51
|
Fernández-Soto P, Sánchez-Hernández A, Gandasegui J, Bajo Santos C, López-Abán J, Saugar JM, Rodríguez E, Vicente B, Muro A. Strong-LAMP: A LAMP Assay for Strongyloides spp. Detection in Stool and Urine Samples. Towards the Diagnosis of Human Strongyloidiasis Starting from a Rodent Model. PLoS Negl Trop Dis 2016; 10:e0004836. [PMID: 27415764 PMCID: PMC4945066 DOI: 10.1371/journal.pntd.0004836] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 06/19/2016] [Indexed: 11/28/2022] Open
Abstract
Background Strongyloides stercoralis, the chief causative agent of human strongyloidiasis, is a nematode globally distributed but mainly endemic in tropical and subtropical regions. Chronic infection is often clinically asymptomatic but it can result in severe hyperinfection syndrome or disseminated strongyloidiasis in immunocompromised patients. There is a great diversity of techniques used in diagnosing the disease, but definitive diagnosis is accomplished by parasitological examination of stool samples for morphological identification of parasite. Until now, no molecular method has been tested in urine samples as an alternative to stool samples for diagnosing strongyloidiasis. This study aimed to evaluate the use of a new molecular LAMP assay in a well-established Wistar rat experimental infection model using both stool and, for the first time, urine samples. The LAMP assay was also clinically evaluated in patients´ stool samples. Methodology/Principal Findings Stool and urine samples were obtained daily during a 28-day period from rats infected subcutaneously with different infective third-stage larvae doses of S. venezuelensis. The dynamics of parasite infection was determined by daily counting the number of eggs per gram of feces from day 1 to 28 post-infection. A set of primers for LAMP assay based on a DNA partial sequence in the 18S rRNA gene from S. venezuelensis was designed. The set up LAMP assay (namely, Strong-LAMP) allowed the sensitive detection of S. venezuelensis DNA in both stool and urine samples obtained from each infection group of rats and was also effective in S. stercoralis DNA amplification in patients´ stool samples with previously confirmed strongyloidiasis by parasitological and real-time PCR tests. Conclusions/Significance Our Strong-LAMP assay is an useful molecular tool in research of a strongyloidiasis experimental infection model in both stool and urine samples. After further validation, the Strong-LAMP could also be potentially applied for effective diagnosis of strongyloidiasis in a clinical setting. Human strongyloidiasis, a soil-transmitted infection mainly caused by Strongyloides stercoralis, is one of the most neglected among the so-called neglected tropical diseases (NTDs). The difficult diagnosis lead to an underreporting of infection rates. Strongyloidiasis can easily be misdiagnosed because many infections remain asymptomatic and the lack of sensitivity of the conventional fecal-based techniques for morphologically identification of infective larvae in feces. Although serologic tests are useful, a limitation in standardization to avoid cross-reactions still remains. There is an urgent need to improve more sensitive and specific diagnostic tests, particularly in immunocompromised patients or candidates to immunosuppressive treatments. Several molecular approaches for Strongyloides spp. DNA detection have already been assayed, but they have a very limited use in routine diagnostic, particularly in endemic areas. In addition, all molecular approaches for Strongyloides spp. DNA detection have always been mainly assayed for stool samples and no other more advantageous biological samples, such as urine, have been investigated for molecular purposes. In this study we have developed, for the first time, a molecular assay using LAMP methodology as a simple, sensible and robust method for the detection of S. venezuelensis DNA in a well-established Wistar rats experimental infection in both stool and urine samples. The LAMP assay was also successfully evaluated in patients´ stool samples. Our LAMP assay (Strong-LAMP) is an useful molecular tool in a strongyloidiasis experimental infection model and could be a potential field-friendly diagnostic test in a clinical setting, following further validation.
Collapse
Affiliation(s)
- Pedro Fernández-Soto
- Unidad de Investigación Enfermedades Infecciosas y Tropicales (e-INTRO), Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (IBSAL-CIETUS), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - Alicia Sánchez-Hernández
- Unidad de Investigación Enfermedades Infecciosas y Tropicales (e-INTRO), Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (IBSAL-CIETUS), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - Javier Gandasegui
- Unidad de Investigación Enfermedades Infecciosas y Tropicales (e-INTRO), Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (IBSAL-CIETUS), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - Cristina Bajo Santos
- Unidad de Investigación Enfermedades Infecciosas y Tropicales (e-INTRO), Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (IBSAL-CIETUS), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - Julio López-Abán
- Unidad de Investigación Enfermedades Infecciosas y Tropicales (e-INTRO), Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (IBSAL-CIETUS), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - José María Saugar
- Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - Esperanza Rodríguez
- Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - Belén Vicente
- Unidad de Investigación Enfermedades Infecciosas y Tropicales (e-INTRO), Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (IBSAL-CIETUS), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - Antonio Muro
- Unidad de Investigación Enfermedades Infecciosas y Tropicales (e-INTRO), Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca (IBSAL-CIETUS), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| |
Collapse
|
52
|
Centeno-Cuadros A, Abbasi I, Nathan R. Sex determination in the wild: a field application of loop-mediated isothermal amplification successfully determines sex across three raptor species. Mol Ecol Resour 2016; 17:153-160. [PMID: 27235333 DOI: 10.1111/1755-0998.12540] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/12/2016] [Accepted: 05/06/2016] [Indexed: 11/26/2022]
Abstract
PCR-based methods are the most common technique for sex determination of birds. Although these methods are fast, easy and accurate, they still require special facilities that preclude their application outdoors. Consequently, there is a time lag between sampling and obtaining results that impedes researchers to take decisions in situ and in real time considering individuals' sex. We present an outdoor technique for sex determination of birds based on the amplification of the duplicated sex-chromosome-specific gene Chromo-Helicase-DNA binding protein using a loop-mediated isothermal amplification (LAMP). We tested our method on Griffon Vulture (Gyps fulvus), Egyptian Vulture (Neophron percnopterus) and Black Kite (Milvus migrans) (family Accipitridae). We introduce the first fieldwork procedure for sex determination of animals in the wild, successfully applied to raptor species of three different subfamilies using the same specific LAMP primers. This molecular technique can be deployed directly in sampling areas because it only needs a voltage inverter to adapt a thermo-block to a car lighter and results can be obtained by the unaided eye based on colour change within the reaction tubes. Primers and reagents are prepared in advance to facilitate their storage at room temperature. We provide detailed guidelines how to implement this procedure, which is simpler (no electrophoresis required), cheaper and faster (results in c. 90 min) than PCR-based laboratory methods. Our successful cross-species application across three different raptor subfamilies posits our set of markers as a promising tool for molecular sexing of other raptor families and our field protocol extensible to all bird species.
Collapse
Affiliation(s)
- A Centeno-Cuadros
- Movement Ecology Lab, Department of Ecology, Evolution and Behaviour, Faculty of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,Estación Biológica de Doñana (EBD-CSIC), Avda. Américo Vespucio, s/n, Isla de la Cartuja, Seville, 41092, Spain
| | - I Abbasi
- Kuvin Center, Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - R Nathan
- Movement Ecology Lab, Department of Ecology, Evolution and Behaviour, Faculty of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
53
|
Budziszewska M, Wieczorek P, Obrępalska-Stęplowska A. One-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) for detection of tomato torrado virus. Arch Virol 2016; 161:1359-64. [PMID: 26887971 PMCID: PMC4839060 DOI: 10.1007/s00705-016-2774-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/26/2016] [Indexed: 11/27/2022]
Abstract
'Torrado' disease caused by tomato torrado virus (ToTV) is responsible for considerable losses in tomato production. Therefore, a one-step reverse transcription loop-mediated isothermal amplification protocol for early and fast detection of ToTV isolates has been developed. The RNA extracted from ToTV-infected plants was tested using this protocol with a set of six primers specific for the Vp35 coat protein gene sequence. The amplified products were analyzed using amplification curves, electrophoresis, and direct staining of DNA. The sensitivity of the protocol was tenfold higher than that of conventional RT-PCR. This new protocol is inexpensive, rapid, simple, and very sensitive.
Collapse
Affiliation(s)
- Marta Budziszewska
- Interdepartmental Laboratory of Molecular Biology, Institute of Plant Protection-National Research Institute, Władysława Wegorka 20, 60-318, Poznan, Poland
| | - Przemysław Wieczorek
- Interdepartmental Laboratory of Molecular Biology, Institute of Plant Protection-National Research Institute, Władysława Wegorka 20, 60-318, Poznan, Poland
| | - Aleksandra Obrępalska-Stęplowska
- Interdepartmental Laboratory of Molecular Biology, Institute of Plant Protection-National Research Institute, Władysława Wegorka 20, 60-318, Poznan, Poland.
| |
Collapse
|
54
|
A protease-based biosensor for the detection of schistosome cercariae. Sci Rep 2016; 6:24725. [PMID: 27090566 PMCID: PMC4835807 DOI: 10.1038/srep24725] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 03/30/2016] [Indexed: 01/18/2023] Open
Abstract
Parasitic diseases affect millions of people worldwide, causing debilitating illnesses and death. Rapid and cost-effective approaches to detect parasites are needed, especially in resource-limited settings. A common signature of parasitic diseases is the release of specific proteases by the parasites at multiple stages during their life cycles. To this end, we engineered several modular Escherichia coli and Bacillus subtilis whole-cell-based biosensors which incorporate an interchangeable protease recognition motif into their designs. Herein, we describe how several of our engineered biosensors have been applied to detect the presence and activity of elastase, an enzyme released by the cercarial larvae stage of Schistosoma mansoni. Collectively, S. mansoni and several other schistosomes are responsible for the infection of an estimated 200 million people worldwide. Since our biosensors are maintained in lyophilised cells, they could be applied for the detection of S. mansoni and other parasites in settings without reliable cold chain access.
Collapse
|
55
|
He P, Song LG, Xie H, Liang JY, Yuan DY, Wu ZD, Lv ZY. Nucleic acid detection in the diagnosis and prevention of schistosomiasis. Infect Dis Poverty 2016; 5:25. [PMID: 27025210 PMCID: PMC4812660 DOI: 10.1186/s40249-016-0116-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 03/14/2016] [Indexed: 11/25/2022] Open
Abstract
Schistosomiasis is an important zoonotic parasitic disease that causes serious harms to humans and animals. Surveillance and diagnosis play key roles in schistosomiasis control, however, current techniques for surveillance and diagnosis of the disease have limitations. As genome data for parasites are increasing, novel techniques for detection incorporating nucleotide sequences are receiving widespread attention. These sensitive, specific, and rapid detection methods are particularly important in the diagnosis of low-grade and early infections, and may prove to have clinical significance. This paper reviews the progress of nucleic acid detection in the diagnosis and prevention of schistosomiasis, including such aspects as the selection of target genes, and development and application of nucleic acid detection methods.
Collapse
Affiliation(s)
- Ping He
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China.,Department of Pathogenic Biology, Medical School, Xizang Minzu University, Xianyang, 712082, China
| | - Lan-Gui Song
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China
| | - Hui Xie
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China
| | - Jin-Yi Liang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China
| | - Dong-Ya Yuan
- Department of Pathogenic Biology, Medical School, Xizang Minzu University, Xianyang, 712082, China
| | - Zhong-Dao Wu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China. .,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China.
| | - Zhi-Yue Lv
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China. .,Key Laboratory of Tropical Disease Control, Ministry of Education, Guangzhou, 510080, China.
| |
Collapse
|
56
|
Weerakoon KG, Gordon CA, Gobert GN, Cai P, McManus DP. Optimisation of a droplet digital PCR assay for the diagnosis of Schistosoma japonicum infection: A duplex approach with DNA binding dye chemistry. J Microbiol Methods 2016; 125:19-27. [PMID: 27021661 DOI: 10.1016/j.mimet.2016.03.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/03/2016] [Accepted: 03/21/2016] [Indexed: 11/19/2022]
Abstract
Schistosomiasis is a chronically debilitating helminth infection with a significant socio-economic and public health impact. Accurate diagnostics play a pivotal role in achieving current schistosomiasis control and elimination goals. However, many of the current diagnostic procedures, which rely on detection of schistosome eggs, have major limitations including lack of accuracy and the inability to detect pre-patent infections. DNA-based detection methods provide a viable alternative to the current tests commonly used for schistosomiasis diagnosis. Here we describe the optimisation of a novel droplet digital PCR (ddPCR) duplex assay for the diagnosis of Schistosoma japonicum infection which provides improved detection sensitivity and specificity. The assay involves the amplification of two specific and abundant target gene sequences in S. japonicum; a retrotransposon (SjR2) and a portion of a mitochondrial gene (nad1). The assay detected target sequences in different sources of schistosome DNA isolated from adult worms, schistosomules and eggs, and exhibits a high level of specificity, thereby representing an ideal tool for the detection of low levels of parasite DNA in different clinical samples including parasite cell free DNA in the host circulation and other bodily fluids. Moreover, being quantitative, the assay can be used to determine parasite infection intensity and, could provide an important tool for the detection of low intensity infections in low prevalence schistosomiasis-endemic areas.
Collapse
Affiliation(s)
- Kosala G Weerakoon
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia; School of Public Health, University of Queensland, Brisbane, Australia; Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka.
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Geoffrey N Gobert
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Pengfei Cai
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Donald P McManus
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| |
Collapse
|
57
|
Weerakoon KG, McManus DP. Cell-Free DNA as a Diagnostic Tool for Human Parasitic Infections. Trends Parasitol 2016; 32:378-391. [PMID: 26847654 DOI: 10.1016/j.pt.2016.01.006] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 12/28/2015] [Accepted: 01/11/2016] [Indexed: 12/18/2022]
Abstract
Parasites often cause devastating diseases and represent a significant public health and economic burden. More accurate and convenient diagnostic tools are needed in support of parasite control programmes in endemic regions, and for rapid point-of-care diagnosis in nonendemic areas. The detection of cell-free DNA (cfDNA) is a relatively new concept that is being applied in the current armamentarium of diagnostics. Here, we review the application of cfDNA detection with nucleic acid amplification tests for the diagnosis and evaluation of different human parasitic infections and highlight the significant benefits of the approach using non-invasive clinical samples.
Collapse
Affiliation(s)
- Kosala G Weerakoon
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia; School of Public Health, University of Queensland, Brisbane, QLD, Australia; Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka.
| | - Donald P McManus
- Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
| |
Collapse
|
58
|
Helminthosis and eosinophilia in Spain (1990-2015). Enferm Infecc Microbiol Clin 2016; 36:120-136. [PMID: 26827134 DOI: 10.1016/j.eimc.2015.11.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/29/2015] [Accepted: 11/30/2015] [Indexed: 12/16/2022]
Abstract
The finding of blood eosinophilia in a patient is a relatively frequent reason to refer him/her to a Clinical Department of Infectious Diseases. The doctor usually intends to rule out a parasitic disease in the autochthonous population, travelers or immigrants. It is uncommon for an eosinophilia to be produced by protozoa infection, whereas helminth parasites are more frequently associated with an increase of eosinophil counts in the infected patient. Eosinophilia can be the only abnormal finding, or it could be part of more complex clinical manifestations suffered by the patient. Furthermore, many, but not all, helminth infections are associated with eosinophilia, and the eosinophil level (low, high) differs according to parasite stages, helminth species, and worm co-infections. The purpose of the present article is to carry out a systematic review of cases and case series on helminth infections and eosinophilia reported in Spain from 1990 to 2015, making a distinction between autochthonous and imported (immigrants and travelers) cases, and studying their relationship with immunodepression situations.
Collapse
|
59
|
Song J, Liu C, Bais S, Mauk MG, Bau HH, Greenberg RM. Molecular Detection of Schistosome Infections with a Disposable Microfluidic Cassette. PLoS Negl Trop Dis 2015; 9:e0004318. [PMID: 26720725 PMCID: PMC4700990 DOI: 10.1371/journal.pntd.0004318] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 12/01/2015] [Indexed: 12/23/2022] Open
Abstract
Parasitic helminths such as schistosomes, as well as filarial and soil-transmitted nematodes, are estimated to infect at least a billion people worldwide, with devastating impacts on human health and economic development. Diagnosis and monitoring of infection dynamics and efficacy of treatment depend almost entirely on methods that are inaccurate, labor-intensive, and unreliable. These shortcomings are amplified and take on added significance in mass drug administration programs, where measures of effectiveness depend on accurate monitoring of treatment success (or failure), changes in disease transmission rates, and emergence of possible drug resistance. Here, we adapt isothermal molecular assays such as loop-mediated isothermal amplification (LAMP) to a simple, hand-held, custom-made field-ready microfluidic device that allows sensitive and specific detection of schistosome cell-free nucleic acids in serum and plasma (separated with a point-of-care plasma separator) from Schistosoma mansoni-infected mice. Cell-free S. mansoni DNA was detected with our device without prior extraction from blood. Our chip exhibits high sensitivity (~2 x 10(-17) g/μL), with a positive signal for S. mansoni DNA detectable as early as one week post infection, several weeks before parasite egg production commences. These results indicate that incorporation of isothermal amplification strategies with our chips could represent a strategy for rapid, simple, low-cost diagnosis of both pre-patent and chronic schistosome infections as well as potential monitoring of treatment efficacy.
Collapse
Affiliation(s)
- Jinzhao Song
- Department of Mechanical Engineering and Applied Mechanics, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Changchun Liu
- Department of Mechanical Engineering and Applied Mechanics, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Swarna Bais
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Michael G. Mauk
- Department of Mechanical Engineering and Applied Mechanics, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Haim H. Bau
- Department of Mechanical Engineering and Applied Mechanics, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Robert M. Greenberg
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
60
|
Abstract
Schistosomiasis is a major neglected tropical disease that afflicts more than 240 million people, including many children and young adults, in the tropics and subtropics. The disease is characterized by chronic infections with significant residual morbidity and is of considerable public health importance, with substantial socioeconomic impacts on impoverished communities. Morbidity reduction and eventual elimination through integrated intervention measures are the focuses of current schistosomiasis control programs. Precise diagnosis of schistosome infections, in both mammalian and snail intermediate hosts, will play a pivotal role in achieving these goals. Nevertheless, despite extensive efforts over several decades, the search for sensitive and specific diagnostics for schistosomiasis is ongoing. Here we review the area, paying attention to earlier approaches but emphasizing recent developments in the search for new diagnostics for schistosomiasis with practical applications in the research laboratory, the clinic, and the field. Careful and rigorous validation of these assays and their cost-effectiveness will be needed, however, prior to their adoption in support of policy decisions for national public health programs aimed at the control and elimination of schistosomiasis.
Collapse
|
61
|
Zhao X, He X, Li H, Zhao J, Huang S, Liu W, Wei X, Ding Y, Wang Z, Zou D, Wang X, Dong D, Yang Z, Yan X, Huang L, Du S, Yuan J. Detection of Streptococcus pyogenes using rapid visual molecular assay. FEMS Microbiol Lett 2015; 362:fnv148. [PMID: 26319025 DOI: 10.1093/femsle/fnv148] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2015] [Indexed: 11/14/2022] Open
Abstract
Streptococcus pyogenes is an increasingly important pathogen in many parts of the world. Rapid and accurate detection of S. pyogenes aids in the control of the infection. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed and validated for the specific detection of S. pyogenes. The assay incorporates two methods: a chromogenic analysis using a calcein/Mn(2+) complex and real-time turbidity monitoring to assess the reaction. Both methods detected the target DNA within 60 min under 64°C isothermal conditions. The assay used specifically designed primers to target spy1258, and correctly identified 111 strains of S. pyogenes and 32 non-S. pyogenes strains, including other species of the genus Streptococcus. Tests using reference strains showed that the LAMP assay was highly specific. The sensitivity of the assay, with a detection limit of 1.49 pg DNA, was 10-fold greater than that of PCR. The LAMP assay established in this study is simple, fast and sensitive, and does not rely upon any special equipment; thus, it could be employed in clinical diagnosis.
Collapse
Affiliation(s)
- Xiangna Zhao
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Xiaoming He
- College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China
| | - Huan Li
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Jiangtao Zhao
- Emergency Center, the Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Simo Huang
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Wei Liu
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Xiao Wei
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Yiwei Ding
- Clinical Laboratory, Navy general hospital, Beijing 100048, China
| | - Zhaoyan Wang
- Department of Pediatrics, Navy general hospital, Beijing 100048, China
| | - Dayang Zou
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Xuesong Wang
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Derong Dong
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Zhan Yang
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Xiabei Yan
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Liuyu Huang
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| | - Shuangkui Du
- College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China
| | - Jing Yuan
- Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing 100071, China
| |
Collapse
|
62
|
Gandasegui J, Fernández-Soto P, Carranza-Rodríguez C, Pérez-Arellano JL, Vicente B, López-Abán J, Muro A. The Rapid-Heat LAMPellet Method: A Potential Diagnostic Method for Human Urogenital Schistosomiasis. PLoS Negl Trop Dis 2015; 9:e0003963. [PMID: 26230990 PMCID: PMC4521856 DOI: 10.1371/journal.pntd.0003963] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 07/07/2015] [Indexed: 12/25/2022] Open
Abstract
Background Urogenital schistosomiasis due to Schistosoma haematobium is a serious underestimated public health problem affecting 112 million people - particularly in sub-Saharan Africa. Microscopic examination of urine samples to detect parasite eggs still remains as definitive diagnosis. This work was focussed on developing a novel loop-mediated isothermal amplification (LAMP) assay for detection of S. haematobium DNA in human urine samples as a high-throughput, simple, accurate and affordable diagnostic tool to use in diagnosis of urogenital schistosomiasis. Methodology/Principal Findings A LAMP assay targeting a species specific sequence of S. haematobium ribosomal intergenic spacer was designed. The effectiveness of our LAMP was assessed in a number of patients´ urine samples with microscopy confirmed S. haematobium infection. For potentially large-scale application in field conditions, different DNA extraction methods, including a commercial kit, a modified NaOH extraction method and a rapid heating method were tested using small volumes of urine fractions (whole urine, supernatants and pellets). The heating of pellets from clinical samples was the most efficient method to obtain good-quality DNA detectable by LAMP. The detection limit of our LAMP was 1 fg/µL of S. haematobium DNA in urine samples. When testing all patients´ urine samples included in our study, diagnostic parameters for sensitivity and specificity were calculated for LAMP assay, 100% sensitivity (95% CI: 81.32%-100%) and 86.67% specificity (95% CI: 75.40%-94.05%), and also for microscopy detection of eggs in urine samples, 69.23% sensitivity (95% CI: 48.21% -85.63%) and 100% specificity (95% CI: 93.08%-100%). Conclusions/Significance We have developed and evaluated, for the first time, a LAMP assay for detection of S. haematobium DNA in heated pellets from patients´ urine samples using no complicated requirement procedure for DNA extraction. The procedure has been named the Rapid-Heat LAMPellet method and has the potential to be developed further as a field diagnostic tool for use in urogenital schistosomiasis-endemic areas. Human schistosomiasis is a disease caused by several species of parasitic worms of the genus Schistosoma that is affecting 200 million people, especially in sub-Saharan Africa. Most people are infected with Schistosoma haematobium, the species that causes urogenital schistosomiasis and also bladder cancer in many chronic infections. The definitive diagnostic test is based on microscopic examination of urine samples to detect parasite eggs. This method has low sensitivity, high day-to-day variability and cannot be carried out in the acute phase of the disease since the parasite has not started yet to lay eggs. New high-throughput diagnostic tools would be desirable, permitting early treatment and preventing the pathology associated with chronic infections. An interesting approach is the loop-mediated isothermal amplification (LAMP) technique because of its simplicity in operation and potential use in clinical diagnosis and surveillance of infectious diseases. In this study, we developed and evaluated a LAMP assay for detection of S. haematobium DNA in patients´ urine samples using heated pellets with no complicated requirement procedure for DNA extraction, namely the Rapid-Heat LAMPellet method. This is a new, easy, rapid and cost-effective LAMP method that should prove useful for mass screening in limited-resource settings in urogenital schistosomiasis-endemic areas.
Collapse
Affiliation(s)
- Javier Gandasegui
- IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - Pedro Fernández-Soto
- IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
- * E-mail:
| | - Cristina Carranza-Rodríguez
- Departamento de Ciencias Médicas y Quirúrgicas, Facultad de Ciencias de la Salud, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - José Luis Pérez-Arellano
- Departamento de Ciencias Médicas y Quirúrgicas, Facultad de Ciencias de la Salud, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Belén Vicente
- IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - Julio López-Abán
- IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - Antonio Muro
- IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| |
Collapse
|
63
|
DNA detection of Schistosoma japonicum: diagnostic validity of a LAMP assay for low-intensity infection and effects of chemotherapy in humans. PLoS Negl Trop Dis 2015; 9:e0003668. [PMID: 25874964 PMCID: PMC4395225 DOI: 10.1371/journal.pntd.0003668] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 03/02/2015] [Indexed: 01/15/2023] Open
Abstract
Background Schistosomiasis has decreased significantly in prevalence and intensity of infection in China, thus more accurate and sensitive methods are desperately needed for the further control of schistosomiasis. The present work aimed to assess the utility of the loop-mediated isothermal amplification (LAMP) for detection of light intensity infection or false-negative patients and patients post-treatment, targeting the highly repetitive retrotransposon SjR2 of Schistosoma japonicum. Methodology/ Principal Findings LAMP was first assessed in rabbits with low intensity infection (EPG<10). Then 110 patient sera from Hunan Province, China, and 47 sera after treatment by praziquantel were used to evaluate the diagnostic validity of LAMP. Meanwhile, 42 sera from healthy individuals in a non-endemic area, and 60 sera from "healthy” residents who were identified as being negative for feces examination and immuno-methods in an endemic area were also examined. The results showed that LAMP could detect S. japonicum DNA in sera from rabbits at 3rd day post-infection. Following administration of praziquantel, the S. japonicum DNA in rabbit sera became negative at 10 weeks post-treatment. Of 110 sera from patients, LAMP showed 95.5% sensitivity, and even for 41 patients with less than 10 EPG, the sensitivity of LAMP still reached to 95.1%. For 47 patients after treatment, the negative conversion rate of S. japonicum DNA in patient sera increased from 23.4%, 61.7% to 83.0% at 3 months, 6 months and 9 months post-treatment, respectively. No false-positive result was obtained for 42 human sera from non-endemic area, while for the 60 “healthy” individuals from endemic area, 10 (16.7%) individuals were positive by LAMP, which suggested that these individuals might be false-negative patients. Conclusions/ Significance The present study demonstrated that the LAMP assay is sensitive, specific, and affordable, which would help reduce schistosomiasis transmission through targeted treatment of individuals, particularly for those with negative stool examinations who may yet remain infected. The LAMP assay may provide a potential tool to support schistosomiasis control and elimination strategies. Accurate diagnostic tests play a key role in patient management and control of schistosomiasis, especially in China where the prevalence and intensity of Schistosoma japonicum infection is low in recent years. The present study aimed to assess the utility of the loop-mediated isothermal amplification (LAMP) assay for detection of light intensity infection or false-negative patients and for the evaluation of chemotherapy effectiveness in patients, targeting the highly repetitive retrotransposon SjR2 of S. japonicum, using 110 serum samples of schistosomiasis patients. The results showed that the LAMP assay had high sensitivity of 95.1% for the diagnosis of S. japonicum infection with the lowest intensity (EPG<10). For the assessment of efficacy after treatment with praziquantel, the negative conversion rate increased from 23.4%, 61.7% to 83.0% at 3 months, 6 months and 9 months post-treatment by LAMP, whereas for ELISA and IHA, the negative conversion rate remains at a low level (25.5% by ELISA and 31.9% by IHA) even at 9 months after treatment. Our results demonstrated that the LAMP assay may provide a valuable tool for the diagnosis of Schistosoma infection, especially for cases of light infection which is coincident with the current endemic situation.
Collapse
|
64
|
Utzinger J, Becker SL, van Lieshout L, van Dam GJ, Knopp S. New diagnostic tools in schistosomiasis. Clin Microbiol Infect 2015; 21:529-42. [PMID: 25843503 DOI: 10.1016/j.cmi.2015.03.014] [Citation(s) in RCA: 181] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 03/21/2015] [Accepted: 03/21/2015] [Indexed: 12/22/2022]
Abstract
Schistosomiasis is a water-based parasitic disease that affects over 250 million people. Control efforts have long been in vain, which is one reason why schistosomiasis is considered a neglected tropical disease. However, since the new millennium, interventions against schistosomiasis are escalating. The initial impetus stems from a 2001 World Health Assembly resolution, urging member states to scale-up deworming of school-aged children with the anthelminthic drug praziquantel. Because praziquantel is safe, efficacious and inexpensive when delivered through the school platform, diagnosis before drug intervention was deemed unnecessary and not cost-effective. Hence, there was little interest in research and development of novel diagnostic tools. With the recent publication of the World Health Organization (WHO) Roadmap to overcome the impact of neglected tropical diseases in 2020, we have entered a new era. Elimination of schistosomiasis has become the buzzword and this has important ramifications for diagnostic tools. Indeed, measuring progress towards the WHO Roadmap and whether local elimination has been achieved requires highly accurate diagnostic assays. Here, we introduce target product profiles for diagnostic tools that are required for different stages of a schistosomiasis control programme. We provide an update of the latest developments in schistosomiasis diagnosis, including microscopic techniques, rapid diagnostic tests for antigen detection, polymerase chain reaction (PCR) assays and proxy markers for morbidity assessments. Particular emphasis is placed on challenges and solutions for new technologies to enter clinical practice.
Collapse
Affiliation(s)
- J Utzinger
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
| | - S L Becker
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Institute of Medical Microbiology and Hygiene, Saarland University Medical Centre, Homburg/Saar, Germany
| | - L van Lieshout
- Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands
| | - G J van Dam
- Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands
| | - S Knopp
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Department of Life Sciences, Natural History Museum, London, UK
| |
Collapse
|