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Takamiya NT, Rogerio LA, Torres C, Leonel JAF, Vioti G, de Sousa Oliveira TMF, Valeriano KC, Porcino GN, de Miranda Santos IKF, Costa CHN, Costa DL, Ferreira TS, Gurgel-Gonçalves R, da Silva JS, Teixeira FR, De Almeida RP, Ribeiro JMC, Maruyama SR. Parasite Detection in Visceral Leishmaniasis Samples by Dye-Based qPCR Using New Gene Targets of Leishmania infantum and Crithidia. Trop Med Infect Dis 2023; 8:405. [PMID: 37624343 PMCID: PMC10457869 DOI: 10.3390/tropicalmed8080405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 08/26/2023] Open
Abstract
Visceral leishmaniasis (VL) is a neglected disease considered a serious public health problem, especially in endemic countries. Several studies have discovered monoxenous trypanosomatids (Leptomonas and Crithidia) in patients with VL. In different situations of leishmaniasis, investigations have examined cases of co-infection between Leishmania spp. and Crithidia spp. These coinfections have been observed in a wide range of vertebrate hosts, indicating that they are not rare. Diagnostic techniques require improvements and more robust tools to accurately detect the causative agent of VL. This study aimed to develop a real-time quantitative dye-based PCR (qPCR) assay capable of distinguishing Leishmania infantum from Crithidia-related species and to estimate the parasite load in samples of VL from humans and animals. The primer LinJ31_2420 targets an exclusive phosphatase of L. infantum; the primer Catalase_LVH60-12060_1F targets the catalase gene of Crithidia. Therefore, primers were designed to detect L. infantum and Crithidia sp. LVH60A (a novel trypanosomatid isolated from VL patients in Brazil), in samples related to VL. These primers were considered species-specific, based on sequence analysis using genome data retrieved from the TriTryp database and the genome assembling of Crithidia sp. LVH60A strain, in addition to experimental and clinical data presented herein. This novel qPCR assay was highly accurate in identifying and quantifying L. infantum and Crithidia sp. LVH60A in samples obtained experimentally (in vitro and in vivo) or collected from hosts (humans, dogs, cats, and vectors). Importantly, the screening of 62 cultured isolates from VL patients using these primers surprisingly revealed that 51 parasite cultures were PCR+ for Crithidia sp. In addition, qPCR assays identified the co-infection of L. infantum with Crithidia sp. LVH60A in two new VL cases in Brazil, confirming the suspicion of co-infection in a previously reported case of fatal VL. We believe that the species-specific genes targeted in this study can be helpful for the molecular diagnosis of VL, as well as for elucidating suspected co-infections with monoxenous-like trypanosomatids, which is a neglected fact of a neglected disease.
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Affiliation(s)
- Nayore Tamie Takamiya
- Department of Genetics and Evolution, Center for Biological Sciences and Health, Federal University of São Carlos (UFSCar), São Carlos 13565-905, SP, Brazil; (N.T.T.); (F.R.T.)
| | - Luana Aparecida Rogerio
- Department of Genetics and Evolution, Center for Biological Sciences and Health, Federal University of São Carlos (UFSCar), São Carlos 13565-905, SP, Brazil; (N.T.T.); (F.R.T.)
| | - Caroline Torres
- Department of Genetics and Evolution, Center for Biological Sciences and Health, Federal University of São Carlos (UFSCar), São Carlos 13565-905, SP, Brazil; (N.T.T.); (F.R.T.)
| | - João Augusto Franco Leonel
- Post-Graduate Program in Experimental Epidemiology Applied to Zoonoses at the Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo 05508-270, SP, Brazil
| | - Geovanna Vioti
- Post-Graduate Program in Experimental Epidemiology Applied to Zoonoses at the Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo 05508-270, SP, Brazil
| | - Tricia Maria Ferreira de Sousa Oliveira
- Post-Graduate Program in Experimental Epidemiology Applied to Zoonoses at the Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo 05508-270, SP, Brazil
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga 13635-900, SP, Brazil
| | - Karoline Camila Valeriano
- Ribeirão Preto Medical School, University of São Paulo, FMRP-USP, Ribeirão Preto 14049-900, SP, Brazil
| | | | | | - Carlos H. N. Costa
- Natan Portela Institute of Tropical Diseases, Teresina 64002-510, PI, Brazil
| | | | - Tauana Sousa Ferreira
- Laboratory of Medical Parasitology and Vector Biology, Faculty of Medicine, University of Brasília, Brasília 70910-900, DF, Brazil
| | - Rodrigo Gurgel-Gonçalves
- Laboratory of Medical Parasitology and Vector Biology, Faculty of Medicine, University of Brasília, Brasília 70910-900, DF, Brazil
| | - João Santana da Silva
- Fiocruz-Bi-Institutional Translational Medicine Project, Oswaldo Cruz Foundation, Ribeirão Preto 14040-900, SP, Brazil
| | - Felipe Roberti Teixeira
- Department of Genetics and Evolution, Center for Biological Sciences and Health, Federal University of São Carlos (UFSCar), São Carlos 13565-905, SP, Brazil; (N.T.T.); (F.R.T.)
| | - Roque Pacheco De Almeida
- Department of Medicine, Center for Biology and Health Sciences, Federal University of Sergipe (UFS), Aracaju 49060-108, SE, Brazil
| | - José M. C. Ribeiro
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, NIH/NIAID, Rockville, MD 20892, USA
| | - Sandra Regina Maruyama
- Department of Genetics and Evolution, Center for Biological Sciences and Health, Federal University of São Carlos (UFSCar), São Carlos 13565-905, SP, Brazil; (N.T.T.); (F.R.T.)
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Ratzlaff FR, Osmari V, da Silva D, de Paula Vasconcellos JS, Pötter L, Fernandes FD, de Mello Filho JA, de Avila Botton S, Vogel FSF, Sangioni LA. Identification of infection by Leishmania spp. in wild and domestic animals in Brazil: a systematic review with meta-analysis (2001-2021). Parasitol Res 2023; 122:1605-1619. [PMID: 37154922 DOI: 10.1007/s00436-023-07862-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 04/28/2023] [Indexed: 05/10/2023]
Abstract
Leishmaniasis is a zoonosis caused by protozoan species of the genus Leishmania. It generates different clinical manifestations in humans and animals, and it infects multiple hosts. Leishmania parasites are transmitted by sandfly vectors. The main objective of this systematic review was to identify the host, or reservoir animal species, of Leishmania spp., with the exception of domestic dogs, that were recorded in Brazil. This review included identification of diagnostic methods, and the species of protozoan circulating in the country. For this purpose, a literature search was conducted across index journals. This study covered the period from 2001 to 2021, and 124 studies were selected. Eleven orders possible hosts were identified, including 229 mammalian species. Perissodactyla had the highest number of infected individuals (30.69%, 925/3014), with the highest occurrence in horses. In Brazil, the most commonly infected species were found to be: horses, domestic cats, rodents, and marsupials. Bats, that were infected by one or more protozoan species, were identified as potential reservoirs of Leishmania spp. Molecular tests were the most commonly used diagnostic methods (94 studies). Many studies have detected Leishmania spp. (n = 1422): Leishmania (Leishmania) infantum (n = 705), Leishmania (Viannia) braziliensis (n = 319), and Leishmania (Leishmania) amazonensis (n = 141). Recognizing the species of animals involved in the epidemiology and biological cycle of the protozoan is important, as this allows for the identification of environmental biomarkers, knowledge of Leishmania species can improve the control zoonotic leishmaniasis.
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Affiliation(s)
- Fabiana Raquel Ratzlaff
- Laboratório de Doenças Parasitárias (LADOPAR), Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, N°1000, Prédio 63D, Bairro Camobi, Santa Maria, RS, CEP 97105900, Brazil
| | - Vanessa Osmari
- Laboratório de Doenças Parasitárias (LADOPAR), Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, N°1000, Prédio 63D, Bairro Camobi, Santa Maria, RS, CEP 97105900, Brazil
| | - Daniele da Silva
- Laboratório de Doenças Parasitárias (LADOPAR), Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, N°1000, Prédio 63D, Bairro Camobi, Santa Maria, RS, CEP 97105900, Brazil
| | - Jaíne Soares de Paula Vasconcellos
- Laboratório de Doenças Parasitárias (LADOPAR), Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, N°1000, Prédio 63D, Bairro Camobi, Santa Maria, RS, CEP 97105900, Brazil
| | - Luciana Pötter
- Laboratório de Pastos e Suplementos, Departamento de Zootecnia, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, N°1000, Bairro Camobi, Santa Maria, RS, CEP 97105900, Brazil
| | - Fagner D'ambroso Fernandes
- Laboratório de Doenças Parasitárias (LADOPAR), Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, N°1000, Prédio 63D, Bairro Camobi, Santa Maria, RS, CEP 97105900, Brazil.
- Centro Universitário Ritter Dos Reis (UniRitter), Campus FAPA, Av. Manoel Elias, 2001 - Passo das Pedras, Porto Alegre, 91240-261, Brazil.
| | - José Américo de Mello Filho
- Laboratório de Análises Ambientais por Geoprocessamento (LAGEO), Departamento de Engenharia Rural, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, N°1000, Prédio 44 J, Bairro Camobi, Santa Maria, RS, CEP 97105-900, Brazil
| | - Sônia de Avila Botton
- Laboratório de Saúde Única (LASUS), Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, nº 1000, Prédio 44, Bairro Camobi, Santa Maria, Rio Grande do Sul, CEP 97105-900, Brazil
| | - Fernanda Silveira Flores Vogel
- Laboratório de Doenças Parasitárias (LADOPAR), Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, N°1000, Prédio 63D, Bairro Camobi, Santa Maria, RS, CEP 97105900, Brazil
| | - Luís Antônio Sangioni
- Laboratório de Doenças Parasitárias (LADOPAR), Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais (CCR), Universidade Federal de Santa Maria (UFSM), Av. Roraima, N°1000, Prédio 63D, Bairro Camobi, Santa Maria, RS, CEP 97105900, Brazil
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Castellanos-Gonzalez A, Cossio A, Jojoa J, Moen S, Travi BL. MiniPCR as a Portable Equipment for the Molecular Diagnosis of American Cutaneous Leishmaniasis. Acta Trop 2023; 243:106926. [PMID: 37088354 DOI: 10.1016/j.actatropica.2023.106926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 04/25/2023]
Abstract
There is an urgent need to improve the diagnostic capacity of cutaneous leishmaniasis (CL) in rural health centers to improve the management of the disease in patients from remote regions where the infection is endemic. Microscopy of Giemsa-stained lesion smears is the standard-of-care diagnostic test in virtually all health centers, but its sensitivity is suboptimal (50-70%) and prone to false negative results. We evaluated the performance of a low-cost DNA extraction buffer (LAB) using a portable miniPCRTM equipment coupled with an inexpensive fluorescence viewer to detect Leishmania DNA with the naked eye or using a commercial photo app. Using ten-fold serial dilutions of Leishmania (V.) panamensis promastigotes the miniPCR-F test detected 10 parasites per µL, which was comparable to real-time PCR. Utilization of DNA from retrospective clinical samples preserved at -80°C from Colombia (n=28) or lesion exudate preserved in filter papers from Peru (n=48) showed that the miniPCR-fluorescent test had a 100% sensitivity and > 90% specificity compared to real-time PCR. This study demonstrated the utility of LAB DNA extraction method for direct amplification of Leishmania using the miniPCR and reading of P51 results with the naked eye or via digital reading with a photo app. These preliminary results indicated that the miniPCR-F test workflow could be amenable to implementation in resource-limited health centers.
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Affiliation(s)
| | - Alexandra Cossio
- Centro Internacional de Entrenamiento e Investigaciones Médicas-CIDEIM, Cali, Colombial
| | - Jimena Jojoa
- Centro Internacional de Entrenamiento e Investigaciones Médicas-CIDEIM, Cali, Colombial
| | - Scott Moen
- Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Bruno L Travi
- Department of Internal Medicine-Division of Infectious Diseases, University of Texas Medical Branch, Galveston, Texas.
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Ferreira JDJG, Costa SCB, Addas-Carvalho M, Pereira MB, França ADO, de Lima RG, Andrade PD, Wanderley JDS, Martins LC, de Almeida EA, Marcon GEB. Evaluation of Molecular Methods to Identify Chagas Disease and Leishmaniasis in Blood Donation Candidates in Two Brazilian Centers. Pathogens 2023; 12:pathogens12040508. [PMID: 37111394 PMCID: PMC10141534 DOI: 10.3390/pathogens12040508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/02/2023] [Accepted: 03/10/2023] [Indexed: 04/29/2023] Open
Abstract
In Brazil, blood donation is regulated by the Brazilian Ministry of Health, and all States follow the same protocol for clinical and laboratory screening. Brazil is an endemic country for Chagas disease (CD), caused by Trypanosoma cruzi, and for leishmaniasis, caused by a species of Leishmania spp. Screening for leishmaniosis is not routinely performed by blood banks. Given the antigenic similarity between T. cruzi and Leishmania spp., cross-reactions in serological tests can occur, and inconclusive results for CD have been found. The objective of this study was to apply molecular techniques, e.g., nPCR, PCR, and qPCR, to clarify cases of blood donation candidates with non-negative serology for CD and to analyze the difference between the melting temperature during real-time PCR using SYBR Green. Thirty-seven cases that showed non-negative results for CD using chemiluminescent microparticle immunoassay (CMIA) tests from blood banks in Campo Grande, MS, and Campinas, SP, were analyzed. In the serum samples, 35 samples were evaluated by ELISA, and 24.3% (9/35) showed positive results for CD. nPCR was able to detect 12 positive results in 35 samples (34.28%). qPCR for T. cruzi was quantifiable in the samples that showed a value ≥0.002 par eq/mL (parasite equivalents per milliliter), and in 35 samples, 11 (31.42%) were positive. Of all evaluated samples using the described tests (CMIA, ELISA, nPCR, and qPCR), 18 (48.6%) were positive for CD. For MCA by qPCR, the melting temperature was 82.06 °C ± 0.46 for T. cruzi and 81.9 °C ± 0.24 for Leishmania infantum. The Mann-Whitney test showed a significant value of p < 0.0001. However, the differentiation between T. cruzi and L. infantum could not be considered due to temperature overlap. For leishmaniasis, of the 35 samples with non-negative serology for CD tested by the indirect fluorescent antibody test (IFAT), only one sample (2.85%) was positive (1:80). The PCR for Leishmania spp. was performed on 36 blood samples from donation candidates, and all were negative. qPCR for L. infantum showed 37 negative results for the 37 analyzed samples. The data presented here show the importance of performing two different tests in CD screening at blood banks. Molecular tests should be used for confirmation, thereby improving the blood donation system.
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Affiliation(s)
- Juliana de Jesus Guimarães Ferreira
- Laboratório de Diagnóstico de Doenças Infecciosas por Técnicas de Biologia Molecular, Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
| | - Sandra Cecília Botelho Costa
- Laboratório de Diagnóstico de Doenças Infecciosas por Técnicas de Biologia Molecular, Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
| | - Marcelo Addas-Carvalho
- Centro de Hematologia e Hemoterapia, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
| | - Mariane Barroso Pereira
- Laboratório de Diagnóstico de Doenças Infecciosas por Técnicas de Biologia Molecular, Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
| | - Adriana de Oliveira França
- Laboratório de Doenças Infecciosas e Parasitárias (LabDIP), Programa de Pós-Graduação em Doenças Infecciosas e Parasitárias, Universidade Federal de Mato Grosso do Sul, Cidade Universitária s/n, Campo Grande 79090-900, MS, Brazil
| | - Rodrigo Gonçalves de Lima
- Laboratório de Diagnóstico de Doenças Infecciosas por Técnicas de Biologia Molecular, Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
| | - Paula Durante Andrade
- Laboratório de Diagnóstico de Doenças Infecciosas por Técnicas de Biologia Molecular, Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
| | - Jamiro da Silva Wanderley
- Grupo de Estudos em Doença de Chagas (GEDoCh), Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
| | - Luiz Cláudio Martins
- Grupo de Estudos em Doença de Chagas (GEDoCh), Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
| | - Eros Antonio de Almeida
- Grupo de Estudos em Doença de Chagas (GEDoCh), Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
| | - Gláucia Elisete Barbosa Marcon
- Laboratório de Diagnóstico de Doenças Infecciosas por Técnicas de Biologia Molecular, Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas 13083-887, SP, Brazil
- Fundação Oswaldo Cruz Mato Grosso do Sul (FIOCRUZ MS), Rua Gabriel Abrão, 92, Jardim das Nações, Campo Grande 79081-746, MS, Brazil
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Detecting Leishmania in dogs: A hierarchical-modeling approach to investigate the performance of parasitological and qPCR-based diagnostic procedures. PLoS Negl Trop Dis 2022; 16:e0011011. [PMID: 36525465 PMCID: PMC9803295 DOI: 10.1371/journal.pntd.0011011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 12/30/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Domestic dogs are primary reservoir hosts of Leishmania infantum, the agent of visceral leishmaniasis. Detecting dog infections is central to epidemiological inference, disease prevention, and veterinary practice. Error-free diagnostic procedures, however, are lacking, and the performance of those available is difficult to measure in the absence of fail-safe "reference standards". Here, we illustrate how a hierarchical-modeling approach can be used to formally account for false-negative and false-positive results when investigating the process of Leishmania detection in dogs. METHODS/FINDINGS We studied 294 field-sampled dogs of unknown infection status from a Leishmania-endemic region. We ran 350 parasitological tests (bone-marrow microscopy and culture) and 1,016 qPCR assays (blood, bone-marrow, and eye-swab samples with amplifiable DNA). Using replicate test results and site-occupancy models, we estimated (a) clinical sensitivity for each diagnostic procedure and (b) clinical specificity for qPCRs; parasitological tests were assumed 100% specific. Initial modeling revealed qPCR specificity < 94%; we tracked the source of this unexpected result to some qPCR plates having subtle signs of possible contamination. Using multi-model inference, we formally accounted for suspected plate contamination and estimated qPCR sensitivity at 49-53% across sample types and dog clinical conditions; qPCR specificity was high (95-96%), but fell to 81-82% for assays run in plates with suspected contamination. The sensitivity of parasitological procedures was low (~12-13%), but increased to ~33% (with substantial uncertainty) for bone-marrow culture in seriously-diseased dogs. Leishmania-infection frequency estimates (~49-50% across clinical conditions) were lower than observed (~60%). CONCLUSIONS We provide statistical estimates of key performance parameters for five diagnostic procedures used to detect Leishmania in dogs. Low clinical sensitivies likely reflect the absence of Leishmania parasites/DNA in perhaps ~50-70% of samples drawn from infected dogs. Although qPCR performance was similar across sample types, non-invasive eye-swabs were overall less likely to contain amplifiable DNA. Finally, modeling was instrumental to discovering (and formally accounting for) possible qPCR-plate contamination; even with stringent negative/blank-control scoring, ~4-5% of positive qPCRs were most likely false-positives. This work shows, in sum, how hierarchical site-occupancy models can sharpen our understanding of the problem of diagnosing host infections with hard-to-detect pathogens including Leishmania.
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Travi BL, Delos Santos MB, Shelite TR, Santos RP, Rosales LA, Castellanos-Gonzalez A, Saldarriaga O, Melby PC. Diagnostic Efficacy of Recombinase-Polymerase-Amplification Coupled with Lateral Flow Strip Reading in Patients with Cutaneous Leishmaniasis from the Amazonas Rainforest of Perú. Vector Borne Zoonotic Dis 2021; 21:941-947. [PMID: 34665665 DOI: 10.1089/vbz.2021.0038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Cutaneous leishmaniasis (CL) is highly prevalent in rural and sylvatic regions of Latin America, with an estimated 55,000 annual cases. Diagnosis in resource-limited areas still relies on microscopy of dermal scrapings, while more sensitive methods like PCR are not attainable due to costs and lack of adequate health infrastructure. Isothermal amplification of Leishmania DNA can be performed without sophisticated equipment and training and may become a point of care (POC) test for health care centers with scarce resources. We evaluated the efficacy of recombinase-polymerase-amplification (RPA-LF) to diagnose CL in 226 patients attending a clinic in Puerto Maldonado within the Peruvian Amazon basin. Conventional PCR targeting kinetoplast DNA (kDNA-PCR) was used as the gold standard. Eight of 226 patients were considered true negatives (microscopy, kDNA-PCR, and RPA-LF negative), while RPA-LF resulted positive in 186 of 204 kDNA-PCR positive patients, yielding 91.2% (confidence interval [CI] = 86.5-94.4%) sensitivity and 93% (CI 88.6-95.8%) positive predictive value. There were 14% (32/226) discrepant samples alternating positive and negative results in similar proportions between both tests. Quantitative PCR used to resolve the discrepancies suggested that they occurred in samples with scarce parasite numbers as determined by high cycle threshold (Ct) values (≥32; cutoff 35.5). Microscopy had the lowest sensitivity of all methods (45.4%). Nested real-time PCR performed in 71 samples determined that Leishmania (Viannia) braziliensis was highly prevalent (69/71), and Leishmania (Viannia) lainsoni was present in only two isolates. Results indicated that RPA-LF has POC potential for CL endemic areas, yet further simplification and optimization coupled with field validation will be necessary to confirm its broad applicability.
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Affiliation(s)
- Bruno L Travi
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.,Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, USA
| | - Maxy B Delos Santos
- Department of Parasitology, U.S. Naval Medical Research Unit 6 (NAMRU-6), Lima, Peru
| | - Thomas R Shelite
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Rocio P Santos
- Department of Parasitology, U.S. Naval Medical Research Unit 6 (NAMRU-6), Lima, Peru
| | - Luis A Rosales
- Department of Parasitology, U.S. Naval Medical Research Unit 6 (NAMRU-6), Lima, Peru
| | - Alejandro Castellanos-Gonzalez
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.,Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, USA
| | - Omar Saldarriaga
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Peter C Melby
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA.,Center for Tropical Diseases, University of Texas Medical Branch, Galveston, Texas, USA
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Castelli G, Bruno F, Reale S, Catanzaro S, Valenza V, Vitale F. Molecular Diagnosis of Leishmaniasis: Quantification of Parasite Load by a Real-Time PCR Assay with High Sensitivity. Pathogens 2021; 10:pathogens10070865. [PMID: 34358015 PMCID: PMC8308825 DOI: 10.3390/pathogens10070865] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 12/21/2022] Open
Abstract
Real-time PCR was developed to quantify Leishmania infantum kinetoplast DNA and optimized to achieve a sensitivity of 1 parasite/mL. For this purpose, we cloned the conserved kDNA fragment of 120 bp into competent cells and correlated them with serial dilutions of DNA extracted from reference parasite cultures calculating that a parasite cell contains approximately 36 molecules of kDNA. This assay was applied to estimate parasite load in clinical samples from visceral, cutaneous leishmaniasis patients and infected dogs and cats comparing with conventional diagnosis. The study aimed to propose a real-time PCR for the detection of Leishmania DNA from clinical samples trying to solve the diagnostic problems due to the low sensitivity of microscopic examination or the low predictive values of serology and resolve problems related to in vitro culture. The quantitative PCR assay in this study allowed detection of Leishmania DNA and quantification of considerably low parasite loads in samples that had been diagnosed negative by conventional techniques. In conclusion, this quantitative PCR can be used for the diagnosis of both human, canine and feline Leishmaniasis with high sensitivity and specificity, but also for evaluating treatment and the endpoint determination of leishmaniasis.
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Affiliation(s)
- Germano Castelli
- Centro di Referenza Nazionale per le Leishmaniosi (C.Re.Na.L.), OIE Leishmania Reference Laboratory, Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy; (G.C.); (S.C.); (V.V.); (F.V.)
| | - Federica Bruno
- Centro di Referenza Nazionale per le Leishmaniosi (C.Re.Na.L.), OIE Leishmania Reference Laboratory, Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy; (G.C.); (S.C.); (V.V.); (F.V.)
- Correspondence: ; Tel.: +39-0916565368
| | - Stefano Reale
- Laboratorio di Tecnologie Diagnostiche Innovative (TDI), Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy;
| | - Simone Catanzaro
- Centro di Referenza Nazionale per le Leishmaniosi (C.Re.Na.L.), OIE Leishmania Reference Laboratory, Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy; (G.C.); (S.C.); (V.V.); (F.V.)
| | - Viviana Valenza
- Centro di Referenza Nazionale per le Leishmaniosi (C.Re.Na.L.), OIE Leishmania Reference Laboratory, Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy; (G.C.); (S.C.); (V.V.); (F.V.)
| | - Fabrizio Vitale
- Centro di Referenza Nazionale per le Leishmaniosi (C.Re.Na.L.), OIE Leishmania Reference Laboratory, Istituto Zooprofilattico Sperimentale della Sicilia, Via Gino Marinuzzi 3, 90129 Palermo, Italy; (G.C.); (S.C.); (V.V.); (F.V.)
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Abdelhaleem A, Dhayhi N, Mahfouz MS, Dafalla O, Mubarki M, Hamedhi F, Al Hazmi A, Al Arishi H. Diagnosis and Causative Species of Visceral Leishmaniasis in Southwest Saudi Arabia. Am J Trop Med Hyg 2021; 105:654-659. [PMID: 34228634 PMCID: PMC8592317 DOI: 10.4269/ajtmh.20-1006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 05/10/2021] [Indexed: 11/07/2022] Open
Abstract
Visceral leishmaniasis (VL) is the most severe clinical form of the disease and has been reported in the Jazan region of southwest Saudi Arabia. This study aimed to diagnose VL by real-time polymerase chain reaction (PCR) and the direct agglutination test (DAT) and to identify the causative Leishmania species. A total of 80 participants, including 30 suspected VL patients, 30 healthy endemic control individuals, and 20 malaria disease controls, were enrolled in this study. Blood samples were collected and tested for Leishmania DNA by real-time PCR and for antibody by the DAT. Sequencing of some amplified PCR products was used to identify the causative Leishmania species. The diagnosis of VL was successfully achieved by both real-time PCR and by DAT with 100% sensitivity. Leishmania donovani and Leishmania infantum species were detected by sequencing both by the kDNA and ITS1 target genes, followed a BLASTn search. The detection of VL antibody by the DAT followed by the confirmatory detection of Leishmania DNA in patient blood by PCR could promote the adoption of the much less invasive and more sensitive methods for the routine diagnosis of VL. Further study with high sample volume to evaluate the PCR and the DAT are needed, to generate more robust evidence. Based on the sequencing results, emerging studies on VL should focus on the causative Leishmania species, reservoirs, and vectors that are important in the study area.
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Affiliation(s)
| | - Nabil Dhayhi
- Department of Pediatric Medicine, King Fahad Central Hospital, Jazan, Saudi Arabia
| | - Mohamed Salih Mahfouz
- Department of Family and Community Medicine, Faculty of Medicine, Jazan University, Jazan, Saudi Arabia
| | - Ommer Dafalla
- The National Center for Disease Prevention and Control, Jazan, Saudi Arabia
| | - Mansour Mubarki
- Department of Pediatric Medicine, Prince Mohamed Bin Nasir Hospital, Jazan, Saudi Arabia
| | - Fahad Hamedhi
- Department of Pediatric Medicine, Prince Mohamed Bin Nasir Hospital, Jazan, Saudi Arabia
| | - Abdullah Al Hazmi
- Department of Pediatric Medicine, Prince Mohamed Bin Nasir Hospital, Jazan, Saudi Arabia
| | - Haider Al Arishi
- Department of Pediatric Medicine, King Fahad Central Hospital, Jazan, Saudi Arabia
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9
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Fayaz S, Fard-Esfahani P, Bahrami F, Parvizi P, Ajdary S. High resolution melting assay in discrimination of the main etiologic agents of leishmaniasis in Iran. IRANIAN JOURNAL OF MICROBIOLOGY 2021; 13:137-144. [PMID: 33889373 PMCID: PMC8043822 DOI: 10.18502/ijm.v13i1.5505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Background and Objectives: The three old world Leishmania species i.e., L. major, L. tropica, and L. infantum are considered as potential etiological agents of the various clinical forms of leishmaniasis in Iran. Different species co-exist in some areas. Accurate differentiation between the species is essential for choosing an appropriate therapy. Conventional and gold standard methods for the detection and characterization of parasites are time-consuming, laborious, and have low sensitivity. A polymerase chain reaction followed by high resolution melting (PCR-HRM) analysis has been employed for detection and species identification. Most of the studies suffer from the use of multiple targets and/or requiring more than one reaction to identify a single sample. The present study aimed to design a PCR method based on the amplification of kinetoplast DNA minicircles (kDNA) and HRM analysis of the amplicons for rapid discrimination of the three mentioned species. Materials and Methods: DNA from reference strains including L. major, L. tropica, and L. infantum and fifty-eight strains subjected to PCR-HRM analysis targeting kDNA. All the samples were also analyzed by conventional kDNA-PCR. Results: The PCR-HRM analysis allowed discrimination between the three Old World species. The normalized HRM curves for the amplicons of kDNA indicated a unique and repeatable melting plot for each species, even in combination with human and mouse genomic DNA. Conventional kDNA-PCR could not properly discriminate L. tropica from L. infantum. Conclusion: PCR-HRM analysis of kDNA proved to be fast and accurate for discrimination of L. major, L. tropica, and L. infantum.
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Affiliation(s)
- Shima Fayaz
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran.,Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
| | | | - Fariborz Bahrami
- Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
| | - Parviz Parvizi
- Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Soheila Ajdary
- Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
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10
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Moulik S, Sengupta S, Chatterjee M. Molecular Tracking of the Leishmania Parasite. Front Cell Infect Microbiol 2021; 11:623437. [PMID: 33692966 PMCID: PMC7937807 DOI: 10.3389/fcimb.2021.623437] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/06/2021] [Indexed: 12/13/2022] Open
Abstract
With the Visceral Leishmaniasis/Kala-azar Elimination Program in South Asia in its consolidation phase, the focus is mainly on case detection, vector control, and identifying potential sources of infection. Accordingly, emphasis is presently on curbing transmission, which is potentially achievable by identification and elimination of potential reservoirs. The strongest contenders for being the disease reservoir are cases of Post Kala-azar Dermal Leishmaniasis (PKDL) which occurs in a minor proportion of individuals apparently cured of Visceral Leishmaniasis (VL). The demonstration of parasites in tissue aspirates despite being a risky and invasive process is the gold standard for diagnosis of VL, but is now being replaced by serological tests e.g., rK39 strip test and direct agglutination test. However, these antibody based tests are limited in their ability to diagnose relapses, detect cases of PKDL, and monitor effectiveness of treatment. Accordingly, detection of antigen or nucleic acids by polymerase chain reaction has been successfully applied for monitoring of parasite kinetics. This review article provides updated information on recent developments regarding the available antibody or antigen/nucleic acid based biomarkers for longitudinal monitoring of patients with VL or PKDL and emphasizes the need for availability of studies pertaining to quantification of treatment response or relapse.
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Affiliation(s)
- Srija Moulik
- Department of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
| | - Shilpa Sengupta
- Department of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
| | - Mitali Chatterjee
- Department of Pharmacology, Institute of Postgraduate Medical Education and Research, Kolkata, India
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11
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Evaluation of a kDNA-Based qPCR Assay for the Detection and Quantification of Old World Leishmania Species. Microorganisms 2020; 8:microorganisms8122006. [PMID: 33339158 PMCID: PMC7765608 DOI: 10.3390/microorganisms8122006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 12/09/2020] [Accepted: 12/14/2020] [Indexed: 02/07/2023] Open
Abstract
The parasite protozoan Leishmania, the causative agent of leishmaniasis, includes two subgenera of medical interest: Leishmania (Leishmania) and Leishmania (Viannia). Parasite species detection and characterization is crucial to choose treatment protocols and to monitor the disease evolution. Molecular approaches can speed up and simplify the diagnostic process. In particular, several molecular assays target the mitochondrial DNA minicircle network (kDNA) that characterizes the Leishmania genus. We previously proposed a qPCR assay targeting kDNA, followed by high resolution melt (HRM) analysis (qPCR-ML) to distinguish L. (L.) infantum and L. (L.) amazonensis from L. Viannia species. Successively, this assay has been integrated with other qPCR assays, to differentiate L. (L.) infantum, L. (L.) amazonensis and L. (L.) mexicana. In this work, we tested the applicability of our qPCR-ML assay on L. (L.) donovani, L. (L.) major, L. (L.) tropica and L. (L.) aethiopica, showing that the qPCR-ML assay can also amplify Old World species, different from L. (L.) infantum, with good quantification limits (1 × 10-4-1 × 10-6 ng/pcr tube). Moreover, we evaluated 11 L. (L.) infantum strains/isolates, evidencing the variability of the kDNA minicircle target molecules among the strains/isolates of the same species, and pointing out the possibility of quantification using different strains as reference. Taken together, these data account for the consideration of qPCR-ML as a quantitative pan-Leishmania assay.
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12
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Ghafari SM, Fotouhi-Ardakani R, Parvizi P. Designing and developing a high-resolution melting technique for accurate identification of Leishmania species by targeting amino acid permease 3 and cytochrome oxidase II genes using real-time PCR and in silico genetic evaluation. Acta Trop 2020; 211:105626. [PMID: 32652055 DOI: 10.1016/j.actatropica.2020.105626] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/05/2020] [Accepted: 07/07/2020] [Indexed: 11/20/2022]
Abstract
Discrimination, accurate identification, and reliable techniques are required for accurate identification of Leishmania parasites. High-resolution melting (HRM) is recognized as an authentic and exact method. The main objective of this research was optimizing HRM analysis for detecting and screening Leishmania major, Leishmania tropica and mix infections. Thirty-six DNA samples of Leishmania parasite were prepared and analyzed. Two gene regions of amino acid permease 3 (AAP3) and cytochrome oxidase II (COII) were targeted and six pairs of specific new primers were designed. Bioinformatics analysis was employed to predict DNA temperature resolution for each species and compared with in-vitro results. The genetic diversity of the selected gene regions was analyzed using PCR-sequencing method and DnaSP 5.10.01 software. They were submitted in GenBank (KU680818- KU680821 and KY041643- KY041649). The haplotype diversity for both AAP3 and COII genes was 96% and 87%, respectively. Tajima's D index was 0.65 for AAP3 and 0.36 for COII. CLC Genomics Workbench 11 software predictions were significant and close to these findings. The designed primers could be able to identify at least two Leishmania species. Temperature variations in HRM technique separated Iranian Leishmania parasites of L. major, L. tropica and mix infections. The target genes and our modified HRM method proved this technique could be useful in both clinical and experimental settings. Also, it can be effective for detecting Leishmania parasites in different hosts such as humans, reservoir hosts and vectors. Indeed, HRM can be used as a technique in Leishmania identification as well as for ecological and epidemiological research.
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Affiliation(s)
- Seyedeh Maryam Ghafari
- Molecular Systematics Laboratory, Parasitology Department, Pasteur Institute of Iran, Tehran, Iran.
| | - Reza Fotouhi-Ardakani
- Cellular and Molecular Research Center, Qom University of Medical Sciences, Qom, Iran; Department of Medical Biotechnology, Faculty of Medicine, Qom University of Medical Sciences, Qom, Iran.
| | - Parviz Parvizi
- Molecular Systematics Laboratory, Parasitology Department, Pasteur Institute of Iran, Tehran, Iran.
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13
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Hong A, Zampieri RA, Shaw JJ, Floeter-Winter LM, Laranjeira-Silva MF. One Health Approach to Leishmaniases: Understanding the Disease Dynamics through Diagnostic Tools. Pathogens 2020; 9:pathogens9100809. [PMID: 33019713 PMCID: PMC7599840 DOI: 10.3390/pathogens9100809] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 01/19/2023] Open
Abstract
Leishmaniases are zoonotic vector-borne diseases caused by protozoan parasites of the genus Leishmania that affect millions of people around the globe. There are various clinical manifestations, ranging from self-healing cutaneous lesions to potentially fatal visceral leishmaniasis, all of which are associated with different Leishmania species. Transmission of these parasites is complex due to the varying ecological relationships between human and/or animal reservoir hosts, parasites, and sand fly vectors. Moreover, vector-borne diseases like leishmaniases are intricately linked to environmental changes and socioeconomic risk factors, advocating the importance of the One Health approach to control these diseases. The development of an accurate, fast, and cost-effective diagnostic tool for leishmaniases is a priority, and the implementation of various control measures such as animal sentinel surveillance systems is needed to better detect, prevent, and respond to the (re-)emergence of leishmaniases.
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Affiliation(s)
- Ahyun Hong
- Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo 05508-090, Brazil; (A.H.); (R.A.Z.); (L.M.F.-W.)
| | - Ricardo Andrade Zampieri
- Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo 05508-090, Brazil; (A.H.); (R.A.Z.); (L.M.F.-W.)
| | - Jeffrey Jon Shaw
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil;
| | - Lucile Maria Floeter-Winter
- Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo 05508-090, Brazil; (A.H.); (R.A.Z.); (L.M.F.-W.)
| | - Maria Fernanda Laranjeira-Silva
- Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo 05508-090, Brazil; (A.H.); (R.A.Z.); (L.M.F.-W.)
- Correspondence:
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14
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HRM-PCR is an accurate and sensitive technique for the diagnosis of cutaneous leishmaniasis as compared with conventional PCR. Acta Parasitol 2020; 65:310-316. [PMID: 31848842 DOI: 10.2478/s11686-019-00154-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 12/03/2019] [Indexed: 01/21/2023]
Abstract
BACKGROUND Cutaneous leishmaniasis (CL) is considered one of the main health problems in Iran. Therefore, it is required for control and therapeutic purposes, an accurate and fast tool for the diagnosis and identification of Leishmania species. METHODS In the present study, three techniques, including microscopic examination, conventional PCR, and high-resolution melting (HRM)-PCR, have been evaluated, to find the most accurate and rapid test. In total, 105 skin scraping smears were taken from suspected dermal lesions of patients belonging to two known endemic CL areas, Gonbad and Bam districts, in Iran. Subsequently, the specimens were analyzed with microscopic, conventional PCR, and HRM-PCR techniques. RESULTS Most positive samples (89.5%) were observed using HRM-PCR, and among the three techniques, HRM-PCR was the most sensitive (89%, 95% CI 81-94) technique. Microscopic examination test had the lowest sensitivity (57%, 95% CI 47-66%). The highest agreement among positive samples was observed between HRM-PCR and conventional PCR tests. DISCUSSION Our results showed that the HRM-PCR technique is the most accurate and sensitive test for recognizing CL, and also a valuable alternative test for conventional PCR to detect various species.
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15
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Differentiation of Leishmania ( L.) infantum, Leishmania ( L.) amazonensis and Leishmania ( L.) mexicana Using Sequential qPCR Assays and High-Resolution Melt Analysis. Microorganisms 2020; 8:microorganisms8060818. [PMID: 32486117 PMCID: PMC7355826 DOI: 10.3390/microorganisms8060818] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/14/2020] [Accepted: 05/28/2020] [Indexed: 12/31/2022] Open
Abstract
Leishmania protozoa are the etiological agents of visceral, cutaneous and mucocutaneous leishmaniasis. In specific geographical regions, such as Latin America, several Leishmania species are endemic and simultaneously present; therefore, a diagnostic method for species discrimination is warranted. In this attempt, many qPCR-based assays have been developed. Recently, we have shown that L. (L.) infantum and L. (L.) amazonensis can be distinguished through the comparison of the Cq values from two qPCR assays (qPCR-ML and qPCR-ama), designed to amplify kDNA minicircle subclasses more represented in L. (L.) infantum and L. (L.) amazonensis, respectively. This paper describes the application of this approach to L. (L.) mexicana and introduces a new qPCR-ITS1 assay followed by high-resolution melt (HRM) analysis to differentiate this species from L. (L.) amazonensis. We show that L. (L.) mexicana can be distinguished from L. (L.) infantum using the same approach we had previously validated for L. (L.) amazonensis. Moreover, it was also possible to reliably discriminate L. (L.) mexicana from L. (L.) amazonensis by using qPCR-ITS1 followed by an HRM analysis. Therefore, a diagnostic algorithm based on sequential qPCR assays coupled with HRM analysis was established to identify/differentiate L. (L.) infantum, L. (L.) amazonensis, L. (L.) mexicana and Viannia subgenus. These findings update and extend previous data published by our research group, providing an additional diagnostic tool in endemic areas with co-existing species.
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16
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Duthie MS, Goto Y, Ghosh P, Mondal D. Impact of sequelae of visceral leishmaniasis and their contribution to ongoing transmission of Leishmania donovani. Pathog Dis 2020; 77:5582598. [PMID: 31589291 PMCID: PMC6830496 DOI: 10.1093/femspd/ftz057] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 10/03/2019] [Indexed: 12/04/2022] Open
Abstract
Visceral leishmaniasis (VL) in the Old World is caused by infection with Leishmania donovani. Although the numbers of new reported cases of VL in Africa have been relatively stable for several years, the low numbers currently reported on the Indian subcontinent suggest a positive impact of new treatments and intervention strategies. In both regions, however, VL relapse and post-kala-azar dermal leishmaniasis (PKDL) maintain infectious reservoirs and therefore present a threat to control programs. In this review, we outline the evolving appreciation of PKDL as an impactful disease in its own right and discuss the various diagnostic methods that can be applied for the detection and characterization of PKDL cases. We also highlight the data that indicate the potential, and likely contribution, of PKDL cases to ongoing transmission of L. donovani.
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Affiliation(s)
- Malcolm S Duthie
- Infectious Disease Research Institute, 1616 Eastlake Ave E, Suite 400, Seattle, WA 98102, USA
| | - Yasuyuki Goto
- Department of Animal Resource Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bungkyo-ku, Tokyo 113-8657, Japan
| | - Prakash Ghosh
- 68 Shaheed Tajuddin Ahmed Saranai, Mokakhali, Dhaka-1212, Bangladesh
| | - Dinesh Mondal
- 68 Shaheed Tajuddin Ahmed Saranai, Mokakhali, Dhaka-1212, Bangladesh
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17
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Ahuja K, Vats A, Beg MA, Kariyawasam KKGDUL, Chaudhury A, Chatterjee M, Karunaweera ND, Selvapandiyan A. High resolution melting based method for rapid discriminatory diagnosis of co-infecting Leptomonas seymouri in Leishmania donovani-induced leishmaniasis. Parasitol Int 2019; 75:102047. [PMID: 31887394 DOI: 10.1016/j.parint.2019.102047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/02/2019] [Accepted: 12/26/2019] [Indexed: 11/28/2022]
Abstract
Leishmania donovani, a protozoan parasite of family Trypanosomatidae, causes fatal visceral leishmaniasis (VL) in the Indian subcontinent and Africa and cutaneous leishmaniasis (CL) in Sri Lanka. Another member of Trypanosomatidae, Leptomonas seymouri, resembling Leishmania was discovered recently to co-exist with L. donovani in the clinical samples from India and Sri Lanka and therefore, interfere with its investigations. We earlier described a method for selective elimination of such co-existing L. seymouri from clinical samples of VL exploiting the differential growth of the parasites at 37 °C in vitro. Here, we explored ways for a rapid discriminatory diagnosis using high resolution melting (HRM) curves to detect co-occurring L. seymouri with L. donovani in clinical samples. Initial attempt with kDNA-minicircle (mitochondrial DNA) based HRM did not display different Tm values between L. donovani and L. seymouri. Surprisingly, all of their minicircle sequences co-existed in similar clades in the dendrogram analysis, although the kDNA sequences are known for its species and strain specific variations among the Trypanosomatids. However, an HRM analysis that targets the HSP70 gene successfully recognized the presence of L. seymouri in the clinical isolates. This discovery will facilitate rapid diagnosis of L. seymouri and further investigations in to this elusive organism, including the clinico-pathological implications of its co-existence with L. donovani in patients.
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Affiliation(s)
- Kavita Ahuja
- JH-Institute of Molecular Medicine, Jamia Hamdard, New Delhi 110062, India; Department of Bio & Nano Technology, Bio & Nano Technology Centre, Guru Jambheshwar University of Science and Technology, Hisar 125001, India
| | - Abhishek Vats
- Department of Research, Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi 110060, India
| | - Mirza Adil Beg
- JH-Institute of Molecular Medicine, Jamia Hamdard, New Delhi 110062, India
| | - K K G D U L Kariyawasam
- Department of Parasitology, Faculty of Medicine, University of Colombo, No. 25, Kynsey Road, Colombo 00800, Sri Lanka
| | - Ashok Chaudhury
- Department of Bio & Nano Technology, Bio & Nano Technology Centre, Guru Jambheshwar University of Science and Technology, Hisar 125001, India
| | - Mitali Chatterjee
- Department of Pharmacology, Institute of Postgraduate Medical Education & Research, Kolkata 700020, India
| | - Nadira D Karunaweera
- Department of Parasitology, Faculty of Medicine, University of Colombo, No. 25, Kynsey Road, Colombo 00800, Sri Lanka
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18
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Reis FC, Minuzzi-Souza TTC, Neiva M, Timbó RV, de Morais IOB, de Lima TM, Hecht M, Nitz N, Gurgel-Gonçalves R. Trypanosomatid infections in captive wild mammals and potential vectors at the Brasilia Zoo, Federal District, Brazil. Vet Med Sci 2019; 6:248-256. [PMID: 31743623 PMCID: PMC7196675 DOI: 10.1002/vms3.216] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/30/2019] [Accepted: 10/13/2019] [Indexed: 11/10/2022] Open
Abstract
Background Conservation projects in zoos may involve translocation of captive animals, which may lead to pathogen spread. Neotropical mammals are important hosts of Trypanosoma cruzi and Leishmania spp. the etiological agents of Chagas disease and Leishmaniasis respectively. Studies of trypanosomatid‐infected mammals and vectors (triatomines and sandflies) in zoos are important for the establishment of surveillance and control measures. Objectives We investigated trypanosomatid infections in captive wild mammals, triatomines and sandflies at the Brasília Zoo. Methods We collected triatomines during active bimonthly surveys, sampled sandflies using light‐traps and obtained blood samples from 74 mammals between 2016 and 2017. We used quantitative PCR to detect trypanosomatids in vectors and mammals. Results We found a colony of 19 Panstrongylus megistus in the porcupine unit and detected T. cruzi infections in five bugs. We captured 17 sandflies of four species including Nyssomyia whitmani and Lutzomyia longipalpis, but no Leishmania infection was detected. qPCR detected 50 T. cruzi‐infected mammals belonging to 24 species and five groups of mammals (Carnivora, Cetartiodactyla, Perissodactyla, Pilosa and Primates); Leishmania DNA was detected in 23 mammals from 15 species, mainly carnivores. We detected trypanosomatid infections in 11 mammals born at the Brasília Zoo. Conclusions Our results suggest vector‐borne transmission of T. cruzi among maned wolves; measures to reduce the risk of new infections should therefore be taken. We also report sandfly presence and Leishmania‐infected mammals at the Brasília Zoo. Translocation of wild mammals in and out of the Brasília Zoo should consider the risk of T. cruzi and Leishmania spread.
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Affiliation(s)
- Filipe C Reis
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasília, Distrito Federal, Brazil.,Fundação Jardim Zoológico de Brasília, Brasília, Distrito Federal, Brazil
| | - Thaís T C Minuzzi-Souza
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasília, Distrito Federal, Brazil
| | - Mariana Neiva
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasília, Distrito Federal, Brazil
| | - Renata V Timbó
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasília, Distrito Federal, Brazil
| | - Igor O B de Morais
- Fundação Jardim Zoológico de Brasília, Brasília, Distrito Federal, Brazil
| | - Thiago M de Lima
- Fundação Jardim Zoológico de Brasília, Brasília, Distrito Federal, Brazil
| | - Mariana Hecht
- Laboratório Interdisciplinar de Biociências, Faculdade de Medicina, Universidade de Brasília, Brasília, Distrito Federal, Brazil
| | - Nadjar Nitz
- Laboratório Interdisciplinar de Biociências, Faculdade de Medicina, Universidade de Brasília, Brasília, Distrito Federal, Brazil
| | - Rodrigo Gurgel-Gonçalves
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasília, Distrito Federal, Brazil
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19
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Mota TF, de Sousa OMF, Silva YDJ, Borja LS, Leite BMM, Solcà MDS, de Melo DA, Brodskyn CI, Dias ES, Veras PST, Fraga DBM. Natural infection by Leishmania infantum in the Lutzomyia longipalpis population of an endemic coastal area to visceral leishmaniasis in Brazil is not associated with bioclimatic factors. PLoS Negl Trop Dis 2019; 13:e0007626. [PMID: 31449534 PMCID: PMC6730935 DOI: 10.1371/journal.pntd.0007626] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 09/06/2019] [Accepted: 07/11/2019] [Indexed: 01/24/2023] Open
Abstract
Visceral leishmaniasis (VL) is a zoonosis caused by the protozoan Leishmania infantum and in Brazil is transmitted mainly by the bite of Lutzomuyia longipalpis sand flies. Data about the presence, distribution, natural infection rate, seasonal and monthly dynamics of the vector population are important for optimizing the measures to control VL in endemic areas. This study aimed to identify sand fly fauna in an endemic area for VL to detect the prevalence of L. infantum infection in the Lu. longipalpis population and to elucidate the influence of bioclimatic factors on the monthly fluctuations of this vector. HP light traps were monthly set in the intradomicile and peridomicile of residences located in the central and beachfront areas of Camaçari, a VL endemic area. The sand fly collection was conducted in two periods: i) period 1-between December 2011 and November 2012 and ii) period 2-August 2014 and July 2015. Sand fly species were identified and detection of L. infantum infection by qPCR was performed in pools of female Lu. longipalpis. For the first time, the parasite load of positive pools was correlated with the number of Lu. longipalpis captured per month in both periods. Correlation analyses between the monthly fluctuation of the sand fly population and bioclimatic indices of the municipality in both collection periods were also performed. In both evaluated periods, more than 98% of the collected sand flies were Lu. longipalpis, confirming the predominance of this species in the region. It was captured mostly in the beachfront area in all months evaluated (99%). For the period 1, Leishmania DNA was detected in 81% of tested pools representing a minimal infection rate of 9.6%. In the period 2, 40% of the pools were positive with a minimal infection rate of 10.2%. Infected sand flies were only detected in the beachfront area in both periods. The parasite load was low and did not vary in the evaluated months despite the number of collected sand flies. No correlation was observed for climatic factors in both areas of Camaçari. These findings emphasize the high risk of Leishmania transmission in Camaçari regardless of the season and that other factors, aside from bioclimatic elements, are influencing the sand fly population monthly fluctuation.
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Affiliation(s)
| | | | | | | | | | - Manuela da Silva Solcà
- Escola de Medicina Veterinária e Zootecnia—Universidade Federal da Bahia, Salvador, Brazil
| | | | | | | | - Patrícia Sampaio Tavares Veras
- Instituto Gonçalo Moniz—Fundação Oswaldo Cruz, Salvador, Brazil
- Instituto Nacional de Ciência e Tecnologia de Doenças Tropicais—INCT-DT, Salvador, Brazil
| | - Deborah Bittencourt Mothé Fraga
- Instituto Gonçalo Moniz—Fundação Oswaldo Cruz, Salvador, Brazil
- Escola de Medicina Veterinária e Zootecnia—Universidade Federal da Bahia, Salvador, Brazil
- Instituto Nacional de Ciência e Tecnologia de Doenças Tropicais—INCT-DT, Salvador, Brazil
- * E-mail:
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Teixeira AIP, Silva DM, Vital T, Nitz N, de Carvalho BC, Hecht M, Oliveira D, Oliveira E, Rabello A, Romero GAS. Improving the reference standard for the diagnosis of canine visceral leishmaniasis: a challenge for current and future tests. Mem Inst Oswaldo Cruz 2019; 114:e180452. [PMID: 30726343 PMCID: PMC6358009 DOI: 10.1590/0074-02760180452] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/04/2019] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Studies aimed at validating canine visceral leishmaniasis diagnostic tests present heterogeneous results regarding test accuracy, partly due to divergences in reference standards used and different infection evolution periods in animals. OBJECTIVE This study aimed to evaluate the accuracy of the rapid test-dual path platform (TR-DPP) (Biomanguinhos®), EIE-Leishmaniose-Visceral-Canina-Biomanguinhos (EIE-LVC) (Biomanguinhos®), enzyme-linked immunosorbent assay (ELISA) rK39 (in-house), and the direct agglutination test (DAT-Canis) against a reference standard comprising parasitological and molecular techniques. METHODS A phase II/III validation study was carried out in sample sera from 123 predominantly asymptomatic dogs living in an area endemic for visceral leishmaniasis. FINDINGS Sixty-nine (56.1%) animals were considered infected according to the reference standard. For each test, the sensitivity and specificity, respectively, were as follows: TR-DPP, 21.74% [confidence interval (CI)95% 13.64% to 32.82%] and 92.59% (CI95% 82.45% to 97.08%); EIE-LVC, 11.59% (CI95% 5.9% to 21.25%) and 90.74% (CI95% 80.09% to 95.98%); ELISA rK39, 37.68% (CI95% 27.18% to 49.48%) and 83.33% (CI95% 71.26% to 90.98%); and DAT-Canis, 18.84% (CI95% 11.35% to 29.61%) and 96.30% (CI95% 87.46% to 98.98%). CONCLUSION We concluded that improving the sensitivity of serum testing for diagnosing asymptomatic dogs must constitute a priority in the process of developing new diagnostic tests to be used in the visceral leishmaniasis control program in Brazil.
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Affiliation(s)
| | | | - Tamires Vital
- Universidade de Brasília, Núcleo de Medicina Tropical, Brasília, DF, Brasil
- Universidade de Brasília, Faculdade de Medicina, Laboratório Interdisciplinar de Biociências, Brasília, DF, Brasil
| | - Nadjar Nitz
- Universidade de Brasília, Faculdade de Medicina, Laboratório Interdisciplinar de Biociências, Brasília, DF, Brasil
| | | | - Mariana Hecht
- Universidade de Brasília, Faculdade de Medicina, Laboratório Interdisciplinar de Biociências, Brasília, DF, Brasil
| | - Diana Oliveira
- Grupo de Pesquisas Clínicas e Políticas Públicas em Doenças Infecciosas e Parasitárias, Belo Horizonte, MG, Brasil
| | - Edward Oliveira
- Grupo de Pesquisas Clínicas e Políticas Públicas em Doenças Infecciosas e Parasitárias, Belo Horizonte, MG, Brasil
| | - Ana Rabello
- Grupo de Pesquisas Clínicas e Políticas Públicas em Doenças Infecciosas e Parasitárias, Belo Horizonte, MG, Brasil
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Ghosh P, Hasnain MG, Hossain F, Khan MAA, Chowdhury R, Faisal K, Mural MA, Baker J, Nath R, Ghosh D, Maruf S, Shomik MS, Haque R, Matlashewski G, Hamano S, Duthie MS, Mondal D. Evaluation of Real-time PCR for Diagnosis of Post-Kala-azar Dermal Leishmaniasis in Endemic Foci of Bangladesh. Open Forum Infect Dis 2018; 5:ofy234. [PMID: 30320150 PMCID: PMC6176879 DOI: 10.1093/ofid/ofy234] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 09/12/2018] [Indexed: 01/09/2023] Open
Abstract
Background Post-kala-azar dermal leishmaniasis (PKDL) is a sequel to visceral leishmaniasis (VL), which is found in VL-endemic countries including Bangladesh. Because of these enigmatic cases, the success of the National Kala-azar Elimination Program is under threat. To date, diagnostic methods for PKDL cases in endemic regions have been limited to clinical examination and rK39 test or microscopy, and a suitable and accurate alternative method is needed. In this study, we investigated the application of real-time polymerase chain reaction (PCR) as a potential method for diagnosis of PKDL in comparison with microscopy. Methods Ninety-one suspected macular PKDL cases from Mymensingh district, Bangladesh, were enrolled in the study after diagnosis by clinical examination and an rK39 strip test. All of them responded after completion of the treatment with miltefosine. During enrollment, a skin biopsy was done for each patient, and both microscopy and real-time PCR were performed for detection and quantification of Leishmania donovan body (LDB) and LD DNA, respectively. Results Real-time PCR detected 83 cases among all suspected PKDL patients, with an encouraging sensitivity of 91.2% (83.4%–96.1%), whereas microscopy showed 50.6% (39.9%–61.2%) sensitivity. Among all suspected PKDL cases, 42 cases were positive in both microscopy and qPCR, whereas 41 cases were detected as positive through qPCR only. Conclusions This study provides evidence that real-time PCR is a promising tool for diagnosis of PKDL in endemic regions. In addition to diagnosis, the quantitative ability of this method could be further exploited for after-treatment prognosis and cure assessment of PKDL cases.
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Affiliation(s)
- Prakash Ghosh
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.,Infectious Disease Research Institute, Seattle, Washington, USA
| | - Md Golam Hasnain
- Centre for Clinical Epidemiology and Biostatistics, School of Medicine and Public Health, Faculty of Health and Medicine, The University of Newcastle, New South Wales, Australia
| | - Faria Hossain
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Md Anik Ashfaq Khan
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Rajashree Chowdhury
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Khaledul Faisal
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Moshtaq Ahmed Mural
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - James Baker
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Rupen Nath
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Debashis Ghosh
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shomik Maruf
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Mohammad Sohel Shomik
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Rashidul Haque
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Greg Matlashewski
- Department of Microbiology and Immunology, McGill University, Montreal, Québec, Canada
| | - Shinjiro Hamano
- Department of Parasitology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | | | - Dinesh Mondal
- Nutrition and Clinical Service Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
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Moreira OC, Yadon ZE, Cupolillo E. The applicability of real-time PCR in the diagnostic of cutaneous leishmaniasis and parasite quantification for clinical management: Current status and perspectives. Acta Trop 2018; 184:29-37. [PMID: 28965842 DOI: 10.1016/j.actatropica.2017.09.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 08/11/2017] [Accepted: 09/24/2017] [Indexed: 01/10/2023]
Abstract
Cutaneous leishmaniasis (CL) is spread worldwide and is the most common manifestation of leishmaniasis. Diagnosis is performed by combining clinical and epidemiological features, and through the detection of Leishmania parasites (or DNA) in tissue specimens or trough parasite isolation in culture medium. Diagnosis of CL is challenging, reflecting the pleomorphic clinical manifestations of this disease. Skin lesions vary in severity, clinical appearance, and duration, and in some cases, they can be indistinguishable from lesions related to other diseases. Over the past few decades, PCR-based methods, including real-time PCR assays, have been developed for Leishmania detection, quantification and species identification, improving the molecular diagnosis of CL. This review provides an overview of many real-time PCR methods reported for the diagnostic evaluation of CL and some recommendations for the application of these methods for quantification purposes for clinical management and epidemiological studies. Furthermore, the use of real-time PCR for Leishmania species identification is also presented. The advantages of real-time PCR protocols are numerous, including increased sensitivity and specificity and simpler standardization of diagnostic procedures. However, despite the numerous assays described, there is still no consensus regarding the methods employed. Furthermore, the analytical and clinical validation of CL molecular diagnosis has not followed international guidelines so far. A consensus methodology comprising a DNA extraction protocol with an exogenous quality control and an internal reference to normalize parasite load is still needed. In addition, the analytical and clinical performance of any consensus methodology must be accurately assessed. This review shows that a standardization initiative is essential to guide researchers and clinical laboratories towards the achievement of a robust and reproducible methodology, which will permit further evaluation of parasite load as a surrogate marker of prognosis and monitoring of aetiological treatment, particularly in multi-centric observational studies and clinical trials.
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Abstract
Visceral leishmaniasis (VL), a deadly parasitic disease, is a major public health concern globally. Countries affected by VL have signed the London Declaration on Neglected Tropical Diseases and committed to eliminate VL as a public health problem by 2020. To achieve and sustain VL elimination, it will become progressively important not to miss any remaining cases in the community who can maintain transmission. This requires accurate identification of symptomatic and asymptomatic carriers using highly sensitive diagnostic tools at the primary health service setting. The rK39 rapid diagnostic test (RDT) is the most widely used tool and with its good sensitivity and specificity is the first choice for decentralized diagnosis of VL in endemic areas. However, this test cannot discriminate between current, subclinical, or past infections and is useless for diagnosis of relapses and as a prognostic (cure) test. Importantly, as the goal of elimination of VL as a public health problem is approaching, the number of people susceptible to infection will increase. Therefore, correct diagnosis using a highly sensitive diagnostic test is crucial for applying appropriate treatment and management of cases. Recent advances in molecular techniques have improved Leishmania detection and quantification, and therefore this technology has become increasingly relevant due to its possible application in a variety of clinical sample types. Most importantly, given current problems in identifying asymptomatic individuals because of poor correlation between the main methods of detection, molecular tests are valuable for VL elimination programs, especially to monitor changes in burden of infection in specific communities. This review provides a comprehensive overview of the available VL diagnostics and discusses the usefulness of molecular methods in the diagnosis, quantification, and species differentiation as well as their clinical applications.
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Affiliation(s)
- Shyam Sundar
- Infectious Disease Research Laboratory, Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India
| | - Om Prakash Singh
- Infectious Disease Research Laboratory, Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, 221 005, India.
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Müller KE, Zampieri RA, Aoki JI, Muxel SM, Nerland AH, Floeter-Winter LM. Amino acid permease 3 (aap3) coding sequence as a target for Leishmania identification and diagnosis of leishmaniases using high resolution melting analysis. Parasit Vectors 2018; 11:421. [PMID: 30012182 PMCID: PMC6048756 DOI: 10.1186/s13071-018-2989-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 07/03/2018] [Indexed: 11/23/2022] Open
Abstract
Background The leishmaniases comprise a spectrum of clinical manifestations caused by different species of Leishmania. Identification of species is important for diagnosis, treatment and follow-up management. However, there is no gold standard for species identification. High resolution melting analysis (HRM) offers a possibility to differentiate Leishmania species without the need for processing of the PCR-product. The amino acid permease 3 (aap3) gene is an exclusive target for trypanosomatids and is conserved among Leishmania spp., thus it can be a valuable target for an HRM assay for diagnosis of the leishmaniases. Results The HRM dissociation profiles of three amplicons targeting the aap3-coding region allowed the discrimination of L. (Leishmania) donovani, L. (L.) infantum, L. (L.) major, L. (L.) tropica, L. (L.) mexicana, L. (L.) amazonensis, L. (Viannia) braziliensis, L. (V.) guyanensis, L. (V.) lainsoni, L. (V.) naiffi and L. (V.) shawi using DNA from promastigote cultures. The protocol was validated with DNA samples from clinical infection in humans and a cat, naturally infected sand flies, and experimentally infected mice. Conclusions HRM analysis using the aap3 coding sequence as target is a relatively cheap, fast and robust strategy to detect and discriminate Leishmania species from all the endemic regions worldwide. The target and method proved to be useful in clinical, field and experimental samples, thus it could be used as a tool in diagnosis as well as ecological and epidemiological studies. Electronic supplementary material The online version of this article (10.1186/s13071-018-2989-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Karl Erik Müller
- Department of Clinical Science, Faculty of Medicine, University of Bergen, Postboks 7804, 5020, Bergen, Norway.
| | - Ricardo Andrade Zampieri
- Department of Physiology, Institute of Biosciences, University of São Paulo, Rua do Matão Travessa 14 no. 101, São Paulo, SP, 05508900, Brazil
| | - Juliana Ide Aoki
- Department of Physiology, Institute of Biosciences, University of São Paulo, Rua do Matão Travessa 14 no. 101, São Paulo, SP, 05508900, Brazil
| | - Sandra Marcia Muxel
- Department of Physiology, Institute of Biosciences, University of São Paulo, Rua do Matão Travessa 14 no. 101, São Paulo, SP, 05508900, Brazil
| | - Audun Helge Nerland
- Department of Clinical Science, Faculty of Medicine, University of Bergen, Postboks 7804, 5020, Bergen, Norway
| | - Lucile Maria Floeter-Winter
- Department of Physiology, Institute of Biosciences, University of São Paulo, Rua do Matão Travessa 14 no. 101, São Paulo, SP, 05508900, Brazil
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25
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de Sousa Ferreira T, Timbó RV, Minuzzi-Souza TTC, de Almeida Rocha D, Neiva M, de Albuquerque Ribeiro J, de Almeida PS, Hecht M, Nitz N, Gurgel-Gonçalves R. High molecular prevalence of Leishmania in phlebotomine sand flies fed on chicken blood in Brazil. Vet Parasitol 2018; 259:80-84. [PMID: 30056989 DOI: 10.1016/j.vetpar.2018.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/12/2018] [Accepted: 07/06/2018] [Indexed: 11/29/2022]
Abstract
Leishmaniases are endemic in Brazil, where Leishmania infantum has been detected in humans, dogs, cats, and phlebotomine vectors. Monitoring synanthropic vector populations is critical for leishmaniasis control-surveillance in such transmission-prone areas. Here, a suite of molecular approaches were used to assess Leishmania infection prevalence and to identify blood-meal sources in a large sample of sand flies collected in anthropic environments of a Leishmania-transmission area in Mato Grosso do Sul State (Rio Verde de Mato Grosso municipality), Central-West Brazil. We sampled sand flies monthly (January-June 2014 and 2016) in one peri-domestic site within each of six neighborhoods with recent records of human visceral and/or tegumentary leishmaniasis. kDNA-qPCR plus rDNA ITS-sequencing were used to detect and identify Leishmania in pooled female sand flies. Individual engorged females (n = 58) were used for blood-meal analyses through High-Resolution Melting (HRM) targeting the mtDNA cytb gene. Overall, 90.5% of 420 CDC trap-nights yielded vectors, for a total catch of 24,989 sand flies. We sub-sampled and identified 3088 sand flies of 12 species, including 2775 Lutzomyia longipalpis (the most abundant species at all sampling sites) and 297 Nyssomyia whitmani. Female sand flies (n = 1261) were grouped in 159 pools, of which 92 Lu. longipalpis (minimum infection rate [MIR] 8%) and 7 Ny. whitmani pools (MIR 7%) were Leishmania kDNA-positive. Most positive Lu. longipalpis were collected in the 2016 rainy season. Sequencing confirmed L. infantum in Lu. longipalpis samples. HRM analyses identified chicken DNA in 57 sand flies (98.3%), 37 of which were Leishmania DNA-positive (64.9%); human blood was found in just one (Leishmania-negative) female. Our data show ongoing risk of L. infantum transmission to humans in the study area, where Leishmania-infected sandfly vectors are common and heavily rely on chicken blood in the peri-domestic environment.
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Affiliation(s)
- Tauana de Sousa Ferreira
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brazil
| | - Renata Velôzo Timbó
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brazil
| | - Thaís T C Minuzzi-Souza
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brazil
| | - Douglas de Almeida Rocha
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brazil
| | - Mariana Neiva
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brazil
| | - Joana de Albuquerque Ribeiro
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brazil
| | - Paulo Silva de Almeida
- Laboratório Regional de Entomologia, Núcleo Regional de Saúde da Secretaria Estadual de Saúde, Dourados, Mato Grosso do Sul, Brazil
| | - Mariana Hecht
- Laboratório Interdisciplinar de Biociências, Faculdade de Medicina, Universidade de Brasília, Brazil
| | - Nadjar Nitz
- Laboratório Interdisciplinar de Biociências, Faculdade de Medicina, Universidade de Brasília, Brazil
| | - Rodrigo Gurgel-Gonçalves
- Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brazil.
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Sevilha-Santos L, Dos Santos Júnior ACM, Medeiros-Silva V, Bergmann JO, da Silva EF, Segato LF, Arabi AYM, de Paula NA, Sampaio RNR, Lima BD, Gomes CM. Accuracy of qPCR for quantifying Leishmania kDNA in different skin layers of patients with American tegumentary leishmaniasis. Clin Microbiol Infect 2018; 25:242-247. [PMID: 29730222 DOI: 10.1016/j.cmi.2018.04.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 04/19/2018] [Accepted: 04/24/2018] [Indexed: 11/18/2022]
Abstract
OBJECTIVES Superficial swab sampling of American tegumentary leishmaniasis (ATL) lesions shows higher amounts of Leishmania than those from biopsy. Subcutaneous involvement is also important in ATL, but parasite quantification according to lesion depth has not been evaluated. We aim to present the best depth at which sampling should be performed for molecular exams of ATL. METHODS Patients with a clinical presentation compatible with ATL were allocated to ATL and control groups. Qualitative and quantitative qPCR assays were performed using SYBR Green and primers amplifying the kDNA minicircle of Leishmania spp. in different skin layers, including the epidermis, the superior dermis, the inferior dermis, and the hypodermis. RESULTS Fifty-nine patients were included in this study, including 40 who had been diagnosed with ATL and 19 controls. The number of parasites was greater in samples of the epidermis and superior dermis (159.1 × 106, range 4.0-781.7, and 75.4 × 106, range 8.0-244.5, mean Leishmania parasite equivalents per μg of tissue DNA, respectively) than those in samples of the inferior dermis and hypodermis (54.6, range 8.0-256.6, and 16.8 × 106, range 8.0-24.1, mean Leishmania parasite equivalents per μg of tissue DNA, respectively). The best diagnostic accuracy was achieved in the superior dermis (77.9%) and was significantly greater than that in the hypodermis (63.3%; p 0.039). CONCLUSIONS We conclude that superficial sampling can retrieve a greater quantity of parasites. Future studies of the role of transepidermal elimination as a mechanism of host defence in ATL must be performed as there is a considerable quantity of Leishmania kDNA in the epidermis.
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Affiliation(s)
- L Sevilha-Santos
- Postgraduate Program in Medical Sciences, Faculty of Medicine, University of Brasília (UnB), Brasília, Brazil
| | - A C M Dos Santos Júnior
- Postgraduate Program in Molecular Pathology, Faculty of Medicine, University of Brasília (UnB), Brasília, Brazil
| | - V Medeiros-Silva
- Postgraduate Program in Health Sciences, Faculty of Health Sciences, University of Brasília (UnB), Brasília, Brazil
| | - J O Bergmann
- Postgraduate Program in Medical Sciences, Faculty of Medicine, University of Brasília (UnB), Brasília, Brazil
| | - E F da Silva
- Department of Statistics, University of Brasília (UnB), Brasília, Brazil
| | - L F Segato
- Dermatology Division, University Hospital of Brasília (HUB), University of Brasília (UnB), Brasília, Brazil
| | - A Y M Arabi
- Faculty of Medicine, University of Brasília, Brasília, Brazil
| | - N A de Paula
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Dermatology Division, Department of Medical Clinics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - R N R Sampaio
- Postgraduate Program in Medical Sciences, Faculty of Medicine, University of Brasília (UnB), Brasília, Brazil; Postgraduate Program in Health Sciences, Faculty of Health Sciences, University of Brasília (UnB), Brasília, Brazil; Dermatomycology Laboratory, Faculty of Medicine, University of Brasília, Brasília, Brazil
| | - B D Lima
- Gene Biology Laboratory, Postgraduate Program in Microbial Biology, Cell Biology Department, Biological Sciences Institute, University of Brasília (UnB), Brasília, DF, Brazil
| | - C M Gomes
- Postgraduate Program in Medical Sciences, Faculty of Medicine, University of Brasília (UnB), Brasília, Brazil; Dermatology Division, University Hospital of Brasília (HUB), University of Brasília (UnB), Brasília, Brazil; Dermatomycology Laboratory, Faculty of Medicine, University of Brasília, Brasília, Brazil; Tropical Medicine Nucleus, University of Brasília, Brasília, Brazil.
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Galluzzi L, Ceccarelli M, Diotallevi A, Menotta M, Magnani M. Real-time PCR applications for diagnosis of leishmaniasis. Parasit Vectors 2018; 11:273. [PMID: 29716641 PMCID: PMC5930967 DOI: 10.1186/s13071-018-2859-8] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 04/18/2018] [Indexed: 11/10/2022] Open
Abstract
Leishmaniasis is a vector-borne disease caused by many Leishmania species, which can infect both humans and other mammals. Leishmaniasis is a complex disease, with heterogeneous clinical manifestations ranging from asymptomatic infections to lesions at cutaneous sites (cutaneous leishmaniasis), mucosal sites (mucocutaneous leishmaniasis) or in visceral organs (visceral leishmaniasis), depending on the species and host characteristics. Often, symptoms are inconclusive and leishmaniasis can be confused with other co-endemic diseases. Moreover, co-infections (mainly with HIV in humans) can produce atypical clinical presentations. A correct diagnosis is crucial to apply the appropriate treatment and the use of molecular techniques in diagnosis of leishmaniasis has become increasingly relevant due to their remarkable sensitivity, specificity and possible application to a variety of clinical samples. Among them, real-time PCR (qPCR)-based approaches have become increasingly popular in the last years not only for detection and quantification of Leishmania species but also for species identification. However, despite qPCR-based methods having proven to be very effective in the diagnosis of leishmaniasis, a standardized method does not exist. This review summarizes the qPCR-based methods in the diagnosis of leishmaniasis focusing on the recent developments and applications in this field.
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Affiliation(s)
- Luca Galluzzi
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, via Saffi 2, 61029 Urbino, PU Italy
| | - Marcello Ceccarelli
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, via Saffi 2, 61029 Urbino, PU Italy
| | - Aurora Diotallevi
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, via Saffi 2, 61029 Urbino, PU Italy
| | - Michele Menotta
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, via Saffi 2, 61029 Urbino, PU Italy
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, via Saffi 2, 61029 Urbino, PU Italy
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Bilbao-Ramos P, Dea-Ayuela MA, Cardenas-Alegría O, Salamanca E, Santalla-Vargas JA, Benito C, Flores N, Bolás-Fernández F. Leishmaniasis in the major endemic region of Plurinational State of Bolivia: Species identification, phylogeography and drug susceptibility implications. Acta Trop 2017; 176:150-161. [PMID: 28751163 DOI: 10.1016/j.actatropica.2017.07.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 07/21/2017] [Accepted: 07/23/2017] [Indexed: 01/23/2023]
Abstract
The Plurinational State of Bolivia is one of the Latin American countries with the highest prevalence of leishmaniasis, highlighting the lowlands of the Department of La Paz where about 50% of the total cases were reported. The control of the disease can be seriously compromised by the intrinsic variability of the circulating species that may limit the efficacy of treatment while favoring the emergence of resistance. Fifty-five isolates of Leishmania from cutaneous and mucocutaneous lesions from patients living in different provinces of the Department of La Paz were tested. Molecular characterization of isolates was carried out by 3 classical markers: the rRNA internal transcribed spacer 1 (ITS-1), the heat shock protein 70 (HSP70) and the mitochondrial cytochrome b (Cyt-b). These markers were amplified by PCR and their products digested by the restriction endonuclease enzymes AseI and HaeIII followed by subsequent sequencing of Cyt-b gene and ITS-1 region for subsequent phylogenetic analysis. The combined use of these 3 markers allowed us to assign 36 isolates (65.5%) to the complex Leishmania (Viannia) braziliensis, 4 isolates (7, 27%) to L. (Viannia) lainsoni. and the remaining 15 isolates (23.7%) to a local variant of L. (Leishmania) mexicana. Concerning in vitro drug susceptibility the amastigotes from all isolates where highly sensitive to Fungizone® (mean IC50 between 0.23 and 0.5μg/mL) whereas against Glucantime® the sensitivity was moderate (mean IC50 ranging from 50.84μg/mL for L. (V.) braziliensis to 18.23μg/mL for L. (L.) mexicana. L. (V.) lainsoni was not sensitive to Glucantime®. The susceptibility to miltefosine was highly variable among species isolates, being L. (L.) mexicana the most sensitive, followed by L. (V.) braziliensis and L. (V.) lainsoni (mean IC50 of 8.24μg/mL, 17.85μg/mL and 23.28μg/mL, respectively).
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Hossain F, Ghosh P, Khan MAA, Duthie MS, Vallur AC, Picone A, Howard RF, Reed SG, Mondal D. Real-time PCR in detection and quantitation of Leishmania donovani for the diagnosis of Visceral Leishmaniasis patients and the monitoring of their response to treatment. PLoS One 2017; 12:e0185606. [PMID: 28957391 PMCID: PMC5619796 DOI: 10.1371/journal.pone.0185606] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 09/17/2017] [Indexed: 11/19/2022] Open
Abstract
Sustained elimination of Visceral Leishmaniasis (VL) requires the reduction and control of parasite reservoirs to minimize the transmission of Leishmania donovani infection. A simple, reproducible and definitive diagnostic procedure is therefore indispensable for the early and accurate detection of parasites in VL, Relapsed VL (RVL) and Post Kala-azar Dermal Leishmaniasis (PKDL) patients, all of whom are potential reservoirs of Leishmania parasites. To overcome the limitations of current diagnostic approaches, a novel quantitative real-time polymerase chain reaction (qPCR) method based on Taqman chemistry was devised for the detection and quantification of L. donovani in blood and skin. The diagnostic efficacy was evaluated using archived peripheral blood buffy coat DNA from 40 VL, 40 PKDL, 10 RVL, 20 cured VL, and 40 cured PKDL along with 10 tuberculosis (TB) cases and 80 healthy endemic controls. Results were compared to those obtained using a Leishmania-specific nested PCR (Ln-PCR). The real time PCR assay was 100% (95% CI, 91.19-100%) sensitive in detecting parasite genomes in VL and RVL samples and 85.0% (95% CI, 70.16-94.29%) sensitive for PKDL samples. In contrast, the sensitivity of Ln-PCR was 77.5% (95% CI, 61.55-89.16%) for VL samples, 100% (95%CI, 69.15-100%) for RVL samples, and 52.5% (95% CI, 36.13-68.49%) for PKDL samples. There was significant discordance between the two methods with the overall sensitivity of the qPCR assay being considerably higher than Ln-PCR. None of the assay detected L. donovani DNA in buffy coats from cured VL cases, and reduced infectious burdens were demonstrated in cured PKDL cases who remained positive in 7.5% (3/40) and 2.5% (1/40) cases by real-time PCR and Ln-PCR, respectively. Both assays were 100% (95% CI, 95.98-100) specific with no positive signals in either endemic healthy control or TB samples. The real time PCR assay we developed offers a molecular tool for accurate detection of circulating L. donovani parasites in VL, PKDL and RVL patients, as well as being capable of assessing response to treatment. As such, this real time PCR assay represents an important contribution in efforts to eliminate VL.
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Affiliation(s)
- Faria Hossain
- Laboratory of Emerging Infections and Parasitology, Nutrition and Clinical science division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Prakash Ghosh
- Laboratory of Emerging Infections and Parasitology, Nutrition and Clinical science division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Md. Anik Ashfaq Khan
- Laboratory of Emerging Infections and Parasitology, Nutrition and Clinical science division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Malcolm S. Duthie
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Aarthy C. Vallur
- InBios International Inc, Seattle, Washington, United States of America
| | - Alessandro Picone
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Randall F. Howard
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Steven G. Reed
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Dinesh Mondal
- Laboratory of Emerging Infections and Parasitology, Nutrition and Clinical science division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
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The use of kDNA minicircle subclass relative abundance to differentiate between Leishmania (L.) infantum and Leishmania (L.) amazonensis. Parasit Vectors 2017; 10:239. [PMID: 28511704 PMCID: PMC5434583 DOI: 10.1186/s13071-017-2181-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 05/09/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Leishmaniasis is a neglected disease caused by many Leishmania species, belonging to subgenera Leishmania (Leishmania) and Leishmania (Viannia). Several qPCR-based molecular diagnostic approaches have been reported for detection and quantification of Leishmania species. Many of these approaches use the kinetoplast DNA (kDNA) minicircles as the target sequence. These assays had potential cross-species amplification, due to sequence similarity between Leishmania species. Previous works demonstrated discrimination between L. (Leishmania) and L. (Viannia) by SYBR green-based qPCR assays designed on kDNA, followed by melting or high-resolution melt (HRM) analysis. Importantly, these approaches cannot fully distinguish L. (L.) infantum from L. (L.) amazonensis, which can coexist in the same geographical area. METHODS DNA from 18 strains/isolates of L. (L.) infantum, L. (L.) amazonensis, L. (V.) braziliensis, L. (V.) panamensis, L. (V.) guyanensis, and 62 clinical samples from L. (L.) infantum-infected dogs were amplified by a previously developed qPCR (qPCR-ML) and subjected to HRM analysis; selected PCR products were sequenced using an ABI PRISM 310 Genetic Analyzer. Based on the obtained sequences, a new SYBR-green qPCR assay (qPCR-ama) intended to amplify a minicircle subclass more abundant in L. (L.) amazonensis was designed. RESULTS The qPCR-ML followed by HRM analysis did not allow discrimination between L. (L.) amazonensis and L. (L.) infantum in 53.4% of cases. Hence, the novel SYBR green-based qPCR (qPCR-ama) has been tested. This assay achieved a detection limit of 0.1 pg of parasite DNA in samples spiked with host DNA and did not show cross amplification with Trypanosoma cruzi or host DNA. Although the qPCR-ama also amplified L. (L.) infantum strains, the Cq values were dramatically increased compared to qPCR-ML. Therefore, the combined analysis of Cq values from qPCR-ML and qPCR-ama allowed to distinguish L. (L.) infantum and L. (L.) amazonensis in 100% of tested samples. CONCLUSIONS A new and affordable SYBR-green qPCR-based approach to distinguish between L. (L.) infantum and L. (L.) amazonensis was developed exploiting the major abundance of a minicircle sequence rather than targeting a hypothetical species-specific sequence. The fast and accurate discrimination between these species can be useful to provide adequate prognosis and treatment.
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de Rezende MB, Herrera HM, Carvalho CME, Carvalho Anjos EA, Ramos CAN, de Araújo FR, Torres JM, de Oliveira CE. Detection of Leishmania spp. in Bats from an Area of Brazil Endemic for Visceral Leishmaniasis. Transbound Emerg Dis 2017; 64:e36-e42. [PMID: 28233434 DOI: 10.1111/tbed.12597] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Indexed: 12/31/2022]
Abstract
The multihost parasites Leishmania spp. infect a broad range of wild mammalian species including bats. Several species of bats have adapted to a variety of food resources and shelters in urban areas. This study aimed to detect Leishmania spp. DNA in bats present in forest fragments located in metropolitan areas endemic for leishmaniasis in Campo Grande, Mato Grosso do Sul (MS), Brazil. Blood samples were obtained from 80 individuals, including eight species of Phyllostomidae and one species of Vespertilionidae. Thirty of the 80 bats were positive for Leishmania spp. using conventional PCR, all belonging to the family Phyllostomidae. Eighteen samples tested by real-time PCR (qPCR) using specific primers for the kDNA of Leishmania infantum were positive. To the best of our knowledge, this is the first report detecting Leishmania spp. in Platyrrhinus incarum in addition to being the first reported detection of L. infantum in the bat species Phyllostomus discolor, Platyrrhinus lineatus, Artibeus planirostris and Artibeus lituratus. Our results show that bats can host Leishmania spp. in areas endemic for leishmaniasis, which must be taken into account in disease control operations by public health authorities.
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Affiliation(s)
- M B de Rezende
- Universidade Católica Dom Bosco - UCDB, Campo Grande, MS, Brazil
| | - H M Herrera
- Universidade Católica Dom Bosco - UCDB, Campo Grande, MS, Brazil
| | - C M E Carvalho
- Universidade Católica Dom Bosco - UCDB, Campo Grande, MS, Brazil
| | - E A Carvalho Anjos
- Universidade Católica Dom Bosco - UCDB, Campo Grande, MS, Brazil.,Bolsista CAPES - Proc. Number 1218-13-1, University of Manitoba, Winnipeg, Canada
| | - C A N Ramos
- Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
| | | | - J M Torres
- Universidade Católica Dom Bosco - UCDB, Campo Grande, MS, Brazil
| | - C E de Oliveira
- Universidade Católica Dom Bosco - UCDB, Campo Grande, MS, Brazil
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de Almeida ME, Koru O, Steurer F, Herwaldt BL, da Silva AJ. Detection and Differentiation of Leishmania spp. in Clinical Specimens by Use of a SYBR Green-Based Real-Time PCR Assay. J Clin Microbiol 2017; 55:281-290. [PMID: 27847378 PMCID: PMC5228241 DOI: 10.1128/jcm.01764-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 11/01/2016] [Indexed: 11/20/2022] Open
Abstract
Leishmaniasis in humans is caused by Leishmania spp. in the subgenera Leishmania and Viannia Species identification often has clinical relevance. Until recently, our laboratory relied on conventional PCR amplification of the internal transcribed spacer 2 (ITS2) region (ITS2-PCR) followed by sequencing analysis of the PCR product to differentiate Leishmania spp. Here we describe a novel real-time quantitative PCR (qPCR) approach based on the SYBR green technology (LSG-qPCR), which uses genus-specific primers that target the ITS1 region and amplify DNA from at least 10 Leishmania spp., followed by analysis of the melting temperature (Tm) of the amplicons on qPCR platforms (the Mx3000P qPCR system [Stratagene-Agilent] and the 7500 real-time PCR system [ABI Life Technologies]). We initially evaluated the assay by testing reference Leishmania isolates and comparing the results with those from the conventional ITS2-PCR approach. Then we compared the results from the real-time and conventional molecular approaches for clinical specimens from 1,051 patients submitted to the reference laboratory of the Centers for Disease Control and Prevention for Leishmania diagnostic testing. Specimens from 477 patients tested positive for Leishmania spp. with the LSG-qPCR assay, specimens from 465 of these 477 patients also tested positive with the conventional ITS2-PCR approach, and specimens from 10 of these 465 patients had positive results because of retesting prompted by LSG-qPCR positivity. On the basis of the Tm values of the LSG-qPCR amplicons from reference and clinical specimens, we were able to differentiate four groups of Leishmania parasites: the Viannia subgenus in aggregate; the Leishmania (Leishmania) donovani complex in aggregate; the species L (L) tropica; and the species L (L) mexicana, L (L) amazonensis, L (L) major, and L (L) aethiopica in aggregate.
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Affiliation(s)
- Marcos E de Almeida
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, Georgia, USA
| | - Ozgur Koru
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, Georgia, USA
- Gulhane Military Medicine Academy, Department of Microbiology, Ankara, Turkey
| | - Francis Steurer
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, Georgia, USA
| | - Barbara L Herwaldt
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, Georgia, USA
| | - Alexandre J da Silva
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Center for Global Health, Atlanta, Georgia, USA
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Field Validation of SYBR Green- and TaqMan-Based Real-Time PCR Using Biopsy and Swab Samples To Diagnose American Tegumentary Leishmaniasis in an Area Where Leishmania (Viannia) braziliensis Is Endemic. J Clin Microbiol 2016; 55:526-534. [PMID: 27927916 DOI: 10.1128/jcm.01954-16] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/24/2016] [Indexed: 11/20/2022] Open
Abstract
The precise diagnosis of American tegumentary leishmaniasis (ATL) is an essential task due to the disease's associated morbidity. A noninvasive, extremely sensitive, and highly specific exam is critical, particularly for mucosal leishmaniasis (ML), in which a low parasite quantity is expected. We aimed to compare the diagnostic accuracy of swab and biopsy sample analysis using SYBR Green- and TaqMan-based real-time PCR (qPCR) assays with that of a composite reference standard consisting of the Montenegro skin test, serology, histopathology, smears, culture, and conventional PCR. In total, 55 patients with ATL (ML, 18 patients; cutaneous leishmaniasis [CL], 37 patients) and 36 patients without ATL were studied. qPCR analysis of swabs was more accurate when using SYBR Green (87.88%; 95% confidence interval [CI], 77.86 to 93.73 patients) than when using TaqMan (78.79%; 95% CI, 67.49 to 86.92%) (P = 0.031). SYBR Green (84.72%; 95% CI, 74.68 to 91.25%) was also more accurate than TaqMan (73.61%; 95% CI, 62.42 to 82.41%) for biopsy samples (P = 0.008). All qPCR methods were 100% specific. Swabs and biopsy specimens had similar sensitivity when using the same chemistry (P = 0.125 for SYBR Green and P = 0.625 for TaqMan). Moreover, qPCR achieved better performance than most existing techniques used for the diagnosis of ATL and also detected the Leishmania parasite in a greater proportion of patients than the associated histopathology, smear, culture, and conventional PCR techniques did. Swabs therefore represent a useful diagnostic tool because they not only are noninvasive but also can achieve an accuracy similar to that of biopsy samples. The high accuracy of SYBR Green-based qPCR may also reduce the requirement for associated parasitological tests for ATL diagnosis.
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Saldarriaga OA, Castellanos-Gonzalez A, Porrozzi R, Baldeviano GC, Lescano AG, de Los Santos MB, Fernandez OL, Saravia NG, Costa E, Melby PC, Travi BL. An Innovative Field-Applicable Molecular Test to Diagnose Cutaneous Leishmania Viannia spp. Infections. PLoS Negl Trop Dis 2016; 10:e0004638. [PMID: 27115155 PMCID: PMC4845993 DOI: 10.1371/journal.pntd.0004638] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/28/2016] [Indexed: 11/30/2022] Open
Abstract
Cutaneous and mucosal leishmaniasis is widely distributed in Central and South America. Leishmania of the Viannia subgenus are the most frequent species infecting humans. L. (V.) braziliensis, L. (V.) panamensis are also responsible for metastatic mucosal leishmaniasis. Conventional or real time PCR is a more sensitive diagnostic test than microscopy, but the cost and requirement for infrastructure and trained personnel makes it impractical in most endemic regions. Primary health systems need a sensitive and specific point of care (POC) diagnostic tool. We developed a novel POC molecular diagnostic test for cutaneous leishmaniasis caused by Leishmania (Viannia) spp. Parasite DNA was amplified using isothermal Recombinase Polymerase Amplification (RPA) with primers and probes that targeted the kinetoplast DNA. The amplification product was detected by naked eye with a lateral flow (LF) immunochromatographic strip. The RPA-LF had an analytical sensitivity equivalent to 0.1 parasites per reaction. The test amplified the principal L. Viannia species from multiple countries: L. (V.) braziliensis (n = 33), L. (V.) guyanensis (n = 17), L. (V.) panamensis (n = 9). The less common L. (V.) lainsoni, L. (V.) shawi, and L. (V.) naiffi were also amplified. No amplification was observed in parasites of the L. (Leishmania) subgenus. In a small number of clinical samples (n = 13) we found 100% agreement between PCR and RPA-LF. The high analytical sensitivity and clinical validation indicate the test could improve the efficiency of diagnosis, especially in chronic lesions with submicroscopic parasite burdens. Field implementation of the RPA-LF test could contribute to management and control of cutaneous and mucosal leishmaniasis. Cutaneous leishmaniasis is a parasitic disease transmitted by the bite of sandflies that produces skin ulcers. The severe, disfiguring form of the disease is characterized by parasite dissemination to the mucosa of the nose and palate. Current diagnosis is based on microscopy which has low sensitivity in chronic cases. Molecular methods (PCR) that detect parasite DNA are highly sensitive but costs and personnel training make it impossible to implement it in resource-limited areas. We developed a novel molecular method (RPA-LF) that could be applied in the field because it does not require sophisticated equipment. It is also very sensitive and specific to detect the principal Leishmania species that produce cutaneous leishmaniasis in Latin America. Future field implementation of RPA-LF could have a positive impact on disease management and control.
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Affiliation(s)
- Omar A. Saldarriaga
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas, United States of America
| | - Alejandro Castellanos-Gonzalez
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas, United States of America
- Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas, United States of America
| | - Renato Porrozzi
- Laboratório de Pesquisa em Leishmaniose, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Andrés G. Lescano
- U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Perú
- Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Olga L. Fernandez
- Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia
| | - Nancy G. Saravia
- Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Cali, Colombia
| | - Erika Costa
- Laboratório de Pesquisa em Leishmaniose, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Peter C. Melby
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas, United States of America
- Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas, United States of America
- Department of Microbiology and Immunology, University of Texas Medical Branch (UTMB), Galveston, Texas, United States of America
| | - Bruno L. Travi
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas, United States of America
- Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas, United States of America
- Department of Microbiology and Immunology, University of Texas Medical Branch (UTMB), Galveston, Texas, United States of America
- * E-mail:
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Castellanos-Gonzalez A, Saldarriaga OA, Tartaglino L, Gacek R, Temple E, Sparks H, Melby PC, Travi BL. A Novel Molecular Test to Diagnose Canine Visceral Leishmaniasis at the Point of Care. Am J Trop Med Hyg 2015; 93:970-5. [PMID: 26240156 DOI: 10.4269/ajtmh.15-0145] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/23/2015] [Indexed: 12/17/2022] Open
Abstract
Dogs are the principal reservoir hosts of zoonotic visceral leishmaniasis (VL) but current serological methods are not sensitive enough to detect all subclinically infected animals, which is crucial to VL control programs. Polymerase chain reaction (PCR) methods have greater sensitivity but require expensive equipment and trained personnel, impairing its implementation in endemic areas. We developed a diagnostic test that uses isothermal recombinase polymerase amplification (RPA) to detect Leishmania infantum. This method was coupled with lateral flow (LF) reading with the naked eye to be adapted as a point-of-care test. The L. infantum RPA-LF had an analytical sensitivity similar to real time-PCR, detecting DNA of 0.1 parasites spiked in dog blood, which was equivalent to 40 parasites/mL. There was no cross amplification with dog or human DNA or with Leishmania braziliensis, Leishmania amazonensis, or Trypanosoma cruzi. The test also amplified Leishmania donovani strains (N = 7). In a group of clinically normal dogs (N = 30), RPA-LF detected more subclinical infections than rK39 strip test, a standard serological method (50% versus 13.3% positivity, respectively; P = 0.005). Also, RPA-LF detected L. infantum in noninvasive mucosal samples of dogs with a sensitivity comparable to blood samples. This novel molecular test may have a positive impact in leishmaniasis control programs.
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Affiliation(s)
- Alejandro Castellanos-Gonzalez
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas
| | - Omar A Saldarriaga
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas
| | - Lilian Tartaglino
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas
| | - Rosana Gacek
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas
| | - Elissa Temple
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas
| | - Hayley Sparks
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas
| | - Peter C Melby
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas
| | - Bruno L Travi
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas; Department of Microbiology and Immunology, Center for Tropical Diseases (CTD), University of Texas Medical Branch (UTMB), Galveston, Texas; Secretaria de Calidad de Vida, Municipalidad de Posadas, Misiones, Argentina; Instituto Municipal de Sanidad Animal, Municipalidad de Posadas, Misiones, Argentina; Baylor University, Waco, Texas
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de Paiva-Cavalcanti M, de Morais RCS, Pessoa-E-Silva R, Trajano-Silva LAM, Gonçalves-de-Albuquerque SDC, Tavares DDHC, Brelaz-de-Castro MCA, Silva RDFE, Pereira VRA. Leishmaniases diagnosis: an update on the use of immunological and molecular tools. Cell Biosci 2015; 5:31. [PMID: 26097678 PMCID: PMC4474361 DOI: 10.1186/s13578-015-0021-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/05/2015] [Indexed: 11/10/2022] Open
Abstract
Leishmaniases are caused by obligate intracellular protozoan parasites of the genus Leishmania. They cause a spectrum of diseases, most notably visceral (VL), cutaneous (CL), and mucosal (ML) leishmaniasis, which affect millions of people around the world, each year. Despite scientific advances, leishmaniases cases are expanding, constituting an important public health problem. Immunological and molecular diagnostic tools have been increasingly applied for the early detection of these parasitic infections, since the existence of limitations in clinical and parasitological examinations may provide false results, thus interfering in epidemiological research and diseases control. Although there is a great diversity of available immunological assays, important common deficiencies persist, which explains the current exploration of the molecular biology in research fields, especially the Polymerase Chain Reaction (PCR) and its variants, such as real-time quantitative PCR. However, in the last years, significant results have also been reached inside of immunological context (especially by Flow Cytometry), for humans and dogs, demonstrated by research works of the New and Old worlds. In spite of their potential to clarify and minimize the present global situation of the diseases, the implementation of molecular or immunological innovative reference assays for VL and CL at health services is still a challenge due to several reasons, including lack of standardization among laboratories and structural concerns. In this article we bring classical and current information about technological advances for the immunological and molecular leishmaniases diagnosis, their features, and applications.
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Affiliation(s)
- Milena de Paiva-Cavalcanti
- Department of Immunology, Aggeu Magalhães Research Center, Oswaldo Cruz Foundation, Av. Prof. Moraes Rego s / n, 50670-420 Recife, PE Brazil
| | - Rayana Carla Silva de Morais
- Department of Immunology, Aggeu Magalhães Research Center, Oswaldo Cruz Foundation, Av. Prof. Moraes Rego s / n, 50670-420 Recife, PE Brazil
| | - Rômulo Pessoa-E-Silva
- Department of Immunology, Aggeu Magalhães Research Center, Oswaldo Cruz Foundation, Av. Prof. Moraes Rego s / n, 50670-420 Recife, PE Brazil
| | | | | | | | | | - Rafael de Freitas E Silva
- Department of Immunology, Aggeu Magalhães Research Center, Oswaldo Cruz Foundation, Av. Prof. Moraes Rego s / n, 50670-420 Recife, PE Brazil ; Department of Natural and Exact Sciences, University of Pernambuco (UPE), St. Capitão Pedro Rodrigues, 105, 55920-000 São José, Garanhuns, PE Brazil
| | - Valéria Rêgo Alves Pereira
- Department of Immunology, Aggeu Magalhães Research Center, Oswaldo Cruz Foundation, Av. Prof. Moraes Rego s / n, 50670-420 Recife, PE Brazil
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Abstract
Leishmania is an infectious protozoan parasite related to African and American trypanosomes. All Leishmania species that are pathogenic to humans can cause dermal disease. When one is confronted with cutaneous leishmaniasis, identification of the causative species is relevant in both clinical and epidemiological studies, case management, and control. This review gives an overview of the currently existing and most used assays for species discrimination, with a critical appraisal of the limitations of each technique. The consensus taxonomy for the genus is outlined, including debatable species designations. Finally, a numerical literature analysis is presented that describes which methods are most used in various countries and regions in the world, and for which purposes.
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Affiliation(s)
- Gert Van der Auwera
- Institute of Tropical Medicine, Department of Biomedical Sciences, Antwerp, Belgium
| | - Jean-Claude Dujardin
- Institute of Tropical Medicine, Department of Biomedical Sciences, Antwerp, Belgium Antwerp University, Department of Biomedical Sciences, Antwerp, Belgium
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Molecular epidemiology of imported cases of leishmaniasis in Australia from 2008 to 2014. PLoS One 2015; 10:e0119212. [PMID: 25734905 PMCID: PMC4348169 DOI: 10.1371/journal.pone.0119212] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 01/28/2015] [Indexed: 02/06/2023] Open
Abstract
Leishmaniasis is a vector borne disease caused by protozoa of the genus Leishmania. Human leishmaniasis is not endemic in Australia though imported cases are regularly encountered. This study aimed to provide an update on the molecular epidemiology of imported leishmaniasis in Australia. Of a total of 206 biopsies and bone marrow specimens submitted to St Vincent’s Hospital Sydney for leishmaniasis diagnosis by PCR, 55 were found to be positive for Leishmania DNA. All PCR products were subjected to restriction fragment length polymorphism analysis for identification of the causative species. Five Leishmania species/species complexes were identified with Leishmania tropica being the most common (30/55). Travel or prior residence in a Leishmania endemic region was the most common route of acquisition with ~47% of patients having lived in or travelled to Afghanistan. Cutaneous leishmaniasis was the most common manifestation (94%) with only 3 cases of visceral leishmaniasis and no cases of mucocutaneous leishmaniasis encountered. This report indicates that imported leishmaniasis is becoming increasingly common in Australia due to an increase in global travel and immigration. As such, Australian clinicians must be made aware of this trend and consider leishmaniasis in patients with suspicious symptoms and a history of travel in endemic areas. This study also discusses the recent identification of a unique Leishmania species found in native kangaroos and a potential vector host which could create the opportunity for the establishment of a local transmission cycle within humans.
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Hernández C, Alvarez C, González C, Ayala MS, León CM, Ramírez JD. Identification of six New World Leishmania species through the implementation of a High-Resolution Melting (HRM) genotyping assay. Parasit Vectors 2014; 7:501. [PMID: 25394418 PMCID: PMC4239372 DOI: 10.1186/s13071-014-0501-y] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 10/23/2014] [Indexed: 02/07/2023] Open
Abstract
Background Leishmaniases are tropical zoonotic diseases, caused by parasites from the genus Leishmania. New World (NW) species are related to sylvatic cycles although urbanization processes have been reported in some South American Countries such as Colombia. This eco-epidemiological complexity imposes a challenge to the detection of circulating parasite species, not only related to human cases but also infecting vectors and reservoirs. Currently, no harmonized methods have been deployed to discriminate the NW Leishmania species. Findings Herein, we conducted a systematic and mechanistic High-Resolution Melting (HRM) assay targeted to HSP70 and ITS1. Specific primers were designed that coupled with a HRM analyses permitted to discriminate six NW Leishmania species. In order to validate the herein described algorithm, we included 35 natural isolates obtained from human cases, insect vectors and mammals. Our genotyping assay allowed the correct assignment of the six NW Leishmania species (L. mexicana, L. infantum (chagasi), L. amazonensis, L. panamensis, L. guyanensis and L. braziliensis) based on reference strains. When the algorithm was applied to a set of well-characterized strains by means of PCR-RFLP, MLEE and monoclonal antibodies (MA) we observed a tailored concordance between the HRM and PCR-RFLP/MLEE/MA (KI = 1.0). Additionally, we tested the limit of detection for the HRM method showing that this is able to detect at least 10 equivalent-parasites per mL. Conclusions This is a rapid and reliable method to conduct molecular epidemiology and host-parasite association studies in endemic areas.
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Affiliation(s)
- Carolina Hernández
- Grupo de Parasitología, Instituto Nacional de Salud, Bogotá, Colombia. .,Grupo de Investigaciones Microbiológicas - UR (GIMUR), Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia.
| | - Catalina Alvarez
- Centro de Investigaciones en Microbiología y Parasitología Tropical (CIMPAT), Departamento de Ciencias Biológicas, Facultad de Ciencias, Universidad de los Andes, Bogotá, Colombia.
| | - Camila González
- Centro de Investigaciones en Microbiología y Parasitología Tropical (CIMPAT), Departamento de Ciencias Biológicas, Facultad de Ciencias, Universidad de los Andes, Bogotá, Colombia.
| | | | - Cielo Maritza León
- Grupo de Investigaciones Microbiológicas - UR (GIMUR), Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia.
| | - Juan David Ramírez
- Grupo de Investigaciones Microbiológicas - UR (GIMUR), Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia.
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Ceccarelli M, Galluzzi L, Sisti D, Bianchi B, Magnani M. Application of qPCR in conjunctival swab samples for the evaluation of canine leishmaniasis in borderline cases or disease relapse and correlation with clinical parameters. Parasit Vectors 2014; 7:460. [PMID: 25331737 PMCID: PMC4207623 DOI: 10.1186/s13071-014-0460-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/26/2014] [Indexed: 12/03/2022] Open
Abstract
Background In leishmaniasis caused by Leishmania infantum, the dog acts as the main reservoir for the disease. Non-invasive sampling for Leishmania detection is pivotal for rapid and affordable diagnosis. Recently, the use of conjunctival swab (CS) has been evaluated as a non-invasive sampling technique for quantitative real-time PCR (qPCR). However, few investigations have been made on the applicability of CS qPCR in particular cases such as dogs with borderline IFAT titres, suspected disease relapse with comorbidity and therapy monitoring. The aims of this study were i) to confirm the efficacy of CS, comparing these samples to buffy coat (BC) samples, as effective non-invasive samples for Leishmania quantitative detection by qPCR and ii) to verify the usefulness of qPCR compared to conventional laboratory and clinical parameters to assist in therapeutic decision making regarding dogs with complex clinical cases. Methods Eighty dogs were divided into 4 groups based on their IFAT titres and clinical histories. Two qPCR assays were performed both on CS raw lysates and on purified DNA from BC samples. The assays were then compared. Z tests for difference of proportion, with Bonferroni correction, were carried out to evaluate the qPCR results. Logistic regression with backward stepwise elimination was performed to detect the subset of haematochemical variables significantly associated with PCR positivity. Results The qPCR performed on CS samples showed better sensitivity (87%) and specificity (96%) than assays carried out using BC samples, regardless of the primers used. The haematochemical parameters haemoglobin and globulins were found to be significantly associated with qPCR positivity. Pearson correlations between Leishmania kDNA load in CS and body condition scores or IFAT titres were calculated in dogs with new leishmaniasis diagnoses. The Leishmania kDNA load in CS correlated moderately with IFAT titres (R = 0.59) but a very weak correlation (R = 0.37) with body condition score (BCS) was found. Conclusions The applicability of CS for Leishmania detection in dogs was confirmed, revealing the usefulness of raw lysates for quantitative purposes. Moreover, the qPCR was found to be particularly useful in cases lacking a clear clinical diagnosis, where the haematochemical values cannot be predictive. Electronic supplementary material The online version of this article (doi:10.1186/s13071-014-0460-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marcello Ceccarelli
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029, Urbino, PU, Italy.
| | - Luca Galluzzi
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029, Urbino, PU, Italy.
| | - Davide Sisti
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029, Urbino, PU, Italy.
| | - Barbara Bianchi
- Veterinary Clinic "Santa Teresa", via Piave 23, 61032, Fano, PU, Italy.
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029, Urbino, PU, Italy.
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Ceccarelli M, Galluzzi L, Migliazzo A, Magnani M. Detection and characterization of Leishmania (Leishmania) and Leishmania (Viannia) by SYBR green-based real-time PCR and high resolution melt analysis targeting kinetoplast minicircle DNA. PLoS One 2014; 9:e88845. [PMID: 24551178 PMCID: PMC3923818 DOI: 10.1371/journal.pone.0088845] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 01/11/2014] [Indexed: 11/25/2022] Open
Abstract
Leishmaniasis is a neglected disease with a broad clinical spectrum which includes asymptomatic infection. A thorough diagnosis, able to distinguish and quantify Leishmania parasites in a clinical sample, constitutes a key step in choosing an appropriate therapy, making an accurate prognosis and performing epidemiological studies. Several molecular techniques have been shown to be effective in the diagnosis of leishmaniasis. In particular, a number of PCR methods have been developed on various target DNA sequences including kinetoplast minicircle constant regions. The first aim of this study was to develop a SYBR green-based qPCR assay for Leishmania (Leishmania) infantum detection and quantification, using kinetoplast minicircle constant region as target. To this end, two assays were compared: the first used previously published primer pairs (qPCR1), whereas the second used a nested primer pairs generating a shorter PCR product (qPCR2). The second aim of this study was to evaluate the possibility to discriminate among subgenera Leishmania (Leishmania) and Leishmania (Viannia) using the qPCR2 assay followed by melting or High Resolution Melt (HRM) analysis. Both assays used in this study showed good sensitivity and specificity, and a good correlation with standard IFAT methods in 62 canine clinical samples. However, the qPCR2 assay allowed to discriminate between Leishmania (Leishmania) and Leishmania (Viannia) subgenera through melting or HRM analysis. In addition to developing assays, we investigated the number and genetic variability of kinetoplast minicircles in the Leishmania (L.) infantum WHO international reference strain (MHOM/TN/80/IPT1), highlighting the presence of minicircle subclasses and sequence heterogeneity. Specifically, the kinetoplast minicircle number per cell was estimated to be 26,566±1,192, while the subclass of minicircles amplifiable by qPCR2 was estimated to be 1,263±115. This heterogeneity, also observed in canine clinical samples, must be taken into account in quantitative PCR-based applications; however, it might also be used to differentiate between Leishmania subgenera.
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Affiliation(s)
- Marcello Ceccarelli
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Fano (PU), Italy
| | - Luca Galluzzi
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Fano (PU), Italy
- * E-mail:
| | | | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Urbino (PU), Italy
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Comparison between conventional and real-time PCR assays for diagnosis of visceral leishmaniasis. BIOMED RESEARCH INTERNATIONAL 2014; 2014:639310. [PMID: 24689047 PMCID: PMC3933315 DOI: 10.1155/2014/639310] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/20/2013] [Accepted: 12/27/2013] [Indexed: 11/17/2022]
Abstract
The diagnosis of visceral leishmaniasis (VL) is a challenging issue and several studies worldwide have evaluated the different tools to reach a diagnostic solution. The polymerase chain reaction (PCR) has proven to be effective in detecting the genome of Leishmania species in different biological samples. In this study, we compared the conventional PCR and real-time PCR using the Sybr Green system and their application in molecular diagnosis of visceral leishmaniasis in peripheral blood as a biological sample. The genus-specific conserved region of kinetoplast DNA (kDNA) was the target of amplification. We studied 30 samples from patients with suspect of visceral leishmaniasis who were treated by the Medical Clinic of Santa Casa de Belo Horizonte Hospital, Brazil. Among the samples studied, 19 had a confirmed diagnosis for VL by serology and/or by clinical findings. Among these 19 samples, 63% (n = 12) presented positive results for serology and 79% (n = 15) positive results in both PCR methodologies. This fact suggests that the PCR technique can assist in the diagnosis of visceral leishmaniasis in patients who do not have detectable antibodies by serology but can present the genome of the parasite circulating in whole blood. Also, it was possible to observe that there was conformity between the results of the techniques of cPCR and qPCR using the Sybr Green system in 100% of samples analyzed. These data suggest that both PCR techniques were equally effective for detection of the genome of the parasite in the patient's blood.
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Rodrigues EHG, Soares FCDS, Werkhäuser RP, de Brito MEF, Fernandes O, Abath FGC, Brandão A. The compositional landscape of minicircle sequences isolated from active lesions and scars of American cutaneous leishmaniasis. Parasit Vectors 2013; 6:228. [PMID: 23924509 PMCID: PMC3750493 DOI: 10.1186/1756-3305-6-228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/02/2013] [Indexed: 11/15/2022] Open
Abstract
Background American cutaneous leishmaniasis (ACL) is characterized by cutaneous lesions that heal spontaneously or after specific treatment. This paper reports on the analysis of kDNA minicircle sequences from clinical samples (typical lesions and scars) that were PCR-amplified with specific primers for Leishmania species of the subgenus Viannia. Methods From 56 clinical isolates we obtained a single amplified fragment (ca. 790 bp), which after cloning and sequencing resulted in 290 minicircle sequences from both active lesions and scars. We aimed to get a compositional profile of these sequences in clinical samples and evaluate the corresponding compositional changes. Sequences were analyzed with the compseq and wordcount (Emboss package) to get the composition of di-, tri-, tetra-, penta- and hexanucleotides. Additionally, we built a nucleotide dictionary with words of 7, 8, 9 and 10 nucleotides. Results This compositional analysis showed that minicircles amplified from active cutaneous lesions and scars have a distinct compositional profile as viewed by nucleotide composition of words up to 10mer. With regard to the most frequent nucleotide words above length 6, there is also a distinct pattern for 7, 8, 9 and 10mer. Conclusion These results indicate that minicircle sequences can be monitored upon direct exposure to a selection/stressing environment (e.g. chemical action) by evaluating their nucleotide compositional profile. It might be useful as a molecular tool in research concerning the evolution of infecting Leishmania in both vector and vertebrate hosts.
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Real-time PCR assay for detection and quantification of Leishmania (Viannia) organisms in skin and mucosal lesions: exploratory study of parasite load and clinical parameters. J Clin Microbiol 2013; 51:1826-33. [PMID: 23554201 DOI: 10.1128/jcm.00208-13] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Earlier histopathology studies suggest that parasite loads may differ between cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML) lesions and between acute and chronic CL. Formal demonstration requires highly sensitive detection and accurate quantification of Leishmania in human lesional tissue. In this study, we developed a quantitative real-time PCR (qPCR) assay targeting minicircle kinetoplast DNA (kDNA) to detect and quantify Leishmania (Viannia) parasites. We evaluated a total of 156 lesion biopsy specimens from CL or ML suspected cases and compared the quantitative performance of our kDNA qPCR assay with that of a previously validated qPCR assay based on the glucose-6-phosphate dehydrogenase (G6PD) gene. We also examined the relationship between parasite load and clinical parameters. The kDNA qPCR sensitivity for Leishmania detection was 97.9%, and its specificity was 87.5%. The parasite loads quantified by kDNA qPCR and G6PD qPCR assays were highly correlated (r = 0.87; P < 0.0001), but the former showed higher sensitivity (P = 0.000). CL lesions had 10-fold-higher parasite loads than ML lesions (P = 0.009). Among CL patients, the parasite load was inversely correlated with disease duration (P = 0.004), but there was no difference in parasite load according to the parasite species, the patient's age, and number or area of lesions. Our findings confirm that CL and recent onset of disease (<3 months) are associated with a high parasite load. Our kDNA qPCR assay proved highly sensitive and accurate for the detection and quantification of Leishmania (Viannia) spp. in lesion biopsy specimens. It has potential application as a diagnostic and follow-up tool in American tegumentary leishmaniasis.
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Cruz I, Millet A, Carrillo E, Chenik M, Salotra P, Verma S, Veland N, Jara M, Adaui V, Castrillón C, Arévalo J, Moreno J, Cañavate C. An approach for interlaboratory comparison of conventional and real-time PCR assays for diagnosis of human leishmaniasis. Exp Parasitol 2013; 134:281-9. [PMID: 23562705 DOI: 10.1016/j.exppara.2013.03.026] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 02/12/2013] [Accepted: 03/04/2013] [Indexed: 11/19/2022]
Abstract
Protozoa of the Leishmania genus are transmitted to humans by the bite of infected sandflies, and are the causative agents of leishmaniasis which ranges from cutaneous to visceral clinical forms. The definitive diagnosis of leishmaniasis has relied traditionally on parasite demonstration, either by microscopy or culture; in the last years, diagnosis based on PCR methods has overcome some drawbacks of traditional methods, increasing sensitivity and allowing using less invasive sampling for diagnosis. However, there are not defined protocols and almost each laboratory applies its own in-house method. Although there are several studies comparing the performance of different methods within the same laboratory, those addressing interlaboratory comparison are scarce, in spite of the growing number of collaborative projects between partners from different leishmaniasis endemic and non-endemic countries. In this work we propose a protocol for interlaboratory comparison of conventional and real-time PCR methods involving four participant laboratories from four different endemic regions in four continents; the protocol includes a quality control step and reduces the variability among the samples tested by each participant. A panel of 77 samples from human origin and 9 from different parasite strains was blindly tested by the participants, aiming to assess the sensitivity of the different methods as well as their usefulness for species identification. Real-time PCR methods targeting the kDNA minicircles returned the highest sensitivity, while both PCR targeting ITS-1 and further HaeIII digestion and a combined algorithm including hsp70 PCR and restriction fragment length polymorphism analysis were the most appropriate approaches for species identification.
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Affiliation(s)
- Israel Cruz
- WHO Collaborating Center for Leishmaniasis, Servicio de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra. Majadahonda-Pozuelo, Km2, 28220 Madrid, Spain.
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Tsukayama P, Núñez JH, De Los Santos M, Soberón V, Lucas CM, Matlashewski G, Llanos-Cuentas A, Ore M, Baldeviano GC, Edgel KA, Lescano AG, Graf PCF, Bacon DJ. A FRET-based real-time PCR assay to identify the main causal agents of New World tegumentary leishmaniasis. PLoS Negl Trop Dis 2013; 7:e1956. [PMID: 23301111 PMCID: PMC3536805 DOI: 10.1371/journal.pntd.0001956] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 10/28/2012] [Indexed: 11/19/2022] Open
Abstract
In South America, various species of Leishmania are endemic and cause New World tegumentary leishmaniasis (NWTL). The correct identification of these species is critical for adequate clinical management and surveillance activities. We developed a real-time polymerase chain reaction (PCR) assay and evaluated its diagnostic performance using 64 archived parasite isolates and 192 prospectively identified samples collected from individuals with suspected leishmaniasis enrolled at two reference clinics in Lima, Peru. The real-time PCR assay was able to detect a single parasite and provided unambiguous melting peaks for five Leishmania species of the Viannia subgenus that are highly prevalent in South America: L. (V.) braziliensis, L. (V.) panamensis, L. (V.) guyanensis, L. (V.) peruviana and L. (V.) lainsoni. Using kinetoplastid DNA-based PCR as a gold standard, the real-time PCR had sensitivity and specificity values of 92% and 77%, respectively, which were significantly higher than those of conventional tests such as microscopy, culture and the leishmanin skin test (LST). In addition, the real-time PCR identified 147 different clinical samples at the species level, providing an overall agreement of 100% when compared to multilocus sequence typing (MLST) data performed on a subset of these samples. Furthermore, the real-time PCR was three times faster and five times less expensive when compared to PCR - MLST for species identification from clinical specimens. In summary, this new assay represents a cost-effective and reliable alternative for the identification of the main species causing NWTL in South America. Leishmaniasis is a neglected disease with more than two million new human infections annually worldwide. Tegumentary leishmaniasis, cutaneous and mucocutaneous, is mainly caused by five Leishmania species of the Viannia complex in South America. Different species can cause disease with similar symptoms but have dissimilar prognoses and may need different therapeutic regimens. Identification of Leishmania species traditionally relies on the multilocus enzyme electrophoresis (MLEE) assay, but it can only be applied to culture-positive samples and takes at least six weeks of intense laboratory work. A reliable and rapid assay for species identification can be a valuable tool. Molecular assays are the fastest and most accurate way to identify the etiological agents causing leishmaniasis. This paper describes a novel real-time PCR assay for identification of the five main species that cause tegumentary leishmaniasis in the New World. The assay correctly identified each of these five species of Leishmania directly from clinical samples. Because of its reliability, speed and simplicity, this assay could be used for species identification in routine laboratory diagnosis of leishmaniasis in endemic regions.
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Affiliation(s)
- Pablo Tsukayama
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Jorge H. Núñez
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Maxy De Los Santos
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Valeria Soberón
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Carmen M. Lucas
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Greg Matlashewski
- Department of Microbiology and Immunology, McGill University, Quebec, Canada
| | - Alejandro Llanos-Cuentas
- Leishmaniasis Working Group, Instituto de Medicina Tropical ‘Alexander von Humboldt’, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | | | - Kimberly A. Edgel
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Andres G. Lescano
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
- * E-mail:
| | - Paul C. F. Graf
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
- Microbiology, Immunology, and Molecular Diagnostics Laboratory Department, Naval Medical Center San Diego, San Diego, California, United States of America
| | - David J. Bacon
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
- Naval Research Laboratory, Washington, D.C., United States of America
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Requena JM, Chicharro C, García L, Parrado R, Puerta CJ, Cañavate C. Sequence analysis of the 3'-untranslated region of HSP70 (type I) genes in the genus Leishmania: its usefulness as a molecular marker for species identification. Parasit Vectors 2012; 5:87. [PMID: 22541251 PMCID: PMC3425316 DOI: 10.1186/1756-3305-5-87] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 04/08/2012] [Indexed: 12/18/2022] Open
Abstract
Background The Leishmaniases are a group of clinically diverse diseases caused by parasites of the genus Leishmania. To distinguish between species is crucial for correct diagnosis and prognosis as well as for treatment decisions. Recently, sequencing of the HSP70 coding region has been applied in phylogenetic studies and for identifying of Leishmania species with excellent results. Methods In the present study, we analyzed the 3’-untranslated region (UTR) of Leishmania HSP70-type I gene from 24 strains representing eleven Leishmania species in the belief that this non-coding region would have a better discriminatory capacity for species typing than coding regions. Results It was observed that there was a remarkable degree of sequence conservation in this region, even between species of the subgenus Leishmania and Viannia. In addition, the presence of many microsatellites was a common feature of the 3´-UTR of HSP70-I genes in the Leishmania genus. Finally, we constructed dendrograms based on global sequence alignments of the analyzed Leishmania species and strains, the results indicated that this particular region of HSP70 genes might be useful for species (or species complex) typing, improving for particular species the discrimination capacity of phylogenetic trees based on HSP70 coding sequences. Given the large size variation of the analyzed region between the Leishmania and Viannia subgenera, direct visualization of the PCR amplification product would allow discrimination between subgenera, and a HaeIII-PCR-RFLP analysis might be used for differentiating some species within each subgenera. Conclusions Sequence and phylogenetic analyses indicated that this region, which is readily amplified using a single pair of primers from both Old and New World Leishmania species, might be useful as a molecular marker for species discrimination.
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Affiliation(s)
- Jose M Requena
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autonoma de Madrid, 28049 Madrid, Spain.
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Bravo N, Muñoz C, Nazal N, Saavedra M, Martínez G, Araya E, Apt W, Zulantay I. Real-Time PCR in faecal samples of Triatoma infestans obtained by xenodiagnosis: proposal for an exogenous internal control. Parasit Vectors 2012; 5:59. [PMID: 22448961 PMCID: PMC3348007 DOI: 10.1186/1756-3305-5-59] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 03/26/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The polymerase chain reaction (PCR) has proved to be a sensitive technique to detect Trypanosoma cruzi in the chronic phase of Chagas disease, which is characterized by low and fluctuating parasitemia. Another technique proposed for parasitological diagnosis in this phase of infection combines a microscopic search for motile trypomastigote forms in faecal samples (FS) obtained by xenodiagnosis (XD) with conventional PCR (XD-PCR). In this study we evaluate the use of human blood DNA as an exogenous internal control (EIC) for real time PCR (qPCR) combined with XD (XD-qPCR) using chromosome 12 (X12) detection. FINDINGS None of the FS-XD evaluated by qPCR amplified for X12. Nevertheless, all the EIC-FS-XD mixtures amplified for X12. CONCLUSIONS We determined that X12 is useful as an EIC for XD-qPCR because we showed that the FS-XD does not contain human DNA after 30 or more days of XD incubation. This information is relevant for research on T. cruzi by XD-qPCR since it allows ruling out inhibition and false negative results due to DNA loss during the process of extraction and purification.
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Affiliation(s)
- Nicolás Bravo
- Faculty of Medicine, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
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