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Fan X, Chen T, Yang H, Gao Y, Chen Y. Encephalomyelomeningitis Caused by Balamuthia mandrillaris: A Case Report and Literature Review. Infect Drug Resist 2023; 16:727-733. [PMID: 36756612 PMCID: PMC9901442 DOI: 10.2147/idr.s400692] [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: 12/16/2022] [Accepted: 01/21/2023] [Indexed: 02/05/2023] Open
Abstract
Central nervous system infection by Balamuthia mandrillaris is a rare and severe condition, which has a fatality rate of approximately 95% and often evades timely diagnosis due to its rarity and non-specific clinical manifestations. Here, we report a case of encephalomyelomeningitis caused by B. mandrillaris in a male who presented with transient coma, nausea, and vomiting when working in a garbage dump. Initial magnetic resonance imaging (MRI) of the brain showed normal signals. Despite receiving steroids as well as antibacterial and antiviral treatment, he developed urinary and fecal dysfunction, inability to walk, and deterioration of consciousness. Both brain and spinal cord MRI revealed abnormal findings, and next-generation sequencing of the cerebrospinal fluid showed the presence of B. mandrillaris. A combination of fluconazole and albendazole was administered; however, the patient deteriorated gradually and died 30 days after the onset. We suggest the unbiased metagenomic sequencing of the affected tissues/CSF in patients with CNS infections that are difficult to diagnose or treat, and multiple tests at different stages of the disease may be required.
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Affiliation(s)
- XueMei Fan
- Department of Neurology, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - TianWen Chen
- Department of Neurology, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Hui Yang
- Department of Neurology, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China
| | - Yue Gao
- Department of General Practice, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China,Yue Gao, Tel +86 13706511908; +86 531-56006851, Email
| | - Yan Chen
- Department of Neurology, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People’s Republic of China,Correspondence: Yan Chen, Department of Neurology, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, No. 261, Huan Sha Road, Shangcheng District, Hangzhou, People’s Republic of China, Tel +86 15397086693; +86 531-56006952, Email
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2
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Son DH, Kim EJ, Matin A, Jung SY. Interaction between Naegleria fowleri and pathogenic Escherichia coli by mannose and changes in N. fowleri protease. Parasitol Res 2022; 121:1805-1809. [DOI: 10.1007/s00436-022-07513-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 04/04/2022] [Indexed: 10/18/2022]
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3
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Various brain-eating amoebae: the protozoa, the pathogenesis, and the disease. Front Med 2021; 15:842-866. [PMID: 34825341 DOI: 10.1007/s11684-021-0865-2] [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: 12/21/2020] [Accepted: 04/25/2021] [Indexed: 10/19/2022]
Abstract
Among various genera of free-living amoebae prevalent in nature, some members are identified as causative agents of human encephalitis, in which Naegleria fowleri followed by Acanthamoeba spp. and Balamuthia mandrillaris have been successively discovered. As the three dominant genera responsible for infections, Acanthamoeba and Balamuthia work as opportunistic pathogens of granulomatous amoebic encephalitis in immunocompetent and immunocompromised individuals, whereas Naegleria induces primary amoebic meningoencephalitis mostly in healthy children and young adults as a more violent and deadly disease. Due to the lack of typical symptoms and laboratory findings, all these amoebic encephalitic diseases are difficult to diagnose. Considering that subsequent therapies are also affected, all these brain infections cause significant mortality worldwide, with more than 90% of the cases being fatal. Along with global warming and population explosion, expanding areas of human and amoebae activity in some regions lead to increased contact, resulting in more serious infections and drawing increased public attention. In this review, we summarize the present information of these pathogenic free-living amoebae, including their phylogeny, classification, biology, and ecology. The mechanisms of pathogenesis, immunology, pathophysiology, clinical manifestations, epidemiology, diagnosis, and therapies are also discussed.
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4
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Bhosale NK, Parija SC. Balamuthia mandrillaris: An opportunistic, free-living ameba - An updated review. Trop Parasitol 2021; 11:78-88. [PMID: 34765527 PMCID: PMC8579774 DOI: 10.4103/tp.tp_36_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 05/27/2021] [Accepted: 06/07/2021] [Indexed: 01/08/2023] Open
Abstract
Balamuthia mandrillaris is an opportunistic, free-living ameba that is pathogenic to humans. It has a worldwide distribution but is mainly detected in warmer regions. Balamuthia infections are rare but have been reported in both immunocompetent and immunocompromised individuals of all ages. B. mandrillaris can enter through wounds on the skin or the nose and cause cutaneous lesions and the usually fatal Balamuthia amebic encephalitis (BAE). Infection usually spreads from the lungs or through nerve fibers, and attacks the central nervous system, forming granulomatous lesions and necrosis in the brain. Balamuthia infection is usually chronic, and patients initially present with nonspecific symptoms, including headache, nausea, myalgia, and low-grade fever. As the disease progresses, the patient becomes paralyzed and comatose, often leading to death. Lack of knowledge of predisposing factors, specific treatment, and standardized detection tools have resulted in a nearly cent percent fatality rate. Although only about 200 cases have been reported worldwide since its characterization in the 1990s, the number of reported cases has increased over the years. BAE is an emerging disease and a major health concern. Few patients have survived Balamuthia infections with antimicrobial treatment that has largely been empirical. Early diagnosis is the key and requires familiarity with the disease and a high degree of suspicion on the part of the diagnostician. There are currently no specific treatment and prevention recommendations. This review highlights our current understanding of B. mandrillaris in terms of its pathogenicity, genomics, and novel diagnostic and therapeutic approaches against BAE infections.
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Affiliation(s)
- Namrata K Bhosale
- Department of Microbiology, Mahatma Gandhi Medical College and Research Institute, Puducherry, India
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5
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Dey R, Mameri MR, Trajkovic-Bodennec S, Bodennec J, Pernin P. Impact of inter-amoebic phagocytosis on the L. pneumophila growth. FEMS Microbiol Lett 2020; 367:5899054. [PMID: 32860684 DOI: 10.1093/femsle/fnaa147] [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] [Received: 05/09/2019] [Accepted: 08/25/2020] [Indexed: 01/21/2023] Open
Abstract
Free-living amoebae are known to act as replication niches for the pathogenic bacterium Legionella pneumophila in freshwater environments. However, we previously reported that some strains of the Willaertia magna species are more resistant to L. pneumophila infection and differ in their ability to support its growth. From this observation, we hypothesize that L. pneumophila growth in environment could be partly dependent on the composition of amoebic populations and on the possible interactions between different amoebic species. We tested this hypothesis by studying the growth of L. pneumophila and of a permissive free-living amoeba, Vermamoeba vermiformis (formerly named Hartmannella vermiformis), in co-culture with or without other free-living amoebae (Acanthamoeba castellanii and W. magna). We demonstrate the occurrence of inter-amoebic phagocytosis with A. castellanii and W. magna being able to ingest V. vermiformis infected or not infected with L. pneumophila. We also found that L. pneumophila growth is strongly impacted by the permissiveness of each interactive amoeba demonstrating that L. pneumophila proliferation and spread are controlled, at least in part, by inter-amoebic interactions.
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Affiliation(s)
- Rafik Dey
- Université claude Bernard Lyon I, 43 boulevard du 11 Novembre 1918, 69100 Villeurbanne, France.,Université Lyon 1; ISPB-Faculté de Pharmacie Laboratoire de Biologie Cellulaire, 8, Avenue Rockefeller, F-69373, France.,School of public health. University of Alberta, Edmonton AB, Canada
| | - Mouh Rayane Mameri
- Amoeba R & D Center, 38 Av des Frères Montgolfier, Chassieu F-69680, France.,Université Lyon 1; ISPB-Faculté de Pharmacie Laboratoire de Biologie Cellulaire, 8, Avenue Rockefeller, F-69373, France
| | | | - Jacques Bodennec
- Université claude Bernard Lyon I, 43 boulevard du 11 Novembre 1918, 69100 Villeurbanne, France.,Université Lyon 1, Lyon Neuroscience Research Center CNRS, UMR 5292, Villeurbanne, F-69622, France.,Université Lyon 1, INSERM, U1028, Tiger Team, Bron, F-69500, France
| | - Pierre Pernin
- Université claude Bernard Lyon I, 43 boulevard du 11 Novembre 1918, 69100 Villeurbanne, France.,Université Lyon 1; ISPB-Faculté de Pharmacie Laboratoire de Biologie Cellulaire, 8, Avenue Rockefeller, F-69373, France
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6
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Affiliation(s)
- Mohammad Ridwane Mungroo
- Department of Biology, Chemistry and Environmental Sciences, College of Arts and Sciences, American University of Sharjah, University City, Sharjah, United Arab Emirates
| | - 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
| | - 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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7
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Hasni I, Chelkha N, Baptiste E, Mameri MR, Lachuer J, Plasson F, Colson P, La Scola B. Investigation of potential pathogenicity of Willaertia magna by investigating the transfer of bacteria pathogenicity genes into its genome. Sci Rep 2019; 9:18318. [PMID: 31797948 PMCID: PMC6892926 DOI: 10.1038/s41598-019-54580-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 11/10/2019] [Indexed: 12/14/2022] Open
Abstract
Willaertia magna c2c maky is a thermophilic amoeba closely related to the genus Naegleria. This free-living amoeba has the ability to eliminate Legionella pneumophila, which is an amoeba-resisting bacterium living in an aquatic environment. To prevent the proliferation of L. pneumophila in cooling towers, the use of W. magna as natural biocide has been proposed. To provide a better understanding of the W. magna genome, whole-genome sequencing was performed through the study of virulence factors and lateral gene transfers. This amoeba harbors a genome of 36.5 megabases with 18,519 predicted genes. BLASTp analyses reported protein homology between 136 W. magna sequences and amoeba-resistant microorganisms. Horizontal gene transfers were observed based on the basis of the phylogenetic reconstruction hypothesis. We detected 15 homologs of N. fowleri genes related to virulence, although these latter were also found in the genome of N. gruberi, which is a non-pathogenic amoeba. Furthermore, the cytotoxicity test performed on human cells supports the hypothesis that the strain c2c maky is a non-pathogenic amoeba. This work explores the genomic repertory for the first draft genome of genus Willaertia and provides genomic data for further comparative studies on virulence of related pathogenic amoeba, N. fowleri.
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Affiliation(s)
- Issam Hasni
- Aix-Marseille Université UM63, Institut de Recherche pour le Développement IRD 198, Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes, Evolution, Phylogeny and Infection (MEΦI), Institut Hospitalo-Universitaire (IHU) - Méditerranée Infection, Marseille, France.,Amoéba, Chassieu, France
| | - Nisrine Chelkha
- Aix-Marseille Université UM63, Institut de Recherche pour le Développement IRD 198, Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes, Evolution, Phylogeny and Infection (MEΦI), Institut Hospitalo-Universitaire (IHU) - Méditerranée Infection, Marseille, France
| | - Emeline Baptiste
- Aix-Marseille Université UM63, Institut de Recherche pour le Développement IRD 198, Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes, Evolution, Phylogeny and Infection (MEΦI), Institut Hospitalo-Universitaire (IHU) - Méditerranée Infection, Marseille, France
| | | | - Joel Lachuer
- ProfileXpert/Viroscan3D, UCBL UMS 3453 CNRS - US7 INSERM, Lyon, France.,Inserm U1052, CNRS UMR5286, Centre de Recherche en Cancérologie de Lyon, Lyon, France.,Université de Lyon, Lyon, France
| | | | - Philippe Colson
- Aix-Marseille Université UM63, Institut de Recherche pour le Développement IRD 198, Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes, Evolution, Phylogeny and Infection (MEΦI), Institut Hospitalo-Universitaire (IHU) - Méditerranée Infection, Marseille, France
| | - Bernard La Scola
- Aix-Marseille Université UM63, Institut de Recherche pour le Développement IRD 198, Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes, Evolution, Phylogeny and Infection (MEΦI), Institut Hospitalo-Universitaire (IHU) - Méditerranée Infection, Marseille, France.
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8
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Chien RCC, Telford CR, Roy S, Ali IKM, Shieh WJ, Confer AW. Canine amoebic meningoencephalitis due to Balamuthia mandrillaris. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2018; 13:156-159. [PMID: 31014865 DOI: 10.1016/j.vprsr.2018.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/26/2018] [Accepted: 06/09/2018] [Indexed: 11/18/2022]
Abstract
A 1-year-old Siberian Husky dog with acute-onset of seizures, recumbency, paddling, and muscular fasciculations was autopsied. A locally extensive hemorrhagic and malacic focus was noted in the right cerebral frontal cortex, and severe necrotizing and hemorrhagic, neutrophilic meningoencephalitis was diagnosed microscopically. Amoebic trophozoites and cysts were identified within the affected cerebral parenchyma and confirmed by indirect immunofluorescence assay and real-time PCR as Balamuthia mandrillaris. B. mandrillaris is found in soil and water and the infection has been reported in both immunocompromised and immunocompetent humans and rarely in the dog.
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Affiliation(s)
- Rory Chia-Ching Chien
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, 250 McElroy Hall, Stillwater, OK 74078, USA.
| | - Corbin R Telford
- Department of Veterinary Clinical Sciences, Center for Veterinary Health Sciences, Oklahoma State University, 2065 W. Farm Road, Stillwater, OK 74078, USA.
| | - Shantanu Roy
- Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, USA.
| | - Ibne Karim M Ali
- Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, USA.
| | - Wun-Ju Shieh
- Centers for Disease Control and Prevention, CLFT Bldg 18 Rm SB108, Atlanta, GA 30329, USA.
| | - Anthony W Confer
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, 250 McElroy Hall, Stillwater, OK 74078, USA.
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9
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Lam C, Jamerson M, Cabral G, Carlesso AM, Marciano-Cabral F. Expression of matrix metalloproteinases in Naegleria fowleri and their role in invasion of the central nervous system. MICROBIOLOGY-SGM 2017; 163:1436-1444. [PMID: 28954644 DOI: 10.1099/mic.0.000537] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Naegleria fowleri is a free-living amoeba found in freshwater lakes and ponds and is the causative agent of primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system (CNS). PAM occurs when amoebae attach to the nasal epithelium and invade the CNS, a process that involves binding to, and degradation of, extracellular matrix (ECM) components. This degradation is mediated by matrix metalloproteinases (MMPs), enzymes that have been described in other pathogenic protozoa, and that have been linked to their increased motility and invasive capability. These enzymes also are upregulated in tumorigenic cells and have been implicated in metastasis of certain tumours. In the present study, in vitro experiments linked MMPs functionally to the degradation of the ECM. Gelatin zymography demonstrated enzyme activity in N. fowleri whole cell lysates, conditioned media and media collected from invasion assays. Western immunoblotting indicated the presence of the metalloproteinases MMP-2 (gelatinase A), MMP-9 (gelatinase B) and MMP-14 [membrane type-1 matrix metalloproteinase (MT1-MMP)]. Highly virulent mouse-passaged amoebae expressed higher levels of MMPs than weakly virulent axenically grown amoebae. The functional relevance of MMPs in media was indicated through the use of the MMP inhibitor, 1,10-phenanthroline. The collective in vitro results suggest that MMPs play a critical role in vivo in invasion of the CNS and that these enzymes may be amenable targets for limiting PAM.
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Affiliation(s)
- Charlton Lam
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| | - Melissa Jamerson
- Department of Clinical Laboratory Sciences, Virginia Commonwealth University, Richmond, VA, USA
| | - Guy Cabral
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| | - Ana Maris Carlesso
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
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10
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Sullivan KE, Bassiri H, Bousfiha AA, Costa-Carvalho BT, Freeman AF, Hagin D, Lau YL, Lionakis MS, Moreira I, Pinto JA, de Moraes-Pinto MI, Rawat A, Reda SM, Reyes SOL, Seppänen M, Tang MLK. Emerging Infections and Pertinent Infections Related to Travel for Patients with Primary Immunodeficiencies. J Clin Immunol 2017; 37:650-692. [PMID: 28786026 PMCID: PMC5693703 DOI: 10.1007/s10875-017-0426-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/21/2017] [Indexed: 12/18/2022]
Abstract
In today's global economy and affordable vacation travel, it is increasingly important that visitors to another country and their physician be familiar with emerging infections, infections unique to a specific geographic region, and risks related to the process of travel. This is never more important than for patients with primary immunodeficiency disorders (PIDD). A recent review addressing common causes of fever in travelers provides important information for the general population Thwaites and Day (N Engl J Med 376:548-560, 2017). This review covers critical infectious and management concerns specifically related to travel for patients with PIDD. This review will discuss the context of the changing landscape of infections, highlight specific infections of concern, and profile distinct infection phenotypes in patients who are immune compromised. The organization of this review will address the environment driving emerging infections and several concerns unique to patients with PIDD. The first section addresses general considerations, the second section profiles specific infections organized according to mechanism of transmission, and the third section focuses on unique phenotypes and unique susceptibilities in patients with PIDDs. This review does not address most parasitic diseases. Reference tables provide easily accessible information on a broader range of infections than is described in the text.
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Affiliation(s)
- Kathleen E Sullivan
- Division of Allergy and Immunology, The Children's Hospital of Philadelphia, 3615 Civic Center Blvd., Philadelphia, PA, 19104, USA.
| | - Hamid Bassiri
- Division of Infectious Diseases and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, 3501 Civic Center Boulevard, Philadelphia, PA, 19104, USA
| | - Ahmed A Bousfiha
- Clinical Immunology Unit, Infectious Department, Hopital d'Enfant Abderrahim Harouchi, CHU Ibn Rochd, Laboratoire d'Immunologie Clinique, d'Inflammation et d'Allergie LICIA, Faculté de Médecine et de Pharmacie, Université Hassan II, Casablanca, Morocco
| | - Beatriz T Costa-Carvalho
- Department of Pediatrics, Federal University of São Paulo, Rua dos Otonis, 725, São Paulo, SP, 04025-002, Brazil
| | - Alexandra F Freeman
- NIAID, NIH, Building 10 Room 12C103, 9000 Rockville, Pike, Bethesda, MD, 20892, USA
| | - David Hagin
- Division of Allergy and Immunology, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine, University of Tel Aviv, 6 Weizmann St, 64239, Tel Aviv, Israel
| | - Yu L Lau
- Department of Paediatrics & Adolescent Medicine, The University of Hong Kong, Rm 106, 1/F New Clinical Building, Pok Fu Lam, Hong Kong.,Queen Mary Hospital, 102 Pokfulam Road, Pok Fu Lam, Hong Kong
| | - Michail S Lionakis
- Fungal Pathogenesis Unit, Laboratory of Clinical Infectious Diseases, National Institute of Allergy & Infectious Diseases (NIAID), National Institutes of Health (NIH), 9000 Rockville Pike, Building 10, Room 11C102, Bethesda, MD, 20892, USA
| | - Ileana Moreira
- Immunology Unit, Hospital de Niños Ricardo Gutiérrez, Gallo 1330, 1425, Buenos Aires, Argentina
| | - Jorge A Pinto
- Division of Immunology, Department of Pediatrics, Federal University of Minas Gerais, Av. Alfredo Balena 190, room # 161, Belo Horizonte, MG, 30130-100, Brazil
| | - M Isabel de Moraes-Pinto
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Federal University of São Paulo, Rua Pedro de Toledo, 781/9°andar, São Paulo, SP, 04039-032, Brazil
| | - Amit Rawat
- Pediatric Allergy and Immunology, Department of Pediatrics, Advanced Pediatrics Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Shereen M Reda
- Pediatric Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Saul Oswaldo Lugo Reyes
- Immunodeficiencies Research Unit, National Institute of Pediatrics, Av Iman 1, Torre de Investigacion, Piso 9, Coyoacan, 04530, Mexico City, Mexico
| | - Mikko Seppänen
- Harvinaissairauksien yksikkö (HAKE), Rare Disease Center, Helsinki University Hospital (HUH), Helsinki, Finland
| | - Mimi L K Tang
- Murdoch Children's Research Institute, The Royal Children's Hospital, University of Melbourne, Melbourne, Australia
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11
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Siddiqui R, Abjani F, Yeo CI, Tiekink ERT, Khan NA. The effects of phosphanegold(I) thiolates on the biological properties of Acanthamoeba castellanii belonging to the T4 genotype. J Negat Results Biomed 2017; 16:6. [PMID: 28366172 PMCID: PMC5376697 DOI: 10.1186/s12952-017-0070-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/09/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Gold compounds have shown promise in the treatment of non-communicable diseases such as rheumatoid arthritis and cancer, and are considered of value as anti-microbial agents against Gram-negative and Gram-positive bacteria, and have anti-parasitic properties against Schistosoma mansoni, Trypanosoma brucei, Plasmodium falciparum, Leishmania infantinum, Giardia lamblia, and Entamoeba histolytica. They are known to affect enzymatic activities that are required for the cellular respiration processes. METHODS Anti-amoebic effects of phosphanegold(I) thiolates were tested against clinical isolate of A. castellanii belonging to the T4 genotype by employing viability assays, growth inhibition assays, encystation assays, excystation assays, and zymographic assays. RESULTS The treatment of A. castellanii with the phosphanegold(I) thiolates tested (i) had no effect on the viability of A. castellanii as determined by Trypan blue exclusion test, (ii) did not affect amoebae growth using PYG growth medium, (iii) did not inhibit cellular differentiation, and (iv) had no effect on the extracellular proteolytic activities of A. castellanii. CONCLUSION Being free-living amoeba, A. castellanii is a versatile respirator and possesses respiratory mechanisms that adapt to various aerobic and anaerobic environments to avoid toxic threats and adverse conditions. For the first time, our findings showed that A. castellanii exhibits resistance to the toxic effects of gold compounds and could prove to be an attractive model to study mechanisms of metal resistance in eukaryotic cells.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia
| | - Farhat Abjani
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia
| | - Chien Ing Yeo
- Research Centre for Crystalline Materials, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia
| | - Edward R T Tiekink
- Research Centre for Crystalline Materials, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia
| | - Naveed Ahmed Khan
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor, Malaysia.
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12
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Siddiqui R, Saleem S, Khan NA. The effect of peptidic and non-peptidic proteasome inhibitors on the biological properties of Acanthamoeba castellanii belonging to the T4 genotype. Exp Parasitol 2016; 168:16-24. [PMID: 27327524 DOI: 10.1016/j.exppara.2016.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/01/2016] [Accepted: 06/17/2016] [Indexed: 10/21/2022]
Abstract
The treatment of Acanthamoeba infections remains problematic, suggesting that new targets and/or chemotherapeutic agents are needed. Bioassay-guided screening of drugs that are clinically-approved for non-communicable diseases against opportunistic eukaryotic pathogens is a viable strategy. With known targets and mode of action, such drugs can advance to clinical trials at a faster pace. Recently Bortezomib (proteasome inhibitor) has been approved by FDA in the treatment of multiple myeloma. As proteasomal pathways are well known regulators of a variety of eukaryotic cellular functions, the overall aim of the present study was to study the effects of peptidic and non-peptidic proteasome inhibitors on the biology and pathogenesis of Acanthamoeba castellanii of the T4 genotype, in vitro. Zymographic assays revealed that inhibition of proteasome had detrimental effects on the extracellular proteolytic activities of A. castellanii. Proteasome inhibition affected A. castellanii growth (using amoebistatic assays), but not viability of A. castellanii. Importantly, proteasome inhibitors affected encystation as determined by trophozoite transformation into the cyst form, as well as excystation, as determined by cyst transformation into the trophozoite form. The ability of proteasome inhibitor to block Acanthamoeba differentiation is significant, as it presents a major challenge in the successful treatment of Acanthamoeba infection. As these drugs are used clinically against non-communicable diseases, the findings reported here have the potential to be tested in a clinical setting against amoebic infections.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, Malaysia
| | - Sahreena Saleem
- Department of Biological and Biomedical Sciences, Aga Khan University, Pakistan
| | - Naveed Ahmed Khan
- Department of Biological Sciences, Faculty of Science and Technology, Sunway University, Malaysia.
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13
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Crossland NA, Ali I, Higbie C, Jackson J, Pirie G, Bauer R. Neurologic amebiasis caused by Balamuthia mandrillaris in an Indian flying fox (Pteropus giganteus). J Vet Diagn Invest 2016; 28:54-8. [PMID: 26762405 DOI: 10.1177/1040638715614346] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A 4-5-month-old intact male Indian flying fox (Pteropus giganteus) was presented to the Baton Rouge Zoo's veterinary hospital with an acute onset of obtundation that was diagnosed with amebic encephalitis. Histologic examination revealed numerous amebic trophozoites within necrotic foci, affecting the occipital cerebrum and surrounding the mesencephalic aqueduct. The etiologic agent, Balamuthia mandrillaris, was determined by multiplex quantitative real-time polymerase chain reaction, immunohistochemistry, and indirect fluorescent antibody test. The current report documented a case of amebic encephalitis within the order Chiroptera.
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Affiliation(s)
- Nicholas A Crossland
- Departments of Pathobiological Sciences (Crossland, Bauer), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LAVeterinary Clinical Sciences (Higbie), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LALouisiana Animal Disease Diagnostic Laboratory, Louisiana State University, Baton Rouge, LA (Bauer)National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA (Ali, Jackson)Baton Rouge Zoo, Baton Rouge, LA (Pirie)
| | - Ibne Ali
- Departments of Pathobiological Sciences (Crossland, Bauer), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LAVeterinary Clinical Sciences (Higbie), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LALouisiana Animal Disease Diagnostic Laboratory, Louisiana State University, Baton Rouge, LA (Bauer)National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA (Ali, Jackson)Baton Rouge Zoo, Baton Rouge, LA (Pirie)
| | - Christine Higbie
- Departments of Pathobiological Sciences (Crossland, Bauer), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LAVeterinary Clinical Sciences (Higbie), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LALouisiana Animal Disease Diagnostic Laboratory, Louisiana State University, Baton Rouge, LA (Bauer)National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA (Ali, Jackson)Baton Rouge Zoo, Baton Rouge, LA (Pirie)
| | - Jonathan Jackson
- Departments of Pathobiological Sciences (Crossland, Bauer), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LAVeterinary Clinical Sciences (Higbie), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LALouisiana Animal Disease Diagnostic Laboratory, Louisiana State University, Baton Rouge, LA (Bauer)National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA (Ali, Jackson)Baton Rouge Zoo, Baton Rouge, LA (Pirie)
| | - Gordon Pirie
- Departments of Pathobiological Sciences (Crossland, Bauer), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LAVeterinary Clinical Sciences (Higbie), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LALouisiana Animal Disease Diagnostic Laboratory, Louisiana State University, Baton Rouge, LA (Bauer)National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA (Ali, Jackson)Baton Rouge Zoo, Baton Rouge, LA (Pirie)
| | - Rudy Bauer
- Departments of Pathobiological Sciences (Crossland, Bauer), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LAVeterinary Clinical Sciences (Higbie), School of Veterinary Medicine, Louisiana State University, Baton Rouge, LALouisiana Animal Disease Diagnostic Laboratory, Louisiana State University, Baton Rouge, LA (Bauer)National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA (Ali, Jackson)Baton Rouge Zoo, Baton Rouge, LA (Pirie)
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Aqeel Y, Siddiqui R, Farooq M, Khan NA. Anaerobic respiration: In vitro efficacy of Nitazoxanide against mitochondriate Acanthamoeba castellanii of the T4 genotype. Exp Parasitol 2015; 157:170-6. [DOI: 10.1016/j.exppara.2015.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 07/22/2015] [Accepted: 08/16/2015] [Indexed: 10/23/2022]
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Aqeel Y, Siddiqui R, Manan Z, Khan NA. The role of G protein coupled receptor-mediated signaling in the biological properties of Acanthamoeba castellanii of the T4 genotype. Microb Pathog 2015; 81:22-7. [DOI: 10.1016/j.micpath.2015.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 03/07/2015] [Accepted: 03/09/2015] [Indexed: 12/21/2022]
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Siddiqui R, Khan NA. Balamuthia mandrillaris: Morphology, biology, and virulence. Trop Parasitol 2015; 5:15-22. [PMID: 25709948 PMCID: PMC4326988 DOI: 10.4103/2229-5070.149888] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 01/22/2015] [Indexed: 11/04/2022] Open
Abstract
Balamuthia mandrillaris is a protist pathogen that can cause encephalitis with a fatality rate of >95%. This is due to our incomplete understanding of the pathogenesis and pathophysiology of B. mandrillaris encephalitis. B. mandrillaris has two stages in its life cycle, an active trophozoite stage during which it divides mitotically. However, under unfavorable conditions, the trophozoite transforms into a dormant cyst stage. A major concern during the course of therapy is that B. mandrillaris can transform into cysts. Cysts are highly resistant to physical and chemical conditions and present a problem in successful antimicrobial chemotherapy. Several lines of evidence suggest that B. mandrillaris encephalitis develops as a result of hematogenous spread, but it is unclear how circulating amoebae enter the central nervous system and cause inflammation, blood-brain barrier disruption, and neuronal injury. Recent studies have identified several parasite-host determinants for B. mandrillaris translocation of the blood-brain barrier, and host inflammatory markers that may be associated with neuronal injury. These determinants may provide important targets for the prevention and treatment of this devastating infection. Here, we present a brief overview of the current understanding of the morphology, biology, pathogenesis, and pathophysiology of B. mandrillaris encephalitis.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
| | - Naveed Ahmed Khan
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
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Vyas IK, Jamerson M, Cabral GA, Marciano-Cabral F. Identification of Peptidases in Highly Pathogenic vs. Weakly Pathogenic Naegleria fowleri
Amebae. J Eukaryot Microbiol 2014; 62:51-9. [DOI: 10.1111/jeu.12152] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 07/09/2014] [Accepted: 07/09/2014] [Indexed: 01/03/2023]
Affiliation(s)
- Ishan K. Vyas
- Department of Microbiology and Immunology; School of Medicine; Virginia Commonwealth University; Richmond Virginia 23298
| | - Melissa Jamerson
- Department of Microbiology and Immunology; School of Medicine; Virginia Commonwealth University; Richmond Virginia 23298
| | - Guy A. Cabral
- Department of Microbiology and Immunology; School of Medicine; Virginia Commonwealth University; Richmond Virginia 23298
| | - Francine Marciano-Cabral
- Department of Microbiology and Immunology; School of Medicine; Virginia Commonwealth University; Richmond Virginia 23298
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Proteases from Entamoeba spp. and Pathogenic Free-Living Amoebae as Virulence Factors. J Trop Med 2013; 2013:890603. [PMID: 23476670 PMCID: PMC3582061 DOI: 10.1155/2013/890603] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 11/28/2012] [Indexed: 02/01/2023] Open
Abstract
The standard reference for pathogenic and nonpathogenic amoebae is the human parasite Entamoeba histolytica; a direct correlation between virulence and protease expression has been demonstrated for this amoeba. Traditionally, proteases are considered virulence factors, including those that produce cytopathic effects in the host or that have been implicated in manipulating the immune response. Here, we expand the scope to other amoebae, including less-pathogenic Entamoeba species and highly pathogenic free-living amoebae. In this paper, proteases that affect mucin, extracellular matrix, immune system components, and diverse tissues and cells are included, based on studies in amoebic cultures and animal models. We also include proteases used by amoebae to degrade iron-containing proteins because iron scavenger capacity is currently considered a virulence factor for pathogens. In addition, proteases that have a role in adhesion and encystation, which are essential for establishing and transmitting infection, are discussed. The study of proteases and their specific inhibitors is relevant to the search for new therapeutic targets and to increase the power of drugs used to treat the diseases caused by these complex microorganisms.
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Abstract
Invasion of the central nervous system (CNS) is a most devastating complication of a parasitic infection. Several physical and immunological barriers provide obstacles to such an invasion. In this broad overview focus is given to the physical barriers to neuroinvasion of parasites provided at the portal of entry of the parasites, i.e., the skin and epithelial cells of the gastrointestinal tract, and between the blood and the brain parenchyma, i.e., the blood-brain barrier (BBB). A description is given on how human pathogenic parasites can reach the CNS via the bloodstream either as free-living or extracellular parasites, by embolization of eggs, or within red or white blood cells when adapted to intracellular life. Molecular mechanisms are discussed by which parasites can interact with or pass across the BBB. The possible targeting of the circumventricular organs by parasites, as well as the parasites' direct entry to the brain from the nasal cavity through the olfactory nerve pathway, is also highlighted. Finally, examples are given which illustrate different mechanisms by which parasites can cause dysfunction or damage in the CNS related to toxic effects of parasite-derived molecules or to immune responses to the infection.
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Abstract
Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri are mitochondria-bearing, free-living eukaryotic amebae that have been known to cause infections of the central nervous system (CNS) of humans and other animals. Several species of Acanthamoeba belonging to several different genotypes cause an insidious and chronic disease, granulomatous amebic encephalitis (GAE), principally in immunocompromised hosts including persons infected with HIV/AIDS. Acanthamoeba spp., belonging to mostly group 2, also cause infection of the human cornea, Acanthamoeba keratitis. Balamuthia mandrillaris causes GAE in both immunocompromised and immunocompetent hosts mostly in the very young or very old individuals. Both Acanthamoeba spp. and B. mandrillaris also cause a disseminated disease including the lungs, skin, kidneys, and uterus. Naegleria fowleri, on the other hand, causes an acute and fulminating, necrotizing infection of the CNS called primary amebic meningoencephalitis (PAM) in children and young adults with a history of recent exposure to warm fresh water. Additionally, another free-living ameba Sappinia pedata, previously described as S. diploidea, also has caused a single case of amebic meningoencephalitis. In this review the biology of these amebae, clinical manifestations, molecular and immunological diagnosis, and epidemiological features associated with GAE and PAM are discussed.
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Affiliation(s)
- Govinda S Visvesvara
- Division of Foodborne, Waterborne & Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
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Aqeel Y, Siddiqui R, Khan NA. Silencing of xylose isomerase and cellulose synthase by siRNA inhibits encystation in Acanthamoeba castellanii. Parasitol Res 2012; 112:1221-7. [DOI: 10.1007/s00436-012-3254-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 12/12/2012] [Indexed: 10/27/2022]
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Trabelsi H, Dendana F, Sellami A, Sellami H, Cheikhrouhou F, Neji S, Makni F, Ayadi A. Pathogenic free-living amoebae: Epidemiology and clinical review. ACTA ACUST UNITED AC 2012; 60:399-405. [DOI: 10.1016/j.patbio.2012.03.002] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 03/02/2012] [Indexed: 10/28/2022]
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Aqeel Y, Iqbal J, Siddiqui R, Gilani AH, Khan NA. Anti-Acanthamoebic properties of resveratrol and demethoxycurcumin. Exp Parasitol 2012; 132:519-23. [PMID: 23010569 DOI: 10.1016/j.exppara.2012.09.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 04/16/2012] [Accepted: 09/12/2012] [Indexed: 12/24/2022]
Abstract
Acanthamoeba is an opportunist protist pathogen that is known to infect the cornea to produce eye keratitis and the central nervous system to produce fatal granulomatous encephalitis. Early diagnosis, followed by aggressive treatment using a combination of drugs is a prerequisite in successful treatment but even then, prognosis remains poor due to lack of effective drugs. The overall aim of the present study was to determine the anti-Acanthamoebic potential of natural compounds, resveratrol and curcuminoids. Adhesion and cytotoxicity assays were performed using primary human brain microvascular endothelial cells, which constitute the blood-brain barrier. Pre-exposure of organisms to 100 μg resveratrol and demethoxy curcumin prevented amoeba binding by 57% and 73%, respectively, while cytotoxicity of host cells was inhibited by 86%. In an assay for viability of amoebae in the absence of host cells, resveratrol and de-methoxy curcumin exhibited significant amoebicidal effects (23% and 25%, respectively) at 100 μg concentrations (P<0.01). Neither resveratrol nor demethoxycurcumin had any effect on the proteolytic activities of Acanthamoeba castellanii. Of both compounds, resveratrol is of most interest for further investigation, because of the selective toxicity of resveratrol on A. castellanii but not the human brain microvascular endothelial cells.
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Affiliation(s)
- Yousuf Aqeel
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
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Singh B, Fleury C, Jalalvand F, Riesbeck K. Human pathogens utilize host extracellular matrix proteins laminin and collagen for adhesion and invasion of the host. FEMS Microbiol Rev 2012; 36:1122-80. [PMID: 22537156 DOI: 10.1111/j.1574-6976.2012.00340.x] [Citation(s) in RCA: 199] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 02/08/2012] [Accepted: 03/29/2012] [Indexed: 01/11/2023] Open
Abstract
Laminin (Ln) and collagen are multifunctional glycoproteins that play an important role in cellular morphogenesis, cell signalling, tissue repair and cell migration. These proteins are ubiquitously present in tissues as a part of the basement membrane (BM), constitute a protective layer around blood capillaries and are included in the extracellular matrix (ECM). As a component of BMs, both Lns and collagen(s), thus function as major mechanical containment molecules that protect tissues from pathogens. Invasive pathogens breach the basal lamina and degrade ECM proteins of interstitial spaces and connective tissues using various ECM-degrading proteases or surface-bound plasminogen and matrix metalloproteinases recruited from the host. Most pathogens associated with the respiratory, gastrointestinal, or urogenital tracts, as well as with the central nervous system or the skin, have the capacity to bind and degrade Lns and collagen(s) in order to adhere to and invade host tissues. In this review, we focus on the adaptability of various pathogens to utilize these ECM proteins as enhancers for adhesion to host tissues or as a targets for degradation in order to breach the cellular barriers. The major pathogens discussed are Streptococcus, Staphylococcus, Pseudomonas, Salmonella, Yersinia, Treponema, Mycobacterium, Clostridium, Listeria, Porphyromonas and Haemophilus; Candida, Aspergillus, Pneumocystis, Cryptococcus and Coccidioides; Acanthamoeba, Trypanosoma and Trichomonas; retrovirus and papilloma virus.
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Affiliation(s)
- Birendra Singh
- Medical Microbiology, Department of Laboratory Medicine Malmö, Skåne University Hospital, Lund University, Malmö, Sweden
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Siddiqui R, Iqbal J, Maugueret MJ, Khan NA. The role of Src kinase in the biology and pathogenesis of Acanthamoeba castellanii. Parasit Vectors 2012; 5:112. [PMID: 22676352 PMCID: PMC3431265 DOI: 10.1186/1756-3305-5-112] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 05/15/2012] [Indexed: 12/02/2022] Open
Abstract
Background Acanthamoeba species are the causative agents of fatal granulomatous encephalitis in humans. Haematogenous spread is thought to be a primary step, followed by blood–brain barrier penetration, in the transmission of Acanthmaoeba into the central nervous system, but the associated molecular mechanisms remain unclear. Here, we evaluated the role of Src, a non-receptor protein tyrosine kinase in the biology and pathogenesis of Acanthamoeba. Methods Amoebistatic and amoebicidal assays were performed by incubating amoeba in the presence of Src kinase-selective inhibitor, PP2 (4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine) and its inactive analog, PP3 (4-amino-7-phenylpyrazolo[3,4-d]pyrimidine). Using this inhibitor, the role of Src kinase in A. castellanii interactions with Escherichia coli was determined. Zymographic assays were performed to study effects of Src kinase on extracellular proteolytic activities of A. castellanii. The human brain microvascular endothelial cells were used to determine the effects of Src kinase on A. castellanii adhesion to and cytotoxicity of host cells. Results Inhibition of Src kinase using a specific inhibitor, PP2 (4-amino-5-(4 chlorophenyl)-7-(t-butyl)pyrazolo [3,4-d] pyrimidine) but not its inactive analog, PP3 (4-amino-7-phenylpyrazolo[3,4-d] pyrimidine), had detrimental effects on the growth of A. castellanii (keratitis isolate, belonging to the T4 genotype). Interestingly, inhibition of Src kinase hampered the phagocytic ability of A. castellanii, as measured by the uptake of non-invasive bacteria, but, on the contrary, invasion by pathogenic bacteria was enhanced. Zymographic assays revealed that inhibition of Src kinases reduced extracellular protease activities of A. castellanii. Src kinase inhibition had no significant effect on A. castellanii binding to and cytotoxicity of primary human brain microvascular endothelial cells, which constitute the blood–brain barrier. Conclusions For the first time, these findings demonstrated that Src kinase is involved in A. castellanii proliferation, protease secretions and phagocytic properties. Conversely, invasion of Acanthamoeba by pathogenic bacteria was stimulated by Src kinase inhibition.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- Department of Biological and Biomedical Sciences, The Aga Khan University, Karachi, Pakistan
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Abstract
The blood-brain barrier (BBB) is a structural and functional barrier that protects the central nervous system (CNS) from invasion by blood-borne pathogens including parasites. However, some intracellular and extracellular parasites can traverse the BBB during the course of infection and cause neurological disturbances and/or damage which are at times fatal. The means by which parasites cross the BBB and how the immune system controls the parasites within the brain are still unclear. In this review we present the current understanding of the processes utilized by two human neuropathogenic parasites, Trypanosoma brucei spp and Toxoplasma gondii, to go across the BBB and consequences of CNS invasion. We also describe briefly other parasites that can invade the brain and how they interact with or circumvent the BBB. The roles played by parasite-derived and host-derived molecules during parasitic and white blood cell invasion of the brain are discussed.
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Affiliation(s)
- Willias Masocha
- Department of Applied Therapeutics, Faculty of Pharmacy, Kuwait University, Kuwait City, Kuwait
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Matin A, Jung SY. Phospholipase activities in clinical and environmental isolates of Acanthamoeba. THE KOREAN JOURNAL OF PARASITOLOGY 2011; 49:1-8. [PMID: 21461262 PMCID: PMC3063920 DOI: 10.3347/kjp.2011.49.1.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 11/30/2010] [Accepted: 12/16/2010] [Indexed: 11/23/2022]
Abstract
The pathogenesis and pathophysiology of Acanthamoeba infections remain incompletely understood. Phos-pholipases are known to cleave phospholipids, suggesting their possible involvement in the host cell plasma membrane disruption leading to host cell penetration and lysis. The aims of the present study were to determine phospholipase activities in Acanthamoeba and to determine their roles in the pathogenesis of Acanthamoeba. Using an encephalitis isolate (T1 genotype), a keratitis isolate (T4 genotype), and an environmental isolate (T7 genotype), we demonstrated that Acanthamoeba exhibited phospholipase A2 (PLA2) and phospholipase D (PLD) activities in a spectrophotometry-based assay. Interestingly, the encephalitis isolates of Acanthamoeba exhibited higher phospholipase activities as compared with the keratitis isolates, but the environmental isolates exhibited the highest phospholipase activities. Moreover, Acanthamoeba isolates exhibited higher PLD activities compared with the PLA2. Acanthamoeba exhibited optimal phospholipase activities at 37℃ and at neutral pH indicating their physiological relevance. The functional role of phospholipases was determined by in vitro assays using human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. We observed that a PLD-specific inhibitor, i.e., compound 48/80, partially inhibited Acanthamoeba encephalitis isolate cytotoxicity of the host cells, while PLA2-specific inhibitor, i.e., cytidine 5'-diphosphocholine, had no effect on parasite-mediated HBMEC cytotoxicity. Overall, the T7 exhibited higher phospholipase activities as compared to the T4. In contract, the T7 exhibited minimal binding to, or cytotoxicity of, HBMEC.
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Affiliation(s)
- Abdul Matin
- Institute of Biomedical and Genetic Engineering, 24 Mauve Area, Sector: G-9/1, Islamabad, Pakistan
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Elsheikha HM, Khan NA. Protozoa traversal of the blood–brain barrier to invade the central nervous system. FEMS Microbiol Rev 2010; 34:532-53. [DOI: 10.1111/j.1574-6976.2010.00215.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Siddiqui R, Jarroll EL, Khan NA. Balamuthia mandrillaris: role of galactose in encystment and identification of potential inhibitory targets. Exp Parasitol 2009; 126:22-7. [PMID: 19766634 DOI: 10.1016/j.exppara.2009.09.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 09/10/2009] [Accepted: 09/14/2009] [Indexed: 11/30/2022]
Abstract
Balamuthia mandrillaris is a causative agent of granulomatous encephalitis that almost always proves fatal. A major concern during the course of therapy is that B. mandrillaris can transform into cysts. Cysts are highly resistant to physical and chemical conditions and present a problem in successful antimicrobial chemotherapy. However, the underlying mechanisms of B. mandrillaris transformation into cysts are not known. In this study, we examined the effects of exogenous sugars on B. mandrillaris encystment. The findings revealed that free exogenous galactose, but not other sugars, enhanced parasite differentiation into cysts, and apparently a galactose-binding protein is involved in B. mandrillaris encystment. Cytoskeletal re-arrangements and phosphatidylinositol 3-kinase (PI3K)-mediated pathways are involved in B. mandrillaris encystment based on inhibitor studies. Dual functionality of galactose-binding protein in B. mandrillaris pathogenesis and encystment is discussed further.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London, England, UK
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Matin A, Khan NA. Demonstration and partial characterization of ecto-ATPase in Balamuthia mandrillaris and its possible role in the host-cell interactions. Lett Appl Microbiol 2009; 47:348-54. [PMID: 18761612 DOI: 10.1111/j.1472-765x.2008.02414.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To investigate the presence and partial characterization of ecto-ATPase in Balamuthia mandrillaris. METHODS AND RESULTS In vitro assays were used to demonstrate that live B. mandrillaris hydrolyses extracellular AtP. Using nondenaturing polyacrylamide gel electrophoresis, B. mandrillaris exhibited a single ecto-ATPase band of molecular mass of more than 545 kDa. This ecto-ATPase was insensitive to ouabain, levamisole, sodium azide and sodium orthovanadate but stimulated by MgCl2. The ecto-ATPase was heat stable, but labile to detergent, sodium dodecyl sulphate. Suramin, an antagonist of P2 purinoreceptors and an inhibitor of some ecto-ATPases, inhibited B. mandrillaris binding to and cytotoxicity of HBMEC (human brain microvascular endothelial cello), in vitro. CONCLUSIONS For the first time, we describe that live B. mandrillaris hydrolyses extracellular ATP and exhibits a > 545kDa ecto-ATPase. SIGNIFICANCE AND IMPACT OF THE STUDY This surface enzyme may play a role in the salvage of purines from the extracellular medium and may be important for the pathogenesis of B. mandrillaris.
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Affiliation(s)
- A Matin
- School of Biological and Chemical Sciences, Birkbeck, University of London, London, England, UK
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Abstract
Balamuthia mandrillaris is an emerging protozoan parasite, an agent of granulomatous amoebic encephalitis involving the central nervous system, with a case fatality rate of >98%. This review presents our current understanding of Balamuthia infections, their pathogenesis and pathophysiology, and molecular mechanisms associated with the disease, as well as virulence traits of Balamuthia that may be potential targets for therapeutic interventions and/or for the development of preventative measures.
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Kim SG, Lee AK, Yoon HK, Park CM. A membrane-bound NAC transcription factor NTL8 regulates gibberellic acid-mediated salt signaling in Arabidopsis seed germination. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 55:77-88. [PMID: 18363782 DOI: 10.1111/j.1365-313x.2008.03493.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Gibberellic acid (GA) plays a key role in seed germination through coordinate interactions with other growth hormones and external signals. However, the way in which external signals are incorporated into the GA-signaling pathway is largely unknown. Here, we demonstrate that a membrane-bound NAC transcription factor NTL8 mediates the salt regulation of seed germination via the GA pathway, primarily independently of ABA. NTL8 is induced by high salinity. Its expression is also elevated by a GA biosynthetic inhibitor paclabutrazol (PAC), but is repressed by GA. Notably, high salinity greatly represses the GA3 oxidase 1 (GA3ox1) gene, supporting the hypothesis that salt signals inhibit seed germination by repressing GA biosynthesis. Induction of NTL8 and repression of GA3ox1 by high salinity still occur in the ABA-deficient aba3-1 mutant. Accordingly, the germination of a T-DNA insertional ntl8-1 mutant seed is resistant to high salinity and PAC. Interestingly, NTL8 is significantly induced during cold imbibition, but the induction declines quickly in germinating seeds, like RGL2. NTL8 activity is also regulated by controlled proteolytic release of the membrane-bound NTL8 form. Its release from the membranes is activated by PAC and high salinity. Our data support that NTL8 modulates GA-mediated salt signaling in regulating seed germination. This regulatory scheme may provide an adaptative fitness, which delays seed germination under high salinity conditions.
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Affiliation(s)
- Sang-Gyu Kim
- Department of Chemistry, Molecular Signaling Laboratory, Seoul National University, Seoul 151-742, Korea
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Abstract
The resistance of Balamuthia mandrillaris to physical, chemical and radiological conditions was tested. Following treatments, viability was determined by culturing amoebae on human brain microvascular endothelial cells for up to 12 days. B. mandrillaris cysts were resistant to repeated freeze–thawing (five times), temperatures of up to 70 °C, 0.5 % SDS, 25 p.p.m. chlorine, 10 μg pentamidine isethionate ml−1 and 200 mJ UV irradiation cm−2.
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Siddiqui R, Khan NA. Balamuthia amoebic encephalitis: An emerging disease with fatal consequences. Microb Pathog 2008; 44:89-97. [PMID: 17913450 DOI: 10.1016/j.micpath.2007.06.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 06/14/2007] [Accepted: 06/21/2007] [Indexed: 10/22/2022]
Abstract
Balamuthia amoebic encephalitis (BAE), caused by the protozoan pathogen, Balamuthia mandrillaris, is a serious human disease with fatal consequences and a mortality rate of more than 95%. A key factor that contributes to the high mortality is the incomplete understanding of its pathogenesis and pathophysiology. The most distressing aspect is that the high level of mortality is due to lack of awareness combined with the lack of effective drugs. Early diagnosis followed by aggressive treatment may lead to cure. Several lines of evidence suggest that BAE develops as a result of haematogenous spread, but it is unclear how circulating amoebae enter the central nervous system and cause inflammation, blood-brain barrier disruption and neuronal injury. Recent studies have identified several parasite-host determinants for B. mandrillaris translocation of the blood-brain barrier, and host inflammatory markers that may be associated with neuronal injury. These determinants may provide important targets for the prevention and treatment of BAE. Here, we present a brief overview of the current understanding of the pathogenesis and pathophysiology of BAE, available diagnostic methods, possible therapeutic interventions and biology of the causative agent.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London, UK
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Matin A, Siddiqui R, Jung SY, Kim KS, Stins M, Khan NA. Balamuthia mandrillaris interactions with human brain microvascular endothelial cells in vitro. J Med Microbiol 2007; 56:1110-1115. [PMID: 17644721 DOI: 10.1099/jmm.0.47134-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Balamuthia amoebic encephalitis (BAE) is a serious human disease almost always leading to death. An important step in BAE is amoebae invasion of the bloodstream, followed by their haematogenous spread. Balamuthia mandrillaris entry into the central nervous system most likely occurs at the blood-brain barrier sites. Using human brain microvascular endothelial cells (HBMECs), which constitute the blood-brain barrier, this study determined (i) the ability of B. mandrillaris to bind to HBMECs and (ii) the associated molecular mechanisms. Adhesion assays revealed that B. mandrillaris exhibited greater than 90 % binding to HBMECs in vitro. To determine whether recognition of carbohydrate moieties on the surface of the HBMECs plays a role in B. mandrillaris adherence to the target cells, adhesion assays were performed in the presence of the saccharides mannose, galactose, xylose, glucose and fucose. It was observed that adherence of B. mandrillaris was significantly reduced by galactose, whilst the other saccharides had no effect. Acetone fixation of amoebae, but not of HBMECs, abolished adhesion, suggesting that B. mandrillaris adhesin(s) bind to galactose-containing glycoproteins of HBMECs. B. mandrillaris also bound to microtitre wells coated with galactose-BSA. By affinity chromatography using a galactose-Sepharose column, a galactose-binding protein (GBP) was isolated from detergent extracts of unlabelled amoebae. The isolation of a GBP from cell-surface-biotin-labelled amoebae suggested its membrane association. One-dimensional SDS-PAGE confirmed the proteinaceous nature of the GBP and determined its molecular mass as approximately 100 kDa. This is the first report suggesting the role of a GBP in B. mandrillaris interactions with HBMECs.
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Affiliation(s)
- Abdul Matin
- School of Biological and Chemical Sciences, Birkbeck, University of London, London WC1E 7HX, UK
| | - Ruqaiyyah Siddiqui
- School of Biological and Chemical Sciences, Birkbeck, University of London, London WC1E 7HX, UK
| | - Suk-Yul Jung
- School of Biological and Chemical Sciences, Birkbeck, University of London, London WC1E 7HX, UK
| | - Kwang Sik Kim
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Monique Stins
- Division of Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Naveed Ahmed Khan
- School of Biological and Chemical Sciences, Birkbeck, University of London, London WC1E 7HX, UK
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Siddiqui R, Matin A, Warhurst D, Stins M, Khan NA. Effect of antimicrobial compounds on Balamuthia mandrillaris encystment and human brain microvascular endothelial cell cytopathogenicity. Antimicrob Agents Chemother 2007; 51:4471-3. [PMID: 17875991 PMCID: PMC2168013 DOI: 10.1128/aac.00373-07] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Cycloheximide, ketoconazole, or preexposure of organisms to cytochalasin D prevented Balamuthia mandrillaris-associated cytopathogenicity in human brain microvascular endothelial cells, which constitute the blood-brain barrier. In an assay for inhibition of cyst production, these three agents prevented the production of cysts, suggesting that the biosynthesis of proteins and ergosterol and the polymerization of actin are important in cytopathogenicity and encystment.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London WC1E 7HX, England, United Kingdom
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Dunnebacke TH. The Ameba Balamuthia mandrillaris Feeds by Entering into Mammalian Cells in Culture. J Eukaryot Microbiol 2007; 54:452-64. [PMID: 17910691 DOI: 10.1111/j.1550-7408.2007.00286.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Microscopic observations of live cultures of the pathogenic ameba Balamuthia mandrillaris and mammalian cells showed that amebic feeding involved the invasion of the pseudopodia, and/or the whole ameba into the cells. The ameba, recognized by their size and flow of organelles in the cytosol, was seen to extend the tip of a pseudopodium into the cytoplasm of a cell where it moved about leaving visible damage when retracted. In rounded cells, whole amebas were seen to enter into and move around before exiting a cell and then remain quiescent for hours. The invaded mammalian cells retained their turgidity and excluded vital dyes until only their denuded nuclei remained. The cytoplasm of the cells was consumed first, then the nuclei, but not their mitotic chromosomes. The feeding pattern of four isolates of B. mandrillaris, two from humans and two from soil samples, was by amebic invasion into the mammalian cells. The resulting ameba population included cysts, amebas on the surface, and free-floating amebas as individuals or in dense-packed clusters. There was no morphologic indication of a cytopathic change in the mammalian cells before their invasion by the amebas. Feeding by cell invasion is a distinctive feature of B. mandrillaris.
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Affiliation(s)
- Thelma H Dunnebacke
- California Department of Health Services, Viral and Rickettsial Disease Laboratory, Richmond, California 94804-6403, USA.
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Matin A, Jeong SR, Stins M, Khan NA. Effects of human serum on Balamuthia mandrillaris interactions with human brain microvascular endothelial cells. J Med Microbiol 2007; 56:30-35. [PMID: 17172513 DOI: 10.1099/jmm.0.46847-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Balamuthia mandrillaris is a free-living amoeba and a causative agent of fatal granulomatous encephalitis. In the transmission of B. mandrillaris into the central nervous system (CNS), haematogenous spread is thought to be the primary step, followed by blood–brain barrier penetration. The objectives of the present study were (i) to determine the effects of serum from healthy individuals on the viability of B. mandrillaris, and (ii) to determine the effects of serum on B. mandrillaris-mediated blood–brain barrier perturbations. It was determined that normal human serum exhibited limited amoebicidal effects, i.e. ∼40 % of trophozoites were killed. The residual subpopulation, although viable, remained static over longer incubations. Using human brain microvascular endothelial cells (HBMEC), which form the blood–brain barrier, it was observed that B. mandrillaris exhibited binding (>80 %) and cytotoxicity (>70 %) to HBMEC. However, normal human serum exhibited more than 60 % inhibition of B. mandrillaris binding and cytotoxicity to HBMEC. ELISAs showed that both serum and saliva samples exhibit the presence of anti-B. mandrillaris antibodies. Western blots revealed that normal human serum reacted with several B. mandrillaris antigens with approximate molecular masses of 148, 115, 82, 67, 60, 56, 44, 42, 40 and 37 kDa. Overall, the results demonstrated that normal human serum has inhibitory effects on B. mandrillaris growth and viability, as well as on their binding and subsequent cytotoxicity to HBMEC. A complete understanding of B. mandrillaris pathogenesis is crucial to develop therapeutic interventions and/or to design preventative measures.
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Affiliation(s)
- Abdul Matin
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London WC1E 7HX, UK
| | - Seok Ryoul Jeong
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London WC1E 7HX, UK
| | - Monique Stins
- Pediatric Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Naveed Ahmed Khan
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London WC1E 7HX, UK
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Affiliation(s)
- Sutherland K Maciver
- Centre for Integrative Physiology, School of Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
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Matin A, Jeong SR, Faull J, Rivas AO, Khan NA. Evaluation of prokaryotic and eukaryotic cells as food source for Balamuthia mandrillaris. Arch Microbiol 2006; 186:261-71. [PMID: 16847651 DOI: 10.1007/s00203-006-0142-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Revised: 06/07/2006] [Accepted: 06/13/2006] [Indexed: 10/24/2022]
Abstract
Balamuthia mandrillaris is a recently identified free-living protozoan pathogen that can cause fatal granulomatous encephalitis in humans. Recent studies have shown that B. mandrillaris consumes eukaryotic cells such as mammalian cell cultures as food source. Here, we studied B. mandrillaris interactions with various eukaryotic cells including, monkey kidney fibroblast-like cells (COS-7), human brain microvascular endothelial cells (HBMEC) and Acanthamoeba (an opportunistic protozoan pathogen) as well as prokaryotes, Escherichia coli. B. mandrillaris exhibited optimal growth on HBMEC compared with Cos-7 cells. In contrast, B. mandrillaris did not grow on bacteria but remained in the trophozoite stage. When incubated with Acanthamoeba trophozoites, B. mandrillaris produced partial Acanthamoeba damage and the remaining Acanthamoeba trophozoites underwent encystment. However, B. mandrillaris were unable to consume Acanthamoeba cysts. Next, we observed that B. mandrillaris-mediated Acanthamoeba encystment is a contact-dependent process that requires viable B. mandrillaris. In support, conditioned medium of B. mandrillaris did not stimulate Acanthamoeba encystment nor did lysates of B. mandrillaris. Overall, these studies suggest that B. mandrillaris target Acanthamoeba in the trophozoite stage; however, Acanthamoeba possess the ability to defend themselves by forming cysts, which are resistant to B. mandrillaris. Further studies will examine the mechanisms associated with food selectivity in B. mandrillaris.
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Affiliation(s)
- Abdul Matin
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London, WC1E 7HX, UK
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