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Minopoli A, Scardapane E, Ventura BD, Tanner JA, Offenhäusser A, Mayer D, Velotta R. Double-Resonant Nanostructured Gold Surface for Multiplexed Detection. ACS Appl Mater Interfaces 2022; 14:6417-6427. [PMID: 35089707 PMCID: PMC8832399 DOI: 10.1021/acsami.1c23438] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/18/2022] [Indexed: 05/17/2023]
Abstract
A novel double-resonant plasmonic substrate for fluorescence amplification in a chip-based apta-immunoassay is herein reported. The amplification mechanism relies on plasmon-enhanced fluorescence (PEF) effect. The substrate consists of an assembly of plasmon-coupled and plasmon-uncoupled gold nanoparticles (AuNPs) immobilized onto a glass slide. Plasmon-coupled AuNPs are hexagonally arranged along branch patterns whose resonance lies in the red band (∼675 nm). Plasmon-uncoupled AuNPs are sprinkled onto the substrate, and they exhibit a narrow resonance at 524 nm. Numerical simulations of the plasmonic response of the substrate through the finite-difference time-domain (FDTD) method reveal the presence of electromagnetic hot spots mainly confined in the interparticle junctions. In order to realize a PEF-based device for potential multiplexing applications, the plasmon resonances are coupled with the emission peak of 5-carboxyfluorescein (5-FAM) fluorophore and with the excitation/emission peaks of cyanine 5 (Cy5). The substrate is implemented in a malaria apta-immunoassay to detect Plasmodium falciparum lactate dehydrogenase (PfLDH) in human whole blood. Antibodies against Plasmodium biomarkers constitute the capture layer, whereas fluorescently labeled aptamers recognizing PfLDH are adopted as the top layer. The fluorescence emitted by 5-FAM and Cy5 fluorophores are linearly correlated (logarithm scale) to the PfLDH concentration over five decades. The limits of detection are 50 pM (1.6 ng/mL) with the 5-FAM probe and 260 fM (8.6 pg./mL) with the Cy5 probe. No sample preconcentration and complex pretreatments are required. Average fluorescence amplifications of 160 and 4500 are measured in the 5-FAM and Cy5 channel, respectively. These results are reasonably consistent with those worked out by FDTD simulations. The implementation of the proposed approach in multiwell-plate-based bioassays would lead to either signal redundancy (two dyes for a single analyte) or to a simultaneous detection of two analytes by different dyes, the latter being a key step toward high-throughput analysis.
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Affiliation(s)
- Antonio Minopoli
- Department
of Physics “E. Pancini”, University
Federico II, Via Cintia 26, 80126 Naples, Italy
- Institute
of Biological Information Processing (IBI-3), Bioelectronics, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Emanuela Scardapane
- Department
of Physics “E. Pancini”, University
Federico II, Via Cintia 26, 80126 Naples, Italy
| | | | - Julian A. Tanner
- School
of Biomedical Sciences, University of Hong
Kong, Hong Kong, China
| | - Andreas Offenhäusser
- Institute
of Biological Information Processing (IBI-3), Bioelectronics, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Dirk Mayer
- Institute
of Biological Information Processing (IBI-3), Bioelectronics, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Raffaele Velotta
- Department
of Physics “E. Pancini”, University
Federico II, Via Cintia 26, 80126 Naples, Italy
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Liu Q, Zhang MY, Zhao B, Chen Y, Jiang W, Geng XL, Wang Q. Diagnostic Value of Circulating Antigens in the Serum of Piglets with Experimental Acute Toxoplasmosis. J Immunol 2022; 208:697-706. [PMID: 35022274 DOI: 10.4049/jimmunol.2100640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/19/2021] [Indexed: 06/14/2023]
Abstract
Toxoplasmosis, caused by Toxoplasma gondii, an apicomplexan parasite, infects all warm-blooded animals, including a third of the human population. Laboratory diagnosis of acute toxoplasmosis is based on the detection of anti-T. gondii IgM and IgG and T. gondii nucleic acid; however, these assays have certain limitations. Circulating Ags (CAgs) are reliable diagnostic indicators of acute infection. In this study, we established a model of acute T. gondii infection in Large White pigs. CAg levels peaked between 3 and 5 d after inoculation, and 28 CAgs were identified using an immunoprecipitation-shotgun approach, among which dolichol-phosphate-mannose synthase family protein (TgDPM), C3HC zinc finger-like protein (TgZFLP3), and ribosomal protein RPL7 (TgRPL7) were selected to further investigate their value in the diagnosis of acute toxoplasmosis. Immunofluorescence assays revealed that TgDPM and TgRPL7 were localized in the membrane surface, while TgZFLP3 was localized in the apical end. Western blotting revealed the presence of the three proteins in the serum during acute infection. Indirect ELISA results indicate that TgZFLP3 is likely to be a novel candidate for the diagnosis of acute toxoplasmosis. However, these three proteins may not be useful as candidate vaccines against toxoplasmosis owing to their low protective ability. In addition, deletion of the zflp3 gene partially attenuated virulence in Kunming mice. Collectively, we identified 28 CAgs in the serum of piglets with experimental acute toxoplasmosis and confirmed that TgZFLP3 is a potential biomarker for acute T. gondii infection. The results of this study provide data to improve the detection efficiency of acute toxoplasmosis.
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Affiliation(s)
- Qi Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, China
| | - Man-Yu Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, China
| | - Bing Zhao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, China
| | - Yun Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, China
| | - Wei Jiang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, China
| | - Xiao-Ling Geng
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, China
| | - Quan Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, China
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3
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Tounkara M, Boulangé A, Thonnus M, Bringaud F, Bélem AMG, Bengaly Z, Thévenon S, Berthier D, Rivière L. Novel protein candidates for serodiagnosis of African animal trypanosomosis: Evaluation of the diagnostic potential of lysophospholipase and glycerol kinase from Trypanosoma brucei. PLoS Negl Trop Dis 2021; 15:e0009985. [PMID: 34919562 PMCID: PMC8719729 DOI: 10.1371/journal.pntd.0009985] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 12/31/2021] [Accepted: 11/08/2021] [Indexed: 11/26/2022] Open
Abstract
African trypanosomosis, a parasitic disease caused by protozoan parasites transmitted by tsetse flies, affects both humans and animals in sub-Saharan Africa. While the human form (HAT) is now limited to foci, the animal form (AAT) is widespread and affects the majority of sub-Saharan African countries, and constitutes a real obstacle to the development of animal breeding. The control of AAT is hampered by a lack of standardized and easy-to used diagnosis tools. This study aimed to evaluate the diagnostic potential of TbLysoPLA and TbGK proteins from Trypanosoma brucei brucei for AAT serodiagnosis in indirect ELISA using experimental and field sera, individually, in combination, and associated with the BiP C-terminal domain (C25) from T. congolense. These novel proteins were characterized in silico, and their sequence analysis showed strong identities with their orthologs in other trypanosomes (more than 60% for TbLysoPLA and more than 82% for TbGK). TbLysoPLA displays a low homology with cattle (<35%) and Piroplasma (<15%). However, TbGK shares more than 58% with cattle and between 45–55% with Piroplasma. We could identify seven predicted epitopes on TbLysoPLA sequence and 14 potential epitopes on TbGK. Both proteins were recombinantly expressed in Escherichia coli. Their diagnostic potential was evaluated by ELISA with sera from cattle experimentally infected with T. congolense and with T.b. brucei, sera from cattle naturally infected with T. congolense, T. vivax and T.b. brucei. Both proteins used separately had poor diagnostic performance. However, used together with the BiP protein, they showed 60% of sensitivity and between 87–96% of specificity, comparable to reference ELISA tests. In conclusion, we showed that the performance of the protein combinations is much better than the proteins tested individually for the diagnosis of AAT. African animal trypanosomiasis (AAT) is an endemic disease in sub-Saharan Africa that hinders the development of livestock production on the continent. The control of the disease is based on chemotherapy, vector control and diagnosis. Misuse, as well as the continuous/regular use of a limited number of anti-trypanosomal drugs, is responsible for the appearance of increasingly drug-resistant strains of trypanosomes. In terms of serological diagnosis, the most efficient test at present suffers from a lack of reagent standardization. Unfortunately, even the most promising candidates fail due to low sensitivity in primately or chronically infected animals. Based on this observation it seems obvious that diagnosis must be revisited. In this study we evaluated the diagnostic potential of two Trypanosoma brucei proteins, TbLysoPLA and TbGK, in indirect ELISA for antibody detection. To provide a proof of concept that the judicious association of immunoreactive proteins could improve the sensitivity and specificity of tests based on recombinant antigens, we used these molecules alone and then in combination, associated or not with the BiP protein of T. congolense. The evaluation in serological diagnosis showed that the two proteins used separately had a poor performance. However, when used together with the BiP protein, they showed a sensitivity of 60% and a specificity between 87 and 96%, comparable to the reference tests. It shows for the first time that the performance of protein combinations is much better than that of the proteins tested individually for the diagnosis of AAT.
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Affiliation(s)
- Magamba Tounkara
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
- CIRAD, UMR INTERTRYP, Bobo-Dioulasso 01, Burkina Faso
- Centre International de Recherche-Développement sur l’Élevage en zone Subhumide (CIRDES), Bobo-Dioulasso 01, Burkina Faso
| | - Alain Boulangé
- CIRAD, UMR INTERTRYP, Bobo-Dioulasso 01, Burkina Faso
- CIRAD, UMR INTERTRYP, Montpellier, France
- INTERTRYP, Univ Montpellier, CIRAD, IRD, Montpellier, France
| | - Magali Thonnus
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | - Frédéric Bringaud
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
| | | | - Zakaria Bengaly
- Centre International de Recherche-Développement sur l’Élevage en zone Subhumide (CIRDES), Bobo-Dioulasso 01, Burkina Faso
| | - Sophie Thévenon
- CIRAD, UMR INTERTRYP, Montpellier, France
- INTERTRYP, Univ Montpellier, CIRAD, IRD, Montpellier, France
| | - David Berthier
- CIRAD, UMR INTERTRYP, Montpellier, France
- INTERTRYP, Univ Montpellier, CIRAD, IRD, Montpellier, France
| | - Loïc Rivière
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux, France
- * E-mail:
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Moore CP, Pieterson K, DeSousa JM, Toote LE, Wright DW. Characterization and utility of immobilized metal affinity-functionalized cellulose membranes for point-of-care malaria diagnostics. J Chromatogr B Analyt Technol Biomed Life Sci 2021; 1186:123023. [PMID: 34788723 PMCID: PMC8633758 DOI: 10.1016/j.jchromb.2021.123023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 11/18/2022]
Abstract
Immobilized metal affinity chromatography (IMAC) is a well-established technique for protein separation and purification. IMAC has been previously utilized to capture the malaria biomarker histidine-rich protein 2 (HRP2) from blood, enhancing the sensitivity of field-appropriate diagnostic tools such as lateral flow assays. However, little work has been done to translate this technique to a truly field-usable design. In this study, IMAC-functionalized cellulose membranes are created and characterized fully for future use in applied malaria diagnostics. IMAC-functionalized cellulose membranes were investigated across a range of cellulose substrates, IMAC ligands, and divalent transition metals before use in a capture and elution flowthrough workflow. Following characterization and optimization, it was found that iminodiacetic acid bound to Zn(II) was the most promising ligand-metal pair, with three available coordination sites and a molar loading capacity of 57.7 μmol of metal/cm3 of cellulose. Using these parameters, more than 99% of HRP2 was captured from a large-volume lysed blood sample in a simple flow-through assay and 89% of the captured protein was eluted from the membrane using the chelating compound ethylenediaminetetraacetic acid. Use of this enhancement protocol on an in-house HRP2 lateral flow assay (LFA) yielded a limit of detection of 7 parasites/μL, a 15.8x enhancement factor compared to traditional LFA methods.
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Affiliation(s)
- Carson P Moore
- Vanderbilt University, Department of Chemistry, 1234 Stevenson Center Lane, Nashville, TN 37212, USA
| | - Kristina Pieterson
- Vanderbilt University, Department of Chemistry, 1234 Stevenson Center Lane, Nashville, TN 37212, USA
| | - Jenna M DeSousa
- Vanderbilt University, Department of Chemistry, 1234 Stevenson Center Lane, Nashville, TN 37212, USA
| | - Lauren E Toote
- Elizabethtown College, Department of Chemistry and Biochemistry, 1 Alpha Drive, Elizabethtown, PA 17022, USA
| | - David W Wright
- Vanderbilt University, Department of Chemistry, 1234 Stevenson Center Lane, Nashville, TN 37212, USA.
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Temporão A, Sanches-Vaz M, Luís R, Nunes-Cabaço H, Smith TK, Prudêncio M, Figueiredo LM. Excreted Trypanosoma brucei proteins inhibit Plasmodium hepatic infection. PLoS Negl Trop Dis 2021; 15:e0009912. [PMID: 34714824 PMCID: PMC8580256 DOI: 10.1371/journal.pntd.0009912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 11/10/2021] [Accepted: 10/15/2021] [Indexed: 11/25/2022] Open
Abstract
Malaria, a disease caused by Plasmodium parasites, remains a major threat to public health globally. It is the most common disease in patients with sleeping sickness, another parasitic illness, caused by Trypanosoma brucei. We have previously shown that a T. brucei infection impairs a secondary P. berghei liver infection and decreases malaria severity in mice. However, whether this effect requires an active trypanosome infection remained unknown. Here, we show that Plasmodium liver infection can also be inhibited by the serum of a mouse previously infected by T. brucei and by total protein lysates of this kinetoplastid. Biochemical characterisation showed that the anti-Plasmodium activity of the total T. brucei lysates depends on its protein fraction, but is independent of the abundant variant surface glycoprotein. Finally, we found that the protein(s) responsible for the inhibition of Plasmodium infection is/are present within a fraction of ~350 proteins that are excreted to the bloodstream of the host. We conclude that the defence mechanism developed by trypanosomes against Plasmodium relies on protein excretion. This study opens the door to the identification of novel antiplasmodial intervention strategies.
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Affiliation(s)
- Adriana Temporão
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Margarida Sanches-Vaz
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Rafael Luís
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Helena Nunes-Cabaço
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Terry K. Smith
- Schools of Biology and Chemistry Biomedical Sciences Research Complex, The North Haugh, The University, St. Andrews, Scotland, United Kingdom
| | - Miguel Prudêncio
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Luisa M. Figueiredo
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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Hagos DG, Kebede Y, Abdulkader M, Nigus E, Gessesse Arefaine Z, Nega G, Schallig HDF, Wolday D. Effect of rK39 testing in guiding treatment initiation and outcome in patients with visceral leishmaniasis in Ethiopia: A prospective cohort study. PLoS One 2021; 16:e0253303. [PMID: 34125865 PMCID: PMC8202953 DOI: 10.1371/journal.pone.0253303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/01/2021] [Indexed: 11/19/2022] Open
Abstract
Background The rapid diagnostic test (RDT) rK39 is currently being used for routine diagnosis of visceral leishmaniasis (VL) in East Africa. However, continuous monitoring of the performance of the assay, in particular its impact on the clinical decision in initiating anti-leishmanial treatment and outcomes remains needed as there are concerns about the diagnostic performance of this test. Methods VL patients prospectively enrolled in a diagnostic trial and with rK39 RDT were included. We evaluated the effect of rK39 testing in guiding treatment initiation and outcome. On the basis of rK39 RDT test result as well as clinical case definition for VL and microscopy examination, the clinicians decide whether to initiate VL therapy or not. Poisson regression models were used to identify factors associated with a decision to initiate VL therapy. In addition, treatment outcomes of those who received VL therapy were compared to those who received non-VL treatment. Results Of 324 VL suspects enrolled, 184 (56.8%) were rK39+ and 140 (43.2%) were rK39‒. In addition, microscopy exam was done on tissue aspirates from a sub-population (140 individuals), which is 43.2% of the suspected cases, comprising of 117 (63.6%) rK39+ and only 23 (16.4%) rK39‒ cases. Of those with microscopy examination, only 87 (62.1%) were found positive. Among 184 (56.8%) patients without microscopy, 67 (36.4%) were rK39+, of whom 83 (65.9%) were positive by microscopy, 21 (16.7%) were negative by microscopy and 22 (17.5%) had no microscopy results. On the other hand, of those who did not receive VL treatment 58/189 (30.7%) were rK39+ and 131 (69.3%) were rK39‒. Of the rK39+ cases who did not receive VL therapy, only 1 (1.7%) patient was microscopy positive, 12 (20.7%) were negative and 45 (77.6%) patients had no microscopy result. Of the rK39‒ cases (n = 131) who did not receive VL treatment, 16 were microscopy negative and 115 without microscopy exams. Whereas positive rK39 result [adjusted Relative Risk (aRR) 0.69; 95% CI: 0.49–0.96, p = 0.029] and positive microscopy results (aRR 0.03; 95% CI: 0.00–0.24, p = 0.001) were independently associated with VL treatment, having confirmed diagnosis other than VL (aRR 1.64; 95% CI: 1.09–2.46, p = 0.018) was independently associated with initiation of non-VL therapy. The proportion of rK39+ patients who received non-VL treatment with no improvement outcome was significantly higher when compared to those who received VL treatment (24.1%, 95% CI: 14.62–37.16 vs. 11.9%, 95%CI: 7.26–18.93; p<0.0001). Conclusion The study shows that a significant proportion of patients with rK39+ results were undertreated. Failure to do microscopy was associated with lack of improved clinical outcome. Including an additional simple point-of-care assay in the diagnostic work-up is urgently needed to correctly identify VL cases and to prevent morbidity and mortality associated with the disease.
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Affiliation(s)
- Dawit Gebreegzabher Hagos
- Mekelle University College of Health Sciences, Mekelle, Ethiopia
- Department of Medical Microbiology, Parasitology Unit, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Yazezew Kebede
- Mekelle University College of Health Sciences, Mekelle, Ethiopia
| | | | - Etsay Nigus
- Mekelle University College of Health Sciences, Mekelle, Ethiopia
| | | | - Gebreab Nega
- Mekelle University College of Health Sciences, Mekelle, Ethiopia
| | - Henk D. F. Schallig
- Department of Medical Microbiology, Parasitology Unit, Amsterdam University Medical Center, Amsterdam, The Netherlands
| | - Dawit Wolday
- Mekelle University College of Health Sciences, Mekelle, Ethiopia
- * E-mail: ,
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van den Hoogen LL, Herman C, Présumé J, Romilus I, Existe A, Boncy J, Joseph V, Stresman G, Tetteh KKA, Drakeley C, Chang MA, Lemoine JF, Eisele TP, Rogier E, Ashton RA. Rapid Screening for Non-falciparum Malaria in Elimination Settings Using Multiplex Antigen and Antibody Detection: Post Hoc Identification of Plasmodium malariae in an Infant in Haiti. Am J Trop Med Hyg 2021; 104:2139-2145. [PMID: 33819177 PMCID: PMC8176464 DOI: 10.4269/ajtmh.20-1450] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 12/24/2020] [Indexed: 01/24/2023] Open
Abstract
Haiti is targeting malaria elimination by 2025. The Grand'Anse department in southwestern Haiti experiences one-third to half of all nationally reported Plasmodium falciparum cases. Although there are historical reports of Plasmodium vivax and Plasmodium malariae, today, non-falciparum infections would remain undetected because of extensive use of falciparum-specific histidine-rich protein 2 (HRP2) rapid diagnostic tests (RDT) at health facilities. A recent case-control study was conducted in Grand'Anse to identify risk factors for P. falciparum infection using HRP2-based RDTs (n = 1,107). Post hoc multiplex Plasmodium antigenemia and antibody (IgG) detection by multiplex bead assay revealed one blood sample positive for pan-Plasmodium aldolase, negative for P. falciparum HRP2, and positive for IgG antibodies to P. malariae. Based on this finding, we selected 52 samples with possible P. malariae infection using IgG and antigenemia data and confirmed infection status by species-specific PCR. We confirmed one P. malariae infection in a 6-month-old infant without travel history. Congenital P. malariae could not be excluded. However, our finding-in combination with historical reports of P. malariae-warrants further investigation into the presence and possible extent of non-falciparum malaria in Haiti. Furthermore, we showed the use of multiplex Plasmodium antigen and IgG detection in selecting samples of interest for subsequent PCR analysis, thereby reducing costs as opposed to testing all available samples by PCR. This is of specific use in low-transmission or eliminating settings where infections are rare.
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Affiliation(s)
- Lotus L. van den Hoogen
- Center for Applied Malaria Research and Evaluation, Tropical Medicine Department, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | | | | | | | | | - Jacques Boncy
- Laboratoire National de Santé Publique, Port-au-Prince, Haiti
| | - Vena Joseph
- Center for Applied Malaria Research and Evaluation, Tropical Medicine Department, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Gillian Stresman
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kevin K. A. Tetteh
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris Drakeley
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Michelle A. Chang
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jean F. Lemoine
- Ministère de la Santé Publique et de la Population, Port-au-Prince, Haiti
| | - Thomas P. Eisele
- Center for Applied Malaria Research and Evaluation, Tropical Medicine Department, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
| | - Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Ruth A. Ashton
- Center for Applied Malaria Research and Evaluation, Tropical Medicine Department, Tulane University School of Public Health and Tropical Medicine, New Orleans, Louisiana
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Vijaykumar LK, Chikkachowdappa PG, Venkatappa MH, Rizvan A, Yogisharadhya R, Shivachandra SB, Bayyappa MRG. Evaluation of recombinant BgSA3 protein based indirect-ELISA for sero-diagnosis and sero-surveillance of Babesia gibsoni in dogs. Vet Parasitol 2020; 289:109338. [PMID: 33359970 DOI: 10.1016/j.vetpar.2020.109338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 11/18/2022]
Abstract
Canine babesiosis, a tick-borne haemoprotozoan disease of dogs, is of significance globally due to its rapid spread. A precise confirmatory diagnosis is required to curtail the rapid spread of infection. Our study described the evaluation of recombinant BgSA3 protein based indirect ELISA for sero-diagnosis and sero-surveillance of Babesia gibsoni infection in dogs. A partial BgSA3 gene segment (1921 bp) of B. gibsoni, encoding for recombinant truncated BgSA3 (75 kDa) protein devoid of predicted signal peptide (23 aa) at N-terminus and transmembrane region (20 aa) at C-terminus, was expressed in E. coli using a pET28a(+) vector. The rBgSA3 protein purified under native conditions using Ni-NTA superflow cartridge was confirmed by SDS-PAGE and Western blotting using sera from dogs infected/uninfected with B. gibsoni, and erythrocyte lysate/ plasma from infected/uninfected dogs. The rBgSA3 protein was specific only to B. gibsoni antibodies but did not react with uninfected sera. Further, rBgSA3 protein was evaluated for sero-diagnosis/sero-surveillance using Indirect-ELISA format. There was no cross reactivity to B. vogeli, E. canis, H. canis and D. repens infected dogs serum samples. The diagnostic sensitivity and specificity of rBgSA3 based I-ELISA was found to be 86.4 and 93.1 % respectively, in comparison with cytb based PCR assay. Additionally, rBgSA3-ELISA evaluated using survey serum samples (n = 287), detected 11.85 % samples as positive. In conclusion, B. gibsoni infection, an emerging disease is prevalent in the present study area and the standardized rBgSA3 protein based indirect-ELISA was found to be a specific and sensitive test for large scale sero-diagnosis and sero-surveillance of B. gibsoni infection in dogs.
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Affiliation(s)
- Lavanya K Vijaykumar
- Veterinary College, Karnataka Veterinary, Animal and Fishries Sciences University (KVAFSU), Bengaluru, 560024, Karnataka, India; Institute of Animal Health and Veterinary Biologicals (IAH&VB), Bengaluru, 560024, Karnataka, India
| | | | - Mohan H Venkatappa
- Veterinary College, Karnataka Veterinary, Animal and Fishries Sciences University (KVAFSU), Bengaluru, 560024, Karnataka, India
| | - Apsana Rizvan
- Institute of Animal Health and Veterinary Biologicals (IAH&VB), Bengaluru, 560024, Karnataka, India
| | - Revanaiah Yogisharadhya
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, 560064, Karnataka, India
| | | | - Manjunatha Reddy G Bayyappa
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, 560064, Karnataka, India.
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Upmanyu K, Matlani M, Yadav P, Rathi U, Mallick PK, Singh R. Allelic variation of msp-3α gene in Plasmodium vivax isolates and its correlation with the severity of disease in vivax malaria. Infect Genet Evol 2020; 85:104530. [PMID: 32896637 DOI: 10.1016/j.meegid.2020.104530] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 08/14/2020] [Accepted: 08/31/2020] [Indexed: 11/17/2022]
Abstract
Malaria is a global socio-economic burden of which Plasmodium vivax contributes for about 70-80 million cases on an annual basis worldwide and 60-65% cases in India. Diversity observed in highly polymorphic Merozoite Surface Protein-3α (msp-3α) encoded by MSP-3 gene family, has been used efficiently for genotyping of P. vivax infection. This study aims to correlate the severity of clinical symptoms with parasite load, genotype of P. vivax and multiplicity of infection. Based on clinical symptoms classification, 31 (67.9%) out of 46 cases were found to be severe while 15 (32.6%) were non-severe and correlation of the severity of vivax infection with parasite load was not observed. Analysis of msp3-α allele genotype showed that out of 31 severe cases, 19 (61.2%) were single-clone infection cases whereas 12 (38.7%) were multi-clone infections. Similarly, out of 15 non-severe cases, 9 (60%) were single clone and 6 (40%) were multi-clone infections indicating the absence of a correlation between the multiplicity of infection and disease severity. Allele frequency observed was 65.9%, 23.4%, 23.4%, and 28.2% for allele A, B, C and D, respectively. An important finding was the greater distribution of allele D than alleles B and C, which has been reported as a rare allele otherwise. Further, of 13 cases with allele D, 76.9% (10/13) cases were severe. This study showed the absence of a correlation between the severity of clinical symptoms with parasite load and multiplicity of infection but at the same time drives a possibility of severe vivax malarial symptoms to have an association with the persistence of allele D in the population. This upon exploration can lead to the development of a target in detection of severe cases of malaria.
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Affiliation(s)
- Kirti Upmanyu
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Monika Matlani
- Department of Microbiology, VMMC, Safdarjung Hospital Campus, New Delhi, India
| | - Priya Yadav
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India
| | - Utkarsh Rathi
- Department of Microbiology, VMMC, Safdarjung Hospital Campus, New Delhi, India
| | | | - Ruchi Singh
- ICMR-National Institute of Pathology, Safdarjung Hospital Campus, New Delhi, India.
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Chebore W, Zhou Z, Westercamp N, Otieno K, Shi YP, Sergent SB, Rondini KA, Svigel SS, Guyah B, Udhayakumar V, Halsey ES, Samuels AM, Kariuki S. Assessment of molecular markers of anti-malarial drug resistance among children participating in a therapeutic efficacy study in western Kenya. Malar J 2020; 19:291. [PMID: 32795367 PMCID: PMC7427724 DOI: 10.1186/s12936-020-03358-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/04/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Anti-malarial drug resistance remains a major threat to global malaria control efforts. In Africa, Plasmodium falciparum remains susceptible to artemisinin-based combination therapy (ACT), but the emergence of resistant parasites in multiple countries in Southeast Asia and concerns over emergence and/or spread of resistant parasites in Africa warrants continuous monitoring. The World Health Organization recommends that surveillance for molecular markers of resistance be included within therapeutic efficacy studies (TES). The current study assessed molecular markers associated with resistance to Artemether-lumefantrine (AL) and Dihydroartemisinin-piperaquine (DP) from samples collected from children aged 6-59 months enrolled in a TES conducted in Siaya County, western Kenya from 2016 to 2017. METHODS Three hundred and twenty-three samples collected pre-treatment (day-0) and 110 samples collected at the day of recurrent parasitaemia (up to day 42) were tested for the presence of drug resistance markers in the Pfk13 propeller domain, and the Pfmdr1 and Pfcrt genes by Sanger sequencing. Additionally, the Pfpm2 gene copy number was assessed by real-time polymerase chain reaction. RESULTS No mutations previously associated with artemisinin resistance were detected in the Pfk13 propeller region. However, other non-synonymous mutations in the Pfk13 propeller region were detected. The most common mutation found on day-0 and at day of recurrence in the Pfmdr1 multidrug resistance marker was at codon 184F. Very few mutations were found in the Pfcrt marker (< 5%). Within the DP arm, all recrudescent cases (8 sample pairs) that were tested for Pfpm2 gene copy number had a single gene copy. None of the associations between observed mutations and treatment outcomes were statistically significant. CONCLUSION The results indicate absence of Pfk13 mutations associated with parasite resistance to artemisinin in this area and a very high proportion of wild-type parasites for Pfcrt. Although the frequency of Pfmdr1 184F mutations was high in these samples, the association with treatment failure did not reach statistical significance. As the spread of artemisinin-resistant parasites remains a possibility, continued monitoring for molecular markers of ACT resistance is needed to complement clinical data to inform treatment policy in Kenya and other malaria-endemic regions.
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Affiliation(s)
- Winnie Chebore
- Kenya Medical Research Institute, Centre for Global Health Research, P.O. Box 1578, Kisumu, Kenya
- Maseno University, Kisumu, Kenya
| | - Zhiyong Zhou
- Centers for Disease Control and Prevention, Malaria Branch, Atlanta, GA, USA
| | - Nelli Westercamp
- Centers for Disease Control and Prevention, Malaria Branch, Atlanta, GA, USA
| | - Kephas Otieno
- Kenya Medical Research Institute, Centre for Global Health Research, P.O. Box 1578, Kisumu, Kenya
| | - Ya Ping Shi
- Centers for Disease Control and Prevention, Malaria Branch, Atlanta, GA, USA
| | - Sheila B Sergent
- Centers for Disease Control and Prevention, Malaria Branch, Atlanta, GA, USA
| | - Kelsey Anne Rondini
- Centers for Disease Control and Prevention, Malaria Branch, Atlanta, GA, USA
- Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Samaly Souza Svigel
- Centers for Disease Control and Prevention, Malaria Branch, Atlanta, GA, USA
| | | | | | - Eric S Halsey
- Centers for Disease Control and Prevention, Malaria Branch, Atlanta, GA, USA
- U.S. President's Malaria Initiative, Atlanta, GA, USA
| | - Aaron M Samuels
- Centers for Disease Control and Prevention, Malaria Branch, Atlanta, GA, USA
- Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Simon Kariuki
- Kenya Medical Research Institute, Centre for Global Health Research, P.O. Box 1578, Kisumu, Kenya.
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11
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Lumbala C, Matovu E, Sendagire H, Kazibwe AJN, Likwela JL, Muhindo Mavoko H, Kayembe S, Lutumba P, Biéler S, Van Geertruyden JP, Ndung’u JM. Performance evaluation of a prototype rapid diagnostic test for combined detection of gambiense human African trypanosomiasis and malaria. PLoS Negl Trop Dis 2020; 14:e0008168. [PMID: 32251426 PMCID: PMC7162526 DOI: 10.1371/journal.pntd.0008168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 04/16/2020] [Accepted: 02/24/2020] [Indexed: 11/18/2022] Open
Abstract
Background Malaria is endemic in all regions where gambiense or rhodesiense human African trypanosomiasis (HAT) is reported, and both diseases have similarities in their symptomatology. A combined test could be useful for both diseases and would facilitate integration of the screening for gambiense HAT (gHAT) and malaria diagnosis. This study aimed to evaluate a combined prototype rapid diagnostic test (RDT) for gHAT and malaria. Methods Blood samples were collected in the Democratic Republic of the Congo and in Uganda to evaluate the performance of a prototype HAT/Malaria Combined RDT in comparison to an individual malaria RDT based on Plasmodium falciparum (P.f.) Histidine Rich Protein II (HRP-II or HRP2) antigen (SD BIOLINE Malaria Ag P.f. RDT) for malaria detection and an individual gHAT RDT based on recombinant antigens, the SD BIOLINE HAT 2.0 RDT for HAT screening. Due to the current low prevalence of gHAT in endemic regions, the set of blood samples that were collected was used to evaluate the specificity of the RDTs for gHAT, and additional archived plasma samples were used to complete the evaluation of the HAT/Malaria Combined RDT in comparison to the HAT 2.0 RDT. Results Frozen whole blood samples from a total of 486 malaria cases and 239 non-malaria controls, as well as archived plasma samples from 246 gHAT positive and 246 gHAT negative individuals were tested. For malaria, the sensitivity and specificity of the malaria band in the HAT/Malaria Combined RDT were 96.9% (95% CI: 95.0–98.3) and 97.1% (95% CI: 94.1–98.8) respectively. The sensitivity and specificity of the SD BIOLINE malaria Ag P.f. RDT were 97.3% (95% CI: 95.5–98.6) and 97.1% (95% CI: 94.1–98.8) respectively. For gHAT, using archived plasma samples, the sensitivity and specificity were respectively 89% (95% CI: 84.4–92.6) and 93.5% (95% CI: 89.7–96.2) with the HAT/Malaria Combined RDT, and 88.2% (95% CI: 83.5–92) and 94.7% (95% CI: 91.1–97.2) with the HAT 2.0 RDT. Using the whole blood samples that were collected during the study, the specificity of the HAT/Malaria Combined RDT for gHAT was 95.8% (95% CI: 94.3–97.0). Conclusion The HAT/Malaria Combined prototype RDT was as accurate as the individual malaria or gHAT RDTs. The HAT/Malaria Combined prototype RDT is therefore suitable for both malaria diagnosis and gHAT screening. However, there is a need to assess its accuracy using fresh samples in prospective clinical trials. The annual number of reported cases of human African trypanosomiasis (HAT), also known as sleeping sickness (SS), is currently below 1,000 cases worldwide. The Democratic Republic of the Congo (DRC), the most affected country, and Uganda, which shares a border with DRC, are both endemic for gambiense HAT (gHAT). The main strategy to control gHAT is screening of at-risk individuals, followed by diagnosis and treatment of confirmed cases. However, this strategy and even the passive screening as currently implemented become less efficient with declining incidence, justifying innovative strategies to efficiently detect the remaining cases. All areas where gHAT occurs are also endemic for malaria, presenting an opportunity to integrate gHAT screening activities within malaria control activities. This integration is warranted by the fact that in early disease stage, gHAT patients present with signs and symptoms strikingly similar to those of malaria. In order to use malaria diagnosis as an entry point to screen for gHAT, Standard Diagnostics (SD), Republic of Korea (now Abbott Diagnostics, Korea Inc–ADK) made a Combined prototype RDT for both malaria and gHAT, expected to be as accurate as the individual gHAT and malaria RDTs. In this study, we evaluated the accuracy of the Combined prototype RDT using whole blood samples collected in Uganda and DRC, and archived plasma samples collected in DRC, Angola and Central African Republic. We found that the Combined prototype performs just as well as individual RDTs.
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Affiliation(s)
- Crispin Lumbala
- Disease Control Directorate, Ministry of Public Health, Democratic Republic of the Congo
- Global Health Institute, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- * E-mail:
| | - Enock Matovu
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Hakim Sendagire
- College of Health Sciences, Makerere University, Kampala, Uganda
| | - Anne J. N. Kazibwe
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Joris L. Likwela
- Public Health Department, Faculty of Medicine and Pharmacy, University of Kisangani, Kisangani, Democratic Republic of the Congo
| | | | - Simon Kayembe
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | - Pascal Lutumba
- Kinshasa University, Kinshasa, Democratic Republic of the Congo
| | - Sylvain Biéler
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
| | | | - Joseph M. Ndung’u
- Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland
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12
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Lo E, Hostetler JB, Yewhalaw D, Pearson RD, Hamid MMA, Gunalan K, Kepple D, Ford A, Janies DA, Rayner JC, Miller LH, Yan G. Frequent expansion of Plasmodium vivax Duffy Binding Protein in Ethiopia and its epidemiological significance. PLoS Negl Trop Dis 2019; 13:e0007222. [PMID: 31509523 PMCID: PMC6756552 DOI: 10.1371/journal.pntd.0007222] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 09/23/2019] [Accepted: 07/23/2019] [Indexed: 01/20/2023] Open
Abstract
Plasmodium vivax invasion of human erythrocytes depends on the Duffy Binding Protein (PvDBP) which interacts with the Duffy antigen. PvDBP copy number has been recently shown to vary between P. vivax isolates in Sub-Saharan Africa. However, the extent of PvDBP copy number variation, the type of PvDBP multiplications, as well as its significance across broad samples are still unclear. We determined the prevalence and type of PvDBP duplications, as well as PvDBP copy number variation among 178 Ethiopian P. vivax isolates using a PCR-based diagnostic method, a novel quantitative real-time PCR assay and whole genome sequencing. For the 145 symptomatic samples, PvDBP duplications were detected in 95 isolates, of which 81 had the Cambodian and 14 Malagasy-type PvDBP duplications. PvDBP varied from 1 to >4 copies. Isolates with multiple PvDBP copies were found to be higher in symptomatic than asymptomatic infections. For the 33 asymptomatic samples, PvDBP was detected with two copies in two of the isolates, and both were the Cambodian-type PvDBP duplication. PvDBP copy number in Duffy-negative heterozygotes was not significantly different from that in Duffy-positives, providing no support for the hypothesis that increased copy number is a specific association with Duffy-negativity, although the number of Duffy-negatives was small and further sampling is required to test this association thoroughly. Plasmodium vivax invasion of human erythrocytes relies on interaction between the Duffy antigen and P. vivax Duffy Binding Protein (PvDBP). Whole genome sequences from P. vivax field isolates in Madagascar identified a duplication of the PvDBP gene and PvDBP duplication has also been detected in non-African P. vivax-endemic countries. Two types of PvDBP duplications have been reported, termed Cambodian and Malagasy-type duplications. Our study used a combination of PCR-based diagnostic method, a novel quantitative real-time PCR assay, and whole genome sequencing to determine the prevalence and type of PvDBP duplications, as well as PvDBP copy number on a broad number of P. vivax samples in Ethiopia. We found that over 65% of P. vivax isolated from the symptomatic infections were detected with PvDBP duplications and PvDBP varied from 1 to >4 copies. The majority of PvDBP duplications belongs to the Cambodian-type while the Malagasy-type duplications was also detected. For the asymptomatic infections, despite a small sample size, the majority of P. vivax were detected with a single-copy based on both PCR and qPCR assays. There was no significant difference in PvDBP copy number between Duffy-null heterozygote and Duffy-positive homozygote/heterozygote. Further investigation is needed with expanded Duffy-null homozygotes to examine the functional significance of PvDBP expansion.
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Affiliation(s)
- Eugenia Lo
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States of America
- * E-mail: (EL); (LHM); (GY)
| | - Jessica B. Hostetler
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Delenasaw Yewhalaw
- Department of Medical Laboratory Sciences and Pathology, College of Public Health and Medical Sciences, Jimma University, Jimma, Ethiopia
| | - Richard D. Pearson
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Muzamil M. A. Hamid
- Department of Parasitology and Medical Entomology, University of Khartoum, Khartoum, Sudan
| | - Karthigayan Gunalan
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Daniel Kepple
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States of America
| | - Anthony Ford
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, United States of America
| | - Daniel A. Janies
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, United States of America
| | - Julian C. Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Louis H. Miller
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (EL); (LHM); (GY)
| | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, United States of America
- * E-mail: (EL); (LHM); (GY)
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13
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Fong MY, Lau YL, Jelip J, Ooi CH, Cheong FW. Genetic characterisation of the erythrocyte-binding protein (PkβII) of Plasmodium knowlesi isolates from Malaysia. J Genet 2019; 98:64. [PMID: 31544794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Plasmodium knowlesi contributes to the majority of human malaria incidences in Malaysia. Its uncontrollable passage among the natural monkey hosts can potentially lead to zoonotic outbreaks. The merozoite of this parasite invades host erythrocytes through interaction between its erythrocyte-binding proteins (EBPs) and their respective receptor on the erythrocytes. The regionII of P. knowlesi EBP, P. knowlesi beta (PkβII) protein is found to be mediating merozoite invasion into monkey erythrocytes by interacting with sialic acid receptors. Hence, the objective of this study was to investigate the genetic diversity, natural selection and haplotype grouping of PkβII of P. knowlesi isolates in Malaysia. Polymerase chain reaction amplifications of PkβII were performed on archived blood samples from Malaysia and 64 PkβII sequences were obtained. Sequence analysis revealed length polymorphism, and its amino acids at critical residues indicate the ability of PkβII to mediate P. knowlesi invasion into monkey erythrocytes. Low genetic diversity (π = 0.007) was observed in the PkβII of Malaysia Borneo compared to Peninsular Malaysia (π = 0.015). The PkβII was found to be under strong purifying selection to retain infectivity in monkeys and it plays a limited role in the zoonotic potential of P. knowlesi. Its haplotypes could be clustered into Peninsular Malaysia and Malaysia Borneo groups, indicating the existence of two distinct P. knowlesi parasites in Malaysia as reported in an earlier study.
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Affiliation(s)
- Mun Yik Fong
- Faculty of Medicine, Department of Parasitology, University of Malaya, 50603 Kuala Lumpur, Malaysia.
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14
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Plucinski MM, Herman C, Jones S, Dimbu R, Fortes F, Ljolje D, Lucchi N, Murphy SC, Smith NT, Cruz KR, Seilie AM, Halsey ES, Udhayakumar V, Aidoo M, Rogier E. Screening for Pfhrp2/3-Deleted Plasmodium falciparum, Non-falciparum, and Low-Density Malaria Infections by a Multiplex Antigen Assay. J Infect Dis 2019; 219:437-447. [PMID: 30202972 PMCID: PMC6325347 DOI: 10.1093/infdis/jiy525] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/30/2018] [Indexed: 11/13/2022] Open
Abstract
Background Detection of Plasmodium antigens provides evidence of malaria infection status and is the basis for most malaria diagnosis. Methods We developed a sensitive bead-based multiplex assay for laboratory use, which simultaneously detects pan-Plasmodium aldolase (pAldo), pan-Plasmodium lactate dehydrogenase (pLDH), and P. falciparum histidine-rich protein 2 (PfHRP2) antigens. The assay was validated against purified recombinant antigens, monospecies malaria infections, and noninfected blood samples. To test against samples collected in an endemic setting, Angolan outpatient samples (n = 1267) were assayed. Results Of 466 Angolan samples positive for at least 1 antigen, the most common antigen profiles were PfHRP2+/pAldo+/pLDH+ (167, 36%), PfHRP2+/pAldo-/pLDH- (163, 35%), and PfHRP2+/pAldo+/pLDH- (129, 28%). Antigen profile was predictive of polymerase chain reaction (PCR) positivity and parasite density. Eight Angolan samples (1.7%) had no or very low PfHRP2 but were positive for 1 or both of the other antigens. PCR analysis confirmed 3 (0.6%) were P. ovale infections and 2 (0.4%) represented P. falciparum parasites lacking Pfhrp2 and/or Pfhrp3. Conclusions These are the first reports of Pfhrp2/3 deletion mutants in Angola. High-throughput multiplex antigen detection can inexpensively screen for low-density P. falciparum, non-falciparum, and Pfhrp2/3-deleted parasites to provide population-level antigen estimates and identify specimens requiring further molecular characterization.
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Affiliation(s)
- Mateusz M Plucinski
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- US President’s Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Camelia Herman
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- CDC Foundation, Atlanta, Georgia
| | - Sophie Jones
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- Atlanta Research and Education Foundation, Georgia
| | - Rafael Dimbu
- National Malaria Control Program, Ministry of Health, Luanda, Angola
| | - Filomeno Fortes
- National Malaria Control Program, Ministry of Health, Luanda, Angola
| | - Dragan Ljolje
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- Atlanta Research and Education Foundation, Georgia
| | - Naomi Lucchi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Sean C Murphy
- Department of Laboratory Medicine, University of Washington, Seattle
- Center for Emerging and Re-emerging Infectious Diseases, University of Washington, Seattle
| | - Nahum T Smith
- Department of Laboratory Medicine, University of Washington, Seattle
| | - Kurtis R Cruz
- Department of Laboratory Medicine, University of Washington, Seattle
| | - Annette M Seilie
- Department of Laboratory Medicine, University of Washington, Seattle
| | - Eric S Halsey
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- US President’s Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Venkatachalam Udhayakumar
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Michael Aidoo
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric Rogier
- Malaria Branch, Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
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15
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Łyp P, Winiarczyk S, Rogalski J, Adaszek Ł. Analysis of the amino acid sequences of 18S RNA strains of Babesia canis isolated from dogs, including the analysis of serum proteome of protozoa infected dogs. Ann Parasitol 2019; 65:145-149. [PMID: 31376344 DOI: 10.17420/ap6502.194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The aim of this paper was to analyse the amino acid sequences of the 18S rRNA gene of Babesia canis strains and the proteomic analysis of the serum of dogs infected with three various genotypes: 18S rRNA B. canis. Material for the research was DNA B. canis obtained from dogs with babesiosis. In total, 60 DNA tested samples were divided into three groups (20 samples each). The groups were formed by DNA samples of the sequences marked as 18S RNA-A (group 1), 18S RNA-B (group 2), and 18S RNA-C (group 3). The basis for the classification of protozoa to a specific group was the location of relevant nucleotides (GA, AG, or TT) in position 150-151 of the tested nucleotide sequence 18S rRNA. Nucleotide sequences were transcribed into amino acid sequences and then analysed using DNASTAR software. From all 60 infected and ten healthy dogs (control group), the serum was taken to make proteomic tests using MALDI-TOF mass spectrometer. It was demonstrated that the mutations found in position 150 and 151 of the nucleotide sequence, result in a change of amino acid sequences. Moreover, it was also demonstrated that the disease course in dogs infected with different strains of protozoa is different. Each of the analysed strains of protozoa induced in the serum of infected animals the appearance of a protein fraction of mass 51 kDa, which may then be treated as a nonspecific disease marker used for the diagnosis of this disease but not to differentiate the protozoa strains.
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Affiliation(s)
- Paweł Łyp
- Department of Epizootiology and Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences, ul. Głęboka 30, 20-612 Lublin, Poland
| | - Stanisław Winiarczyk
- Department of Epizootiology and Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences, ul. Głęboka 30, 20-612 Lublin, Poland
| | - Jerzy Rogalski
- Department of Biochemistry, Faculty of Biology and Biotechnology, Maria Curie Skłodowska University, ul. Akademicka 19, 20-033 Lublin, Poland
| | - Łukasz Adaszek
- Department of Epizootiology and Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences, ul. Głęboka 30, 20-612 Lublin, Poland
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Costa JG, Vilariño MJ. Semiquantitative Dot Blot with the GRA8 antigen to differentiate the stages of toxoplasmosis infection. J Microbiol Methods 2018; 149:9-13. [PMID: 29684398 DOI: 10.1016/j.mimet.2018.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 11/17/2022]
Abstract
In this work we present a novel methodology to differentiate the phases of toxoplasmosis infection: the "semiquantitative Dot Blot". It is a simple technique that does not require expensive equipment, does not involve a long technique development, and can be used in a low-complexity laboratory. In this study, two recombinant sequences of Toxoplasma gondii GRA8 antigen were used, and specific IgG antibodies were detected in selected patient samples. This method makes it possible to obtain a score for each serum and define whether the patient is in the acute or chronic phase of the infection. The sensitivity and specificity results varied depending on the antigenic sequence used. With GRA8A, 62.1% and 72.7% were obtained, while with GRA8B, 82.8% and 72.1% were obtained, respectively. Although the sensitivity and specificity values were not close to 100%, they were similar to those reported with the same antigens in ELISA. Therefore, this quantitative technique would be a good alternative to ELISA.
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Affiliation(s)
- Juan Gabriel Costa
- Cátedra de Fisicoquímica, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria, Santa Fe, Santa Fe, Argentina.
| | - María Julia Vilariño
- Hospital Escuela Eva Perón, Av. San Martín 1645, Granadero Baigorria, Santa Fe, Argentina
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Nogueira CT, Cistia MLD, Urbaczek AC, Jusi MMG, Velásquez AMA, Machado RZ, Ferreira H, Henrique-Silva F, Langoni H, da Costa PI, Graminha MAS. Potential application of rLc36 protein for diagnosis of canine visceral leishmaniasis. Mem Inst Oswaldo Cruz 2018; 113:197-201. [PMID: 29412359 PMCID: PMC5804312 DOI: 10.1590/0074-02760170171] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 10/24/2017] [Indexed: 01/20/2023] Open
Abstract
Visceral leishmaniasis (VL) is fatal if left untreated. Infected dogs are important reservoirs of the disease, and thus specific identification of infected animals is very important. Several diagnostic tests have been developed for canine VL (CVL); however, these tests show varied specificity and sensitivity. The present study describes the recombinant protein rLc36, expressed by Leishmania infantum, as potential antigen for more sensitive and specific diagnosis of CVL based on an immunoenzymatic assay. The concentration of 1.0 μg/mL of rLc36 enabled differentiation of positive and negative sera and showed a sensitivity of 85% and specificity of 71% (with 95% confidence), with an accuracy of 76%.
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Affiliation(s)
- Camila Tita Nogueira
- Universidade Estadual Paulista, Instituto de Química, Campus de Araraquara, Araraquara, SP, Brasil
| | - Mayara Lúcia Del Cistia
- Universidade Estadual Paulista, Faculdade de Ciências Farmacêuticas, Campus de Araraquara, Araraquara, SP, Brasil
| | - Ana Carolina Urbaczek
- Universidade de São Paulo, Instituto de Química, Campus de São Carlos, São Carlos, SP, Brasil
| | - Márcia MG Jusi
- Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Campus de Jaboticabal, Jaboticabal, SP, Brasil
| | | | - Rosângela Zacarias Machado
- Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Campus de Jaboticabal, Jaboticabal, SP, Brasil
| | - Henrique Ferreira
- Universidade Estadual Paulista, Instituto de Biociências, Campus de Rio Claro, Rio Claro, SP, Brasil
| | - Flávio Henrique-Silva
- Universidade Federal de São Carlos, Departamento de Genética e Evolução, São Carlos, SP, Brasil
| | - Hélio Langoni
- Universidade Estadual Paulista, Faculdade de Medicina Veterinária e de Zootecnia, Campus de Botucatu, Botucatu, SP, Brasil
| | - Paulo Inácio da Costa
- Universidade Estadual Paulista, Faculdade de Ciências Farmacêuticas, Campus de Araraquara, Araraquara, SP, Brasil
| | - Márcia AS Graminha
- Universidade Estadual Paulista, Instituto de Química, Campus de Araraquara, Araraquara, SP, Brasil
- Universidade Estadual Paulista, Faculdade de Ciências Farmacêuticas, Campus de Araraquara, Araraquara, SP, Brasil
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Plucinski MM, Dimbu PR, Fortes F, Abdulla S, Ahmed S, Gutman J, Kachur SP, Badiane A, Ndiaye D, Talundzic E, Lucchi N, Aidoo M, Udhayakumar V, Halsey E, Rogier E. Posttreatment HRP2 Clearance in Patients with Uncomplicated Plasmodium falciparum Malaria. J Infect Dis 2018; 217:685-692. [PMID: 29220497 PMCID: PMC11023016 DOI: 10.1093/infdis/jix622] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 12/04/2017] [Indexed: 11/13/2022] Open
Abstract
Background The response to antimalarial treatment is assessed using serial microscopy. New techniques for accurate measurement of the Plasmodium falciparum histidine-rich protein 2 (HRP2) antigen have allowed for monitoring of the antigen concentration over time, offering a potential alternative for assessing treatment response. Methods Posttreatment HRP2 concentrations were measured in samples obtained longitudinally from 537 individuals with P. falciparum malaria who were participating in efficacy trials in Angola, Tanzania, and Senegal. The HRP2 half-life was estimated using a first-order kinetics clearance model. The association between the HRP2 concentration 3 days after treatment and recrudescence of infection was assessed. Results Despite substantial variation in HRP2 concentrations among participants at baseline, concentrations consistently showed a first-order exponential decline. The median half-life of HRP2 was estimated to be 4.5 days (interquartile range [IQR], 3.3-6.6 days) in Angola, 4.7 days (IQR, 4.0-5.9 days) in Tanzania, and 3.0 days (IQR, 2.1-4.5 days) in Senegal. The day 3 HRP2 concentration was predictive of eventual recrudescence, with an area under the receiver operating characteristic curve of 0.86 (95% confidence interval, .73-.99). Conclusions Consistent HRP2 clearance dynamics following successful antimalarial treatment imply a common underlying mechanism of biological clearance. Patients who ultimately did not respond to treatment did not exhibit this same pattern of clearance, even in the absence of other indications of inadequate response to treatment.
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Affiliation(s)
- Mateusz M Plucinski
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- US President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Filomeno Fortes
- National Malaria Control Program, Ministry of Health, Luanda, Angola
| | - Salim Abdulla
- Ifakara Health Institute, Ifakara Health Research and Development Center, Tanzania
| | - Saumu Ahmed
- Ifakara Health Institute, Ifakara Health Research and Development Center, Tanzania
| | - Julie Gutman
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - S Patrick Kachur
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Aida Badiane
- School of Medicine, Pharmacy and Odontology, Cheikh Anta Diop University, Dakar, Senegal
| | - Daouda Ndiaye
- School of Medicine, Pharmacy and Odontology, Cheikh Anta Diop University, Dakar, Senegal
| | - Eldin Talundzic
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Naomi Lucchi
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Michael Aidoo
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Venkatachalam Udhayakumar
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric Halsey
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
- US President's Malaria Initiative, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Eric Rogier
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia
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Abstract
We report a new enzyme-free electrochemical sensor for ultrasensitive measurements of protein biomarkers in plasma and whole blood samples based on a unique electrochemical-chemical-chemical (ECC) redox cycling signal amplification scheme. This scheme uses methylene blue (MB) as a redox indicator which undergoes an endergonic reaction with Ru(NH3)63+ and a highly exergonic reaction with tris(2-carboxyethyl)phosphine (TCEP). This approach offers improved detection sensitivity and sensor stability compared with enzyme-based ECC redox cycling techniques, while involving a simpler sensor modification process and detection protocol. This redox cycling scheme was combined with a robust immunosandwich assay for quantitative measurements of protein biomarkers. For proof of principle, Plasmodium falciparum histidine-rich protein 2 (PfHRP2) was measured in human plasma and whole blood samples, which could be detected down to 10 fg mL-1 and 18 fg mL-1, respectively. Furthermore, this immunosensor exhibits high selectivity, excellent reproducibility and good stability for up to 2 weeks, making it a promising platform for point-of-care testing, especially for detecting extremely low biomarker concentrations in raw biofluids.
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Affiliation(s)
- Gorachand Dutta
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824, USA.
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20
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Tijani MK, Babalola OA, Odaibo AB, Anumudu CI, Asinobi AO, Morenikeji OA, Asuzu MC, Langer C, Reiling L, Beeson JG, Wahlgren M, Nwuba RI, Persson KEM. Acquisition, maintenance and adaptation of invasion inhibitory antibodies against Plasmodium falciparum invasion ligands involved in immune evasion. PLoS One 2017; 12:e0182187. [PMID: 28787025 PMCID: PMC5546579 DOI: 10.1371/journal.pone.0182187] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 07/13/2017] [Indexed: 11/18/2022] Open
Abstract
Erythrocyte-binding antigens (EBAs) and P. falciparum reticulocyte-binding homologue proteins (PfRhs) are two important protein families that can vary in expression and utilization by P. falciparum to evade inhibitory antibodies. We evaluated antibodies at repeated time-points among individuals living in an endemic region in Nigeria over almost one year against these vaccine candidates. Antibody levels against EBA140, EBA175, EBA181, PfRh2, PfRh4, and MSP2, were measured by ELISA. We also used parasites with disrupted EBA140, EBA175 and EBA181 genes to show that all these were targets of invasion inhibitory antibodies. However, antigenic targets of inhibitory antibodies were not stable and changed substantially over time in most individuals, independent of age. Antibodies levels measured by ELISA also varied within and between individuals over time and the antibodies against EBA181, PfRh2 and MSP2 declined more rapidly in younger individuals (≤15 years) compared with older (>15). The breadth of high antibody responses over time was more influenced by age than by the frequency of infection. High antibody levels were associated with a more stable invasion inhibitory response, which could indicate that during the long process of formation of immunity, many changes not only in levels but also in functional responses are needed. This is an important finding in understanding natural immunity against malaria, which is essential for making an efficacious vaccine.
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Affiliation(s)
- Muyideen K. Tijani
- Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, University of Ibadan, Ibadan, Nigeria
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
| | - Oluwatoyin A. Babalola
- Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, University of Ibadan, Ibadan, Nigeria
| | - Alex B. Odaibo
- Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, University of Ibadan, Ibadan, Nigeria
| | - Chiaka I. Anumudu
- Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, University of Ibadan, Ibadan, Nigeria
| | - Adanze O. Asinobi
- Department of Paediatrics, University College Hospital, University of Ibadan, Ibadan, Nigeria
| | - Olajumoke A. Morenikeji
- Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, University of Ibadan, Ibadan, Nigeria
| | - Michael C. Asuzu
- Department of Preventive Medicine and Primary Care, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Christine Langer
- The Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Linda Reiling
- The Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - James G. Beeson
- The Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Mats Wahlgren
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
| | - Roseangela I. Nwuba
- Cellular Parasitology Programme, Cell Biology and Genetics Unit, Department of Zoology, University of Ibadan, Ibadan, Nigeria
| | - Kristina E. M. Persson
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
- Department of Laboratory Medicine, University Hospital, Lund University, Lund, Sweden
- * E-mail:
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Argy N, Kendjo E, Augé-Courtoi C, Cojean S, Clain J, Houzé P, Thellier M, Hubert V, Deloron P, Houzé S. Influence of host factors and parasite biomass on the severity of imported Plasmodium falciparum malaria. PLoS One 2017; 12:e0175328. [PMID: 28410415 PMCID: PMC5391917 DOI: 10.1371/journal.pone.0175328] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 03/23/2017] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVES Imported malaria in France is characterized by various clinical manifestations observed in a heterogeneous population of patients such as travelers/expatriates and African migrants. In this population, host factors and parasite biomass associated with severe imported malaria are poorly known. METHODS From data collected by the Centre National de Référence du Paludisme, we identified epidemiological, demographic and biological features including parasite biomass and anti-plasmodial antibody levels (negative, positive and strongly positive serology) associated with different disease severity groups (very severe, moderately severe, and uncomplicated malaria) in 3 epidemiological groups (travelers/expatriates, first- and second-generation migrants). RESULTS Age, ethnicity, absence of prior infection with P. falciparum, antibody levels, plasma PfHRP2 levels, total and circulating parasite biomass were related to severe malaria onset. Sequestered parasite biomass tended to be increased in very severe malaria, and was strongly correlated to the antibody level of the host. CONCLUSIONS Prior exposure to P. falciparum is associated with high anti-plasmodial antibody levels which influence clinical presentation of imported malaria and its correlated circulating and sequestered parasite burden.
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Affiliation(s)
- Nicolas Argy
- Laboratoire de parasitologie, hôpital Bichat-Claude Bernard, APHP, Paris, France
- Centre National de Référence du Paludisme, hôpital Bichat-Claude Bernard, APHP, Paris, France
- Faculté de Pharmacie, Université Paris Descartes, COMUE Sorbonne Paris Cité, Paris, France
- UMR MERIT 216, Institut de recherche pour le développement, Paris, France
| | - Eric Kendjo
- Centre National de Référence du Paludisme, hôpital Bichat-Claude Bernard, APHP, Paris, France
| | - Claire Augé-Courtoi
- Faculté de Pharmacie, Université Paris Descartes, COMUE Sorbonne Paris Cité, Paris, France
- UMR MERIT 216, Institut de recherche pour le développement, Paris, France
| | - Sandrine Cojean
- Centre National de Référence du Paludisme, hôpital Bichat-Claude Bernard, APHP, Paris, France
| | - Jérôme Clain
- Centre National de Référence du Paludisme, hôpital Bichat-Claude Bernard, APHP, Paris, France
- Faculté de Pharmacie, Université Paris Descartes, COMUE Sorbonne Paris Cité, Paris, France
- UMR MERIT 216, Institut de recherche pour le développement, Paris, France
| | - Pascal Houzé
- Faculté de Pharmacie, Université Paris Descartes, COMUE Sorbonne Paris Cité, Paris, France
- Laboratoire de pharmacologie, hôpital Saint-Louis, APHP, Paris, France
| | - Marc Thellier
- Laboratoire de parasitologie, hôpital Pitié-Salpêtrière, APHP, Paris, France
- Faculté de Médecine, Université Pierre et Marie Curie, COMUE Sorbonne Paris Cité, Paris, France
| | - Veronique Hubert
- Centre National de Référence du Paludisme, hôpital Bichat-Claude Bernard, APHP, Paris, France
| | - Philippe Deloron
- Faculté de Pharmacie, Université Paris Descartes, COMUE Sorbonne Paris Cité, Paris, France
- UMR MERIT 216, Institut de recherche pour le développement, Paris, France
| | - Sandrine Houzé
- Laboratoire de parasitologie, hôpital Bichat-Claude Bernard, APHP, Paris, France
- Centre National de Référence du Paludisme, hôpital Bichat-Claude Bernard, APHP, Paris, France
- Faculté de Pharmacie, Université Paris Descartes, COMUE Sorbonne Paris Cité, Paris, France
- UMR MERIT 216, Institut de recherche pour le développement, Paris, France
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Costa JG, Peretti LE, García VS, Peverengo L, González VDG, Gugliotta LM, Dalla Fontana ML, Lagier CM, Marcipar IS. P35 and P22 Toxoplasma gondii antigens abbreviate regions to diagnose acquired toxoplasmosis during pregnancy: toward single-sample assays. Clin Chem Lab Med 2017; 55:595-604. [PMID: 27658149 DOI: 10.1515/cclm-2016-0331] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 08/16/2016] [Indexed: 11/15/2022]
Abstract
BACKGROUND P35 and P22 Toxoplasma gondii proteins are recognized by specific IgG at the early infection stage, making them ideal for acute toxoplasmosis pregnancy control. Both proteins have been studied to discriminate between acute and chronic toxoplasmosis. However, results were hardly comparable because different protein obtainment procedures led to different antigens, the reference panels used were not optimally typified, and avidity tests were either not performed or narrowly examined. METHODS We bioinformatically predicted P35 and P22 regions with the highest density of epitopes, and expressed them in pET32/BL21DE3 alternative expression system, obtaining the soluble proteins rP35a and rP22a. We assessed their diagnostic performance using pregnant woman serum samples typified as: not infected, NI (IgG-, IgM-), typical-chronic, TC (IgM-, IgG+), presumably acute, A (IgG+, IgM+, low-avidity IgG), and recently chronic, RC (IgG+, IgM+, high-avidity IgG). RESULTS rP35a performed better than rP22a to differentiate A from RC, the areas under the curve (AUC) being 0.911 and 0.818, respectively. They, however, performed similarly to differentiate A from TC+RC (AUC: 0.915 and 0.907, respectively). rP35a and rP22a evaluation by avidity ELISA to discriminate A from RC rendered AUC values of 0.974 and 0.921, respectively. The indirect ELISA and avidity ELISA results analyzed in tandem were consistent with those obtained using commercial kits. CONCLUSIONS rP35a and rP22a features suggest that, with complementary use, they could replace parasite lysate for toxoplasmosis infection screening and for acute toxoplasmosis diagnosis. Our proposal should be validated by a longitudinal study and may lead to a reliable toxoplasmosis pregnancy control, performing tests in only one serum sample.
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Srivastava S, Mishra J, Gupta AK, Singh A, Shankar P, Singh S. Laboratory confirmed miltefosine resistant cases of visceral leishmaniasis from India. Parasit Vectors 2017; 10:49. [PMID: 28137296 PMCID: PMC5282768 DOI: 10.1186/s13071-017-1969-z] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 01/04/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Miltefosine unresponsive and relapse cases of visceral leishmaniasis (VL) are increasingly being reported. However, there has been no laboratory confirmed reports of miltefosine resistance in VL. Here, we report two laboratory confirmed cases of VL from India. METHODS Two patients with VL were referred to us with suspected VL. The first patient was a native of the VL endemic state of Bihar, but residing in Delhi, a VL non-endemic area. He was treated with broad-spectrum antibiotics and antipyretics but was unresponsive to treatment. The second patient was from Jharkhand state in eastern India (adjoining Bihar), another endemic state for VL. He was refractory to anti-leishmanial treatment, which included administration of miltefosine. Following investigation, both patients were serologically positive for VL, and blood buffy coat from both patients grew Leishmania donovani. The isolates derived from both cases were characterized for their drug susceptibility, genetically characterised, and SNPs typed for LdMT and LdROS gene expression. Both patients were successfully treated with amphotericin B. RESULTS The in vitro drug susceptibility assays carried out on both isolates showed good IC50 values to amphotericin B (0.1 ± 0.0004 μg/ml and 0.07 ± 0.0019 μg/ml). One isolate was refractory to SbIII with an IC50 of > 200 μM while the second isolate was sensitive to SbIII with an IC50 of 36.70 ± 3.2 μM. However, in both the isolates, IC50 against miltefosine was more than 10-fold higher (> 100 μM) than the standard strain DD8 (6.8 ± 0.1181 μM). Furthermore, genetic analyses demonstrated single nucleotide polymorphisms (SNPs) (354Tyr↔Phe and 1078Phe↔Tyr) in the LdMT gene of the parasites. CONCLUSIONS Here, we document two laboratory confirmed cases of miltefosine resistant VL from India. Our finding highlights the urgent need to establish control measures to prevent the spread of these strains. We also propose that LdMT gene mutation analysis could be used as a molecular marker of miltefosine resistance in L. donovani.
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Affiliation(s)
- Saumya Srivastava
- 0000 0004 1767 6103grid.413618.9Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Jyotsna Mishra
- 0000 0004 1767 6103grid.413618.9Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Anil Kumar Gupta
- 0000 0004 1767 6103grid.413618.9Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Amit Singh
- 0000 0004 1767 6103grid.413618.9Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Prem Shankar
- 0000 0004 1767 6103grid.413618.9Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
| | - Sarman Singh
- 0000 0004 1767 6103grid.413618.9Division of Clinical Microbiology and Molecular Medicine, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India
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Abd Elreheim AM, Farid AA, Mahana NA, Bauiomy IR, Elameer AM. SANDWICH-ELISA DEVELOPMENT FOR THE DIAGNOSIS OF TOXOPLASMA GONDI. J Egypt Soc Parasitol 2016; 46:429-440. [PMID: 30152953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Toxoplasmosis is one of the most world-wide spread zoonosis representing a very serious clinical and veterinary problem. Although rare, congenital toxoplasmosis can cause severe ne- urological or ocular disease (leading to blindness) as well as cardiac and cerebral anomalies. Prenatal care must include education about prevention of toxoplasmosis. Thus, a standardized and approachable diagnostic tool for the serodiagnosis of toxoplasmosis is still needed. Serological tests are the most widely used biological tools for the diagnosis of toxoplasmosis worldwide. Sandwich-ELISA is a solid phase diagnostic method for detection of antigen or antibody that is used widely for diagnosis of protozoan and metazoan diseases of human and animals. In the present study, T. gondii SAG2 antigen was early detected in patient sera using Ssndwich-ELISA, PAb was prepared from anti-rabbit sera and used for coating and as conjugate in Sandwich-ELISA technique. 46 patients out of 50 were positive to Toxoplsama spp. with sensitivity and specificity 92% and 90%, respectively. The PPV was 90.2% and NPV was 83.3%. Finally, the result of our study showed that the Sandwich-ELISA designed in our study is easy to perform, not expensive, safe, and simple with good sensitivity and specificity.
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Abstract
Colorimetric detection methods that produce results readable by eye are important for diagnostic tests in resource-limited settings. In this work, we have compared three main types of colorimetric methods - enzymatic reactions, silver deposition catalyzed by gold nanoparticles, and polymerization-based amplification - in a paper-based immunoassay for detection of Plasmodium falciparum histidine-rich protein 2, a biomarker of malarial infection. We kept the binding events in the immunoassay constant in order to isolate the effect of the detection method on the outcome of the test. We have highlighted that the optimal readout time in a test can vary significantly - ranging from immediately after addition of a visualization agent to 25 minutes after addition of a visualization agent - depending on the colorimetric method being used, and accurate time keeping is essential to prevent false positives in methods where substantial color develops over time in negative tests. We have also shown that the choice of a colorimetric method impacts the calculated limit-of-detection, the ease of visual perception of the readout, and the total cost of the assay, and therefore directly impacts the feasibility and the ease-of-use of a test in field settings.
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Affiliation(s)
- Shefali Lathwal
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
| | - Hadley D Sikes
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
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Prasad R, Mishra OP. Acute Kidney Injury in Children with Plasmodium falciparum Malaria: Determinants for Mortality. Perit Dial Int 2016; 36:213-7. [PMID: 26429418 PMCID: PMC4803368 DOI: 10.3747/pdi.2014.00254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 05/03/2015] [Indexed: 02/03/2023] Open
Abstract
UNLABELLED ♦ BACKGROUND Acute kidney injury (AKI) in P. falciparum malaria infection is an important morbidity in children. The purpose of the present study was done to observe the renal involvement, associated morbidities and outcome. ♦ METHODS Out of 156 patients with severe P. falciparum malaria, diagnosed on the basis of compatible clinical presentations and positive malarial parasites in the peripheral blood smear and/or histidine rich protein 2 antigen, 31 had AKI at presentation and were analyzed. ♦ RESULTS Of 31 (19.9%) patients with AKI, 4 were classified at risk, 11 injury, and 16 failure stage, as per pRIFLE criteria (pediatric version of RIFLE [R = risk, I = injury, F = failure, L = loss E = end-stage kidney disease]). Mean age of children with AKI was 7.7 ± 3.2 years. A significantly higher proportion of patients with AKI had hypoglycemia (41.9%), pulmonary edema (32.2%), and disseminated intravascular coagulation (DIC) (29.0%) compared to those without AKI (18.4%, 4.8%, and 3.2%, respectively). Twelve patients (38.7%) required peritoneal dialysis (PD), 8 (25.8%) died, and all were in failure stage. The non-survivors had significantly higher blood urea (p = 0.005) and serum creatinine levels (p = 0.042), lower glomerular filtration rate (p < 0.001), longer duration of illness (p = 0.003), and oliguria/anuria (p = 0.001) than survivors at admission. On logistic regression analysis, the disseminated intravascular coagulation (DIC), jaundice and parasite density (≥ 3+) were found to be significant factors contributing to mortality in children with AKI. ♦ CONCLUSIONS Acute kidney injury in falciparum malaria is one of the severe systemic complications. Duration of illness and presence of comorbidities adversely affected the outcome.
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Affiliation(s)
- Rajniti Prasad
- Division of Pediatric Nephrology, Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Om P Mishra
- Division of Pediatric Nephrology, Department of Pediatrics, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
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de Haan F, Onyamboko MA, Fanello CI, Woodrow CJ, Lubell Y, Boon WPC, Dondorp AM. Exploring health practitioners' acceptability of a prospective semi-quantitative pfHRP2 device to define severe malaria in the Democratic Republic of Congo. Malar J 2015; 14:503. [PMID: 26670489 PMCID: PMC4681050 DOI: 10.1186/s12936-015-0963-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 10/24/2015] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND A rapid diagnostic tool is being developed to discern severely ill children with severe malaria from children who are ill with alternative febrile diseases but have coincidental peripheral blood parasitaemia. The device semi-quantitatively measures plasma pfHRP2 and has the potential to reduce mortality in children with severe febrile illnesses by improving diagnosis. The aim of this study is to identify contributing and inhibiting factors that affect healthcare practitioners' acceptability of this prospective diagnostic device in a high malaria transmission setting in the Democratic Republic of Congo. METHODS Data were collected qualitatively by conducting semi-structured interviews with a purposeful sample of health professionals in Kinshasa, capital of Democratic Republic of Congo. In total, 11 interviews were held with professionals at four different institutes. RESULTS Four key findings emerged: (1) Congolese practitioners perceive the semi-quantitative pfHRP2 device as a welcome intervention as they recognize the limited reliability of their current diagnostic and therapeutic approaches to severe febrile illnesses; (2) compatibility of the semi-quantitative pfHRP2 device with clinical equipment and competences of Congolese health practitioners is considered to be limited, especially in rural settings; (3) a formal training programme is crucial for correct understanding and application of the semi-quantitative pfHRP2 device; and, (4) provision of evidence to practitioners, and support from health authorities would be important to establish confidence in the semi-quantitative pfHRP2 device. CONCLUSIONS Congolese practitioners perceive the prospective semi-quantitative pfHRP2 device as a welcome addition to their clinical equipment. The device could improve current diagnostic work-up of severe febrile illness, which might consequently improve treatment choices. However, despite this recognized potential, several hurdles and drivers need to be taken into account when implementing this device in DR Congo.
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Affiliation(s)
- Freek de Haan
- Innovation Studies Group, Copernicus Institute, Utrecht University, Utrecht, The Netherlands.
| | - Marie A Onyamboko
- Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo.
| | - Caterina I Fanello
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Charles J Woodrow
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Yoel Lubell
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Wouter P C Boon
- Innovation Studies Group, Copernicus Institute, Utrecht University, Utrecht, The Netherlands.
| | - Arjen M Dondorp
- Centre for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Fong MY, Ahmed MA, Wong SS, Lau YL, Sitam F. Genetic Diversity and Natural Selection of the Plasmodium knowlesi Circumsporozoite Protein Nonrepeat Regions. PLoS One 2015; 10:e0137734. [PMID: 26379157 PMCID: PMC4575020 DOI: 10.1371/journal.pone.0137734] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 08/21/2015] [Indexed: 11/18/2022] Open
Abstract
Background Plasmodium knowlesi is a simian malaria parasite that has been identified to cause malaria in humans. To date, several thousand cases of human knowlesi malaria have been reported around Southeast Asia. Thus far, there is no detailed study on genetic diversity and natural selection of P. knowlesi circumsporozoite protein (CSP), a prominent surface antigen on the sporozoite of the parasite. In the present study, the genetic diversity and natural selection acting on the nonrepeat regions of the gene encoding P. knowlesi CSP were investigated, focusing on the T-cell epitope regions at the C-terminal of the protein. Methods Blood samples from 32 knowlesi malaria patients and 2 wild monkeys (Macaca fascicularis) were used. The CSP of the P. knowlesi isolates was amplified by PCR, cloned into Escherichia coli, and sequenced. The nonrepeat regions of the CSP gene were analysed for genetic diversity, natural selection and haplotypic grouping using MEGA5 and DnaSP version 5.10.00 programmes. A haplotype network was constructed based on the C-terminal (Th2R/Th3R) T-cell epitope regions using the Median-Joining method in the NETWORK version 4.6.1.2 programme. Previously published sequences from other regions (Malaysia Borneo, Singapore) were also included in the analysis. Results A total of 123 P. knowlesi CSP sequences were analysed. Multiple sequence alignment revealed 58 amino acid changes, and 42 novel amino acid haplotypes were identified. Polymorphism was higher in the C-terminal Th2R/Th3R epitope (π = 0.0293, n = 123) region compared to the overall combined nonrepeat regions (π = 0.0120, n = 123). Negative natural selection was observed within the nonrepeat regions of the CSP gene. Within the C-terminal Th2R/Th3R epitope regions, there was evidence of slight positive selection. Based on haplotype network analysis of the Th2R/Th3R regions, five abundant haplotypes were identified. Sharing of haplotypes between humans and macaques were observed. Conclusion This study contributes to the understanding of the type and distribution of naturally occurring polymorphism in the P. knowlesi CSP gene. This study also provides a measurement of the genetic diversity of P. knowlesi and identifies the predominant haplotypes within Malaysia based on the C-terminal Th2R/Th3R regions.
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Affiliation(s)
- Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- * E-mail:
| | - Md Atique Ahmed
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Shen Siang Wong
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Frankie Sitam
- Department of Wildlife and National Parks Peninsular Malaysia, Kuala Lumpur, Malaysia
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Lia YX, Chen LJ, Li W, Nie DP, Luo M, He JF, Shen LJ. [Analysis of sites of Toxoplasma gondii SAG2 gene in blood of HIV-positive people in Lincang City, Yunnan Province]. Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi 2015; 27:32-35. [PMID: 26094410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To preliminarily understand the genotype characteristics of Toxoplasma gondii in blood of HIV-positive persons in Lincang City, Yunnan Province. METHOD Two segments of SAG2 gene of T. gondii from blood samples of HIV-positive persons in Lincang City were extracted and amplified by using the nested PCR method and the genotype was identified and compared with the standard strain (Type I) of Toxoplasma gondii. RESULTS Thirty-five SAG2 genes (241 bp) and 35 SAG2 genes (221 bp) of T. gondii were amplified from 170 blood samples of the HIV-positive people, and 4 of each case were selected and digested with enzyme, then 2 aim gene fragments of each case were chosen and compared with the standard strain (Type I) of T. gondii. The digestion of SAG2 gene (241 bp) showed the genotype of the blood samples was Type I or Type II, and the digestion of SAG2 gene (221 bp) confirmed that the genotype was Type I. CONCLUSION It is preliminarily confirmed that the genotype of T. gondii in blood of HIV-positive persons in Lincang City, Yunnan Province is Type I.
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Abstract
Optical detection technologies based on mobile devices can be utilized to enable many mHealth applications, including a reader for lateral-flow immunoassay (LFIA). However, an intrinsic challenge associated with LFIA for clinical diagnostics is the limitation in sensitivity. Therefore, rapid and simple specimen processing strategies can directly enable more sensitive LFIA by purifying and concentrating biomarkers. Here, a binary reagent system is presented for concentrating analytes from a larger volume specimen to improve the malaria LFIA's limit of detection (LOD). The biomarker enrichment process utilizes temperature-responsive gold-streptavidin conjugates, biotinylated antibodies, and temperature-responsive magnetic nanoparticles. The temperature-responsive gold colloids were synthesized by modifying the citrate-stabilized gold colloids with a diblock copolymer, containing a thermally responsive poly(N-isopropylacrylamide) (pNIPAAm) segment and a gold-binding block composed of NIPAAm-co-N,N-dimethylaminoethylacrylamide. The gold-streptavidin conjugates were synthesized by conjugating temperature-responsive gold colloids with streptavidin via covalent linkages using carbodiimide chemistry chemistry. The gold conjugates formed half-sandwiches, gold labeled biomarker, by complexing with biotinylated antibodies that were bound to Plasmodium falciparum histidine-rich protein 2 (PfHRP2), a malaria antigen. When a thermal stimulus was applied in conjunction with a magnetic field, the half-sandwiches and temperature-responsive magnetic nanoparticles that were both decorated with pNIPAAm formed large aggregates that were efficiently magnetically separated from human plasma. The binary reagent system was applied to a large volume (500 μL) specimen for concentrating biomarker 50-fold into a small volume and applied directly to an off-the-shelf malaria LFIA to improve the signal-to-noise ratio.
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Affiliation(s)
- James J Lai
- Department of Bioengineering, University of Washington, Seattle, WA, 98195, USA
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Zhang F, Ma X, Zhu Y, Wang H, Liu X, Zhu M, Ma H, Wen H, Fan H, Ding J. Identification, expression and phylogenetic analysis of EgG1Y162 from Echinococcus granulosus. Int J Clin Exp Pathol 2014; 7:5655-5664. [PMID: 25337206 PMCID: PMC4203177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 08/23/2014] [Indexed: 06/04/2023]
Abstract
OBJECTIVE This study was to clone, identify and analyze the characteristics of egG1Y162 gene from Echinococcus granulosus. METHODS Genomic DNA and total RNAs were extracted from four different developmental stages of protoscolex, germinal layer, adult and egg of Echinococcus granulosus, respectively. Fluorescent quantitative PCR was used for analyzing the expression of egG1Y162 gene. Prokaryotic expression plasmid of pET41a-EgG1Y162 was constructed to express recombinant His-EgG1Y162 antigen. Western blot analysis was performed to detect antigenicity of EgG1Y162 antigen. Gene sequence, amino acid alignment and phylogenetic tree of EgG1Y162 were analyzed by BLAST, online Spidey and MEGA4 software, respectively. RESULTS EgG1Y162 gene was expressed in four developmental stages of Echinococcus granulosus. And, egG1Y162 gene expression was the highest in the adult stage, with the relative value of 19.526, significantly higher than other three stages. Additionally, Western blot analysis revealed that EgG1Y162 recombinant protein had good reaction with serum samples from Echinococcus granulosus infected human and dog. Moreover, EgG1Y162 antigen was phylogenetically closest to EmY162 antigen, with the similarity over 90%. CONCLUSION Our study identified EgG1Y162 antigen in Echinococcus granulosus for the first time. EgG1Y162 antigen had a high similarity with EmY162 antigen, with the genetic differences mainly existing in the intron region. And, EgG1Y162 recombinant protein showed good antigenicity.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Protozoan/blood
- Antigens, Helminth/blood
- Antigens, Helminth/genetics
- Antigens, Helminth/immunology
- Antigens, Helminth/isolation & purification
- Blotting, Western
- Cloning, Molecular
- Databases, Genetic
- Dogs
- Echinococcosis/blood
- Echinococcosis/parasitology
- Echinococcus granulosus/genetics
- Echinococcus granulosus/growth & development
- Echinococcus granulosus/immunology
- Humans
- Mice
- Molecular Sequence Data
- Phylogeny
- Protozoan Proteins/blood
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Protozoan Proteins/isolation & purification
- Real-Time Polymerase Chain Reaction
- Recombinant Proteins/immunology
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Analysis, Protein
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Affiliation(s)
- Fengbo Zhang
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research, The First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054, Xinjiang, P.R. China
| | - Xiumin Ma
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research, The First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054, Xinjiang, P.R. China
| | - Yuejie Zhu
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research, The First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054, Xinjiang, P.R. China
| | - Hongying Wang
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research, The First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054, Xinjiang, P.R. China
| | - Xianfei Liu
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research, The First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054, Xinjiang, P.R. China
| | - Min Zhu
- Department of Immunology, Xinjiang Medical UniversityUrumqi 830011, Xinjiang, P.R. China
| | - Haimei Ma
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research, The First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054, Xinjiang, P.R. China
| | - Hao Wen
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research, The First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054, Xinjiang, P.R. China
| | - Haining Fan
- Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Qinghai University251 Xining Road, Xining 810000, Qinghai, China
| | - Jianbing Ding
- State Key Laboratory Incubation Base of Xinjiang Major Diseases Research, The First Affiliated Hospital of Xinjiang Medical UniversityUrumqi 830054, Xinjiang, P.R. China
- Department of Immunology, Xinjiang Medical UniversityUrumqi 830011, Xinjiang, P.R. China
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Lee S, Manjunatha DH, Jeon W, Ban C. Cationic surfactant-based colorimetric detection of Plasmodium lactate dehydrogenase, a biomarker for malaria, using the specific DNA aptamer. PLoS One 2014; 9:e100847. [PMID: 24992632 PMCID: PMC4081113 DOI: 10.1371/journal.pone.0100847] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 05/30/2014] [Indexed: 02/07/2023] Open
Abstract
A simple, sensitive, and selective colorimetric biosensor for the detection of the malarial biomarkers Plasmodium vivax lactate dehydrogenase (PvLDH) and Plasmodium falciparum LDH (PfLDH) was demonstrated using the pL1 aptamer as the recognition element and gold nanoparticles (AuNPs) as probes. The proposed method is based on the aggregation of AuNPs using hexadecyltrimethylammonium bromide (CTAB). The AuNPs exhibited a sensitive color change from red to blue, which could be seen directly with the naked eye and was monitored using UV-visible absorption spectroscopy and transmission electron microscopy (TEM). The reaction conditions were optimized to obtain the maximum color intensity. PvLDH and PfLDH were discernible with a detection limit of 1.25 pM and 2.94 pM, respectively. The applicability of the proposed biosensor was also examined in commercially available human serum.
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Affiliation(s)
- Seonghwan Lee
- Department of Chemistry, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - D H Manjunatha
- Department of Chemistry, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Weejeong Jeon
- Department of Chemistry, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Changill Ban
- Department of Chemistry, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
- * E-mail:
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Affiliation(s)
- May M. Paing
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Niraj H. Tolia
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- * E-mail:
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Nagarkatti R, de Araujo FF, Gupta C, Debrabant A. Aptamer based, non-PCR, non-serological detection of Chagas disease biomarkers in Trypanosoma cruzi infected mice. PLoS Negl Trop Dis 2014; 8:e2650. [PMID: 24454974 PMCID: PMC3894185 DOI: 10.1371/journal.pntd.0002650] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 12/03/2013] [Indexed: 12/18/2022] Open
Abstract
Chagas disease affects about 5 million people across the world. The etiological agent, the intracellular parasite Trypanosoma cruzi (T. cruzi), can be diagnosed using microscopy, serology or PCR based assays. However, each of these methods has their limitations regarding sensitivity and specificity, and thus to complement these existing diagnostic methods, alternate assays need to be developed. It is well documented that several parasite proteins called T. cruzi Excreted Secreted Antigens (TESA), are released into the blood of an infected host. These circulating parasite antigens could thus be used as highly specific biomarkers of T. cruzi infection. In this study, we have demonstrated that, using a SELEx based approach, parasite specific ligands called aptamers, can be used to detect TESA in the plasma of T. cruzi infected mice. An Enzyme Linked Aptamer (ELA) assay, similar to ELISA, was developed using biotinylated aptamers to demonstrate that these RNA ligands could interact with parasite targets. Aptamer L44 (Apt-L44) showed significant and specific binding to TESA as well as T. cruzi trypomastigote extract and not to host proteins or proteins of Leishmania donovani, a related trypanosomatid parasite. Our result also demonstrated that the target of Apt-L44 is conserved in three different strains of T. cruzi. In mice infected with T. cruzi, Apt-L44 demonstrated a significantly higher level of binding compared to non-infected mice suggesting that it could detect a biomarker of T. cruzi infection. Additionally, Apt-L44 could detect these circulating biomarkers in both the acute phase, from 7 to 28 days post infection, and in the chronic phase, from 55 to 230 days post infection. Our results show that Apt-L44 could thus be used in a qualitative ELA assay to detect biomarkers of Chagas disease. Chagas disease, caused by the parasite Trypanosoma cruzi, is a major health concern for people living in Latin America. There are no vaccines to prevent this disease and only two drugs are prescribed for treatment. Current methods to diagnose patients are not always successful and thus new methods need to be developed. One approach to develop an alternate method is to detect proteins and metabolites that are secreted by parasites into the blood of infected individuals. We have utilized a selection based method to isolate ligands that bind to these secreted proteins. These ligands, called aptamers, have been used to develop an assay that can detect the circulating parasite targets in the plasma or serum of an infected host. In an animal model of Chagas disease, our assay can detect parasite biomarkers as early as seven days after infection and as late as 230 days post infection. As the laboratory instruments and procedures are similar to performing an ELISA, the aptamer assay reported here could be easily performed at diagnostic facilities. Further improvement in this assay can lead to a new quantitative diagnostic test for Chagas disease. A similar selection based approach could also be used to develop ligands for the detection of biomarkers in other diseases.
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Affiliation(s)
- Rana Nagarkatti
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Fernanda Fortes de Araujo
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Charu Gupta
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Alain Debrabant
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, U. S. Food and Drug Administration, Bethesda, Maryland, United States of America
- * E-mail:
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Lauinger IL, Vivas L, Perozzo R, Stairiker C, Tarun A, Zloh M, Zhang X, Xu H, Tonge PJ, Franzblau SG, Pham DH, Esguerra CV, Crawford AD, Maes L, Tasdemir D. Potential of lichen secondary metabolites against Plasmodium liver stage parasites with FAS-II as the potential target. J Nat Prod 2013; 76:1064-70. [PMID: 23806111 PMCID: PMC4119598 DOI: 10.1021/np400083k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Chemicals targeting the liver stage (LS) of the malaria parasite are useful for causal prophylaxis of malaria. In this study, four lichen metabolites, evernic acid (1), vulpic acid (2), psoromic acid (3), and (+)-usnic acid (4), were evaluated against LS parasites of Plasmodium berghei. Inhibition of P. falciparum blood stage (BS) parasites was also assessed to determine stage specificity. Compound 4 displayed the highest LS activity and stage specificity (LS IC50 value 2.3 μM, BS IC50 value 47.3 μM). The compounds 1-3 inhibited one or more enzymes (PfFabI, PfFabG, and PfFabZ) from the plasmodial fatty acid biosynthesis (FAS-II) pathway, a potential drug target for LS activity. To determine species specificity and to clarify the mechanism of reported antibacterial effects, 1-4 were also evaluated against FabI homologues and whole cells of various pathogens (S. aureus, E. coli, M. tuberculosis). Molecular modeling studies suggest that lichen acids act indirectly via binding to allosteric sites on the protein surface of the FAS-II enzymes. Potential toxicity of compounds was assessed in human hepatocyte and cancer cells (in vitro) as well as in a zebrafish model (in vivo). This study indicates the therapeutic and prophylactic potential of lichen metabolites as antibacterial and antiplasmodial agents.
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Affiliation(s)
- Ina L. Lauinger
- Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University of London, London WC1N 1AX, UK
| | - Livia Vivas
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Remo Perozzo
- School of Pharmaceutical Sciences, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Christopher Stairiker
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA 152614, USA
| | - Alice Tarun
- Department of Infectious Diseases and Microbiology, University of Pittsburgh, Pittsburgh, PA 152614, USA
| | - Mire Zloh
- Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University of London, London WC1N 1AX, UK
| | - Xujie Zhang
- Institute for Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, NY 11794, USA
| | - Hua Xu
- Institute for Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, NY 11794, USA
| | - Peter J. Tonge
- Institute for Chemical Biology and Drug Discovery, Department of Chemistry, Stony Brook University, NY 11794, USA
| | - Scott G. Franzblau
- Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Duc-Hung Pham
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, 3000 Leuven, Belgium
| | - Camila V. Esguerra
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, 3000 Leuven, Belgium
| | - Alexander D. Crawford
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, 3000 Leuven, Belgium
| | - Louis Maes
- Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, 2610 Antwerp, Belgium
| | - Deniz Tasdemir
- Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University of London, London WC1N 1AX, UK
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Azcárate IG, Marín-García P, Camacho N, Pérez-Benavente S, Puyet A, Diez A, Ribas de Pouplana L, Bautista JM. Insights into the preclinical treatment of blood-stage malaria by the antibiotic borrelidin. Br J Pharmacol 2013; 169:645-58. [PMID: 23488671 PMCID: PMC3682711 DOI: 10.1111/bph.12156] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 01/09/2013] [Accepted: 02/01/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND PURPOSE Blood-stage Plasmodium parasites cause morbidity and mortality from malaria. Parasite resistance to drugs makes development of new chemotherapies an urgency. Aminoacyl-tRNA synthetases have been validated as antimalarial drug targets. We explored long-term effects of borrelidin and mupirocin in lethal P. yoelii murine malaria. EXPERIMENTAL APPROACH Long-term (up to 340 days) immunological responses to borrelidin or mupirocin were measured after an initial 4 day suppressive test. Prophylaxis and cure were evaluated and the inhibitory effect on the parasites analysed. KEY RESULTS Borrelidin protected against lethal malaria at 0.25 mg·kg⁻¹·day⁻¹. Antimalarial activity of borrelidin correlated with accumulation of trophozoites in peripheral blood. All infected mice treated with borrelidin survived and subsequently developed immunity protecting them from re-infection on further challenges, 75 and 340 days after the initial infection. This long-term immunity in borrelidin-treated mice resulted in negligible parasitaemia after re-infections and marked increases in total serum levels of antiparasite IgGs with augmented avidity. Long-term memory IgGs mainly reacted against high and low molecular weight parasite antigens. Immunofluorescence microscopy showed that circulating IgGs bound predominantly to late intracellular stage parasites, mainly schizonts. CONCLUSIONS AND IMPLICATIONS Low borrelidin doses protected mice from lethal malaria infections and induced protective immune responses after treatment. Development of combination therapies with borrelidin and selective modifications of the borrelidin molecule to specifically inhibit plasmodial threonyl tRNA synthetase should improve therapeutic strategies for malaria.
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Affiliation(s)
- I G Azcárate
- Department of Biochemistry and Molecular Biology IV and Research Institute Hospital 12 de Octubre, Universidad Complutense de Madrid, Madrid, Spain
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Barry AE, Schultz L, Senn N, Nale J, Kiniboro B, Siba PM, Mueller I, Reeder JC. High levels of genetic diversity of Plasmodium falciparum populations in Papua New Guinea despite variable infection prevalence. Am J Trop Med Hyg 2013; 88:718-25. [PMID: 23400571 PMCID: PMC3617858 DOI: 10.4269/ajtmh.12-0056] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 11/30/2012] [Indexed: 11/07/2022] Open
Abstract
High levels of genetic diversity in Plasmodium falciparum populations are an obstacle to malaria control. Here, we investigate the relationship between local variation in malaria epidemiology and parasite genetic diversity in Papua New Guinea (PNG). Cross-sectional malaria surveys were performed in 14 villages spanning four distinct malaria-endemic areas on the north coast, including one area that was sampled during the dry season. High-resolution msp2 genotyping of 2,147 blood samples identified 761 P. falciparum infections containing a total of 1,392 clones whose genotypes were used to measure genetic diversity. Considerable variability in infection prevalence and mean multiplicity of infection was observed at all of the study sites, with the area sampled during the dry season showing particularly striking local variability. Genetic diversity was strongly associated with multiplicity of infection but not with infection prevalence. In highly endemic areas, differences in infection prevalence may not translate into a decrease in parasite population diversity.
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Affiliation(s)
- Alyssa E Barry
- Centre for Population Health, Burnet Institute, Melbourne, Australia.
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Hendriksen ICE, White LJ, Veenemans J, Mtove G, Woodrow C, Amos B, Saiwaew S, Gesase S, Nadjm B, Silamut K, Joseph S, Chotivanich K, Day NPJ, von Seidlein L, Verhoef H, Reyburn H, White NJ, Dondorp AM. Defining falciparum-malaria-attributable severe febrile illness in moderate-to-high transmission settings on the basis of plasma PfHRP2 concentration. J Infect Dis 2013; 207:351-61. [PMID: 23136222 PMCID: PMC3532834 DOI: 10.1093/infdis/jis675] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 08/23/2012] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND In malaria-endemic settings, asymptomatic parasitemia complicates the diagnosis of malaria. Histidine-rich protein 2 (HRP2) is produced by Plasmodium falciparum, and its plasma concentration reflects the total body parasite burden. We aimed to define the malaria-attributable fraction of severe febrile illness, using the distributions of plasma P. falciparum HRP2 (PfHRP2) concentrations from parasitemic children with different clinical presentations. METHODS Plasma samples were collected from and peripheral blood slides prepared for 1435 children aged 6-60 months in communities and a nearby hospital in northeastern Tanzania. The study population included children with severe or uncomplicated malaria, asymptomatic carriers, and healthy control subjects who had negative results of rapid diagnostic tests. The distributions of plasma PfHRP2 concentrations among the different groups were used to model severe malaria-attributable disease. RESULTS The plasma PfHRP2 concentration showed a close correlation with the severity of infection. PfHRP2 concentrations of >1000 ng/mL denoted a malaria-attributable fraction of severe disease of 99% (95% credible interval [CI], 96%-100%), with a sensitivity of 74% (95% CI, 72%-77%), whereas a concentration of <200 ng/mL denoted severe febrile illness of an alternative diagnosis in >10% (95% CI, 3%-27%) of patients. Bacteremia was more common among patients in the lowest and highest PfHRP2 concentration quintiles. CONCLUSIONS The plasma PfHRP2 concentration defines malaria-attributable disease and distinguishes severe malaria from coincidental parasitemia in African children in a moderate-to-high transmission setting.
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Affiliation(s)
- Ilse C E Hendriksen
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Eksi S, Morahan BJ, Haile Y, Furuya T, Jiang H, Ali O, Xu H, Kiattibutr K, Suri A, Czesny B, Adeyemo A, Myers TG, Sattabongkot J, Su XZ, Williamson KC. Plasmodium falciparum gametocyte development 1 (Pfgdv1) and gametocytogenesis early gene identification and commitment to sexual development. PLoS Pathog 2012; 8:e1002964. [PMID: 23093935 PMCID: PMC3475683 DOI: 10.1371/journal.ppat.1002964] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 08/27/2012] [Indexed: 12/13/2022] Open
Abstract
Malaria transmission requires the production of male and female gametocytes in the human host followed by fertilization and sporogonic development in the mosquito midgut. Although essential for the spread of malaria through the population, little is known about the initiation of gametocytogenesis in vitro or in vivo. Using a gametocyte-defective parasite line and genetic complementation, we show that Plasmodium falciparumgametocyte development 1 gene (Pfgdv1), encoding a peri-nuclear protein, is critical for early sexual differentiation. Transcriptional analysis of Pfgdv1 negative and positive parasite lines identified a set of gametocytogenesis early genes (Pfge) that were significantly down-regulated (>10 fold) in the absence of Pfgdv1 and expression was restored after Pfgdv1 complementation. Progressive accumulation of Pfge transcripts during successive rounds of asexual replication in synchronized cultures suggests that gametocytes are induced continuously during asexual growth. Comparison of Pfge gene transcriptional profiles in patient samples divided the genes into two groups differing in their expression in mature circulating gametocytes and providing candidates to evaluate gametocyte induction and maturation separately in vivo. The expression profile of one of the early gametocyte specific genes, Pfge1, correlated significantly with asexual parasitemia, which is consistent with the ongoing induction of gametocytogenesis during asexual growth observed in vitro and reinforces the need for sustained transmission-blocking strategies to eliminate malaria. As malaria control efforts move toward eradication it becomes increasingly important to develop interventions that block transmission. Consequently, advances are needed in our understanding of the production of gametocytes, which are required to transmit the disease. This report provides a first view of the initial stages of gametocytogenesis in vitro and in vivo and demonstrates that during each asexual replication cycle a subpopulation of parasites convert to gametocyte development providing a long transmission window. We also identify a gene that is critical for gametocyte production, P. falciparumgametocyte development 1 (Pfgdv1) and a set of genes specifically expressed during early gametocytogenesis in P. falciparum (Pfge genes). The expression profile and peri-nuclear location of Pfgdv1 in a subpopulation of schizonts is consistent with a role in an early step in gametocytogenesis. The RNA levels of Pfgdv1 and the Pfge genes accumulated gradually over several asexual cycles in vitro suggesting ongoing gametocyte formation during asexual growth. The further evaluation of these genes in a cohort of malaria infected patients indicated they are good candidates for markers to distinguish ring stage parasites committed to gametocyte production from circulating mature gametocytes, allowing direct analysis of the initiation of sexual differentiation in vivo.
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Affiliation(s)
- Saliha Eksi
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Belinda J. Morahan
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Yoseph Haile
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Tetsuya Furuya
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hongying Jiang
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Omar Ali
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Huichun Xu
- Center for Research on Genomics and Global Health, Inherited Disease Research Branch, National Human Genomics Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kirakorn Kiattibutr
- Department of Entomology, U.S. Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Amreena Suri
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Beata Czesny
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Adebowale Adeyemo
- Center for Research on Genomics and Global Health, Inherited Disease Research Branch, National Human Genomics Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Timothy G. Myers
- Genomic Technologies Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jetsumon Sattabongkot
- Department of Entomology, U.S. Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Xin-zhuan Su
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kim C. Williamson
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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Nash MA, Waitumbi JN, Hoffman AS, Yager P, Stayton PS. Multiplexed enrichment and detection of malarial biomarkers using a stimuli-responsive iron oxide and gold nanoparticle reagent system. ACS Nano 2012; 6:6776-85. [PMID: 22804625 PMCID: PMC4085275 DOI: 10.1021/nn3015008] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
There is a need for simple yet robust biomarker and antigen purification and enrichment strategies that are compatible with current rapid diagnostic modalities. Here, a stimuli-responsive nanoparticle system is presented for multiplexed magneto-enrichment and non-instrumented lateral flow strip detection of model antigens from spiked pooled plasma. The integrated reagent system allows purification and enrichment of the gold-labeled biomarker half-sandwich that can be applied directly to lateral flow test strips. A linear diblock copolymer with a thermally responsive poly(N-isopropylacrylamide) (pNIPAm) segment and a gold-binding block composed of NIPAm-co-N,N-dimethylaminoethylacrylamide was prepared by reversible addition-fragmentation chain transfer polymerization. The diblock copolymer was used to functionalize gold nanoparticles (AuNPs), with subsequent bioconjugation to yield thermally responsive pNIPAm-AuNPs that were co-decorated with streptavidin. These AuNPs efficiently complexed biotinylated capture antibody reagents that were bound to picomolar quantities of pan-aldolase and Plasmodium falciparum histidine-rich protein 2 (PfHRP2) in spiked pooled plasma samples. The gold-labeled biomarker half-sandwich was then purified and enriched using 10 nm thermally responsive magnetic nanoparticles that were similarly decorated with pNIPAm. When a thermal stimulus was applied in conjunction with a magnetic field, coaggregation of the AuNP half-sandwiches with the pNIPAm-coated iron oxide nanoparticles created large aggregates that were efficiently magnetophoresed and separated from bulk serum. The purified biomarkers from a spiked pooled plasma sample could be concentrated 50-fold into a small volume and applied directly to a commercial multiplexed lateral flow strip to dramatically improve the signal-to-noise ratio and test sensitivity.
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Affiliation(s)
- Michael A Nash
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
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Remarque EJ, Roestenberg M, Younis S, Walraven V, van der Werff N, Faber BW, Leroy O, Sauerwein R, Kocken CHM, Thomas AW. Humoral immune responses to a single allele PfAMA1 vaccine in healthy malaria-naïve adults. PLoS One 2012; 7:e38898. [PMID: 22768052 PMCID: PMC3387192 DOI: 10.1371/journal.pone.0038898] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 05/14/2012] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Plasmodium falciparum: apical membrane antigen 1 (AMA1) is a candidate malaria vaccine antigen expressed on merozoites and sporozoites. The polymorphic nature of AMA1 may compromise vaccine induced protection. The humoral response induced by two dosages (10 and 50 µg) of a single allele AMA1 antigen (FVO) formulated with Alhydrogel, Montanide ISA 720 or AS02 was investigated in 47 malaria-naïve adult volunteers. Volunteers were vaccinated 3 times at 4 weekly intervals and serum samples obtained four weeks after the third immunization were analysed for (i) Antibody responses to various allelic variants, (ii) Domain specificity, (iii) Avidity, (iv) IgG subclass levels, by ELISA and (v) functionality of antibody responses by Growth Inhibition Assay (GIA). About half of the antibodies induced by vaccination cross reacted with heterologous AMA1 alleles. The choice of adjuvant determined the magnitude of the antibody response, but had only a marginal influence on specificity, avidity, domain recognition or subclass responses. The highest antibody responses were observed for AMA1 formulated with AS02. The Growth Inhibition Assay activity of the antibodies was proportional to the amount of antigen specific IgG and the functional capacity of the antibodies was similar for heterologous AMA1-expressing laboratory strains. TRIAL REGISTRATION ClinicalTrials.gov NCT00730782.
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Biswas S, Spencer AJ, Forbes EK, Gilbert SC, Holder AA, Hill AVS, Draper SJ. Recombinant viral-vectored vaccines expressing Plasmodium chabaudi AS apical membrane antigen 1: mechanisms of vaccine-induced blood-stage protection. J Immunol 2012; 188:5041-53. [PMID: 22504652 PMCID: PMC3378655 DOI: 10.4049/jimmunol.1101106] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Apical membrane Ag 1 (AMA1) is one of the leading candidate Ags for inclusion in a subunit vaccine against blood-stage malaria. However, the efficacy of Ab-inducing recombinant AMA1 protein vaccines in phase IIa/b clinical trials remains disappointing. In this article, we describe the development of recombinant human adenovirus serotype 5 and modified vaccinia virus Ankara vectors encoding AMA1 from the Plasmodium chabaudi chabaudi strain AS. These vectors, when used in a heterologous prime-boost regimen in BALB/c mice, are capable of inducing strong transgene-specific humoral and cellular immune responses. We show that this vaccination regimen is protective against a nonlethal P. chabaudi chabaudi strain AS blood-stage challenge, resulting in reduced peak parasitemias. The role of vaccine-induced, AMA1-specific Abs and T cells in mediating the antiparasite effect was investigated by in vivo depletion of CD4(+) T cells and adoptive-transfer studies into naive and immunodeficient mice. Depletion of CD4(+) T cells led to a loss of vaccine-induced protection. Adoptive-transfer studies confirmed that efficacy is mediated by both CD4(+) T cells and Abs functioning in the context of an intact immune system. Unlike previous studies, these results confirm that Ag-specific CD4(+) T cells, induced by a clinically relevant vaccine-delivery platform, can make a significant contribution to vaccine blood-stage efficacy in the P. chabaudi model. Given that cell-mediated immunity may also contribute to parasite control in human malaria, these data support the clinical development of viral-vectored vaccines that induce both T cell and Abs against Plasmodium falciparum blood-stage malaria Ags like AMA1.
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MESH Headings
- Adenoviruses, Human/genetics
- Adenoviruses, Human/immunology
- Animals
- Antibodies, Protozoan/biosynthesis
- Antibodies, Protozoan/blood
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/blood
- Antigens, Protozoan/blood
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Female
- Genetic Vectors/administration & dosage
- Genetic Vectors/immunology
- Humans
- Malaria Vaccines/administration & dosage
- Malaria Vaccines/genetics
- Malaria Vaccines/immunology
- Malaria, Falciparum/blood
- Malaria, Falciparum/immunology
- Malaria, Falciparum/prevention & control
- Membrane Proteins/blood
- Membrane Proteins/genetics
- Membrane Proteins/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Knockout
- Mice, Nude
- Molecular Sequence Data
- Plasmodium chabaudi/genetics
- Plasmodium chabaudi/immunology
- Plasmodium falciparum/genetics
- Plasmodium falciparum/immunology
- Protozoan Proteins/blood
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Vaccines, Subunit/administration & dosage
- Vaccines, Subunit/genetics
- Vaccines, Subunit/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Vaccinia virus/genetics
- Vaccinia virus/immunology
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Affiliation(s)
- Sumi Biswas
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, United Kingdom.
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Rubach MP, Mukemba J, Florence S, John B, Crookston B, Lopansri BK, Yeo TW, Piera KA, Alder SC, Weinberg JB, Anstey NM, Granger DL, Mwaikambo ED. Plasma Plasmodium falciparum histidine-rich protein-2 concentrations are associated with malaria severity and mortality in Tanzanian children. PLoS One 2012; 7:e35985. [PMID: 22586457 PMCID: PMC3346811 DOI: 10.1371/journal.pone.0035985] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 03/29/2012] [Indexed: 11/30/2022] Open
Abstract
Plasma Plasmodium falciparum histidine-rich protein-2 (PfHRP-2) concentrations, a measure of parasite biomass, have been correlated with malaria severity in adults, but not yet in children. We measured plasma PfHRP-2 in Tanzanian children with uncomplicated (n = 61) and cerebral malaria (n = 45; 7 deaths). Median plasma PfHRP-2 concentrations were higher in cerebral malaria (1008 [IQR 342–2572] ng/mL) than in uncomplicated malaria (465 [IQR 36–1426] ng/mL; p = 0.017). In cerebral malaria, natural log plasma PfHRP-2 was associated with coma depth (r = −0.42; p = 0.006) and mortality (OR: 3.0 [95% CI 1.03–8.76]; p = 0.04). In this relatively small cohort study in a mesoendemic transmission area of Africa, plasma PfHRP-2 was associated with pediatric malaria severity and mortality. Further studies among children in areas of Africa with higher malaria transmission and among children with different clinical manifestations of severe malaria will help determine the wider utility of quantitative PfHRP-2 as a measure of parasite biomass and prognosis in sub-Saharan Africa.
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Affiliation(s)
- Matthew P. Rubach
- University of Utah School of Medicine and Veterans Affairs Medical Center, Salt Lake City, Utah, United States of America
| | - Jackson Mukemba
- Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
| | - Salvatore Florence
- Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
| | - Bernard John
- Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
| | - Benjamin Crookston
- University of Utah School of Medicine and Veterans Affairs Medical Center, Salt Lake City, Utah, United States of America
| | - Bert K. Lopansri
- Loyola University Medical Center, Maywood, Illinois, United States of America
| | - Tsin W. Yeo
- Menzies School for Health Research and Charles Darwin University, Darwin, Australia
- Royal Darwin Hospital, Darwin, Australia
| | - Kim A. Piera
- Menzies School for Health Research and Charles Darwin University, Darwin, Australia
| | - Stephen C. Alder
- University of Utah School of Medicine and Veterans Affairs Medical Center, Salt Lake City, Utah, United States of America
| | - J. Brice Weinberg
- VA Medical Centers and Duke University, Durham, North Carolina, United States of America
| | - Nicholas M. Anstey
- Menzies School for Health Research and Charles Darwin University, Darwin, Australia
- Royal Darwin Hospital, Darwin, Australia
| | - Donald L. Granger
- University of Utah School of Medicine and Veterans Affairs Medical Center, Salt Lake City, Utah, United States of America
- * E-mail:
| | - Esther D. Mwaikambo
- Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
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Oleinikov AV, Voronkova VV, Frye IT, Amos E, Morrison R, Fried M, Duffy PE. A plasma survey using 38 PfEMP1 domains reveals frequent recognition of the Plasmodium falciparum antigen VAR2CSA among young Tanzanian children. PLoS One 2012; 7:e31011. [PMID: 22295123 PMCID: PMC3266279 DOI: 10.1371/journal.pone.0031011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 12/30/2011] [Indexed: 11/29/2022] Open
Abstract
PfEMP1 proteins comprise a family of variant antigens that appear on the surface of P. falciparum-infected erythrocytes and bind to multiple host receptors. Using a mammalian expression system and BioPlex technology, we developed an array of 24 protein constructs representing 38 PfEMP1 domains for high throughput analyses of receptor binding as well as total and functional antibody responses. We analyzed the reactivity of 561 plasma samples from 378 young Tanzanian children followed up to maximum 192 weeks of life in a longitudinal birth cohort. Surprisingly, reactivity to the DBL5 domain of VAR2CSA, a pregnancy malaria vaccine candidate, was most common, and the prevalence of reactivity was stable throughout early childhood. Reactivity to all other PfEMP1 constructs increased with age. Antibodies to the DBL2βC2PF11_0521 domain, measured as plasma reactivity or plasma inhibition of ICAM1 binding, predicted reduced risk of hospitalization for severe or moderately severe malaria. These data suggest a role for VAR2CSA in childhood malaria and implicate DBL2βC2PF11_0521 in protective immunity.
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Affiliation(s)
- Andrew V Oleinikov
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America.
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Hendriksen ICE, Mwanga-Amumpaire J, von Seidlein L, Mtove G, White LJ, Olaosebikan R, Lee SJ, Tshefu AK, Woodrow C, Amos B, Karema C, Saiwaew S, Maitland K, Gomes E, Pan-Ngum W, Gesase S, Silamut K, Reyburn H, Joseph S, Chotivanich K, Fanello CI, Day NPJ, White NJ, Dondorp AM. Diagnosing severe falciparum malaria in parasitaemic African children: a prospective evaluation of plasma PfHRP2 measurement. PLoS Med 2012; 9:e1001297. [PMID: 22927801 PMCID: PMC3424256 DOI: 10.1371/journal.pmed.1001297] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 07/13/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In African children, distinguishing severe falciparum malaria from other severe febrile illnesses with coincidental Plasmodium falciparum parasitaemia is a major challenge. P. falciparum histidine-rich protein 2 (PfHRP2) is released by mature sequestered parasites and can be used to estimate the total parasite burden. We investigated the prognostic significance of plasma PfHRP2 and used it to estimate the malaria-attributable fraction in African children diagnosed with severe malaria. METHODS AND FINDINGS Admission plasma PfHRP2 was measured prospectively in African children (from Mozambique, The Gambia, Kenya, Tanzania, Uganda, Rwanda, and the Democratic Republic of the Congo) aged 1 month to 15 years with severe febrile illness and a positive P. falciparum lactate dehydrogenase (pLDH)-based rapid test in a clinical trial comparing parenteral artesunate versus quinine (the AQUAMAT trial, ISRCTN 50258054). In 3,826 severely ill children, Plasmadium falciparum PfHRP2 was higher in patients with coma (p = 0.0209), acidosis (p<0.0001), and severe anaemia (p<0.0001). Admission geometric mean (95%CI) plasma PfHRP2 was 1,611 (1,350-1,922) ng/mL in fatal cases (n = 381) versus 1,046 (991-1,104) ng/mL in survivors (n = 3,445, p<0.0001), without differences in parasitaemia as assessed by microscopy. There was a U-shaped association between log(10) plasma PfHRP2 and risk of death. Mortality increased 20% per log(10) increase in PfHRP2 above 174 ng/mL (adjusted odds ratio [AOR] 1.21, 95%CI 1.05-1.39, p = 0.009). A mechanistic model assuming a PfHRP2-independent risk of death in non-malaria illness closely fitted the observed data and showed malaria-attributable mortality less than 50% with plasma PfHRP2≤174 ng/mL. The odds ratio (OR) for death in artesunate versus quinine-treated patients was 0.61 (95%CI 0.44-0.83, p = 0.0018) in the highest PfHRP2 tertile, whereas there was no difference in the lowest tertile (OR 1.05; 95%CI 0.69-1.61; p = 0.82). A limitation of the study is that some conclusions are drawn from a mechanistic model, which is inherently dependent on certain assumptions. However, a sensitivity analysis of the model indicated that the results were robust to a plausible range of parameter estimates. Further studies are needed to validate our findings. CONCLUSIONS Plasma PfHRP2 has prognostic significance in African children with severe falciparum malaria and provides a tool to stratify the risk of "true" severe malaria-attributable disease as opposed to other severe illnesses in parasitaemic African children.
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Affiliation(s)
- Ilse C. E. Hendriksen
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | | | | | - George Mtove
- National Institute for Medical Research, Amani Centre, Tanga, Tanzania
| | - Lisa J. White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | | | - Sue J. Lee
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Antoinette K. Tshefu
- Kinshasa School of Public Health, Kingasani Research Centre, Kinshasa, Democratic Republic of the Congo
| | - Charles Woodrow
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Ben Amos
- Teule Hospital, Muheza, Tanzania
| | - Corine Karema
- Malaria Control Program, Ministry of Health, Kigali, Rwanda
| | - Somporn Saiwaew
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kathryn Maitland
- Kenya Medical Research Institute (KEMRI)–Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Wirichada Pan-Ngum
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Samwel Gesase
- National Institute for Medical Research, Tanga Medical Research Centre, Tanga, Tanzania
| | - Kamolrat Silamut
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Hugh Reyburn
- London School of Tropical Medicine & Hygiene, London, United Kingdom
| | - Sarah Joseph
- Medical Research Council, London, United Kingdom
| | - Kesinee Chotivanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Caterina I. Fanello
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Nicholas P. J. Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Nicholas J. White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Arjen M. Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
- * E-mail:
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47
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Gil JF, Hoyos CL, Cimino RO, Krolewiecki AJ, López Quiroga I, Cajal SP, Juárez M, García Bustos MF, Mora MC, Marco JD, Nasser JR. [Role of three ELISA tests using promastigote homogenates of Leishmania braziliensis, L. amazonensis and L. guyanensis in the diagnosis of tegumentary leishmaniasis]. Medicina (B Aires) 2011; 71:420-428. [PMID: 22057166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
It is important to know whether the variability of species of Leishmania parasites circulating in a region affects the performance of the ELISA test for the diagnosis of leishmaniasis. Therefore, the aim of this study was to analyze the reactivity of the ELISA using homogenates of promastigotes of Leishmania (V.) braziliensis (ELISAb), Leishmania (L) amazonensis (ELISAa) and Leishmania (V.) guyanensis (ELISAg) against different sera groups. Samples from individuals with cutaneous leishmaniasis (n = 37), mucocutaneous leishmaniasis (n = 8), healthy controls (n = 52), persons infected with Trypanosoma cruzi (n = 11) and mixed infections (n = 14) were included in the study. We calculated sensitivities, specificities, cut offs, and predictive values for the three tests and compared them using ANOVA, kappa index, ROC curves comparison, and confidence intervals calculated by the bootstrap method. Significant differences were found when comparing the OD levels of sera from patients with cutaneous leishmaniasis against healthy controls, but there were no differences when comparing the different ELISAs. The sensitivities calculated for ELISAb and ELISAa were 84.6 and of 88.5% for ELISAg, while the value of specificity for the three tests was 96.2. The kappa index (0.87) and comparison of ROC curves showed similar performance for the three ELISAs (p = 0.225). The high reactivity obtained for these ELISAs in sera of patients with mucocutaneous leishmaniasis indicates this test as an important complement in the diagnosis of the disease.
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Affiliation(s)
- José F Gil
- Instituto de Investigaciones en Enfermedades Tropicales (IIET), Sede Regional Orán.
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Khan HM, Shujatullah F, Shahid M, Raza A, Malik R. Evaluation of Diagnos Malaria Stix test (antigen detection assay) for diagnosis of malaria. J Commun Dis 2010; 42:153-156. [PMID: 22471175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Malaria is one of the most common parasitic infection in India. The diagnosis largely depends on peripheral blood smear examination. Newer diagnostic methods like various antigen detection assays are now in use for prompt diagnosis and treatment. This study was done to determine the effectiveness of Diagnos Malaria Stix (antigen detection) assay in diagnosis of malaria. This involves detection of PfHRP-2 antigen and P.V. specific pLDH antigen. 162 patients with signs and symptoms of malaria included in the study. Leishman stained blood smear examination was done for all patients. Commercially available Diagnos Malaria Stix assay was used. Diagnos Malaria Stix showed sensitivity, specificity positive and negative predictive values of 100% each while Sensitivity, specificity, positive and negative predictive values of Leishman stained blood smear examination were 45.45%, 100%, 100% and 92% respectively.
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Affiliation(s)
- Haris M Khan
- Dept. of Microbiology, J.N. Medical College, Aligarh, UP
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Cho SY, Park KS, Lim GY, Kim MJ, Lee MS, Oh SH, Suh JT, Lee HJ, Park TS. Plasmodium falciparum malaria detected by HRP-2 antigenemia before microscopic- and PCR-positive conversion. Ann Clin Lab Sci 2010; 40:172-177. [PMID: 20421630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We describe a case of relapsed Plasmodium falciparum malaria detected by rapid diagnostic testing (RDT) 19 days before microscopic- or PCR-positive conversion. Three malaria tests gave discrepant results; the malaria smear and polymerase chain reaction (PCR) tests were both negative, while malaria RDT with a commercial kit to detect malarial antigens, including histidine-rich protein 2 (HRP-2), was repeatedly positive for P. falciparum. About 3 weeks after the onset of symptoms, the patient was hospitalized because of a high fever. Blood and urine cultures and malaria smears were all negative, and a subsequent bone marrow study was performed to evaluate fever of unknown origin. Unexpectedly, 19 days after the positive RDT result, malaria parasites were detected by microscopy in the bone marrow and peripheral blood. The malaria PCR result also became positive for P. falciparum on the same day. This case report shows that a positive RDT result discordant with microscopy and PCR should not be viewed as a failure of RDT, but must be evaluated carefully to rule out infection at a low parasite density. In such unusual cases, frequent follow-up tests with multiple methods are recommended for an accurate diagnosis. The RDT may achieve earlier detection than methods targeting parasitemia in some patients with malaria.
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Affiliation(s)
- Sun Young Cho
- Deptartment of Laboratory Medicine, School of Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-702, Korea
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50
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Stauffer WM, Cartwright CP, Olson DA, Juni BA, Taylor CM, Bowers SH, Hanson KL, Rosenblatt JE, Boulware DR. Diagnostic performance of rapid diagnostic tests versus blood smears for malaria in US clinical practice. Clin Infect Dis 2009; 49:908-13. [PMID: 19686072 PMCID: PMC2912215 DOI: 10.1086/605436] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Approximately 4 million US travelers to developing countries are ill enough to seek health care, with 1500 malaria cases reported in the United States annually. The diagnosis of malaria is frequently delayed because of the time required to prepare malaria blood films and lack of technical expertise. An easy, reliable rapid diagnostic test (RDT) with high sensitivity and negative predictive value (NPV), particularly for Plasmodium falciparum, would be clinically useful. The objective of this study was to determine the diagnostic performance of a RDT approved by the US Food and Drug Administration compared with traditional thick and thin blood smears for malaria diagnosis. METHODS This prospective study tested 852 consecutive blood samples that underwent thick and thin smears and blinded malaria RDTs at 3 hospital laboratories during 2003-2006. Polymerase chain reaction verified positive test results and discordant results. RESULTS Malaria was noted in 95 (11%) of the 852 samples. The RDT had superior performance than the standard Giemsa thick blood smear (p = .003). The RDT's sensitivity for all malaria was 97% (92 of 95 samples), compared with 85% (81 of 95) for the blood smear, and the RDT had a superior NPV of 99.6%, compared with 98.2% for the blood smear (p = .001). The P. falciparum performance was excellent, with 100% rapid test sensitivity, compared with only 88% (65 of 74) by blood smear (p = .003). CONCLUSIONS This operational study demonstrates that the US Food and Drug Administration-approved RDT for malaria is superior to a single set of blood smears performed under routine US clinical laboratory conditions. The most valuable clinical role of the RDT is in the rapid diagnosis or the exclusion of P. falciparum malaria, which is particularly useful in outpatient settings when evaluating febrile travelers.
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Affiliation(s)
- William M Stauffer
- Department of Medicine, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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