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Saldanha I, Betson M, Vrettou C, Paxton E, Nixon J, Tennant P, Ritchie A, Matthews KR, Morrison LJ, Torr SJ, Cunningham LJ. Consistent detection of Trypanosoma brucei but not T. congolense DNA in faeces of experimentally infected cattle. Sci Rep 2024; 14:4158. [PMID: 38378867 PMCID: PMC10879203 DOI: 10.1038/s41598-024-54857-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 02/17/2024] [Indexed: 02/22/2024] Open
Abstract
Animal African trypanosomiasis (AAT) is a significant food security and economic burden in sub-Saharan Africa. Current AAT empirical and immunodiagnostic surveillance tools suffer from poor sensitivity and specificity, with blood sampling requiring animal restraint and trained personnel. Faecal sampling could increase sampling accessibility, scale, and species range. Therefore, this study assessed feasibility of detecting Trypanosoma DNA in the faeces of experimentally-infected cattle. Holstein-Friesian calves were inoculated with Trypanosoma brucei brucei AnTat 1.1 (n = 5) or T. congolense Savannah IL3000 (n = 6) in separate studies. Faecal and blood samples were collected concurrently over 10 weeks and screened using species-specific PCR and qPCR assays. T. brucei DNA was detected in 85% of post-inoculation (PI) faecal samples (n = 114/134) by qPCR and 50% by PCR between 4 and 66 days PI. However, T. congolense DNA was detected in just 3.4% (n = 5/145) of PI faecal samples by qPCR, and none by PCR. These results confirm the ability to consistently detect T. brucei DNA, but not T. congolense DNA, in infected cattle faeces. This disparity may derive from the differences in Trypanosoma species tissue distribution and/or extravasation. Therefore, whilst faeces are a promising substrate to screen for T. brucei infection, blood sampling is required to detect T. congolense in cattle.
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Affiliation(s)
- Isabel Saldanha
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK.
| | - Martha Betson
- School of Veterinary Medicine, University of Surrey, Guildford, UK
| | | | - Edith Paxton
- Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - James Nixon
- Large Animal Research and Imaging Facility, University of Edinburgh, Edinburgh, UK
| | - Peter Tennant
- Large Animal Research and Imaging Facility, University of Edinburgh, Edinburgh, UK
| | - Adrian Ritchie
- Large Animal Research and Imaging Facility, University of Edinburgh, Edinburgh, UK
| | - Keith R Matthews
- Institute of Immunology and Infection, University of Edinburgh, Edinburgh, UK
| | | | - Stephen J Torr
- Vector Biology Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Lucas J Cunningham
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, UK
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Sereno D, Oury B, Geiger A, Vela A, Karmaoui A, Desquesnes M. Isothermal Nucleic Acid Amplification to Detect Infection Caused by Parasites of the Trypanosomatidae Family: A Literature Review and Opinion on the Laboratory to Field Applicability. Int J Mol Sci 2022; 23:ijms23147543. [PMID: 35886895 PMCID: PMC9322063 DOI: 10.3390/ijms23147543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/03/2022] [Accepted: 07/04/2022] [Indexed: 12/13/2022] Open
Abstract
Isothermal amplification of nucleic acids has the potential to be applied in resource-limited areas for the detection of infectious agents, as it does not require complex nucleic purification steps or specific and expensive equipment and reagents to perform the reaction and read the result. Since human and animal infections by pathogens of the Tryponasomatidae family occur mainly in resource-limited areas with scant health infrastructures and personnel, detecting infections by these methodologies would hold great promise. Here, we conduct a narrative review of the literature on the application of isothermal nucleic acid amplification for Trypanosoma and Leishmania infections, which are a scourge for human health and food security. We highlight gaps and propose ways to improve them to translate these powerful technologies into real-world field applications for neglected human and animal diseases caused by Trypanosomatidae.
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Affiliation(s)
- Denis Sereno
- Institut de Recherche pour le Développement, Université de Montpellier, UMR INTERTRYP IRD, CIRAD, Parasite Infectiology and Public Health Group, 34032 Montpellier, France;
- Correspondence:
| | - Bruno Oury
- Institut de Recherche pour le Développement, Université de Montpellier, UMR INTERTRYP IRD, CIRAD, Parasite Infectiology and Public Health Group, 34032 Montpellier, France;
| | - Anne Geiger
- Centre International de Recherche en Agronomie pour le Développement, Institut de Recherche pour le Développement, Université de Montpellier, UMR INTERTRYP IRD, 34032 Montpellier, France;
| | - Andrea Vela
- One Health Research Group, Facultad de Ciencias de la Salud, Universidad de las Américas-Quito, Calle de los Colimes y Avenida De los Granados, Quito 170513, Ecuador;
| | - Ahmed Karmaoui
- Bioactives (Health and Environmental, Epigenetics Team), Faculty of Sciences and Techniques, Errachidia (UMI), Moroccan Center for Culture and Sciences, University Moulay Ismail, Meknes 50000, Morocco;
| | - Marc Desquesnes
- CIRAD, UMR INTERTRYP, 31076 Toulouse, France;
- INTERTRYP, Université de Montpellier, CIRAD, IRD, 34032 Montpellier, France
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Gummery L, Jallow S, Raftery AG, Bennet E, Rodgers J, Sutton DGM. Comparison of loop-mediated isothermal amplification (LAMP) and PCR for the diagnosis of infection with Trypanosoma brucei ssp. in equids in The Gambia. PLoS One 2020; 15:e0237187. [PMID: 32833981 PMCID: PMC7444819 DOI: 10.1371/journal.pone.0237187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 07/21/2020] [Indexed: 11/18/2022] Open
Abstract
Introduction Infection of equids with Trypanosoma brucei (T. brucei) ssp. is of socioeconomic importance across sub-Saharan Africa as the disease often progresses to cause fatal meningoencephalitis. Loop-mediated isothermal amplification (LAMP) has been developed as a cost-effective molecular diagnostic test and is potentially applicable for use in field-based laboratories. Part I Threshold levels for T. brucei ssp. detection by LAMP were determined using whole equine blood specimens spiked with known concentrations of parasites. Results were compared to OIE antemortem gold standard of T. brucei-PCR (TBR-PCR). Results I Threshold for detection of T. brucei ssp. on extracted DNA from whole blood was 1 parasite/ml blood for LAMP and TBR-PCR, and there was excellent agreement (14/15) between tests at high (1 x 103/ml) concentrations of parasites. Detection threshold was 100 parasites/ml using LAMP on whole blood (LWB). Threshold for LWB improved to 10 parasites/ml with detergent included. Performance was excellent for LAMP at high (1 x 103/ml) concentrations of parasites (15/15, 100%) but was variable at lower concentrations. Agreement between tests was weak to moderate, with the highest for TBR-PCR and LAMP on DNA extracted from whole blood (Cohen’s kappa 0.95, 95% CI 0.64–1.00). Part II A prospective cross-sectional study of working equids meeting clinical criteria for trypanosomiasis was undertaken in The Gambia. LAMP was evaluated against subsequent TBR-PCR. Results II Whole blood samples from 321 equids in The Gambia were processed under field conditions. There was weak agreement between LWB and TBR-PCR (Cohen’s kappa 0.34, 95% CI 0.19–0.49) but excellent agreement when testing CSF (100% agreement on 6 samples). Conclusions Findings support that LAMP is comparable to PCR when used on CSF samples in the field, an important tool for clinical decision making. Results suggest repeatability is low in animals with low parasitaemia. Negative samples should be interpreted in the context of clinical presentation.
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Affiliation(s)
- Lauren Gummery
- Weipers Centre Equine Hospital, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
| | - Saloum Jallow
- Gambia Horse and Donkey Trust, Sambel Kunda, The Gambia
| | - Alexandra G. Raftery
- Weipers Centre Equine Hospital, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Euan Bennet
- Weipers Centre Equine Hospital, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Jean Rodgers
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - David G. M. Sutton
- Weipers Centre Equine Hospital, School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Nambala P, Musaya J, Hayashida K, Maganga E, Senga E, Kamoto K, Chisi J, Sugimoto C. Comparative evaluation of dry and liquid RIME LAMP in detecting trypanosomes in dead tsetse flies. ACTA ACUST UNITED AC 2018; 85:e1-e6. [PMID: 30326717 PMCID: PMC6324077 DOI: 10.4102/ojvr.v85i1.1543] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 07/23/2018] [Accepted: 07/25/2018] [Indexed: 11/06/2022]
Abstract
Xenomonitoring is an important approach in assessing the progress of trypanosomiasis control as well as in estimating the endemicity of trypanosomes in affected areas. One of the major challenges in this approach is the unavailability of sensitive and easy to use xenomonitoring tools that can be used in the remote areas where the disease occurs. One tool that has been used successfully in detecting the parasites in tsetse flies is the repetitive insertion mobile element loop-mediated isothermal amplification (RIME LAMP). This tool has recently been modified from the liquid form to dry form for use in remote areas; however, uptake for use in the field has been slow. Field-collected tsetse flies were used to evaluate the performance of dry RIME LAMP over the conventional liquid RIME LAMP. All the samples were also subjected to internal transcribed spacer 1 (ITS1) ribosomal deoxyribonucleic acid (DNA) polymerase chain reaction (PCR) as a standard. ITS1-PCR-positive samples were further sequenced for confirmation of the species. A total of 86 wild tsetse flies were left to dry at room temperature for 3 months and DNA was extracted subsequently. All 86 flies were Glossina morsitans morsitans. From these, dry RIME LAMP detected 16.3% while liquid RIME LAMP detected 11.6% as infected with trypanosomes. Ten positive samples on ITS1-PCR were sequenced and all were shown to be trypanosomes. The use of dry RIME LAMP in the field for xenomonitoring of trypanosomes in tsetse flies will greatly contribute towards control of this neglected tropical disease as it provides the cheapest, fastest and simplest way to estimate possible human infective trypanosome infection rates in the tsetse fly vectors.
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Affiliation(s)
- Peter Nambala
- Department of Basic Medical Sciences, University of Malawi.
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Simwango M, Ngonyoka A, Nnko HJ, Salekwa LP, Ole-Neselle M, Kimera SI, Gwakisa PS. Molecular prevalence of trypanosome infections in cattle and tsetse flies in the Maasai Steppe, northern Tanzania. Parasit Vectors 2017; 10:507. [PMID: 29061160 PMCID: PMC5654092 DOI: 10.1186/s13071-017-2411-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 09/28/2017] [Indexed: 11/16/2022] Open
Abstract
Background African trypanosomosis is a disease of public health and economic importance that poses a major threat to the livelihoods of people living in the Maasai Steppe, where there is a significant interaction between people, livestock and wildlife. The vulnerability of the Maasai people to the disease is enhanced by the interaction of their cattle, which act as vehicles for trypanosomes, and tsetse flies close to wildlife in protected areas. This study was aimed at identification of trypanosome infections circulating in cattle and tsetse flies in order to understand their distribution and prevalence in livestock/wildlife interface areas in the Maasai Steppe. Methods A total of 1002 cattle and 886 tsetse flies were sampled from June 2015 to February 2016 in five villages and PCR was conducted to amplify the internal transcribed spacer 1 (ITS1) from trypanosomes. All Trypanosoma brucei-positive samples were further tested for the presence of the serum resistance-associated (SRA) gene found in human-infective trypanosomes using the SRA-LAMP technique. Results The overall prevalence of trypanosome infections was 17.2% in cattle and 3.4% in tsetse flies. Using a nested PCR, prevalence and abundance of five trypanosome species, Trypanosoma vivax, T. brucei, T. simiae, T. theileri and T. congolense, were determined, which varied with season and location. The highest prevalence of the identified trypanosome species was recorded at the end of wet season with an exception of T. brucei which was high at the beginning of the wet season. No human-infective trypanosomes were detected in both cattle and tsetse fly DNA. Conclusions This study confirms that seasonality and location have a significant contribution to the prevalence of trypanosome species in both mammalian and vector hosts. These results are important for designing of community-wide vector and disease control interventions and planning of sustainable regimes for reduction of the burden of trypanosomosis in endemic pastoral areas, such as the Maasai Steppe in northern Tanzania.
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Affiliation(s)
- Mary Simwango
- Department of Veterinary Medicine and Public Health, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture (SUA), P.O box 3015, Morogoro, Tanzania.
| | - Anibariki Ngonyoka
- Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, P. O. Box 447, Arusha, Tanzania.,Department of Geography and Environmental Studies, University of Dodoma, P. O. Box 395, Dodoma, Tanzania
| | - Happiness J Nnko
- Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, P. O. Box 447, Arusha, Tanzania.,Department of Geography and Environmental Studies, University of Dodoma, P. O. Box 395, Dodoma, Tanzania
| | - Linda P Salekwa
- Genome Sciences Centre, Department of Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Moses Ole-Neselle
- FAO Emergency Centre for Transboundary Animal Disease (ECTAD), P.O Box 2, Dar es Salaam, Tanzania
| | - Sharadhuli I Kimera
- Department of Veterinary Medicine and Public Health, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture (SUA), P.O box 3015, Morogoro, Tanzania
| | - Paul S Gwakisa
- Genome Sciences Centre, Department of Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
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Nnko HJ, Ngonyoka A, Salekwa L, Estes AB, Hudson PJ, Gwakisa PS, Cattadori IM. Seasonal variation of tsetse fly species abundance and prevalence of trypanosomes in the Maasai Steppe, Tanzania. JOURNAL OF VECTOR ECOLOGY : JOURNAL OF THE SOCIETY FOR VECTOR ECOLOGY 2017; 42:24-33. [PMID: 28504437 DOI: 10.1111/jvec.12236] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 11/20/2016] [Indexed: 06/07/2023]
Abstract
Tsetse flies, the vectors of trypanosomiasis, represent a threat to public health and economy in sub-Saharan Africa. Despite these concerns, information on temporal and spatial dynamics of tsetse and trypanosomes remain limited and may be a reason that control strategies are less effective. The current study assessed the temporal variation of the relative abundance of tsetse fly species and trypanosome prevalence in relation to climate in the Maasai Steppe of Tanzania in 2014-2015. Tsetse flies were captured using odor-baited Epsilon traps deployed in ten sites selected through random subsampling of the major vegetation types in the area. Fly species were identified morphologically and trypanosome species classified using PCR. The climate dataset was acquired from the African Flood and Drought Monitor repository. Three species of tsetse flies were identified: G. swynnertoni (70.8%), G. m. morsitans (23.4%), and G.pallidipes (5.8%). All species showed monthly changes in abundance with most of the flies collected in July. The relative abundance of G. m. morsitans and G. swynnertoni was negatively correlated with maximum and minimum temperature, respectively. Three trypanosome species were recorded: T. vivax (82.1%), T. brucei (8.93%), and T. congolense (3.57%). The peak of trypanosome infections in the flies was found in October and was three months after the tsetse abundance peak; prevalence was negatively correlated with tsetse abundance. A strong positive relationship was found between trypanosome prevalence and temperature. In conclusion, we find that trypanosome prevalence is dependent on fly availability, and temperature drives both tsetse fly relative abundance and trypanosome prevalence.
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Affiliation(s)
- Happiness J Nnko
- School of Life Sciences and Bioengineering, The Nelson Mandela African Institution of Science and Technology, Arusha 477, Tanzania
- Department of Geography and Environmental Studies, University of Dodoma, Dodoma, Tanzania
| | - Anibariki Ngonyoka
- School of Life Sciences and Bioengineering, The Nelson Mandela African Institution of Science and Technology, Arusha 477, Tanzania
- Department Conservation Biology, University of Dodoma, Dodoma, Tanzania
| | - Linda Salekwa
- Genome Science Centre and Department of Microbiology, Parasitology and Immunology, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Anna B Estes
- School of Life Sciences and Bioengineering, The Nelson Mandela African Institution of Science and Technology, Arusha 477, Tanzania
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences and Department of Biology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Peter J Hudson
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences and Department of Biology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Paul S Gwakisa
- School of Life Sciences and Bioengineering, The Nelson Mandela African Institution of Science and Technology, Arusha 477, Tanzania
- Genome Science Centre and Department of Microbiology, Parasitology and Immunology, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Isabella M Cattadori
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences and Department of Biology, Pennsylvania State University, University Park, PA 16802, U.S.A
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Kampmann ML, Schnell IB, Jensen RH, Axtner J, Sander AF, Hansen AJ, Bertelsen MF, Greenwood AD, Gilbert MTP, Wilting A. Leeches as a source of mammalian viral DNA and RNA—a study in medicinal leeches. EUR J WILDLIFE RES 2017. [DOI: 10.1007/s10344-017-1093-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Loop-Mediated Isothermal Amplification Test for Trypanosoma gambiense Group 1 with Stem Primers: A Molecular Xenomonitoring Test for Sleeping Sickness. J Trop Med 2017; 2017:8630708. [PMID: 28321260 PMCID: PMC5339478 DOI: 10.1155/2017/8630708] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/06/2017] [Indexed: 11/18/2022] Open
Abstract
The World Health Organization has targeted Human African Trypanosomiasis (HAT) for elimination by 2020 with zero incidence by 2030. To achieve and sustain this goal, accurate and easy-to-deploy diagnostic tests for Gambian trypanosomiasis which accounts for over 98% of reported cases will play a crucial role. Most needed will be tools for surveillance of pathogen in vectors (xenomonitoring) since population screening tests are readily available. The development of new tests is expensive and takes a long time while incremental improvement of existing technologies that have potential for xenomonitoring may offer a shorter pathway to tools for HAT surveillance. We have investigated the effect of including a second set of reaction accelerating primers (stem primers) to the standard T. brucei gambiense LAMP test format. The new test format was analyzed with and without outer primers. Amplification was carried out using Rotorgene 6000 and the portable ESE Quant amplification unit capable of real-time data output. The stem LAMP formats indicated shorter time to results (~8 min), were 10–100-fold more sensitive, and indicated higher diagnostic sensitivity and accuracy compared to the standard LAMP test. It was possible to confirm the predicted product using ESE melt curves demonstrating the potential of combining LAMP and real-time technologies as possible tool for HAT molecular xenomonitoring.
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Cunningham LJ, Lingley JK, Haines LR, Ndung’u JM, Torr SJ, Adams ER. Illuminating the Prevalence of Trypanosoma brucei s.l. in Glossina Using LAMP as a Tool for Xenomonitoring. PLoS Negl Trop Dis 2016; 10:e0004441. [PMID: 26890882 PMCID: PMC4758712 DOI: 10.1371/journal.pntd.0004441] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 01/16/2016] [Indexed: 11/23/2022] Open
Abstract
Background As the reality of eliminating human African trypanosomiasis (HAT) by 2020 draws closer, the need to detect and identify the remaining areas of transmission increases. Here, we have explored the feasibility of using commercially available LAMP kits, designed to detect the Trypanozoon group of trypanosomes, as a xenomonitoring tool to screen tsetse flies for trypanosomes to be used in future epidemiological surveys. Methods and Findings The DNA extraction method was simplified and worked with the LAMP kits to detect a single positive fly when pooled with 19 negative flies, and the absolute lowest limit of detection that the kits were able to work at was the equivalent of 0.1 trypanosome per ml. The DNA from Trypanosoma brucei brucei could be detected six days after the fly had taken a blood meal containing dead trypanosomes, and when confronted with a range of non-target species, from both laboratory-reared flies and wild-caught flies, the kits showed no evidence of cross-reacting. Conclusion We have shown that it is possible to use a simplified DNA extraction method in conjunction with the pooling of tsetse flies to decrease the time it would take to screen large numbers of flies for the presence of Trypanozoon trypanosomes. The use of commercially-available LAMP kits provides a reliable and highly sensitive tool for xenomonitoring and identifying potential sleeping sickness transmission sites. Recent control efforts have reduced the global incidence of Gambiense human African trypanosomiasis (HAT) to <5,000 cases per year, strengthening the prospect of eliminating the disease as a public health problem by 2020. To meet this goal, new methods for identifying transmission must be explored to provide a cost-effective way of identifying hotspots and areas of re-emergence; commercial loop-mediated isothermal amplification (LAMP) kits that detect the trypanosome subgenus, responsible for the two forms of sleeping sickness, have been developed. The LAMP kits were tested to assess their sensitivity, specificity and suitability as a method of screening the vector of the disease, Glossina, for Trypanozoon infection, in xenomonitoring campaigns. A simplified DNA extraction process that worked in conjunction with the LAMP kits on pooled samples demonstrated a faster method of processing large numbers of flies compared to other molecular tools. The kits performed well in our experiments and demonstrated the ability of detecting low levels of target DNA, equivalent to 0.1 trypanosome per ml. The lack of cross reaction with non-target species of trypanosomes makes the kits reliable in so far as they will only react with the Trypanozoon group of parasites of which the two human forms of the disease belong, however, further species-specific tests would need to be undertaken to identify HAT areas on selected samples.
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Affiliation(s)
- Lucas J. Cunningham
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- * E-mail:
| | - Jessica K. Lingley
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Lee R. Haines
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Joseph M. Ndung’u
- Neglected Tropical Disease Programme, Foundation for Innovation New Diagnostics (FIND), Geneva, Switzerland
| | - Stephen J. Torr
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Emily R. Adams
- Parasitology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Warwick Medical School, University of Warwick, Coventry, United Kingdom
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Deng J, Pei J, Gou H, Ye Z, Liu C, Chen J. Rapid and simple detection of Japanese encephalitis virus by reverse transcription loop-mediated isothermal amplification combined with a lateral flow dipstick. J Virol Methods 2014; 213:98-105. [PMID: 25512133 DOI: 10.1016/j.jviromet.2014.12.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 11/07/2014] [Accepted: 12/05/2014] [Indexed: 11/26/2022]
Abstract
Japanese encephalitis virus (JEV) is a major cause of viral encephalitis in geographical areas, such as Asia and Western Pacific, where it is a threat to human and animal health. To control this disease, it is necessary to develop a rapid, simple, accurate method for diagnosis. In this study, a method based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) coupled with a lateral flow dipstick (LFD) has been developed to detect JEV (JEV RT-LAMP-LFD). The entire assay can be completed within 70 min, and in this study, no false positive results were observed when other pathogens were tested, indicating that the assay is a highly specific method for the detection of JEV. Additionally, the sensitivity of the RT-LAMP-LFD assay for SA14-14-2 strain was 50 pg of RNA, which was similar to that of RT-PCR and RT-LAMP combined with gel electrophoresis, and was 10-fold more sensitive than RT-LAMP combined with calcein. The limit of detection for this assay was 5 pg of RNA. In addition, no false positive results were obtained with 14 serum samples. Our results indicate that this RT-LAMP-LFD assay will be of great value for JEV infection testing due to its rapid and highly specific and sensitive properties.
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Affiliation(s)
- Jieru Deng
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jingjing Pei
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Hongchao Gou
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Zuodong Ye
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Cuicui Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Jinding Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
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