1
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Borkens Y. The Pathology of the Brain Eating Amoeba Naegleria fowleri. Indian J Microbiol 2024; 64:1384-1394. [PMID: 39282207 PMCID: PMC11399382 DOI: 10.1007/s12088-024-01218-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 02/02/2024] [Indexed: 09/18/2024] Open
Abstract
The genus Naegleria is a taxonomic subfamily consisting of 47 free-living amoebae. The genus can be found in warm aqueous or soil habitats worldwide. The species Naegleria fowleri is probably the best-known species of this genus. As a facultative parasite, the protist is not dependent on hosts to complete its life cycle. However, it can infect humans by entering the nose during water contact, such as swimming, and travel along the olfactory nerve to the brain. There it causes a purulent meningitis (primary amoebic meningoencephalitis or PAME). Symptoms are severe and death usually occurs within the first week. PAME is a frightening infectious disease for which there is neither a proven cure nor a vaccine. In order to contain the disease and give patients any chance to survival, action must be taken quickly. A rapid diagnosis is therefore crucial. PAME is diagnosed by the detection of amoebae in the liquor and later in the cerebrospinal fluid. For this purpose, CSF samples are cultured and stained and finally examined microscopically. Molecular techniques such as PCR or ELISA support the microscopic analysis and secure the diagnosis.
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Affiliation(s)
- Yannick Borkens
- Institut für Pathologie, Charité Campus Mitte, Virchowweg 15, Charité, 10117 Berlin, Germany
- Humboldt-Universität zu Berlin, Unter den Linden 6, 10117 Berlin, Germany
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2
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Wang L, Mai Y, Li S, Shu L, Fang J. Efficient inactivation of amoeba spores and their intraspore bacteria by solar/chlorine: Kinetics and mechanisms. WATER RESEARCH 2023; 242:120288. [PMID: 37419027 DOI: 10.1016/j.watres.2023.120288] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/21/2023] [Accepted: 06/28/2023] [Indexed: 07/09/2023]
Abstract
Amoebae are widespread in water and serve as environment vectors for pathogens, which may threaten public health. This study evaluated the inactivation of amoeba spores and their intraspore bacteria by solar/chlorine. Dictyostelium discoideum and Burkholderia agricolaris B1qs70 were selected as model amoebae and intraspore bacteria, respectively. Compared to solar irradiation and chlorine, solar/chlorine enhanced the inactivation of amoeba spores and intraspore bacteria, with 5.1 and 5.2-log reduction at 20 min, respectively. The enhancement was similar in real drinking water by solar/chlorine under natural sunlight. However, the spore inactivation decreased to 2.97-log by 20 min solar/chlorine under oxygen-free condition, indicating that ozone played a crucial role in the spore inactivation, as also confirmed by the scavenging test using tert‑butanol to scavenge the ground-state atomic oxygen (O(3P)) as a ozone precursor. Moreover, solar/chlorine induced the shape destruction and structural collapse of amoeba spores by scanning electron microscopy. As for intraspore bacteria, their inactivation was likely ascribed to endogenous reactive oxygen species. As pH increased from 5.0 to 9.0, the inactivation of amoeba spores decreased, whereas that of intraspore bacteria was similar at pH 5.0 and 6.5 during solar/chlorine treatment. This study first reports the efficient inactivation of amoeba spores and their intraspore pathogenic bacteria by solar/chlorine in drinking water.
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Affiliation(s)
- Liping Wang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China
| | - Yingwen Mai
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China
| | - Shenzhou Li
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China
| | - Longfei Shu
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China.
| | - Jingyun Fang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275 China.
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3
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Padua MFFE, Masangkay FR, Alejandro GJD, Milanez GDJ. Detection of Acanthamoeba spp. in groundwater sources in a rural area in the Philippines. JOURNAL OF WATER AND HEALTH 2023; 21:138-146. [PMID: 36705503 DOI: 10.2166/wh.2023.258] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Research on free-living amoebae (FLA) and its public health implication as an etiologic agent of parasitic infection in humans has recently gained traction in the Philippines. This study aimed to identify potential FLAs in collected groundwater samples from Masinloc, Zambales, Philippines. Fifty-four (54) water samples were collected in 250-mL sterile polyethylene containers by purposive sampling from selected groundwater sources in six (6) barangays of Masinloc. The samples were vacuum filtered through a 1.2-μm pore glass microfiber filter, cultured onto non-nutrient agar (NNA) lawned with Escherichia coli, and observed microscopically for amoebic growth for 14 days using light microscopy. Amoebic growth was observed in 11.1% (6/54) of water samples. DNAs from positive samples were extracted and were made to react with polymerase chain reaction using Acanthamoeba-specific JDP1 (5'-GGCCCAGATCGTTTACCGTGAA-3') and JDP2 (5'-TCTCACAAGCTGCTAGGGAGTCA-3') primers, and universal primer Euk A (5'-AACCTGGTTGATCCTGCCAGT-3') and Euk B (5'-TGATCCTTCTGCAGGTTCACCTAC-3'). The presence of Acanthamoeba genotypes T4, T7, and T11 was confirmed using molecular and phylogenetic analysis. Our results confirmed that groundwater sources from two of six sampling sites (33.3%) in Masinloc, Zambales, were contaminated with potentially pathogenic FLAs. Proper identification of risk factors that may cause contamination consequently leads to the implementation of programs that will prevent future infections.
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Affiliation(s)
- Mark F F E Padua
- The Graduate School, University of Santo Tomas, Manila 1015, Philippines; Department of Medical Technology, Far Eastern University, Manila 1008, Philippines
| | - Frederick Ramirez Masangkay
- Department of Medical Technology, Faculty of Pharmacy, University of Santo Tomas, Manila 1015, Philippines E-mail:
| | | | - Giovanni De Jesus Milanez
- Department of Medical Technology, Faculty of Pharmacy, University of Santo Tomas, Manila 1015, Philippines E-mail:
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Salazar-Ardiles C, Asserella-Rebollo L, Andrade DC. Free-Living Amoebas in Extreme Environments: The True Survival in our Planet. BIOMED RESEARCH INTERNATIONAL 2022; 2022:2359883. [PMID: 36303587 PMCID: PMC9596261 DOI: 10.1155/2022/2359883] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/08/2022] [Indexed: 12/03/2022]
Abstract
Free-living amoebas (FLAs) are microorganisms, unicellular protozoa widely distributed in nature and present in different environments, such as water or soil; they are maintained in ecosystems and play a fundamental role in the biological control of bacteria, other protozoa, and mushrooms. In particular circumstances, some can reach humans or animals, promoting several health complications. Notably, FLAs are characterized by a robust capacity to survive in extreme environments. However, currently, there is no updated information on the existence and distribution of this protozoan in inhospitable places. Undoubtedly, the cellular physiology of these protozoan microorganisms is very particular. They can resist and live in extreme environments due to their encysting capacity and tolerance to different osmolarities, temperatures, and other environmental factors, which give them excellent adaptative resistance. In this review, we summarized the most relevant evidence related to FLAs and the possible mechanism, which could explain their adaptative capacity to several extreme environments.
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Affiliation(s)
- Camila Salazar-Ardiles
- Research Center in High Altitude Medicine and Physiology, Biomedical Department, Faculty of Health Science, University of Antofagasta, Antofagasta, Chile
| | | | - David C. Andrade
- Research Center in High Altitude Medicine and Physiology, Biomedical Department, Faculty of Health Science, University of Antofagasta, Antofagasta, Chile
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Jin C, Mo Y, Zhao L, Xiao Z, Zhu S, He Z, Chen Z, Zhang M, Shu L, Qiu R. Host-Endosymbiont Relationship Impacts the Retention of Bacteria-Containing Amoeba Spores in Porous Media. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:12347-12357. [PMID: 35916900 DOI: 10.1021/acs.est.2c02899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Amoebae are protists that are commonly found in water, soil, and other habitats around the world and have complex interactions with other microorganisms. In this work, we investigated how host-endosymbiont interactions between amoebae and bacteria impacted the retention behavior of amoeba spores in porous media. A model amoeba species, Dictyostelium discoideum, and a representative bacterium, Burkholderia agricolaris B1qs70, were used to prepare amoeba spores that carried bacteria. After interacting with B. agricolaris, the retention of D. discoideum spores was enhanced compared to noninfected spores. Diverse proteins, especially proteins contributing to the looser exosporium structure and cell adhesion functionality, are secreted in higher quantities on the exosporium surface of infected spores compared to that of noninfected ones. Comprehensive examinations using a quartz crystal microbalance with dissipation (QCM-D), a parallel plate chamber, and a single-cell force microscope present coherent evidence that changes in the exosporium of D. discoideum spores due to infection by B. agricolaris enhance the connections between spores in the suspension and the spores that were previously deposited on the collector surface, thus resulting in more retention compared to the uninfected ones in porous media. This work provides novel insight into the retention of amoeba spores after bacterial infection in porous media and suggests that the host-endosymbiont relationship regulates the fate of biocolloids in drinking water systems, groundwater, and other porous environments.
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Affiliation(s)
- Chao Jin
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Yijun Mo
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Lingan Zhao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Zihan Xiao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Shishu Zhu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Zhenzhen He
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Zijian Chen
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Miaoyue Zhang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Longfei Shu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510006, P. R. China
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510006, P. R. China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, P. R. China
- Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, P. R. China
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6
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Aykur M, Dagci H. Evaluation of molecular characterization and phylogeny for quantification of Acanthamoeba and Naegleria fowleri in various water sources, Turkey. PLoS One 2021; 16:e0256659. [PMID: 34437614 PMCID: PMC8389491 DOI: 10.1371/journal.pone.0256659] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/11/2021] [Indexed: 01/02/2023] Open
Abstract
Free-living amoeba (FLA) is widely distributed in the natural environment. Since these amoebae are widely found in various waters, they pose an important public health problem. The aim of this study was to detect the presence of Acanthamoeba, B. mandrillaris, and N. fowleri in various water resources by qPCR in Izmir, Turkey. A total of (n = 27) 18.24% Acanthamoeba and (n = 4) 2.7% N. fowleri positives were detected in six different water sources using qPCR with ITS regions (ITS1) specific primers. The resulting concentrations varied in various water samples for Acanthamoeba in the range of 3.2x105-1.4x102 plasmid copies/l and for N. fowleri in the range of 8x103-11x102 plasmid copies/l. The highest concentration of Acanthamoeba and N. fowleri was found in seawater and damp samples respectively. All 27 Acanthamoeba isolates were identified in genotype level based on the 18S rRNA gene as T4 (51.85%), T5 (22.22%), T2 (14.81%) and T15 (11.11%). The four positive N. fowleri isolate was confirmed by sequencing the ITS1, ITS2 and 5.8S rRNA regions using specific primers. Four N. fowleri isolates were genotyped (three isolate as type 2 and one isolate as type 5) and detected for the first time from water sources in Turkey. Acanthamoeba and N. fowleri genotypes found in many natural environments are straightly related to human populations to have pathogenic potentials that may pose a risk to human health. Public health professionals should raise awareness on this issue, and public awareness education should be provided by the assistance of civil authorities. To the best of our knowledge, this is the first study on the quantitative detection and distribution of Acanthamoeba and N. fowleri genotypes in various water sources in Turkey.
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Affiliation(s)
- Mehmet Aykur
- Department of Parasitology, Faculty of Medicine, Tokat Gaziosmanpasa University Tokat, Tokat, Turkey
- Department of Parasitology, Faculty of Medicine, Ege University, Bornova, İzmir, Turkey
- * E-mail:
| | - Hande Dagci
- Department of Parasitology, Faculty of Medicine, Ege University, Bornova, İzmir, Turkey
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Jin C, Zhao L, Zhao W, Wang L, Zhu S, Xiao Z, Mo Y, Zhang M, Shu L, Qiu R. Transport and Retention of Free-Living Amoeba Spores in Porous Media: Effects of Operational Parameters and Extracellular Polymeric Substances. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8709-8720. [PMID: 34138552 DOI: 10.1021/acs.est.1c00785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Amoebas are protists that are widespread in water and soil environments. Some species are pathogenic, inducing potentially lethal effects on humans, making them a major threat to public health. Nonpathogenic amoebas are also of concern because they have the potential to carry a mini-microbiome of bacteria, either transiently or via more long-term stable transport. Due to their resistance to disinfection processes, the physical removal of amoeba by filtration is necessary to prevent their propagation throughout drinking water distribution networks and occurrence in tap water. In this study, a model amoeba species Dictyostelium discoideum was used to study the transport and retention behavior of amoeba spores in porous media. The key factors affecting the transport behavior of amoeba spores in fully saturated media were comprehensively evaluated, with experiments performed using a quartz crystal microbalance with dissipation monitoring (QCM-D) and parallel plate chamber system. The effects of ionic strength (IS) on the deposition of spores were found to be in contrast to the predicted Derjaguin-Landau-Verwey-Overbeek (DLVO) theory that more deposition is observed under lower-IS conditions. The presence of extracellular polymeric substances (EPS) was found to be the main contributor to deposition behavior. Overall, these results provide plausible evidence for the presence of amoeba in tap water. Furthermore, this is one of the first studies to examine the mechanisms affecting the fate of amoeba spores in porous media, providing a significant baseline for future research to minimize the safety risk presented by amoeba in drinking water systems.
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Affiliation(s)
- Chao Jin
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Lingan Zhao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Weigao Zhao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Department of Environmental Engineering, Tianjin University, Tianjin 300072, China
| | - Luting Wang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Shishu Zhu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zihan Xiao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yijun Mo
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Miaoyue Zhang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
| | - Longfei Shu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
- Environmental Microbiomics Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-Sen University, Guangzhou 510275, China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
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Siddiqui R, Makhlouf Z, Khan NA. The Increasing Importance of Vermamoeba vermiformis. J Eukaryot Microbiol 2021; 68:e12857. [PMID: 33987951 DOI: 10.1111/jeu.12857] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Vermamoeba vermiformis are one of the most prevalent free-living amoebae. These amoebae are ubiquitous and also thermotolerant. Of concern, V. vermiformis have been found in hospital water networks. Furthermore, associations between V. vermiformis and pathogenic bacteria have been reported, such as Legionella pneumophila. Moreover, V. vermiformis are well known to host viruses, bacteria, and other microorganisms and cases of keratitis due to V. vermiformis in conjunction with other amoebae have been reported. Despite the preceding, the medical importance of V. vermiformis is still an ongoing discussion and its genome has been only recently sequenced. Herein, we present a review of the current understanding of the biology and pathogenesis pertaining to V. vermiformis, as well as its' role as an etiological agent and trojan horse. An approach known as theranostics which combines both diagnosis and therapy could be utilized to eradicate and diagnose keratitis cases caused by such amoebae. Given the rise in global warming, it is imperative to investigate these rarely studied amoebae and to understand their importance in human health.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, Sharjah, UAE
| | - Zinb Makhlouf
- College of Arts and Sciences, American University of Sharjah, Sharjah, UAE
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, UAE.,Research Institute for Medical and Health Sciences, University of Sharjah, Sharjah, UAE
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Li Q, Yu S, Yang S, Yang W, Que S, Li W, Qin Y, Yu W, Jiang H, Zhao D. Eukaryotic community diversity and pathogenic eukaryotes in a full-scale drinking water treatment plant determined by 18S rRNA and metagenomic sequencing. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:17417-17430. [PMID: 33394404 DOI: 10.1007/s11356-020-12079-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
In this study, 18S rRNA high-throughput sequencing was applied to investigate the eukaryotic community in a full-scale drinking water treatment plant. Eukaryotic species and microbial functions in raw water and filter biofilms were identified by metagenomic sequencing. The eukaryotic species richness and diversity presented declining trends throughout the treatment process. The lowest eukaryotic species richness was observed in disinfected water. Arthropoda, Ciliophora, Ochrophyta, and Rotifera were the dominant eukaryotic phyla and exhibited high variations in relative abundance among the different treatment units. Sedimentation significantly decreased the abundance of all eukaryotes except Arthropoda. Biological activated carbon (BAC) filtration and chlorine disinfection exerted strong effects on community composition. The eukaryotic communities in water were distinct from those in filter biofilms, as were the communities of different filter biofilms from each other. In contrast, communities were functionally similar among different filter biofilms, with the category metabolism being the dominant category represented, within which amino acid transport and metabolism (E) and energy production and conversion (C) dominated among subcategories. Seventy-one eukaryotic species pathogenic to humans were identified in raw water and filter biofilms. Quantitative PCR (qPCR) results showed that Acanthamoeba spp. and Vermamoeba vermiformis were present during some treatment processes, with concentrations of 12-1.2 × 105 copies/mL and 1 copy/mL, respectively. Neither of the two pathogenic amoebae was found in disinfected water. Canonical correspondence analysis (CCA) showed that pH was the most important environmental factor affecting eukaryotic community composition. Overall, the results provide insights into the eukaryotic community diversity in drinking water treatment plants and the potential eukaryotic hazards involved in drinking water production.
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Affiliation(s)
- Qi Li
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China.
| | - Shuili Yu
- College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
| | - Shengfa Yang
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Wei Yang
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Sisi Que
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Wenjie Li
- National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Yu Qin
- Engineering Laboratory of Environmental & Hydraulic Engineering, Chongqing Municipal Development and Reform Commission, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Weiwei Yu
- Engineering Laboratory of Environmental & Hydraulic Engineering, Chongqing Municipal Development and Reform Commission, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Hui Jiang
- Engineering Laboratory of Environmental & Hydraulic Engineering, Chongqing Municipal Development and Reform Commission, Chongqing Jiaotong University, Chongqing, 400074, China
| | - Deqiang Zhao
- Engineering Laboratory of Environmental & Hydraulic Engineering, Chongqing Municipal Development and Reform Commission, Chongqing Jiaotong University, Chongqing, 400074, China
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Dušeková A, Garajová M, Lukáč M, Mrva M. Derivatisation of metronidazole enhances cytotoxic effect against Acanthamoeba genotype T4 isolates and leads to cytomorphological changes in trophozoites. Acta Trop 2021; 216:105830. [PMID: 33465352 DOI: 10.1016/j.actatropica.2021.105830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 11/25/2022]
Abstract
Amoebae of the genus Acanthamoeba are worldwide distributed causative agents of serious human infections such as granulomatous amoebic encephalitis (GAE) and Acanthamoeba keratitis (AK). To date, treatment of these infections is non-uniform and frequently unsuccessful. Recently, the phosphonium salts were studied for their high levels of antimicrobial activity. This work was aimed to investigate the cytotoxic effect of metronidazole and two phosphonium salts (PS1, PS2) on two clinical Acanthamoeba isolates. The isolates showed distinctly higher susceptibility to both phosphonium salts than to metronidazole. The highest susceptibility was noted to PS1 after 48 h of incubation. Metronidazole derivate PS2 showed higher susceptibility than metronidazole. The values of EC50 of PS2 were approximately twenty times lower than EC50 of metronidazole for Acanthamoeba lugdunensis strain and sixteen times lower for Acanthamoeba quina strain after 48 h. Although the therapeutic effect of metronidazole in Acanthamoeba infections is usually insufficient, its derivatisation can result in a significantly higher amoebicidal effect. Cytomorphological changes of trophozoites after exposure to tested compounds included rounding up of the cells, damage of membrane integrity, presence of pathological protrusions, elongation of the cells or pseudocyst-like stages. Obtained results indicate possible therapeutic potential of studied phosphonium salts.
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Wu J, Xie H. Orthokeratology lens-related Acanthamoeba keratitis: case report and analytical review. J Int Med Res 2021; 49:3000605211000985. [PMID: 33752507 PMCID: PMC7995463 DOI: 10.1177/03000605211000985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 02/16/2021] [Indexed: 11/17/2022] Open
Abstract
Acanthamoeba keratitis (AK) is a rare but severe ocular infection with a significant risk of vision loss. Contact lens use is the main risk factor for AK. The orthokeratology (OK) lens, a specially designed contact lens, has been used worldwide as an effective method of myopia control. However, the OK lens is associated with an increased risk of Acanthamoeba infection. Many primary practitioners are concerned about this infection because of its relative rarity, the lack of promising therapeutic medications, and the need for referral. We herein report two cases of AK associated with OK lenses, present a systematic review of such cases, and discuss the possible reasons for the higher incidence rate of this infection in patients who wear OK lenses. We combined the clinical knowledge and skills of corneal specialists and lens experts with the sole objective of addressing these OK lens-related AK cases. We found that the most common risk factors were rinsing the lenses or lens cases with tap water. Prompt and accurate diagnosis along with adequate amoebicidal treatment are essential to ensure desirable outcomes for OK lens wearers who develop AK. Appropriate OK lens parameters and regular checkups are also important.
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Affiliation(s)
- Jinfang Wu
- Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, China
| | - Huatao Xie
- Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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“Feast-Fit-Fist-Feat”: Overview of Free-living Amoeba Interactions with Fungi and Virulence as a Foundation for Success in Battle. CURRENT TROPICAL MEDICINE REPORTS 2021. [DOI: 10.1007/s40475-020-00220-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Üstüntürk-Onan M. Isolation and identification of free-living amoebae isolated from well water in Istanbul. JOURNAL OF WATER AND HEALTH 2020; 18:1139-1145. [PMID: 33328382 DOI: 10.2166/wh.2020.255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Free-living amoebae (FLA) are ubiquitous protozoa commonly found in water and soil environments. FLA belonging to various genera, including Acanthamoeba, Balamuthia, Naegleria, and Vermamoeba, can cause opportunistic and non-opportunistic infections in humans and animals such as keratitis or meningoencephalitis. In addition, some of them serve as hosts for a large number of pathogenic bacteria, yeasts, and viruses. The purpose of the present study was to assess the prevalence and molecular characterization of FLA in well water samples in İstanbul. Ten well water samples were collected from the taps and the presence of FLA was monitored both by the culture and polymerase chain reaction methods. FLA were isolated in 8 out of the 10 samples (80%) included in this study. Morphological analysis and partial sequencing of the 18S rDNA revealed the presence of Acanthamoeba genotypes T3 and T4, and Vermamoeba vermiformis in the investigated well water samples. This study reports for the first time the detection of Acanthamoeba genotype T3 in well water samples in İstanbul. The presence of potentially pathogenic amoebae in habitats related to human activities supports the relevance of FLA as a potential public health concern.
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Affiliation(s)
- Miray Üstüntürk-Onan
- Faculty of Science, Department of Biology, Fundamental and Industrial Microbiology Division, Istanbul University, 34134 Vezneciler-Istanbul, Turkey E-mail:
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Isolation and Phylogenetic Analysis of Free-Living Amoebae (Acanthamoeba, Naegleria, and Vermamoeba) in the Farmland Soils and Recreational Places in Iran. Acta Parasitol 2020; 65:36-43. [PMID: 31571139 DOI: 10.2478/s11686-019-00126-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 09/17/2019] [Indexed: 11/20/2022]
Abstract
PURPOSE Free-living amoeba (FLA) including Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria are among the soil-born parasites. There are reports of FLA-related keratitis with a history of contact with soil and dust sources, particularly among the farmers. Due to lack of the previous studies on the farmland soils and a limited number of researches conducted on recreational soils in Iran, the present study was conducted. METHODS A total of 93 soil samples including farming lands and recreational places were tested for the presence of Acanthamoeba spp. Balamuthia mandrillaris, Naegleria, and Vermamoeba using morphological key and sequencing-based tools. Pathogenicity of Acanthamoeba positive strains was also evaluated. To verify genetic associations and taxonomic status of isolated amoeba, a phylogenetic tree was built by MEGA 5.05 software inferred by the 18S rRNA gene based on maximum likelihood algorithm. RESULTS Overall, 28 samples (30%) were contaminated with potentially pathogenic FLA, and according to the sequencing data, 17 strains were successfully sequenced. The isolated Acanthamoeba belonged to T2, T4, T5, mixed T4 and T5 contaminations, and T11. ITS sequencing revealed the occurrence of one strain of Naegleria canariensis. Four strains of Vermamoeba vermiformis were also confirmed. Morphological survey and PCR assay failed to show any positive results for Balamuthia mandrillaris. Pathogenic potential of the Acanthamoeba strains showed that T2, T4, and T11 genotypes were highly pathogenic, whereas T5 genotypes demonstrated lower pathogenic potential. CONCLUSION The results indicate that soil could be a serious hazard to human health, and therefore, further studies are expected to investigate the source of infection in patients developing FLA-related diseases. The present study is the first to investigate FLA in the farmland soils in Iran and the first to report the presence of N. canariensis in the country.
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Orosz E, Posta K. Genotyping of Acantamoeba spp. from rhisophere in Hungary. Acta Microbiol Immunol Hung 2019; 67:171-175. [PMID: 31833382 DOI: 10.1556/030.66.2019.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 10/14/2019] [Indexed: 11/19/2022]
Abstract
The protista Acanthamoeba is a free-living amoeba existing in various environments. A number of species among protista are recognized as human pathogens, potentially causing Acanthamoeba keratitis (AK), granulomatous amoebic encephalitis (GAE), and chronic granulomatous lesions. In this study, 10 rhizosphere samples were collected from maize and alfalfa plants in experimental station at Institute of Genetics, Microbiology and Biotechnology, Szent István University. We detected Acanthamoeba based on the quantitative real-time PCR assay and sequence analysis of the 18S rRNA gene. All studied molecular biological methods are suitable for the detection of Acanthamoeba infection in humans. The quantitative real-time PCR-based methods are more sensitive, simple, and easy to perform; moreover, these are opening avenue to detect the effect of number of parasites on human disease. Acanthamoeba species were detected in five (5/10; 50%) samples. All Acanthamoeba strains belonged to T4 genotype, the main AK-related genotype worldwide. Our result confirmed Acanthamoeba strains in rhizosphere that should be considered as a potential health risk associated with human activities in the environment.
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Affiliation(s)
- Erika Orosz
- 1 Department of Parasitology, National Public Health Center, Budapest, Hungary
| | - Katalin Posta
- 2 Institute of Genetics, Microbiology and Biotechnology, Szent István University, Gödöllo, Hungary
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Valciņa O, Pūle D, Mališevs A, Trofimova J, Makarova S, Konvisers G, Bērziņš A, Krūmiņa A. Co-Occurrence of Free-Living Amoeba and Legionella in Drinking Water Supply Systems. MEDICINA-LITHUANIA 2019; 55:medicina55080492. [PMID: 31443316 PMCID: PMC6723719 DOI: 10.3390/medicina55080492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/07/2019] [Accepted: 08/12/2019] [Indexed: 12/15/2022]
Abstract
Background and Objectives:Legionella is one of the most important water-related pathogens. Inside the water supply systems and the biofilms, Legionella interact with other bacteria and free-living amoeba (FLA). Several amoebas may serve as hosts for bacteria in aquatic systems. This study aimed to investigate the co-occurrence of Legionella spp. and FLA in drinking water supply systems. Materials and Methods: A total of 268 water samples were collected from apartment buildings, hotels, and public buildings. Detection of Legionella spp. was performed in accordance with ISO 11731:2017 standard. Three different polymerase chain reaction (PCR) protocols were used to identify FLA. Results: Occurrence of Legionella varied from an average of 12.5% in cold water samples with the most frequent occurrence observed in hot water, in areas receiving untreated groundwater, where 54.0% of the samples were Legionella positive. The occurrence of FLA was significantly higher. On average, 77.2% of samples contained at least one genus of FLA and, depending on the type of sample, the occurrence of FLA could reach 95%. In the samples collected during the study, Legionella was always isolated along with FLA, no samples containing Legionella in the absence of FLA were observed. Conclusions: The data obtained in our study can help to focus on the extensive distribution, close interaction, and long-term persistence of Legionella and FLA. Lack of Legionella risk management plans and control procedures may promote further spread of Legionella in water supply systems. In addition, the high incidence of Legionella-related FLA suggests that traditional monitoring methods may not be sufficient for Legionella control.
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Affiliation(s)
- Olga Valciņa
- Institute of Food Safety, Animal Health and Environment "BIOR", LV-1076 Rīga, Latvia.
| | - Daina Pūle
- Institute of Food Safety, Animal Health and Environment "BIOR", LV-1076 Rīga, Latvia
- Department of Water Engineering and Technology, Riga Technical University, LV-1658 Rīga, Latvia
| | - Artjoms Mališevs
- Institute of Food Safety, Animal Health and Environment "BIOR", LV-1076 Rīga, Latvia
| | - Jūlija Trofimova
- Institute of Food Safety, Animal Health and Environment "BIOR", LV-1076 Rīga, Latvia
| | - Svetlana Makarova
- Institute of Food Safety, Animal Health and Environment "BIOR", LV-1076 Rīga, Latvia
| | - Genadijs Konvisers
- Institute of Food Safety, Animal Health and Environment "BIOR", LV-1076 Rīga, Latvia
| | - Aivars Bērziņš
- Institute of Food Safety, Animal Health and Environment "BIOR", LV-1076 Rīga, Latvia
| | - Angelika Krūmiņa
- Department of Infectology and Dermatology, Riga Stradiņš University, LV-1007 Rīga, Latvia
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