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Phuakrod A, Sripumkhai W, Jeamsaksiri W, Pattamang P, Loymek S, Brindley PJ, Sarasombath PT, Wongkamchai S. A miniPCR-Duplex Lateral Flow Dipstick Platform for Rapid and Visual Diagnosis of Lymphatic Filariae Infection. Diagnostics (Basel) 2021; 11:diagnostics11101855. [PMID: 34679553 PMCID: PMC8534866 DOI: 10.3390/diagnostics11101855] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/18/2021] [Accepted: 09/29/2021] [Indexed: 11/16/2022] Open
Abstract
Lymphatic filariasis (LF) is a neglected major tropical disease that is a leading cause of permanent and long-term disability worldwide. Significant progress made by the Global Programme to Eliminate Lymphatic Filariasis (GPELF) has led to a substantial decrease in the levels of infection. In this limitation, DNA detection of lymphatic filariae could be useful due to it capable of detecting low level of the parasites. In the present study, we developed a diagnostic assay that combines a miniPCR with a duplex lateral flow dipstick (DLFD). The PCR primers were designed based on the HhaI and SspI repetitive noncoding DNA sequences of Brugia malayi and Wuchereria bancrofti, respectively. The limits of detection and crossreactivity of the assay were evaluated. In addition, blood samples were provided by Thais living in a brugian filariasis endemic area. The miniPCR-DLFD assay exhibited a detection limit of 2 and 4 mf per milliliter (mL) of blood for B. malayi as well as W. bancrofti, respectively, and crossamplification was not observed with 11 other parasites. The result obtained from the present study was in accordance with the thick blood smear staining for the known cases. Thus, a miniPCR-DLFD is an alternative tool for the diagnosis of LF in point-of-collection settings with a modest cost (~USD 5) per sample.
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Affiliation(s)
- Achinya Phuakrod
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand;
| | - Witsaroot Sripumkhai
- Thai Microelectronic Center, National Electronics and Computer Technology Center, Thailand Science Park, Pathum Thani 12110, Thailand; (W.S.); (W.J.); (P.P.)
| | - Wutthinan Jeamsaksiri
- Thai Microelectronic Center, National Electronics and Computer Technology Center, Thailand Science Park, Pathum Thani 12110, Thailand; (W.S.); (W.J.); (P.P.)
| | - Pattaraluck Pattamang
- Thai Microelectronic Center, National Electronics and Computer Technology Center, Thailand Science Park, Pathum Thani 12110, Thailand; (W.S.); (W.J.); (P.P.)
| | - Sumat Loymek
- Office of Disease Prevention and Control, Region 12, Department of Disease Control, The Ministry of Public Health, Songkhla 9000, Thailand;
| | - Paul J. Brindley
- Immunology & Tropical Medicine & Research Center for Neglected Diseases of Poverty, Department of Microbiology, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA;
| | - Patsharaporn T. Sarasombath
- Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Correspondence: (P.T.S.); (S.W.); Tel.: +66-2-419-6468 (P.T.S. & S.W.); Fax: +66-2-419-6470 (P.T.S. & S.W.)
| | - Sirichit Wongkamchai
- Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Correspondence: (P.T.S.); (S.W.); Tel.: +66-2-419-6468 (P.T.S. & S.W.); Fax: +66-2-419-6470 (P.T.S. & S.W.)
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Formenti F, Tang THT, Tamarozzi F, Silva R, La Marca G, Pajola B, Piubelli C, Perandin F, Rubio JM, Escolar EM, Bisoffi Z, Gobbi F. Preliminary comparison between an in-house real-time PCR vs microscopy for the diagnosis of Loa loa and Mansonella perstans. Acta Trop 2021; 216:105838. [PMID: 33484727 DOI: 10.1016/j.actatropica.2021.105838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/05/2021] [Accepted: 01/09/2021] [Indexed: 11/24/2022]
Abstract
Infections with the filarial nematodes Loa loa and Mansonella perstans are among the most neglected filarial infections. L. loa is endemic in 11 countries of Central and West Africa and loiasis is estimated to affect about 20 million people. M. perstans infection is widespread in more than 30 countries of sub-Saharan Africa. Due to the difficulty in diagnosing loiasis and M. perstans mansonellosis on a clinical basis, the diagnosis of infection with L. loa and M. perstans relies on laboratory techniques. Definitive diagnosis is based on the detection, identification, and quantification of circulating microfilariae (mf) by microscopy of concentrated blood. However, this is impractical for screening purposes as it requires expert laboratory personnel, considerable blood manipulation, and is time consuming, especially for the final issue of negative result reports, which are very common in the population visited outside endemic areas. The aim of the current work is the preliminary evaluation of the performance of the in-house real-time PCR described by Ta and colleagues compared to the routine microscopic approach for the screening of filarial infections in the clinical setting outside endemic areas, using samples from patients accessing the dedicated outpatient clinics for migrants and travelers of a reference centre for tropical diseases in Northern Italy.
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Takagi H, Yahathugoda TC, Tojo B, Rathnapala UL, Nagaoka F, Weerasooriya MV, Itoh M. Surveillance of Wuchereria bancrofti infection by anti-filarial IgG4 in urine among schoolchildren and molecular xenomonitoring in Sri Lanka: a post mass drug administration study. Trop Med Health 2019; 47:39. [PMID: 31223271 PMCID: PMC6567434 DOI: 10.1186/s41182-019-0166-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 05/28/2019] [Indexed: 11/10/2022] Open
Abstract
Background Surveillance of hidden foci or resurgence of the bancroftian filariasis has high priority to maintain the elimination status in Sri Lanka. For the surveillance, two methods were applied in Matotagama, Matara, Sri Lanka; (i) molecular xenomonitoring (MX) by PCR to detect parasite DNA in the vector, Culex (Cx) quinquefasciatus and (ii) survey of anti-filarial IgG4 in urine samples from schoolchildren. Results Mosquitoes were collected monthly from index houses for 17 months (2013 to 2014) to confirm the existence of bancroftian parasite. Index houses in Matotagama had recorded microfilaria-positive cases in the recent past. Five schools were selected considering Matotagama as the catchment area and all students who presented on the day were tested for urine anti-filarial IgG4 in 2015. Wuchereria bancrofti DNA in Cx. quinquefasciatus pools were found in 14 of 17 months studied and ranged between 0 and 1.4%. The MX rate was greatly increased at least two times in the year following the driest months (March, August). A total of 735 schoolchildren were tested for urine anti-filarial IgG4. Three schools located closer to the MX area had higher positive rates, 3.4%, 3.6%, and 6.6%. Both highest positive rates of MX and urine were located in a nearer vicinity. Conclusion Monthly collections to study lymphatic filariasis (LF) transmission by MX was conducted for the first time in Sri Lanka. We observed that the filarial DNA-positive rate had an association with seasonal cycle of precipitation. More than 1% filarial DNA and > 5% anti-filarial antibody rates confirmed ongoing transmission in Matotagama. The combination of two non-invasive surveys, the urine anti-filarial IgG4 levels of schoolchildren and MX of vector mosquitoes, would be a convenient package to monitor the ongoing transmission (hotspots) of LF in the surveillance.
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Affiliation(s)
- Hidekazu Takagi
- 1Department of Microbiology & Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195 Japan
| | - Thishan C Yahathugoda
- 3Filariasis Research Training and Service Unit (FRTSU), Department of Parasitology, Faculty of Medicine, University of Ruhuna, Galle, Sri Lanka
| | - Bumpei Tojo
- 2School of Tropical Medicine and Global Health, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, 852-8523 Japan
| | - Upeksha L Rathnapala
- 3Filariasis Research Training and Service Unit (FRTSU), Department of Parasitology, Faculty of Medicine, University of Ruhuna, Galle, Sri Lanka
| | - Fumiaki Nagaoka
- 1Department of Microbiology & Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195 Japan
| | - Mirani V Weerasooriya
- 3Filariasis Research Training and Service Unit (FRTSU), Department of Parasitology, Faculty of Medicine, University of Ruhuna, Galle, Sri Lanka
| | - Makoto Itoh
- 1Department of Microbiology & Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195 Japan
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Seroepidemiology of helminths and the association with severe malaria among infants and young children in Tanzania. PLoS Negl Trop Dis 2018; 12:e0006345. [PMID: 29579050 PMCID: PMC5886694 DOI: 10.1371/journal.pntd.0006345] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 04/05/2018] [Accepted: 02/24/2018] [Indexed: 01/23/2023] Open
Abstract
The disease burden of Wuchereria bancrofti and Plasmodium falciparum malaria is high, particularly in Africa, and co-infection is common. However, the effects of filarial infection on the risk of severe malaria are unknown. We used the remaining serum samples from a large cohort study in Muheza, Tanzania to describe vector-borne filarial sero-reactivity among young children and to identify associations between exposure to filarial parasites and subsequent severe malaria infections. We identified positive filarial antibody responses (as well as positive antibody responses to Strongyloides stercoralis) among infants as young as six months. In addition, we found a significant association between filarial seropositivity at six months of age and subsequent severe malaria. Specifically, infants who developed severe malaria by one year of age were 3.9 times more likely (OR = 3.9, 95% CI: 1.2, 13.0) to have been seropositive for filarial antigen at six months of age compared with infants who did not develop severe malaria. In this paper, we used a multiplexed, serologic assessment to identify children with previous or current exposure to or infection with filarial parasites or S. stercoralis (a soil transmitted helminth), enhancing our understanding of co-infections in early childhood. We identified an increasing prevalence of filarial antibodies over time in a population of children as young as 6 months old. In addition, we found a significant association between filarial seropositivity at six months of age and subsequent severe malaria.
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Imported Asymptomatic Bancroftian Filariasis Discovered from a Plasmodium vivax Infected Patient: A Case Report from Singapore. Case Rep Infect Dis 2017; 2017:1972587. [PMID: 28804661 PMCID: PMC5540382 DOI: 10.1155/2017/1972587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 06/01/2017] [Indexed: 11/20/2022] Open
Abstract
Human lymphatic filariasis is a vector-borne disease mainly caused by the parasitic nematode Wuchereria bancrofti and transmitted worldwide within the tropical and subtropical regions. Singapore was once endemic for bancroftian filariasis but recent reports are scarce and the disease is nearly forgotten. The case report presented here reports the incidental hospital laboratory finding of an asymptomatic microfilaremia in a relapsing Plasmodium vivax imported case during a malaria treatment follow-up appointment. The parasite was identified by microscopy as W. bancrofti and retrospective investigation of the sample collected during malaria onset was found to be also positive. Additional confirmation was obtained by DNA amplification, sequencing, and phylogenetic analysis of the mitochondrial cox1 gene that further related the parasite to W. bancrofti strains from the Indian region. Considering the large proportion of asymptomatic filariasis with microfilaremia, the high number of migrants and travellers arriving from the surrounding endemic countries, and the common presence of local competent mosquito vectors, Singapore remains vulnerable to the introduction, reemergence, and the spread of lymphatic filariasis. This report brings out from the shadow the potential risk of lymphatic filariasis in Singapore and could help to maintain awareness about this parasitic disease and its public health importance.
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Weitzel T, Rosas R, Fica A, Dabanch J, Polanco M, Egaña A, Triantafilo V, Pfarr K, Hoerauf A, Reiter-Owona I. Is there a risk of filarial infection during long-term missions in Haiti? Travel Med Infect Dis 2016; 14:137-42. [PMID: 26750186 DOI: 10.1016/j.tmaid.2015.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 12/09/2015] [Accepted: 12/10/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND Haiti has the highest prevalence of lymphatic filariasis (Wuchereria bancrofti) in the Western Hemisphere. Still, the risk of filarial infection for long-term visitors such as humanitarian aid workers or military personnel is uncertain. The presented study analyzed the exposure to W. bancrofti in Chilean participants of the UN Stabilization Mission in Haiti (MINUSTAH) in 2011. METHODS Blood samples collected from 531 participants were screened for antifilarial antibodies by IgG ELISA, and, if positive, analyzed by immunofluorescence assay (IFA), IgG4 ELISA, Real-Time PCR, and circulating filarial antigen (CFA) card test. RESULTS ELISA screening was positive in 10 cases. Seroconversion occurred in only two cases (0.38%) based on ELISA values determined in samples taken before and after deployment. Positive IgG ELISA values could not be confirmed by IFA and IgG4 ELISA. Real-Time PCR and CFA testing did not reveal the presence of filaria. CONCLUSIONS Our data indicate that in the examined cohort of MINUSTAH participants in 2011, the risk of filarial exposure or infection was low.
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Affiliation(s)
- Thomas Weitzel
- Programa Medicina del Viajero, Clínica Alemana, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile; Laboratorio Clínico, Clínica Alemana, Facultad de Medicina Clínica Alemana, Universidad del Desarrollo, Santiago, Chile.
| | - Reinaldo Rosas
- Programa de Prevención de la Salud del Personal en Comisión de Servicio en el Extranjero, Comando de Salud del Ejército, Fuerzas Armadas de Chile, Santiago, Chile
| | - Alberto Fica
- Servicio de Infectología, Hospital Militar, Santiago, Chile
| | | | - Myriam Polanco
- Programa de Prevención de la Salud del Personal en Comisión de Servicio en el Extranjero, Comando de Salud del Ejército, Fuerzas Armadas de Chile, Santiago, Chile
| | - Alicia Egaña
- Laboratorio Clínico, Hospital Militar, Santiago, Chile
| | | | - Kenneth Pfarr
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinic Bonn, Bonn, Germany
| | - Achim Hoerauf
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinic Bonn, Bonn, Germany
| | - Ingrid Reiter-Owona
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinic Bonn, Bonn, Germany
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Oi M, Sato Y, Nakagaki K, Nogami S. Detection of Dirofilaria immitis DNA in host serum by nested PCR. Parasitol Res 2015; 114:3645-8. [PMID: 26109256 DOI: 10.1007/s00436-015-4591-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/16/2015] [Indexed: 12/13/2022]
Abstract
The heartworm Dirofilaria immitis is the causative agent of dirofilariasis in dogs. Studies have shown that parasite-derived cell-free DNA (cfDNA) can be detected in host blood and may be a promising diagnostic marker for parasitic infections. Thus, our aim was to detect D. immitis-derived cfDNA in host serum by nested PCR. Sera were collected from 12 dogs with natural D. immitis infections; eight were microfilaria (mf)-positive, and the remaining four were mf-negative. Culture fluids derived from single-sex adult D. immitis worms (mf-producing females and males) were also tested for cfDNA. All mf-positive sera were positive by nested PCR, whereas no amplification products were detected in mf-negative sera. The culture fluid of mf-producing females was positive by nested PCR but that of males was negative. All products amplified by nested PCR were sequenced to confirm that the amplicons were those of D. immitis. These results indicate that D. immitis DNA circulates freely in dog serum, except in mf-negative dogs. Additionally, D. immitis cfDNA may primarily be derived from the mf, and adult worms appeared to be minor contributors of cfDNA concentrations in serum; however, the contribution of D. immitis cfDNA derived from larvae of other developmental stages is unclear. An evaluation of the kinetics of D. immitis cfDNA in host serum throughout the parasite life cycle could facilitate the development of early molecular diagnostic techniques. To the best of our knowledge, this is the first report of the detection of mitochondrial DNA from a filarial parasite in host serum.
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Affiliation(s)
- Masaaki Oi
- Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan,
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Pritt BS. Molecular Diagnostics in the Diagnosis of Parasitic Infection. METHODS IN MICROBIOLOGY 2015. [DOI: 10.1016/bs.mim.2015.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Plichart C, Lemoine A. Monitoring and evaluation of lymphatic filariasis interventions: an improved PCR-based pool screening method for high throughput Wuchereria bancrofti detection using dried blood spots. Parasit Vectors 2013; 6:110. [PMID: 23597068 PMCID: PMC3637190 DOI: 10.1186/1756-3305-6-110] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 04/14/2013] [Indexed: 11/29/2022] Open
Abstract
Background Effective diagnostic tools are necessary to monitor and evaluate interruption of Lymphatic Filariasis (LF) transmission. Accurate detection of Wuchereria bancrofti (Wb) microfilaria (mf) is essential to measure the impact of community treatment programmes. PCR-based assays are specific, highly sensitive tools allowing the detection of Wuchereria bancrofti DNA in human blood samples. However, current protocols describing the pool screening approach, use samples of less than 60 μl of blood, which limits the sensitivity of the pool-screen PCR assay. The purpose of this study was to improve the pool-screen PCR protocol to enhance its sensitivity and usefulness for population scale studies. Findings DNA extractions were performed with the DNeasy kit, the PCR with the Wb LDR primers and the SYBR-Green dye. Improvements of our pool-screen real-time PCR (qPCR) assay allowed the detection of as little as one Wb microfilaria diluted in a pool of at least 12 blood samples of 60 μl each. Using this assay, mf burdens can be predicted using a standard curve derived from mf spiked dried blood samples. The sensitivity achieved is equivalent to the detection of a single LF positive individual carrying a mf burden as low as 18 mf/ml, in a pool of blood samples from at least 12 individuals. Conclusions Due to its sensitivity, rapidity and cost-effectiveness, we suggest this qPCR pool-screening assay could be used as a diagnostic tool for population- scale filariasis elimination monitoring and evaluation.
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Gürtler L, Bauerfeind U, Blümel J, Burger R, Drosten C, Gröner A, Heiden M, Hildebrandt M, Jansen B, Montag-Lessing T, Offergeld R, Pauli G, Seitz R, Schlenkrich U, Schottstedt V, Strobel J, Willkommen H. Arbonematodes - nematode infections transmissible by arthropods: arbeitskreis blut, untergruppe «bewertung blutassoziierter krankheitserreger»*. ACTA ACUST UNITED AC 2013; 40:50-62. [PMID: 23637651 DOI: 10.1159/000345752] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 06/02/2012] [Indexed: 11/19/2022]
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McNulty SN, Mitreva M, Weil GJ, Fischer PU. Inter and intra-specific diversity of parasites that cause lymphatic filariasis. INFECTION GENETICS AND EVOLUTION 2012. [PMID: 23201850 DOI: 10.1016/j.meegid.2012.11.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Lymphatic filariasis is caused by three closely related nematode parasites: Wuchereria bancrofti, Brugia malayi and Brugia timori. These species have many ecological variants that differ in several aspects of their biology such as mosquito vector species, host range, periodicity, and morphology. Although the genome of B. malayi (the first genome sequenced from a parasitic nematode) has been available for more than five years, very little is known about genetic variability among the lymphatic dwelling filariae. The genetic diversity among these worms is not only interesting from a biological perspective, but it may have important practical implications for the Global Program to Eliminate Lymphatic Filariasis, as the parasites may respond differently to diagnostic tests and/or medical interventions. Therefore, better information on their genetic variability is urgently needed. With improved methods for nucleic acid extraction and recent advances in sequencing chemistry and instrumentation, this gap can be filled relatively inexpensively. Improved information on filarial genetic diversity may increase the chances of success for lymphatic filariasis elimination programs.
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Affiliation(s)
- Samantha N McNulty
- Infectious Diseases Division, Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO, United States
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Takagi H, Itoh M, Kasai S, Yahathugoda TC, Weerasooriya MV, Kimura E. Development of loop-mediated isothermal amplification method for detecting Wuchereria bancrofti DNA in human blood and vector mosquitoes. Parasitol Int 2011; 60:493-7. [PMID: 21930238 DOI: 10.1016/j.parint.2011.08.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 08/25/2011] [Accepted: 08/30/2011] [Indexed: 10/17/2022]
Abstract
We have developed loop-mediated isothermal amplification (LAMP) method to detect Wuchereria bancrofti DNA. The sensitivity and specificity of LAMP method were equivalent to those of PCR method which detects SspI repeat sequence in W. bancrofti genomic DNA: both methods detected one thousandth of W. bancrofti DNA from one microfilaria (Mf), and did not cross-react with DNAs of Brugia malayi, B. pahangi, Dirofilaria immitis, human and Culex quinquefasciatus. We also examined the sensitivity of LAMP using the mimic samples of patient's blood or blood-fed mosquitoes containing one W. bancrofti Mf per sample. The LAMP method was able to detect W. bancrofti DNA in 1000 μl of blood or in a pool of 60 mosquitoes, indicating its usefulness in detecting/monitoring W. bancrofti infection in humans and vector mosquitoes in endemic areas.
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Affiliation(s)
- Hidekazu Takagi
- Department of Parasitology, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan.
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Toward molecular parasitologic diagnosis: enhanced diagnostic sensitivity for filarial infections in mobile populations. J Clin Microbiol 2010; 49:42-7. [PMID: 20980560 DOI: 10.1128/jcm.01697-10] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The diagnosis of filarial infections among individuals residing in areas where the disease is not endemic requires both strong clinical suspicion and expert training in infrequently practiced parasitological methods. Recently developed filarial molecular diagnostic assays are highly sensitive and specific but have limited availability and have not been closely evaluated for clinical use outside populations residing in areas of endemicity. In this study, we assessed the performance of a panel of real-time PCR assays for the four most common human filarial pathogens among blood and tissue samples collected from a cohort of patients undergoing evaluation for suspected filarial infections. Compared to blood filtration, real-time PCR was equally sensitive for the detection of microfilaremia due to Wuchereria bancrofti (2 of 46 samples positive by both blood filtration and PCR with no discordant results) and Loa loa (24 of 208 samples positive by both blood filtration and PCR, 4 samples positive by PCR only, and 3 samples positive by blood filtration only). Real-time PCR of skin snip samples was significantly more sensitive than microscopic examination for the detection of Onchocerca volvulus microfiladermia (2 of 218 samples positive by both microscopy and PCR and 12 samples positive by PCR only). The molecular assays required smaller amounts of blood and tissue than conventional methods and could be performed by laboratory personnel without specialized parasitology training. Taken together, these data demonstrate the utility of the molecular diagnosis of filarial infections in mobile populations.
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Weckelmann A, Viebahn C, Püschel B. Subcellular Redistribution of the Mitochondrial PG2 Epitope during Development from Cleavage to Primordial Germ Cell Formation in the Rabbit Embryo. Sex Dev 2008; 2:31-42. [DOI: 10.1159/000117717] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Accepted: 01/17/2008] [Indexed: 11/19/2022] Open
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Mishra K, Raj DK, Hazra RK, Dash AP, Supakar PC. The development and evaluation of a single step multiplex PCR method for simultaneous detection of Brugia malayi and Wuchereria bancrofti. Mol Cell Probes 2007; 21:355-62. [PMID: 17560074 DOI: 10.1016/j.mcp.2007.05.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2006] [Revised: 04/21/2007] [Accepted: 05/01/2007] [Indexed: 11/22/2022]
Abstract
A single step novel multiplex polymerase chain reaction (PCR) has been developed for simultaneous detection of human filarial parasites, Brugia malayi and Wuchereria bancrofti, from blood samples and mosquitoes. The primers used were novel and have been tested with the parasite DNA amplifying 188bp (BM) and 129bp (WB) DNA fragments, specific to B. malayi and W. bancrofti, respectively, in a single reaction. The specificity of the PCR product was confirmed by DNA sequencing and slot blot hybridization assay. The test was found highly sensitive for both B. malayi and W. bancrofti by detecting the parasitaemia up to the level of one microfilaria per reaction. The assay was further evaluated on 98 blood samples and 144 mosquito samples collected from filarial endemic areas. The PCR was found to be more efficient in comparison to microscopy by detecting 8% and 5% more filarial parasites in field-collected blood and mosquito samples, respectively. This novel PCR that offers scope for simultaneous detection of both the parasites may be used as a diagnostic tool for the detection of filariasis in population and can be adopted for rapid surveillance and monitoring of mosquitoes for use in the effective control of filariasis.
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Affiliation(s)
- Kirti Mishra
- Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar 751023, India
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Kanjanavas P, Tan-ariya P, Khawsak P, Pakpitcharoen A, Phantana S, Chansiri K. Detection of lymphatic Wuchereria bancrofti in carriers and long-term storage blood samples using semi-nested PCR. Mol Cell Probes 2005; 19:169-72. [PMID: 15797816 DOI: 10.1016/j.mcp.2004.11.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Accepted: 11/08/2004] [Indexed: 10/25/2022]
Abstract
The semi-nested PCR was conducted for detection of Wuchereria bancrofti in patients' blood. The primers were designed based on the repetitive DNA sequences of the parasite. The results demonstrated that the semi-nested PCR could detect as little as 0.001 fg of parasite DNA. In addition, the primers showed no PCR amplification from human and other hemoparasites such as Brugia malayi, Plasmodium falciparum and P. vivax DNAs. This technique was used for detection of 18 W. bancrofti infected blood samples with a long-term storage, the data revealed that all samples were positive. The results obtained from this study clearly indicated that the semi-nested PCR is specific, sensitive, and suitable for detection of the disease carriers.
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Affiliation(s)
- P Kanjanavas
- Department of Biochemistry, Faculty of Medicine, Srinakharinwirot University, Sukhumvit 23, Bangkok 10110, Thailand
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17
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Mishra K, Raj DK, Dash AP, Hazra RK. Combined detection of Brugia malayi and Wuchereria bancrofti using single PCR. Acta Trop 2005; 93:233-7. [PMID: 15715996 DOI: 10.1016/j.actatropica.2005.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2004] [Revised: 12/22/2004] [Accepted: 01/03/2005] [Indexed: 11/21/2022]
Abstract
A single step PCR method has been developed for the combined detection of the human filarial parasites, Brugia malayi and Wuchereria bancrofti. Parasites' DNA were isolated from filaria positive blood samples that were collected from endemic areas. The primers used were Hha1 and Ssp I, which amplified the DNA fragments of 322 bp and 188 bp specific to B. malayi and W. bancrofti, respectively. The sensitivity of the assay was tested with blood and mosquito samples having one W. bancrofti in a pool of 10 B. malayi. The assay was further evaluated on field collected blood and mosquito samples. Use of this assay as a diagnostic tool for the detection of filariasis being the most promising aspect of this study, offers scope for detection of both the parasites even at low levels of infection.
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Affiliation(s)
- Kirti Mishra
- Division of Vector Borne Diseases, Institute of Life Sciences, Nalco Square, Chandrasekharpur, Bhubaneswar 751023, India
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18
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Lulitanond V, Intapan PM, Pipitgool V, Choochote W, Maleewong W. Rapid detection of Wuchereria bancrofti in mosquitoes by LightCycler polymerase chain reaction and melting curve analysis. Parasitol Res 2004; 94:337-41. [PMID: 15449180 DOI: 10.1007/s00436-004-1221-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Accepted: 08/11/2004] [Indexed: 10/26/2022]
Abstract
A LightCycler real-time polymerase chain reaction (PCR) assay was developed to detect Wuchereria bancrofti DNA in blood-fed mosquitoes. The assay is based on fluorescence melting curve analysis of the PCR product generated from a family of repeated DNA elements: the 182 bp SspI repeat, specific to the genus Wuchereria. According to the melting temperature, W. bancrofti infected-mosquitoes were differentiated from Brugia malayi-infected and non-infected mosquitoes as well as from genomic DNA of Dirofilaria immitis and human DNA. The method proved to be 100% sensitive in all W. bancrofti-infected mosquitoes. Melting curve analysis offers a rapid alternative for the specific detection of W. bancrofti in mosquitoes. It is very accurate and sensitive, allows a high throughput and can be performed on very small samples. The method therefore has great potential for application in epidemiological studies.
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Affiliation(s)
- Virapong Lulitanond
- Department of Microbiology, Faculty of Medicine, Khon Kaen University, 40002 Khon Kaen, Thailand.
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19
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Williams SA, Laney SJ, Bierwert LA, Saunders LJ, Boakye DA, Fischer P, Goodman D, Helmy H, Hoti SL, Vasuki V, Lammie PJ, Plichart C, Ramzy RMR, Ottesen EA. Development and standardization of a rapid, PCR-based method for the detection of Wuchereria bancrofti in mosquitoes, for xenomonitoring the human prevalence of bancroftian filariasis. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2002; 96 Suppl 2:S41-6. [PMID: 12625916 DOI: 10.1179/000349802125002356] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PCR has recently been studied as a promising tool for monitoring the progress of efforts to eliminate lymphatic filariasis. PCR can be used to test concurrently at least 30 pools, with as many as 40 mosquitoes in each pool, for the presence of filarial larvae. The SspI PCR assay for the detection of Wuchereria bancrofti DNA in pools of mosquitoes has been used since 1994 in a variety of laboratories worldwide. During that time, the original assay has been modified in these different laboratories and no standardized assay currently exists. In an effort to standardize and improve the assay, a meeting was held on 15-16 November 2001, at Emory University in Atlanta, with representatives from most of the laboratories currently using the assay. The first round of testing was designed to test the four most promising methods for DNA extraction from pools of mosquitoes. Two of the four methods stood out as clearly the best and these will be now optimised and evaluated in two further rounds of testing.
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Affiliation(s)
- S A Williams
- Clark Science Center, Smith College, Northampton, MA 01063, USA.
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20
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McCarroll L, Hemingway J. Can insecticide resistance status affect parasite transmission in mosquitoes? INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2002; 32:1345-1351. [PMID: 12225925 DOI: 10.1016/s0965-1748(02)00097-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- L McCarroll
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK
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21
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Abstract
Lymphatic filariasis has afflicted people in the tropical areas of the world for thousands of years but even up to comparatively recent times it has been poorly understood and its importance under recognised. In the last 2 decades or so there has been a flurry of activity in filariasis research, which has provided new insights into the global problem of filariasis, the pathogenesis of filarial disease, diagnosis and control.
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Affiliation(s)
- Wayne D Melrose
- Lymphatic Filariasis Support Centre, School of Public Health and Tropical Medicine, James Cook University, Townsville, QLD 4811, Australia.
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22
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Rao UR, Williams SA, Klei TR. Quantification of PCR amplification products of Brugia HhaI repeat DNA using a semiautomated Q-PCR system. Mol Cell Probes 2002; 16:13-23. [PMID: 12005443 DOI: 10.1006/mcpr.2001.0393] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The sensitive, rapid and species-specific diagnosis of Brugia infections in humans or animal models is important in determining the level of parasitemia and the efficacy of chemotherapy or vaccinations. The HhaI family of highly repeated DNA sequences from Brugia have been useful in polymerase chain reaction (PCR)-based diagnosis of brugian filarial infections in blood samples and in mosquitoes. A PCR assay was developed using a biotinylated primer, a non-biotinylated primer and a species-specific chemiluminescent probe [tris[2,2'bipyridine] ruthenium (II) chelate, TBR] to detect PCR amplified Hhal family repeats. Individual blood samples from jirds infected with Brugia malayi or B. pahangi and with different levels of microfilaremia were tested in this assay. Known concentrations of Brugia DNA and DNA from the blood of uninfected control jirds were used as positive and negative controls, respectively. The PCR products generated by this method were analyzed using a semi-automated quantitative (Q)-PCR system. The levels of parasite DNA can be calculated from the luminosity units generated. Significant amounts of parasite DNA were detected in blood samples from infected jirds, and these values were correlated with the levels of microfilaremia. In contrast, reductions in circulating microfilaria following treatment with ivermectin correlated with low levels of measurable DNA. Using this system, we were also able to detect HhaI repeat DNA in the spleens of B. pahangi- infected jirds at 56 days post-infection when circulating microfilariae were not readily detectable. The results indicate that the species-specific Hhal Q-PCR detection and quantification method is rapid and sensitive, is useful in the detection of Brugia DNA in blood and other tissues and is suited for use in clinical settings because it does not require radioactive isotopes and gel-based protocols.
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Affiliation(s)
- U R Rao
- Department of Microbiology and Parasitology, School of Veterinary Medicine, Louisiana State University, Baton Rouge, USA.
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23
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Njenga SM, Wamae CN. Evaluation of ICT filariasis card test using whole capillary blood: comparison with Knott's concentration and counting chamber methods. J Parasitol 2001; 87:1140-3. [PMID: 11695380 DOI: 10.1645/0022-3395(2001)087[1140:eoifct]2.0.co;2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
An immunochromatographic card test (ICT) that uses fingerprick whole blood instead of serum for diagnosis of bancroftian filariasis has recently been developed. The card test was validated in the field in Kenya by comparing its sensitivity to the combined sensitivity of Knott's concentration and counting chamber methods. A total of 102 (14.6%) and 117 (16.7%) persons was found to be microfilaremic by Knott's concentration and counting chamber methods, respectively. The geometric mean intensities (GMI) were 74.6 microfilariae (mf)/ml and 256.5 mf/ml by Knott's concentration and counting chamber methods, respectively. All infected individuals detected by both Knott's concentration and counting chamber methods were also antigen positive by the ICT filariasis card test (100% sensitivity). Further, of 97 parasitologically amicrofilaremic persons, 24 (24.7%) were antigen positive by the ICT. The overall prevalence of antigenemia was 37.3%. Of 100 nonendemic area control persons, none was found to be filarial antigen positive (100% specificity). The results show that the new version of the ICT filariasis card test is a simple, sensitive, specific, and rapid test that is convenient in field settings.
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Affiliation(s)
- S M Njenga
- Centre for Clinical Research, Kenya Medical Research Institute, Nairobi
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24
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Chansiri K, Kwoasak P, Tananyutthawongese C, Sukhumsirichart W, Sarataphan N, Phantana S. Detection of Plasmodium falciparum and Wuchereria bancrofti infected blood samples using multiplex PCR. Mol Cell Probes 2001; 15:201-7. [PMID: 11513554 DOI: 10.1006/mcpr.2001.0359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A rapid and sensitive multiplex PCR has been developed for the diagnosis of multiple parasitic infection in human blood. Infection is detected by a single multiplex PCR reaction containing two pairs of oligonucleotide primers whereby each primer is specific for each parasite species. These primer sets amplified 400 and 450-bp fragments for Wuchereria bancrofti and 208-bp fragment for Plasmodium falciparum. The PCR products derived from each parasite species were visualized in ethidium bromide-stained agarose gels, therefore allowing the rapid identification of any, or all, of the two human parasites, if present, in a single amplification reaction. This multiplex PCR was very sensitive with the ability to detect the presence of as little as 10 pg of parasite DNA. The primers used in this multiplex PCR also showed highly specific amplification of each respective parasite DNA without the presence of non-specific and non-target PCR products. This multiplex PCR system was used to analyse 36 human blood samples of Myanmar workers in the endemic area at Tak Province, Thailand. Two samples showed the multiple infection, 27 samples were either infected with W. bancrofti or P. falciparum and seven samples were negative for both methods. The high sensitivity, specificity and rapidity of this multiplex PCR method make it suitable for large-scale epidemiological studies and following of drug treatment.
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Affiliation(s)
- K Chansiri
- Department of Biochemistry, Faculty of Medicine, Srinakharinwirot University, Sukhumvit 23, Bangkok 10110, Thailand.
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25
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Morales-Hojas R, Post RJ, Shelley AJ, Maia-Herzog M, Coscarón S, Cheke RA. Characterisation of nuclear ribosomal DNA sequences from Onchocerca volvulus and Mansonella ozzardi (Nematoda: Filarioidea) and development of a PCR-based method for their detection in skin biopsies. Int J Parasitol 2001; 31:169-77. [PMID: 11239937 DOI: 10.1016/s0020-7519(00)00156-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The internal transcribed spacer region (ITS1, 5.8S gene and ITS2) of the two filarial nematodes Onchocerca volvulus and Mansonella ozzardi was sequenced, and two species-specific primers designed in the ITS2 to develop a PCR-based method for their specific detection and differentiation. When used with a universal reverse primer, the two species-specific primers gave amplification products of different size, which were readily separated in an agarose gel. The PCR was tested on skin biopsies from 51 people from three localities in Brazil where M. ozzardi is present, and results have been compared with those of parasitological examination of blood. The species-specific PCR gave a higher percentage of detection of infection by M. ozzardi than the parasitological examination of blood. No infection with O. volvulus was detected by PCR. This PCR-based assay may assist in determining the nature of infection in areas where both filarial species exist in sympatry.
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Affiliation(s)
- R Morales-Hojas
- Department of Entomology, The Natural History Museum, Cromwell Road, SW7 5BD, London, UK.
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26
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Thanomsub BW, Chansiri K, Sarataphan N, Phantana S. Differential diagnosis of human lymphatic filariasis using PCR-RFLP. Mol Cell Probes 2000; 14:41-6. [PMID: 10722791 DOI: 10.1006/mcpr.1999.0283] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Filariasis is still a public health problem in tropical countries. The most common causative agents of human filariasis are Wuchereria bancrofti and Brugia malayi. Traditional methods used to detect filarial parasites in human, animal and vector populations are tedious, time consuming, and confer little guarantee of sensitivity and species specificity. We have developed a rapid and specific method to detect filarial parasite DNAs in blood and mosquito samples using the polymerase chain reaction (PCR) technique. The primers used are MF/F and MF/R which amplify a 1.5 kb glutathione peroxidase gene of filarial worms. Using the restriction fragment length polymorphism (RFLP) technique, these PCR products will be further digested with restriction enzymes either Hpa I, Pst I, Alu I or Hinf I to differentiate the genus of filaria. This PCR-RFLP technique can be apply to use in diagnosis and to differentiate between species of filaria in humans the reservoir host and the mosquito vector in endemic areas
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Affiliation(s)
- B W Thanomsub
- Department of Microbiology, Faculty of Medicine, Srinakharinwirot University, Sukhumvit 23, Bangkok, 10110, Thailand.
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27
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Rahmah N, Anuar AK, A'shikin AN, Lim BH, Mehdi R, Abdullah B, Zurainee MN. A Brugia malayi antigen specifically recognized by infected individuals. Biochem Biophys Res Commun 1998; 250:586-8. [PMID: 9784388 DOI: 10.1006/bbrc.1998.9360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Western blot analyses were performed on 444 serum specimens: 40 sera from microfilaraemic individuals, 10 sera from elephantiasis patients, 24 treated individuals, 50 sera from residents of endemic areas without anti-filarial IgG4 antibodies (endemic normals), 20 sera from amicrofilaraemic individuals with high anti-filarial IgG4 antibodies, 200 sera from healthy city-dwellers (non-endemic samples), and 100 sera from soil-transmitted helminth-infected individuals. Phast electrophoresis system was used to electrophorese Brugia malayi soluble adult worm antigen on 10-15% SDS-PAGE gradient gels followed by electrophoretic transfer onto PVDF membranes. Membrane strips were then successively incubated with blocking solution, human sera, and monoclonal anti-human IgG4 antibody-HRP, with adequate washings done in between each incubation step. Luminol chemiluminescence detection was then used to develop the blots. An antigenic band with the MW of approximately 37 kDa was found to be consistently present in the Western blots of all microfilaraemic sera, all amicrofilaraemic sera with high titres of anti-filarial IgG4 antibodies, some treated patients, and some elephantiasis patients. The antigen did not occur in immunoblots of individuals with other helminthic infections, normal endemic individuals, and city dwellers. Therefore the B. malayi antigen of with the MW of approximately 37 kDa demonstrated specific reactions with sera of B. malayi-infected individuals and thus may be useful for diagnostic application.
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Affiliation(s)
- N Rahmah
- School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia.
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28
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Rahmah N, Ashikin AN, Anuar AK, Ariff RH, Abdullah B, Chan GT, Williams SA. PCR-ELISA for the detection of Brugia malayi infection using finger-prick blood. Trans R Soc Trop Med Hyg 1998; 92:404-6. [PMID: 9850392 DOI: 10.1016/s0035-9203(98)91066-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
A polymerase chain reaction assay based on the enzyme-linked immunosorbent assay (PCR-ELISA) has been developed to detect Brugia malayi infection in an area of low endemicity in Malaysia. Blood samples from 239 subjects were tested: 192 amicrofilaraemic individuals, 14 microfilaraemic persons and 3 chronic elephantiasis cases from endemic areas and 30 city-dwellers (non-endemic controls). PCR products were examined by ELISA and Southern hybridization. In the PCR-ELISA, digoxigenin-labelled PCR products were hybridized to a biotin-labelled probe. This was followed by incubation in streptavidin-coated microtitre wells and detection using anti-digoxigenin-peroxidase and ABTS [2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid)]. All microfilaraemic samples were positive by PCR-ELISA and Southern hybridization and all samples from non-endemic subjects and chronic elephantiasis patients were negative. The PCR-ELISA detected 12 times as many B. malayi infections as did thick blood film examination. Nineteen of the 194 samples from the endemic area gave positive results by both PCR-ELISA and Southern hybridization, and an additional 5 samples were positive by PCR-ELISA only. The PCR-ELISA was specific and sensitive, detected more infections, and was more reproducible than Southern hybridization.
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Affiliation(s)
- N Rahmah
- Department of Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.
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29
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Lucena WA, Dhalia R, Abath FG, Nicolas L, Regis LN, Furtado AF. Diagnosis of Wuchereria bancrofti infection by the polymerase chain reaction using urine and day blood samples from amicrofilaraemic patients. Trans R Soc Trop Med Hyg 1998; 92:290-3. [PMID: 9861400 DOI: 10.1016/s0035-9203(98)91016-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A sensitive and specific polymerase chain reaction (PCR) based on a highly repeated deoxyribonucleic acid (DNA) sequence (188 bp; SspI repeat) was tested for the detection of Wuchereria bancrofti DNA in blood and urine samples collected during the day from individuals in Coque, Recife, Brazil, an endemic area for W. bancrofti. All microfilaraemic individuals were also positive by PCR, irrespective of the samples used. The PCR system was capable of detecting W. bancrofti DNA in amicrofilaraemic individuals: c. 93% were positive by PCR when day blood samples were used and 59.7% when urine samples collected at 07:00 were used. Thus, nocturnally periodic W. bancrofti infection can be detected in blood samples collected during the day, which is convenient for large-scale screening. In addition, non-invasive urine collection provided suitable samples for PCR, which is clearly advantageous for preliminary mass diagnosis.
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Affiliation(s)
- W A Lucena
- Departamento de Entomologia, Centro de Pesquisas Aggeu Magalhães-FIOCRUZ, Recife, PE, Brasil.
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Nicolas L. New tools for diagnosis and monitoring of bancroftian filariasis parasitism: The polynesian experience. ACTA ACUST UNITED AC 1997; 13:370-5. [PMID: 15275149 DOI: 10.1016/s0169-4758(97)01125-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bancroftian filariasis is endemic in French Polynesia and control programs with diethylcarbamazine, started in the 1950s, led to a sharp reduction of the microfilaria prevalence. Consequently, the control program was interrupted in 1982. Ten years later, however, the incidence of the parasitism again reached pre-control levels (20-30% microfilaremia in some islands), indicating that the adult worms (for which no diagnostic tool was available) had persisted. Apart from research on chemotherapy strategies, the Institut Malardé has been actively involved in developing and evaluating more-powerful diagnostic tools than the unique detection of microfilariae by blood smear examination. These include: (1) the detection of adult worm circulating antigens in humans, and (2) the detection of Wuchereria bancrofti larvae in mosquitoes, using DNA probes. In this paper, Luc Nicolas reviews the available diagnostic tools to detect W. bancrofti and their implementation in epidemiological areas, based on the Polynesian experience.
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Affiliation(s)
- L Nicolas
- Institut Territorial de Recherches Médicales Louis, Malardé, BP 30, Papeete Tahiti, French Polynesia.
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