient alternatives especially against the cyst form. The current study was undertaken to investigate, for the first time, the potential potency of miltefosine against Toxoplasma gondii infection in acute and chronic experimental toxoplasmosis. Results showed that there is no evidence of anti-parasitic activity of miltefosine against T. gondii tachyzoites in acute experimental toxoplasmosis. However, anti-parasitic activity of miltefosine against T. gondii cyst stage in chronic experimental toxoplasmosis could not be excluded as demonstrated by significant reduction in brain cyst burden. Moreover, considerable morphological changes in the cysts were revealed by light and electron microscopy study and also by amelioration of pathological changes in the brain. Future studies should focus on enhancement of anti-toxoplasma activity of miltefosine against chronic toxoplasmosis using formulation based nanotechnology. To the best of our knowledge, this is the first study highlighting efficacy of miltefosine against chronic toxoplasmosis, thus, increasing the list of diseases that can be targeted by this drug.
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Affiliation(s)
- Maha M Eissa
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | | | - Eglal I Amer
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt.
| | - Layla K Younis
- Department of Pathology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
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Artemether Exhibits Amoebicidal Activity against Acanthamoeba castellanii through Inhibition of the Serine Biosynthesis Pathway. Antimicrob Agents Chemother 2015; 59:4680-8. [PMID: 26014935 DOI: 10.1128/aac.04758-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 05/18/2015] [Indexed: 11/20/2022] Open
Abstract
Acanthamoeba sp. parasites are the causative agents of Acanthamoeba keratitis, fatal granulomatous amoebic encephalitis, and cutaneous infections. However, there are currently no effective drugs for these organisms. Here, we evaluated the activity of the antimalarial agent artemether against Acanthamoeba castellanii trophozoites and identified potential targets of this agent through a proteomic approach. Artemether exhibited in vitro amoebicidal activity in a time- and dose-dependent manner and induced ultrastructural modification and cell apoptosis. The iTRAQ quantitative proteomic analysis identified 707 proteins that were differentially expressed after artemether treatment. We focused on phosphoglycerate dehydrogenase and phosphoserine aminotransferase in the serine biosynthesis pathway because of their importance to the growth and proliferation of protozoan and cancer cells. The expression of these proteins in Acanthamoeba was validated using quantitative real-time PCR and Western blotting after artemether treatment. The changes in the expression levels of phosphoserine aminotransferase were consistent with those of phosphoglycerate dehydrogenase. Therefore, the downregulation of phosphoserine aminotransferase may be due to the downregulation of phosphoglycerate dehydrogenase. Furthermore, exogenous serine might antagonize the activity of artemether against Acanthamoeba trophozoites. These results indicate that the serine biosynthesis pathway is important to amoeba survival and that targeting these enzymes would improve the treatment of Acanthamoeba infections. Artemether may be used as a phosphoglycerate dehydrogenase inhibitor to control or block Acanthamoeba infections.
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Jha BK, Seo I, Kong HH, Suh SI, Suh MH, Baek WK. Tigecycline inhibits proliferation of Acanthamoeba castellanii. Parasitol Res 2015; 114:1189-95. [DOI: 10.1007/s00436-014-4302-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 12/23/2014] [Indexed: 10/24/2022]
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Abstract
The list of emerging and reemerging pathogens that cause neurologic disease is expanding. Various factors, including population growth and a rise in international travel, have contributed to the spread of pathogens to previously nonendemic regions. Recent advances in diagnostic methods have led to the identification of novel pathogens responsible for infections of the central nervous system. Furthermore, new issues have arisen surrounding established infections, particularly in an increasingly immunocompromised population due to advances in the treatment of rheumatologic disease and in transplant medicine.
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Affiliation(s)
- Felicia C Chow
- Division of Infectious Diseases, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Carol A Glaser
- Division of Infectious Diseases, Department of Pediatrics, University of California, San Francisco, San Francisco, CA, USA
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Chloroquine has a cytotoxic effect on Acanthamoeba encystation through modulation of autophagy. Antimicrob Agents Chemother 2014; 58:6235-41. [PMID: 25114131 DOI: 10.1128/aac.03164-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Encystation of Acanthamoeba castellanii is associated with resistance to chemotherapeutic agents. Blocking the encystation process could potentiate the efficacy of chemotherapeutic agents and biocides. During encystation, autophagy is highly stimulated and required for proper encystation of Acanthamoeba. In this study, the cytotoxic effect of chloroquine, a well-known autophagy-inhibitory drug, was tested in A. castellanii. Chloroquine was able to selectively reduce cell survival during the encystation of A. castellanii. However, A. castellanii trophozoites and mature cysts were resistant to chloroquine. Chloroquine treatment led to an increase in the number and size of lysosomes in encysting cells. Moreover, chloroquine inhibited the degradation of long-lived proteins in the encysting cells. Decreased autophagic flux, indicated by an increased number of lysosomes and decreased degradation of long-lived proteins, may be the mechanism by which cell death is induced by chloroquine in encysting Acanthamoeba. These results suggest a potential novel therapeutic application of chloroquine as an anti-Acanthamoeba drug. Our findings also suggest that targeting autophagy could be a therapeutic strategy against Acanthamoeba infection.
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Cysticidal activity of antifungals against different genotypes of Acanthamoeba. Antimicrob Agents Chemother 2014; 58:5626-8. [PMID: 25001304 DOI: 10.1128/aac.02635-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antifungal drugs have been proposed as a novel treatment for Acanthamoeba keratitis. The cysticidal activity of several antifungal compounds was tested against different genotypes of culture collection and clinical isolates of Acanthamoeba. Only voriconazole and posaconazole were found to be cysticidal, with no differences in activity observed between clinical and culture collection isolates.
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Zamora A, Henderson H, Swiatlo E. Acanthamoeba encephalitis: A Case Report and Review of Therapy. Surg Neurol Int 2014; 5:68. [PMID: 24991471 PMCID: PMC4078452 DOI: 10.4103/2152-7806.132239] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 03/14/2014] [Indexed: 11/25/2022] Open
Abstract
Background: Acanthamoeba is a rare cause of encephalitis yet is associated with high mortality. Treatment protocols vary greatly and generally include combination therapy across a wide spectrum of antiinfective classes. Case Description: A 63-year-old male who underwent renal transplantation presented 6 months after transplantation with depressed level of consciousness. Imaging of the head with computerized tomography showed an enhancing lesion suspicious for brain abscess. Biopsy of the lesion showed Acanthamoeba cysts. The patient was treated with sulfadiazine, fluconazole, flucytosine, azithromycin, and miltefosine but without success. We review recently published cases of Acanthamoeba encephalitis with an emphasis on treatment protocols and outcomes. Conclusion: Free-living protozoans such as Acanthamoeba are ubiquitous in the environment and should be suspected in immunosuppressed persons who present with central nervous system findings and brain abscess. Biopsy is critical to establish the etiology so that appropriate combination therapy can be deployed.
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Affiliation(s)
- A Zamora
- Department of Medicine, University of Mississippi Medical Center, MS USA
| | - H Henderson
- Department of Medicine, University of Mississippi Medical Center, MS USA
| | - E Swiatlo
- Department of Medicine, University of Mississippi Medical Center, MS USA ; G.V. (Sonny) Montgomery VA Medical Center, Jackson, MS USA
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In vitro efficacy of corifungin against Acanthamoeba castellanii trophozoites and cysts. Antimicrob Agents Chemother 2013; 58:1523-8. [PMID: 24366747 DOI: 10.1128/aac.02254-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Painful blinding keratitis and fatal granulomatous amebic encephalitis are caused by the free-living amebae Acanthamoeba spp. Several prescription eye medications are used to treat Acanthamoeba keratitis, but the infection can be difficult to control because of recurrence of infection. For the treatment of encephalitis, no single drug was found useful, and in spite of the use of a combination of multiple drugs, the mortality rate remains high. Therefore, efficient, novel drugs are urgently needed for the treatment of amebic keratitis and granulomatous amebic encephalitis. In this study, we identified corifungin, a water-soluble polyene macrolide, as amebicidal. In vitro, it was effective against both the trophozoites and the cysts. Transmission electron microscopy of Acanthamoeba castellanii incubated with corifungin showed the presence of swollen mitochondria, electron-dense granules, degeneration of cytoplasm architecture, and loss of nuclear chromatin structure. These changes were followed by lysis of amebae. Corifungin also induced the encystment process of A. castellanii. There were alterations in the cyst cell wall followed by lysis of the cysts. Corifungin is a promising therapeutic option for keratitis and granulomatous amebic encephalitis.
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In vitro efficacies of clinically available drugs against growth and viability of an Acanthamoeba castellanii keratitis isolate belonging to the T4 genotype. Antimicrob Agents Chemother 2013; 57:3561-7. [PMID: 23669391 DOI: 10.1128/aac.00299-13] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The effects of clinically available drugs targeting muscarinic cholinergic, adrenergic, dopaminergic, and serotonergic receptors; intracellular calcium levels and/or the function of calcium-dependent biochemical pathways; ion channels; and cellular pumps were tested against a keratitis isolate of Acanthamoeba castellanii belonging to the T4 genotype. In vitro growth inhibition (amoebistatic) assays were performed by incubating A. castellanii with various concentrations of drugs in the growth medium for 48 h at 30°C. To determine amoebicidal effects, amoebae were incubated with drugs in phosphate-buffered saline for 24 h, and viability was determined using trypan blue exclusion staining. For controls, amoebae were incubated with the solvent alone. Of the eight drugs tested, amlodipine, prochlorperazine, and loperamide showed potent amoebicidal effects, as no viable trophozoites were observed (>95% kill rate), while amiodarone, procyclidine, digoxin, and apomorphine exhibited up to 50% amoebicidal effects. In contrast, haloperidol did not affect viability, but all the drugs tested inhibited A. castellanii growth. Importantly, amlodipine, prochlorperazine, and loperamide showed compelling cysticidal effects. The cysticidal effects were irreversible, as cysts treated with the aforementioned drugs did not reemerge as viable amoebae upon inoculation in the growth medium. Except for apomorphine and haloperidol, all the tested drugs blocked trophozoite differentiation into cysts in encystation assays. Given the limited availability of effective drugs to treat amoebal infections, the clinically available drugs tested in this study represent potential agents for managing keratitis and granulomatous amoebic encephalitis caused by Acanthamoeba spp. and possibly against other meningoencephalitis-causing amoebae, such as Balamuthia mandrillaris and Naegleria fowleri.
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