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Kumar S, Prichard RK, Long T. Droplet digital PCR as a tool to detect resistant isolates of Dirofilaria immitis. Int J Parasitol Drugs Drug Resist 2023; 23:10-18. [PMID: 37540993 PMCID: PMC10407818 DOI: 10.1016/j.ijpddr.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 07/14/2023] [Accepted: 07/16/2023] [Indexed: 08/06/2023]
Abstract
Prevention of canine heartworm disease, caused by Dirofilaria immitis, relies on macrocyclic lactones for which drug resistance is now a concern. Although genetic polymorphisms have been associated with resistance in D. immitis populations, the mechanism is still not well understood. The lack of reliable in vitro assays to detect resistance is a limitation for confirming resistance. Ten single nucleotide polymorphisms (SNPs) were previously clinically validated in D. immitis resistant isolates, using the MiSeq platform. This technique although useful for research studies is expensive and does not facilitate rapid detection of these markers in small numbers of clinical samples. We developed a droplet digital PCR protocol for detecting SNPs correlating with ML resistance. Specific primers and hydrolysis probes encompassing the wildtype and mutant alleles were designed to amplify the SNP targets from genomic DNA of different D. immitis isolates. Allele frequencies were determined and the suitability of the ddPCR assay was assessed and compared with MiSeq data. The ddPCR assay accurately detected and quantified alternate nucleotides in two isolates of reference, the ML-susceptible Missouri (MO) and ML-resistant JYD-34, at the previously identified SNP positions. The presence of the SNPs was also determined in additional isolates with known or putative susceptible or resistant phenotypes. We observed SNP1 and SNP2 are more predictive markers and appear suitable for rapid detection and monitoring of drug resistance. Our results suggested that ddPCR could be employed to distinguish infection due to actual genetic resistance from infection with susceptible parasites and also for rapid detection of isolates not only with ML susceptible and resistant genotypes but also mixed genotypes that correspond to heterogeneous isolates containing a mixed population of ML susceptible and resistant parasites. DdPCR may be a useful tool for conducting surveys, or assessments of individual isolates, for genetic evidence of resistance or developing resistance.
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Affiliation(s)
- Sohini Kumar
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, H9X3V9, QC, Canada
| | - Roger K Prichard
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, H9X3V9, QC, Canada
| | - Thavy Long
- Institute of Parasitology, McGill University, 21111 Lakeshore Road, Sainte-Anne-de-Bellevue, H9X3V9, QC, Canada.
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Molecular diagnostics for gastrointestinal helminths in equids: Past, present and future. Vet Parasitol 2023; 313:109851. [PMID: 36521296 DOI: 10.1016/j.vetpar.2022.109851] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022]
Abstract
This review is aimed to (i) appraise the literature on the use of molecular techniques for the detection, quantification and differentiation of gastrointestinal helminths (GIH) of equids, (ii) identify the knowledge gaps and, (iii) discuss diagnostic prospects in equine parasitology. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, we retrieved 54 studies (horses: 50/54; donkeys and zebras: 4/54) from four databases. Polymerase chain reaction (PCR) was employed in all of the studies whereas PCR amplicons were sequenced in only 18 of them. Other techniques used (including modifications of PCR) were reverse line blot, quantitative (q)PCR, restriction fragment length polymorphism, nested-PCR, PCR-directed next-generation sequencing, Southern blotting, single strand conformation polymorphism, PCR-enzyme linked immunosorbent assay, matrix-assisted laser desorption/ionisation-time of flight and random amplification of polymorphic DNA. Most of the studies (53/54) used nuclear ribosomal RNA (including the internal transcribed spacers, intergenic spacer, 5.8 S, 18 S, 28 S and 12 S) as target loci while cytochrome c oxidase subunit 1 and random genomic regions were targeted in only three and one studies, respectively. Overall, to date, the majority of molecular studies have focused on the diagnosis and identification of GIHs of equids (i.e. species of Anoplocephala, Craterostomum, cyathostomins, Oesophagodontus, Parascaris, Strongylus, Strongyloides and Triodontophorus), with a recent shift towards investigations on anthelmintic resistance and the use of high-throughput nemabiome metabarcoding. With the increasing reports of anthelmintic resistance in equid GIHs, it is crucial to develop and apply techniques such as advanced metabarcoding for surveillance of parasite populations in order to gain detailed insights into their diversity and sustainable control. To the best of our knowledge, this is the first systematic review that evaluates molecular investigations published on the diagnosis and quantification of equid GIHs and provides useful insights into important knowledge gaps and future research directions in equid molecular parasitology.
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Nascimento RC, Melo GB, Fonseca PDM, Gryschek RCB, Paula FM. Evaluation of targets for Strongyloides genus specific molecular diagnosis in experimental strongyloidiasis. Exp Parasitol 2021; 230:108157. [PMID: 34543651 DOI: 10.1016/j.exppara.2021.108157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 11/18/2022]
Abstract
Strongyloides venezuelensis has been used in different experimental studies, such as those aimed at the evaluation of diagnostic techniques for human strongyloidiasis, mainly the molecular diagnosis. In this study, three regions (genus, 18S and 28S targets) of Strongyloides ribosomal DNA were evaluated for the molecular diagnosis of experimental strongyloidiasis. Rats were infected subcutaneously with 400 or 4000 S. venezuelensis infective larvae (400iL3 and 4000iL3), and kept for 35 days. Fecal samples were collected daily to count eggs per gram of feces (EPG) and to perform the polymerase chain reaction (PCR). Egg count started on the 5th day post-infection (pi) and ended on days 33 and 34 pi, in 400iL3 and 4000iL3 groups, respectively. Based in EPG, fecal samples were selected from days 2, 5, 8, 11, 15, 23 and 35 pi for DNA extraction; PCR (genus, 18S and 28S); and sequencing. The PCR-28S products showed higher values of identity (95-100%) in the database with the Strongyloides sequences. Therefore, it is possible to reinforce the application of PCR-28S in the diagnosis of experimental and human strongyloidiasis.
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Affiliation(s)
- Rafael C Nascimento
- Laboratório de Investigação Médica (LIM-06) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil; Instituto de Medicina Tropical, Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - Gessica B Melo
- Laboratório de Investigação Médica (LIM-06) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil; Instituto de Medicina Tropical, Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - Priscilla D M Fonseca
- Laboratório de Investigação Médica (LIM-06) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil; Instituto de Medicina Tropical, Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - Ronaldo C B Gryschek
- Laboratório de Investigação Médica (LIM-06) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil; Instituto de Medicina Tropical, Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - F M Paula
- Laboratório de Investigação Médica (LIM-06) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Brazil; Instituto de Medicina Tropical, Faculdade de Medicina da Universidade de São Paulo, Brazil.
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4
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Tabraue-Chávez M, Luque-González MA, Marín-Romero A, Sánchez-Martín RM, Escobedo-Araque P, Pernagallo S, Díaz-Mochón JJ. A colorimetric strategy based on dynamic chemistry for direct detection of Trypanosomatid species. Sci Rep 2019; 9:3696. [PMID: 30842455 PMCID: PMC6403333 DOI: 10.1038/s41598-019-39946-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 01/29/2019] [Indexed: 11/15/2022] Open
Abstract
Leishmaniasis and Chagas disease are endemic in many countries, and re-emerging in the developed countries. A rapid and accurate diagnosis is important for early treatment for reducing the duration of infection as well as for preventing further potential health complications. In this work, we have developed a novel colorimetric molecular assay that integrates nucleic acid analysis by dynamic chemistry (ChemNAT) with reverse dot-blot hybridization in an array format for a rapid and easy discrimination of Leishmania major and Trypanosoma cruzi. The assay consists of a singleplex PCR step that amplifies a highly homologous DNA sequence which encodes for the RNA component of the large ribosome subunit. The amplicons of the two different parasites differ between them by single nucleotide variations, known as “Single Nucleotide Fingerprint” (SNF) markers. The SNF markers can be easily identified by naked eye using a novel micro Spin-Tube device "Spin-Tube", as each of them creates a specific spot pattern. Moreover, the direct use of ribosomal RNA without requiring the PCR pre-amplification step is also feasible, further increasing the simplicity of the assay. The molecular assay delivers sensitivity capable of identifying up to 8.7 copies per µL with single mismatch specificity. The Spin-Tube thus represents an innovative solution providing benefits in terms of time, cost, and simplicity, all of which are crucial for the diagnosis of infectious disease in developing countries.
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Affiliation(s)
- Mavys Tabraue-Chávez
- DestiNA Genomica S.L. Parque Tecnológico Ciencias de la Salud (PTS), Avenida de la Innovación 1, Edificio BIC, 18016, Armilla, Granada, Spain
| | - María Angélica Luque-González
- GENYO Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government. PTS Granada - Avenida de la Ilustración, 114- 18016, Granada, Spain.,Department Medicinal and Organic Chemistry, School of Pharmacy, University of Granada, Campus Cartuja s/n, 18071, Granada, Spain
| | - Antonio Marín-Romero
- DestiNA Genomica S.L. Parque Tecnológico Ciencias de la Salud (PTS), Avenida de la Innovación 1, Edificio BIC, 18016, Armilla, Granada, Spain.,GENYO Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government. PTS Granada - Avenida de la Ilustración, 114- 18016, Granada, Spain.,Department Medicinal and Organic Chemistry, School of Pharmacy, University of Granada, Campus Cartuja s/n, 18071, Granada, Spain
| | - Rosario María Sánchez-Martín
- GENYO Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government. PTS Granada - Avenida de la Ilustración, 114- 18016, Granada, Spain.,Department Medicinal and Organic Chemistry, School of Pharmacy, University of Granada, Campus Cartuja s/n, 18071, Granada, Spain
| | - Pablo Escobedo-Araque
- ECsens, CITIC-UGR, Department of Electronics and Computer Technology, University of Granada, Campus Aynadamar, 18071, Granada, Spain
| | - Salvatore Pernagallo
- DestiNA Genomica S.L. Parque Tecnológico Ciencias de la Salud (PTS), Avenida de la Innovación 1, Edificio BIC, 18016, Armilla, Granada, Spain. .,DestiNA Genomics Ltd., 7-11 Melville St, Edinburgh, EH3 7PE, United Kingdom.
| | - Juan José Díaz-Mochón
- DestiNA Genomica S.L. Parque Tecnológico Ciencias de la Salud (PTS), Avenida de la Innovación 1, Edificio BIC, 18016, Armilla, Granada, Spain. .,GENYO Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government. PTS Granada - Avenida de la Ilustración, 114- 18016, Granada, Spain. .,Department Medicinal and Organic Chemistry, School of Pharmacy, University of Granada, Campus Cartuja s/n, 18071, Granada, Spain.
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Ma Q, Yao J, Yuan S, Liu H, Wei N, Zhang J, Shan W. Development of a lateral flow recombinase polymerase amplification assay for rapid and visual detection of Cryptococcus neoformans/C. gattii in cerebral spinal fluid. BMC Infect Dis 2019; 19:108. [PMID: 30717679 PMCID: PMC6360735 DOI: 10.1186/s12879-019-3744-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/25/2019] [Indexed: 12/21/2022] Open
Abstract
Background For definitive diagnosis of cryptococcal meningitis, Cryptococcus neoformans and/or C. gattii must be identified within cerebral spinal fluid from the patients. The traditional methods for detecting Cryptococcus spp. such as India ink staining and culture are not ideal. Although sensitive and specific enough, detection of cryptococcal antigen polysaccharide has a high dose hook effect. Therefore, the aim of this study was to introduce a new rapid and simple detection method of Cryptococcus neoformans and C. gattii in cerebral spinal fluid. Methods The lateral flow strips combined with recombinase polymerase amplification (LF-RPA) assay was constructed to detect the specific DNA sequences of C. neoformans and C. gattii. The detection limit was evaluated using serial dilutions of C. neoformans and C. gattii genomic DNA. The specificity was assessed by excessive amount of other pathogens genomic DNA. The optimal detection time and amplification temperature were also analyzed. The diagnostic parameters were first calculated using 114 clinical specimens and then compared with that of other diagnostic method. A brief analysis and comparison of different DNA extraction methods was discussed, too. Results The LF-RPA assay could detect 0.64 pg of genomic DNA of C. neoformans per reaction within 10 min and was highly specific for Cryptococcus spp.. The system could work well at a wide range of temperature from 25 to 45 °C. The overall sensitivity and specificity were 95.2 and 95.8% respectively. As amplification template for LF-RPA assay, both cell lysates and genomic DNA produce similar experimental results. Conclusions The LF-RPA system described here is shown to be a sensitive and specific method for the visible, rapid, and accurate detection of Cryptococcus spp. in cerebral spinal fluid and might be useful for clinical preliminary screening of cryptococcal meningitis.
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Affiliation(s)
- Qinglin Ma
- Institute of Maternity and Child Medical Research, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, No.2004 Hongli Road, Shenzhen, 518028, Guangdong, China.,Clinical Laboratory, Shenzhen Third People's Hospital, No.29 Bulan Road, Shenzhen, 518112, Guangdong, China
| | - Jilong Yao
- Institute of Maternity and Child Medical Research, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, No.2004 Hongli Road, Shenzhen, 518028, Guangdong, China
| | - Shixin Yuan
- Institute of Maternity and Child Medical Research, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, No.2004 Hongli Road, Shenzhen, 518028, Guangdong, China
| | - Houming Liu
- Clinical Laboratory, Shenzhen Third People's Hospital, No.29 Bulan Road, Shenzhen, 518112, Guangdong, China
| | - Ning Wei
- Personnel Section, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, No.2004 Hongli Road, Shenzhen, 518028, Guangdong, China.
| | - Jianming Zhang
- Institute of Maternity and Child Medical Research, Shenzhen Maternity and Child Healthcare Hospital, Southern Medical University, No.2004 Hongli Road, Shenzhen, 518028, Guangdong, China.
| | - Wanshui Shan
- Clinical Laboratory, Shenzhen Third People's Hospital, No.29 Bulan Road, Shenzhen, 518112, Guangdong, China.
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Vidal JE. HIV-Related Cerebral Toxoplasmosis Revisited: Current Concepts and Controversies of an Old Disease. J Int Assoc Provid AIDS Care 2019; 18:2325958219867315. [PMID: 31429353 PMCID: PMC6900575 DOI: 10.1177/2325958219867315] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/14/2019] [Accepted: 06/28/2019] [Indexed: 01/06/2023] Open
Abstract
Cerebral toxoplasmosis is the most common cause of expansive brain lesions in people living with HIV/AIDS (PLWHA) and continues to cause high morbidity and mortality. The most frequent characteristics are focal subacute neurological deficits and ring-enhancing brain lesions in the basal ganglia, but the spectrum of clinical and neuroradiological manifestations is broad. Early initiation of antitoxoplasma therapy is an important feature of the diagnostic approach of expansive brain lesions in PLWHA. Pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) seem to present similar efficacy, but TMP-SMX shows potential practical advantages. The immune reconstitution inflammatory syndrome is uncommon in cerebral toxoplasmosis, and we now have more effective, safe, and friendly combined antiretroviral therapy (cART) options. As a consequence of these 2 variables, the initiation of cART can be performed within 2 weeks after initiation of antitoxoplasma therapy. Herein, we will review historical and current concepts of epidemiology, diagnosis, and treatment of HIV-related cerebral toxoplasmosis.
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Affiliation(s)
- José Ernesto Vidal
- Departamento de Neurologia, Instituto de Infectologia Emílio Ribas, São
Paulo, Brazil
- Departamento de Moléstias Infecciosas e Parasitárias, Hospital das Clínicas
HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
- Laboratório de Investigação Médica em Protozoologia, Bacteriologia e
Resistência Antimicrobiana (LIM 49), Instituto de Medicina Tropical, Universidade de São
Paulo, São Paulo, Brazil
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7
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Evaluation of a new multiplex PCR assay (ParaGENIE G-Amoeba Real-Time PCR kit) targeting Giardia intestinalis, Entamoeba histolytica and Entamoeba dispar/Entamoeba moshkovskii from stool specimens: evidence for the limited performances of microscopy-based approach for amoeba species identification. Clin Microbiol Infect 2018; 24:1205-1209. [DOI: 10.1016/j.cmi.2018.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 02/04/2018] [Accepted: 02/06/2018] [Indexed: 11/19/2022]
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Unraveling cryptic epizootiology of equid trypanosomosis in Punjab state of India by parasitological and sero-molecular techniques. Acta Trop 2018; 185:18-26. [PMID: 29698659 DOI: 10.1016/j.actatropica.2018.04.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/01/2018] [Accepted: 04/16/2018] [Indexed: 12/17/2022]
Abstract
To unravel equid trypanosomosis caused by Trypanosoma evansi in Punjab state of India, a cross sectional study was designed by utilizing parasitological and sero-molecular tools with objective to assess the prevalence of T. evansi in association with various risk factors in all agroclimatic zones of Punjab state of India. Parasitological Romanowksy stained thin blood smears (RSTBS) to detect patent infection, molecular techniques polymerase chain reaction I (PCR I; TBR 1/2 primers; targeting minichromosomal satellite DNA of T. evansi), polymerase chain reaction II (PCR II; TR 3/4 primers; targeting variable surface glycoprotein region DNA of T. evansi) & LAMP (Loop mediated isothermal amplification) assay to detect latent infection and serological assays card agglutination test (CATT/T. evansi) & ELISA (Enzyme linked immunosorbent assay) to detect exposure status of trypanosomosis were utilized in the present study. A total 429 equid blood and serum samples from all the five agroclimatic zones of Punjab state tested by these techniques showed a prevalence of 1.39% (CL: 0-15.28) by RSTBS, 6.52% (10.94-45.09) by both TBR 1/2 PCR and LAMP assay, 5.82% (11.57-38.42) by TR 3/4 PCR, 15.15% (36.57-135.42) with CATT/T. evansi and 22.84% (17.77-840.22) with ELISA. Interpretation of various risk factors revealed that the donkey/mules population (RR = 5.46, 95% [CI] = 0.15-15.56) was found to be at higher risk of T. evansi infection predominantly at 'unorganized' farms (RR = 4.06, 95% [CI] = 0.12-4.51). Animal used for commercial purposes (RR = 3.25, 95% [CI] = 0.06-7.42), rearing of equids with other domestic animals (RR = 2.36, 95% [CI] = 0.10-17.11) and farms without application of fly repellant/insecticides/net (RR = 3.68, 95% [CI] = 0.08-5.94) made them more prone to the disease. This comprehensive report utilizing the classical, serological and molecular diagnostic tools for epidemiology of T. evansi establishes the endemic stability of this infection in all agro climatic zones of Punjab with LAMP assay to be a promisingly sensitive and specific technique for the diagnosis of T. evansi under isothermal conditions in field situations.
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Soliman H, Kumar G, El-Matbouli M. Recombinase polymerase amplification assay combined with a lateral flow dipstick for rapid detection of Tetracapsuloides bryosalmonae, the causative agent of proliferative kidney disease in salmonids. Parasit Vectors 2018; 11:234. [PMID: 29642952 PMCID: PMC5896054 DOI: 10.1186/s13071-018-2825-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/28/2018] [Indexed: 01/28/2023] Open
Abstract
Background The myxozoan Tetracapsuloides bryosalmonae, the causative agent of proliferative kidney disease (PKD), is responsible for considerable losses in farmed and wild fish populations in Europe and North America. Recently, T. bryosalmonae was detected in many European countries, and strategy to control the disease in the wild and farmed fish population is yet to be developed. Recombinase polymerase amplification (RPA) is a novel isothermal nucleic acid amplification technology that does not require any thermal cycling, and lateral flow dipstick (LFD) is a rapid, cost-effective, and easy-to-handle assay that enables stable detection. Results In this study, we developed and optimized a rapid and sensitive RPA assay combined with an LFD for the detection of T. bryosalmonae. The PKD-RPA assay was specific to T. bryosalmonae, as no cross-reaction or false positive signals were observed with any of the other tested DNAs. The developed PKD-RPA assay was ten times more sensitive than an existing diagnostic polymerase chain reaction (PCR) assay for this parasite. The estimated time to perform PKD-RPA assay is 25 min compared to 4 h for PKD-PCR assay. Conclusions A novel PKD-RPA assay for the detection of T. bryosalmonae was developed. The assay offers considerable advantages including speed, sensitivity, specificity and visual detection. Applying the PKD-RPA assay combined with an LFD enhances the surveillance and early detection of T. bryosalmonae in salmonids.
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Affiliation(s)
- Hatem Soliman
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Gokhlesh Kumar
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
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Ortega MV, Moreno I, Domínguez M, de la Cruz ML, Martín AB, Rodríguez-Bertos A, López R, Navarro A, González S, Mazariegos M, Goyache J, Domínguez L, García N. Application of a specific quantitative real-time PCR (qPCR) to identify Leishmania infantum DNA in spleen, skin and hair samples of wild Leporidae. Vet Parasitol 2017; 243:92-99. [DOI: 10.1016/j.vetpar.2017.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/20/2017] [Accepted: 05/19/2017] [Indexed: 12/15/2022]
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11
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Markowitz KN, Williams JD, Krause MK. Development of quantitative PCR assay for detection of the trematode parasite Proctoeces maculatus in the blue mussel Mytilus edulis. DISEASES OF AQUATIC ORGANISMS 2016; 122:125-136. [PMID: 28000603 DOI: 10.3354/dao03072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The digenean trematode Proctoeces maculatus is an important parasite of the blue mussel Mytilus edulis. The parasite reduces mussel quality and yield, negatively impacting mussel aquaculture efforts. Typically, the trematode is detected by visual observation. To provide a better diagnostic tool able to detect this parasite at any life stage and at low intensities, we designed a species-specific molecular assay to detect P. maculatus in M. edulis tissue. Primers targeting the 18S nuclear ribosomal DNA (rDNA) from P. maculatus were used to develop an end-point polymerase chain reaction assay and a quantitative polymerase chain reaction (qPCR) assay. Analytical specificity of the assays was demonstrated using DNA from 4 other digenean trematodes. The qPCR assay was linear from 6.79 × 102 to 6.79 × 107 copies of the cloned target DNA and had a conservative detection limit of 68 copies. The qPCR assay detected single cercariae, and the number of isolated cercariae was linearly correlated with the threshold cycle (CT). Diagnostic sensitivity of the PCR-based methods was 100%. The assays also detected the parasite in 6 additional samples from the 57 tested through microscopy. We used the assays to verify the presence of encapsulated sporocysts in the mantle and to document infected mussels from Dover, New Hampshire, extending the previously described northern range of the species. Thus, this work has important implications for detection of the parasite in aquaculture and in monitoring its potential spread with climate change.
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Affiliation(s)
- Kelly N Markowitz
- Department of Biology, Hofstra University, Hempstead, NY 11549-1140, USA
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McCarthy MW, Walsh TJ. PCR methodology and applications for the detection of human fungal pathogens. Expert Rev Mol Diagn 2016; 16:1025-36. [PMID: 27484841 DOI: 10.1080/14737159.2016.1219253] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Polymerase chain reaction (PCR) has emerged as a promising technology for the rapid and reliable detection and identification of medical mycoses. Recent technological advancements - including microarray, multiplex PCR with magnetic resonance, and beacon probes - have mitigated the technical difficulties of performing nucleic amplification in fungi, thereby improving the sensitivity and specificity of PCR-based assays. In this paper, we examine current applications of PCR in the diagnosis of human fungal infections and look ahead to emerging techniques that may play a larger role in molecular diagnostics in the future. AREAS COVERED This review includes a brief overview of the advantages and disadvantages of PCR using various clinical specimens, manual versus automated DNA extraction procedures, panfungal versus specific targets, and spectrum of pathogens detected. This is followed by a brief synopsis of species-specific PCR approaches and a more in-depth look at the obstacles to widespread implementation. Expert commentary: The review concludes with a short perspective for the next five years, including the hurdles to standardization and validation, as well as the role of PCR coupled with electrospray-ionization mass spectrometry (PCR/ESI-MS) or nuclear magnetic resonance for the diagnosis of medical mycoses.
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Affiliation(s)
- Matthew William McCarthy
- a Hospital Medicine , Joan and Sanford I Weill Medical College of Cornell University Ringgold Standard Institution , New York , NY , USA
| | - Thomas J Walsh
- b Transplantation-Oncology Infectious Diseases Program , Weill Cornell Medical Center , New York , NY , USA
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13
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Molecular testing for clinical diagnosis and epidemiological investigations of intestinal parasitic infections. Clin Microbiol Rev 2016; 27:371-418. [PMID: 24696439 DOI: 10.1128/cmr.00122-13] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Over the past few decades, nucleic acid-based methods have been developed for the diagnosis of intestinal parasitic infections. Advantages of nucleic acid-based methods are numerous; typically, these include increased sensitivity and specificity and simpler standardization of diagnostic procedures. DNA samples can also be stored and used for genetic characterization and molecular typing, providing a valuable tool for surveys and surveillance studies. A variety of technologies have been applied, and some specific and general pitfalls and limitations have been identified. This review provides an overview of the multitude of methods that have been reported for the detection of intestinal parasites and offers some guidance in applying these methods in the clinical laboratory and in epidemiological studies.
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Gashout A, Amro A, Erhuma M, Al-Dwibe H, Elmaihub E, Babba H, Nattah N, Abudher A. Molecular diagnosis of Toxoplasma gondii infection in Libya. BMC Infect Dis 2016; 16:157. [PMID: 27083153 PMCID: PMC4833959 DOI: 10.1186/s12879-016-1491-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 03/31/2016] [Indexed: 11/19/2022] Open
Abstract
Background Toxoplasma gondii infections are prevalent in humans and animals throughout Libya. Current diagnosis is based on detection of Toxoplasma-specific IgM and IgG. In this study, we established and optimized a diagnostic PCR assay for molecular diagnosis of T. gondii in Libya. Methods From January to December, 2010, 177 blood and serum samples were collected from suspected patients. This includes: 140 women who have had spontaneous abortions, 26 HIV-positive patients, nine patients with leukemia and lymphoma, and two infants with ocular infection. Samples were screened for anti-Toxoplasma IgG and IgM antibodies before DNA extraction. The surface antigen gene 2 (SAG2) was targeted in a semi-nested PCR to amplify a 999 bp and a 614 bp fragment in the first and the second run respectively. Results A total of 54/140 (38.5 %) women who have had spontaneous abortions, 23/26 (88 %) HIV patients, 6/9 (66.6 %) of the leukaemia and lymphoma patients, and one child with ocular infection were seropositive for anti-Toxoplasma IgG and/or IgM. Genomic DNA was extracted from 38 selected seropositive samples. The PCR was sensitive enough to detect DNA concentration of 12 ng/μL. PCR analysis was performed for 38 selected seropositive patients (16 women who have had spontaneous abortions, 15 positive HIV patients, six leukaemia patients and one child with ocular infection). Our designed primers were successfully amplified in 22/38 (57.9 %) samples; 5/12 (35.7 %) from serum and 17/26 (65.8 %) from whole blood samples. All PCR positive samples were IgG-positive except two samples which were IgM and IgG & IgM-positive serum samples respectively. The semi-nested PCR confirmed five more samples. These included two leukaemia and two HIV-positive whole blood samples and one serum sample from an aborted woman. Conclusion The ability of PCR to diagnose active toxoplasmosis is needed in immunocompromised patients and congenital toxoplasmosis cases, especially when serological techniques fail. For the first time in Libya, we established and optimized semi-nested PCR of SAG2 gene. The developed PCR method was able to detect as little as 12 ng/μL of T. gondii DNA and was useful to diagnose the diseases in women who have had spontaneous abortions, HIV-positive patients, patients with leukemia and lymphoma, and infants with ocular infection.
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Affiliation(s)
- Aisha Gashout
- Faculty of Medical Technology Pathology Department, University of Tripoli, Tripoli, Libya
| | - Ahmad Amro
- Faculty of Pharmacy, Al-Quds University, Main Campus, Abu Dis, P.O. Box 5100, Jerusalem, Palestine.
| | - Mabruk Erhuma
- Medical Laboratory Department, Immunology Unit, Tripoli Central Hospital, Tripoli, Libya
| | - Hamida Al-Dwibe
- Faculty of Medicine, Dermatology Department, University of Tripoli, Tripoli, Libya
| | - Eanas Elmaihub
- Scientific College - Sabrata, Zoology Department, University of Zawia, Zawia, Libya
| | - Hamouda Babba
- Laboratoire de Parasitologie-Mycologie à la Faculté de Pharmacie, Monastir, Tunisia
| | - Nabil Nattah
- Genetic Laboratory at Bio- technologies Researches Centre, Tripoli, Libya
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de la Escosura-Muñiz A, Baptista-Pires L, Serrano L, Altet L, Francino O, Sánchez A, Merkoçi A. Magnetic Bead/Gold Nanoparticle Double-Labeled Primers for Electrochemical Detection of Isothermal Amplified Leishmania DNA. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:205-213. [PMID: 26578391 DOI: 10.1002/smll.201502350] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 09/26/2015] [Indexed: 06/05/2023]
Abstract
A novel methodology for the isothermal amplification of Leishmania DNA using labeled primers combined with the advantages of magnetic purification/preconcentration and the use of gold nanoparticle (AuNP) tags for the sensitive electrochemical detection of such amplified DNA is developed. Primers labeled with AuNPs and magnetic beads (MBs) are used for the first time for the isothermal amplification reaction, being the amplified product ready for the electrochemical detection. The electrocatalytic activity of the AuNP tags toward the hydrogen evolution reaction allows the rapid quantification of the DNA on screen-printed carbon electrodes. Amplified products from the blood of dogs with Leishmania (positive samples) are discriminated from those of healthy dogs (blank samples). Quantitative studies demonstrate that the optimized method allows us to detect less than one parasite per microliter of blood (8 × 10(-3) parasites in the isothermal amplification reaction). This pioneering approach is much more sensitive than traditional methods based on real-time polymerase chain reaction (PCR), and is also more rapid, cheap, and user-friendly.
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Affiliation(s)
- Alfredo de la Escosura-Muñiz
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and Barcelona Institute of Science and Technology, Campus UAB, 08193, Barcelona, Spain
| | - Luis Baptista-Pires
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and Barcelona Institute of Science and Technology, Campus UAB, 08193, Barcelona, Spain
| | - Lorena Serrano
- Vetgenomics, Edifici Eureka, Parc de Recerca UAB, 08193, Bellaterra (Barcelona), Spain
| | - Laura Altet
- Vetgenomics, Edifici Eureka, Parc de Recerca UAB, 08193, Bellaterra (Barcelona), Spain
| | - Olga Francino
- Vetgenomics, Edifici Eureka, Parc de Recerca UAB, 08193, Bellaterra (Barcelona), Spain
- Department of Animal and Food Science, Autonomous University of Barcelona, Campus UAB, 08193, Bellaterra (Barcelona), Spain
| | - Armand Sánchez
- Department of Animal and Food Science, Autonomous University of Barcelona, Campus UAB, 08193, Bellaterra (Barcelona), Spain
- Centre for Research in Agricultural Genomics-CSIC-IRTA-UAB-UB, Campus UAB, 08193, Cerdanyola del Valles, Catalonia, Spain
| | - Arben Merkoçi
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and Barcelona Institute of Science and Technology, Campus UAB, 08193, Barcelona, Spain
- ICREA-Institucio Catalana de Recerca i Estudis Avançats, 08010, Barcelona, Spain
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Mousavi MZ, Chen HY, Lee KL, Lin H, Chen HH, Lin YF, Wong CS, Li HF, Wei PK, Cheng JY. Urinary micro-RNA biomarker detection using capped gold nanoslit SPR in a microfluidic chip. Analyst 2015; 140:4097-104. [DOI: 10.1039/c5an00145e] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Diagnosis of acute kidney injury by detecting urinary miRNA using capped gold nanoslit SPR in a microfluidic chip.
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Affiliation(s)
| | - Huai-Yi Chen
- Research Center for Applied Sciences
- Academia Sinica
- Taiwan
- Department of Engineering and System Science
- National Tsing Hua University
| | - Kuang-Li Lee
- Research Center for Applied Sciences
- Academia Sinica
- Taiwan
- Institute of Physics
- Academia Sinica
| | - Heng Lin
- Department of Physiology
- School of Medicine
- College of Medicine
- Taipei Medical University
- Taipei
| | - Hsi-Hsien Chen
- Department of Internal Medicine
- School of Medicine
- College of Medicine
- Taipei Medical University
- Taipei
| | - Yuh-Feng Lin
- Department of Internal Medicine
- School of Medicine
- College of Medicine
- Taipei Medical University
- Taipei
| | - Chung-Shun Wong
- Graduate Institute of Clinical Medicine
- College of Medicine
- Taipei Medical University
- Taiwan
- Department of Emergency Medicine
| | - Hsiao Fen Li
- Department of Physiology
- School of Medicine
- College of Medicine
- Taipei Medical University
- Taipei
| | - Pei-Kuen Wei
- Research Center for Applied Sciences
- Academia Sinica
- Taiwan
| | - Ji-Yen Cheng
- Research Center for Applied Sciences
- Academia Sinica
- Taiwan
- Nano Science and Technology Program
- Taiwan International Graduate Program
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Chakraborty S, Kumar A, Tiwari R, Rahal A, Malik Y, Dhama K, Pal A, Prasad M. Advances in diagnosis of respiratory diseases of small ruminants. Vet Med Int 2014; 2014:508304. [PMID: 25028620 PMCID: PMC4082846 DOI: 10.1155/2014/508304] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 05/01/2014] [Indexed: 01/11/2023] Open
Abstract
Irrespective of aetiology, infectious respiratory diseases of sheep and goats contribute to 5.6 percent of the total diseases of small ruminants. These infectious respiratory disorders are divided into two groups: the diseases of upper respiratory tract, namely, nasal myiasis and enzootic nasal tumors, and diseases of lower respiratory tract, namely, peste des petits ruminants (PPR), parainfluenza, Pasteurellosis, Ovine progressive pneumonia, mycoplasmosis, caprine arthritis encephalitis virus, caseous lymphadenitis, verminous pneumonia, and many others. Depending upon aetiology, many of them are acute and fatal in nature. Early, rapid, and specific diagnosis of such diseases holds great importance to reduce the losses. The advanced enzyme-linked immunosorbent assays (ELISAs) for the detection of antigen as well as antibodies directly from the samples and molecular diagnostic assays along with microsatellites comprehensively assist in diagnosis as well as treatment and epidemiological studies. The present review discusses the advancements made in the diagnosis of common infectious respiratory diseases of sheep and goats. It would update the knowledge and help in adapting and implementing appropriate, timely, and confirmatory diagnostic procedures. Moreover, it would assist in designing appropriate prevention protocols and devising suitable control strategies to overcome respiratory diseases and alleviate the economic losses.
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Affiliation(s)
- Sandip Chakraborty
- Animal Resources Development Department, Pt. Nehru Complex, Agartala 799006, India
| | - Amit Kumar
- Department of Veterinary Microbiology, College of Veterinary Sciences and Animal Husbandry, Uttar Pradesh Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishwa Vidyalaya Evam Go-Anusandhan Sansthan (DUVASU), Mathura 281001, India
| | - Ruchi Tiwari
- Department of Veterinary Microbiology, College of Veterinary Sciences and Animal Husbandry, Uttar Pradesh Pandit Deen Dayal Upadhayay Pashu Chikitsa Vigyan Vishwa Vidyalaya Evam Go-Anusandhan Sansthan (DUVASU), Mathura 281001, India
| | - Anu Rahal
- Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar 243122, India
| | - Yash Malik
- Division of Standardization, Indian Veterinary Research Institute, Izatnagar 243122, India
| | - Kuldeep Dhama
- Division of Pathology, Indian Veterinary Research Institute, Izatnagar 243122, India
| | - Amar Pal
- Division of Surgery, Indian Veterinary Research Institute, Izatnagar 243122, India
| | - Minakshi Prasad
- Department of Animal Biotechnology, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences (LLRUVAS), Hisar 125004, India
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Wong SSY, Fung KSC, Chau S, Poon RWS, Wong SCY, Yuen KY. Molecular diagnosis in clinical parasitology: When and why? Exp Biol Med (Maywood) 2014; 239:1443-60. [DOI: 10.1177/1535370214523880] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Microscopic detection and morphological identification of parasites from clinical specimens are the gold standards for the laboratory diagnosis of parasitic infections. The limitations of such diagnostic assays include insufficient sensitivity and operator dependence. Immunoassays for parasitic antigens are not available for most parasitic infections and have not significantly improved the sensitivity of laboratory detection. Advances in molecular detection by nucleic acid amplification may improve the detection in asymptomatic infections with low parasitic burden. Rapidly accumulating genomic data on parasites allow the design of polymerase chain reaction (PCR) primers directed towards multi-copy gene targets, such as the ribosomal and mitochondrial genes, which further improve the sensitivity. Parasitic cell or its free circulating parasitic DNA can be shed from parasites into blood and excreta which may allow its detection without the whole parasite being present within the portion of clinical sample used for DNA extraction. Multiplex nucleic acid amplification technology allows the simultaneous detection of many parasitic species within a single clinical specimen. In addition to improved sensitivity, nucleic acid amplification with sequencing can help to differentiate different parasitic species at different stages with similar morphology, detect and speciate parasites from fixed histopathological sections and identify anti-parasitic drug resistance. The use of consensus primer and PCR sequencing may even help to identify novel parasitic species. The key limitation of molecular detection is the technological expertise and expense which are usually lacking in the field setting at highly endemic areas. However, such tests can be useful for screening important parasitic infections in asymptomatic patients, donors or recipients coming from endemic areas in the settings of transfusion service or tertiary institutions with transplantation service. Such tests can also be used for monitoring these recipients or highly immunosuppressed patients, so that early preemptive treatment can be given for reactivated parasitic infections while the parasitic burden is still low.
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Affiliation(s)
- Samson SY Wong
- Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong
| | - Kitty SC Fung
- Department of Pathology, United Christian Hospital, Kwun Tong of New Kowloon, Hong Kong
| | - Sandy Chau
- Department of Pathology, United Christian Hospital, Kwun Tong of New Kowloon, Hong Kong
| | - Rosana WS Poon
- Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong
| | - Sally CY Wong
- Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong
| | - Kwok-Yung Yuen
- Department of Microbiology, The University of Hong Kong, Queen Mary Hospital, Pok Fu Lam, Hong Kong
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Paula FM, Sitta RB, Malta FM, Gottardi M, Corral MA, Gryschek RCB, Chieffi PP. Parasitological and molecular diagnosis in experimental Strongyloides venezuelensis infection. Rev Inst Med Trop Sao Paulo 2013; 55:141-3. [PMID: 23563772 DOI: 10.1590/s0036-46652013000200015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 12/07/2012] [Indexed: 11/22/2022] Open
Abstract
Strongyloides venezuelensis is a parasitic nematode of rats which is frequently used as a model to study human and animal strongyloidiasis. The aim of this study was to evaluate the correlation between parasitological and molecular diagnosis in Strongyloides venezuelensis infection. PCR assays were used to detect S. venezuelensis DNA in fecal samples obtained from experimentally infected Rattus norvegicus. The results showed a higher sensitivity of the PCR assay in detecting the infection compared to parasitological methods.
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Affiliation(s)
- Fabiana Martins Paula
- Hospital das Clínicas da Faculdade de Medicina, Instituto de Medicina Tropical de São Paulo, USP, São Paulo, SP, Brazil.
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Tavassoli M, Ghorbanzadehghan M, Esmaeilnejad B. Foll Detection of Toxoplasma gondii in sheep and goats blood samples by PCR-RFLP in Urmia. VETERINARY RESEARCH FORUM : AN INTERNATIONAL QUARTERLY JOURNAL 2013; 4:43-7. [PMID: 25593685 PMCID: PMC4293896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 07/24/2011] [Accepted: 03/15/2013] [Indexed: 11/19/2022]
Abstract
Infection by the protozoan parasite Toxoplasma gondii, is widespread in humans and many other warm-blooded animals. More than half billion of world human population has serum antibodies to T. gondii and Sheep and goats are more widely infected with T. gondii. T. gondii infection can be diagnosed indirectly with serological methods and directly by polymerase chain reaction (PCR), hybridization, isolation and histology. A total number of 124 goats and 113 sheep blood samples were collected from Urmia region and PCR was used for detection of the pathogenic protozoan T. gondii using B1 gene. The targeted B1 gene is highly conserved in all T. gondii strains and is multiple copy genes whit in the T. gondii genome. The method used for the characterization of T. gondii strains implied digestion with AluI restriction enzyme of the fragments amplified. The results indicated three positive sheep (1.26%) with one RFLP patterns. The results indicated that the same strain of T. gondii has infected sheep in the region.
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Affiliation(s)
- Mousa Tavassoli
- Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran; ,Correspondence: Mousa Tavassoli. DVM, PhD, Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran. E-mail:
| | | | - Bijan Esmaeilnejad
- Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran;
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Mousavi MZ, Chen HY, Wu SH, Peng SW, Lee KL, Wei PK, Cheng JY. Magnetic nanoparticle-enhanced SPR on gold nanoslits for ultra-sensitive, label-free detection of nucleic acid biomarkers. Analyst 2013; 138:2740-8. [DOI: 10.1039/c3an36655c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Conventional polymerase chain reaction for the diagnosis of neurotoxoplasmosis: comparison of three sets of primers for the B1 gene using CSF samples. Diagn Microbiol Infect Dis 2012. [PMID: 23182076 DOI: 10.1016/j.diagmicrobio.2012.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Polymerase chain reaction (PCR) has made a significant improvement in the diagnosis of toxoplasmic encephalitis (TE). Nevertheless, a wide variety of targets and primers has been used in different assays, and few comparative studies had been carried out. The aim of the present study was to compare the efficiency of 3 conventional PCR methods by using 3 sets of primers targeting the repetitive B1 gene in the diagnosis of TE. Diagnostic sensitivity and specificity of PCR and nested-PCR protocols were assessed for 207 (nested-PCR/T1-T4), 200 (nested-PCR/S1-AS1), and 206 (PCR/B22-B23) cerebrospinal fluid (CSF) samples, including AIDS and HIV-negative patients. The diagnostic sensitivity of PCR and nested-PCR assays was 50.85%, 68.97%, and 72.41% for T1-T4, S1-AS1, and B22-B23, respectively. The diagnostic specificity was high for all the assays showing values between 95% and 97%. In general, the best results were obtained for the B22-B23 set of primers, suggesting their usefulness compared with 2 nested-PCR protocols and showing that this simple and rapid strategy may be the preferred one for the diagnosis of TE in AIDS patients.
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Belinchón-Lorenzo S, Iniesta V, Parejo JC, Fernández-Cotrina J, Muñoz-Madrid R, Soto M, Alonso C, Gómez Nieto LC. Detection of Leishmania infantum kinetoplast minicircle DNA by Real Time PCR in hair of dogs with leishmaniosis. Vet Parasitol 2012; 192:43-50. [PMID: 23218222 DOI: 10.1016/j.vetpar.2012.11.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 11/05/2012] [Accepted: 11/06/2012] [Indexed: 10/27/2022]
Abstract
It is known that hair can accumulate environmental toxics and excrete foreign chemical or biological substances. In this context, we hypothesized that foreign DNA could be found in the hair of an infected organism, and thus, be detected by Real Time PCR in the hair of Leishmania infantum naturally infected dogs. A population of 28 dogs living in Leishmania endemic areas was divided into two groups: A (13 Leishmania infected dogs) and B (15 healthy dogs). Blood, lymph node and ear hair samples from all of them were tested for the presence of parasite kinetoplast DNA (kDNA). For the same purpose, hair of several body areas and hair sections of two infected dogs were also analyzed. Epidermal keratinocytes from an infected animal were also analyzed for reactivity against Leishmania antigens by ELISA and for the presence of kDNA. Regarding to dogs from group A, parasite kDNA was detected in the 100% of lymph node samples. The sensitivity of Real Time PCR in ear hair was similar to that obtained in blood (9 positive out of 13 versus 8 positive out of 13, respectively). Moreover, the presence of L. infantum kDNA was also detected in the hair of all the analyzed body zones, in all hair sections and in epidermal keratinocytes. In infected dogs, parasite kDNA could be detected and quantified from just one single hair, whereas it was not detected in any of the samples of the healthy dogs. This work describes a new method for a reliable and non-invasive diagnosis of canine leishmaniosis using hair samples of infected animals. The data presented also provide some insights for the understanding of the physiology of keratinocytes and the role of hair as a specialized tissue in the kidnapping and removal of foreign DNA.
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Affiliation(s)
- Silvia Belinchón-Lorenzo
- LeishmanCeres Laboratory (GLP Compliance Certified), Parasitology Unit, Veterinary Faculty, University of Extremadura, Avenida de la Universidad s/n, 10003 Cáceres, Spain.
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Choi HJ, Hwang JY, Choi DL, Huh MD, Park MA. A study of diagnostic methods for Marteilioides chungmuensis infections in the Pacific oyster Crassostrea gigas. J Invertebr Pathol 2012; 111:27-32. [PMID: 22634519 DOI: 10.1016/j.jip.2012.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 05/07/2012] [Accepted: 05/09/2012] [Indexed: 11/17/2022]
Abstract
The eggs of the Pacific oyster, Crassostraea gigas, become infertile when infected by the parasite Marteilioides chungmuensis. Histologically, M. chungmuensis infects the oyster oocyte cytoplasm, and the ovaries take on a "lumpy" appearance once infected, which lowers commercial value of the oyster. This has a negative economic impact on oyster farms in South Korea and Japan. In this study, we compared traditional diagnostic methods (histology) with two molecular-based methods (polymerase chain reaction [PCR] amplification and in situ hybridization [ISH]) to identify M. chungmuensis-infected oysters. The efficacy of PCR and ISH to identify M. chungmuensis-infected oysters was compared to that of routine histology in 100 oysters. Thirty infections were identified using PCR and 16 using histology, whereas 31 infections were identified using ISH. The ISH and PCR assays were more sensitive compared to using histology with standard epidemiological methods. We strongly recommend that early parasitic invasion should be monitored with PCR/ISH methodologies as a basis for developing effective diagnostic techniques to identify M. chungmuensis-infected oysters.
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Affiliation(s)
- Hee Jung Choi
- Fish Pathology Division, National Fisheries Research and Development Institute (NFRDI), 408-1 Silang, Gijang, Busan, Republic of Korea
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Vidal JE, Diaz AVH, de Oliveira ACP, Dauar RF, Colombo FA, Pereira-Chioccola VL. Importance of high IgG anti-Toxoplasma gondii titers and PCR detection of T. gondii DNA in peripheral blood samples for the diagnosis of AIDS-related cerebral toxoplasmosis: a case-control study. Braz J Infect Dis 2012; 15:356-9. [PMID: 21861006 DOI: 10.1016/s1413-8670(11)70204-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 01/10/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Cerebral toxoplasmosis (CT) continues to cause significant morbidity and mortality in human immunodeficiency virus (HIV)-infected patients in Brazil. In clinical practice, the initial diagnosis is usually presumptive and alternative diagnosis tools are necessary. Our objective was to evaluate whether the detection of high titers of IgG anti-Toxoplasma gondii and T. gondii DNA in blood samples are associated with the diagnosis of CT. METHODS In this case-control study we included 192 patients with HIV-1 infection: 64 patients with presumptive CT (cases) and 128 patients with other diseases (controls). Blood samples to perform indirect immunofluorescense reaction (IFI) to detect anti-T. gondii IgG antibodies and polymerase chain reaction (PCR) were collected before or within the first three days of anti-Toxoplasma therapy. Two multivariate logistic regression models were performed: one including the variable qualitative serology and another including quantitative serology. RESULTS In the first model, positive IgG anti-T. gondii (OR 4.7, 95% CI 1.2-18.3; p = 0.027) and a positive T. gondii PCR result (OR 132, 95% CI 35-505; p < 0.001) were associated with the diagnosis. In the second model, IgG anti-T. gondii titres > 1:1024 (OR 7.6, 95% CI 2.3-25.1; p = 0.001) and a positive T. gondii PCR result (OR 147, 95% CI 35-613; p < 0.001) were associated with the diagnosis. CONCLUSIONS Quantitative serology and molecular diagnosis in peripheral blood samples were independently associated with the diagnosis of CT in HIV-infected patients. These diagnostic tools can contribute to a timely diagnosis of CT in settings where Toxoplasma infection is common in the general population.
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Affiliation(s)
- José E Vidal
- Department of Neurology, Instituto de Infectologia Emílio Ribas, São Paulo, Brazil.
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The interspecific relationship between prevalence of blood parasites and sexual traits in birds when considering recent methodological advancements. Behav Ecol Sociobiol 2011. [DOI: 10.1007/s00265-011-1259-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Bellan LM, Wu D, Langer RS. Current trends in nanobiosensor technology. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2011; 3:229-46. [PMID: 21391305 PMCID: PMC4126610 DOI: 10.1002/wnan.136] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The development of tools and processes used to fabricate, measure, and image nanoscale objects has lead to a wide range of work devoted to producing sensors that interact with extremely small numbers (or an extremely small concentration) of analyte molecules. These advances are particularly exciting in the context of biosensing, where the demands for low concentration detection and high specificity are great. Nanoscale biosensors, or nanobiosensors, provide researchers with an unprecedented level of sensitivity, often to the single molecule level. The use of biomolecule-functionalized surfaces can dramatically boost the specificity of the detection system, but can also yield reproducibility problems and increased complexity. Several nanobiosensor architectures based on mechanical devices, optical resonators, functionalized nanoparticles, nanowires, nanotubes, and nanofibers have been demonstrated in the lab. As nanobiosensor technology becomes more refined and reliable, it is likely it will eventually make its way from the lab to the clinic, where future lab-on-a-chip devices incorporating an array of nanobiosensors could be used for rapid screening of a wide variety of analytes at low cost using small samples of patient material.
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Affiliation(s)
- Leon M Bellan
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Bellan LM, Wu D, Langer RS. Current trends in nanobiosensor technology. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2011. [PMID: 21391305 DOI: 10.1002/wnan.v3.310.1002/wnan.136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
The development of tools and processes used to fabricate, measure, and image nanoscale objects has lead to a wide range of work devoted to producing sensors that interact with extremely small numbers (or an extremely small concentration) of analyte molecules. These advances are particularly exciting in the context of biosensing, where the demands for low concentration detection and high specificity are great. Nanoscale biosensors, or nanobiosensors, provide researchers with an unprecedented level of sensitivity, often to the single molecule level. The use of biomolecule-functionalized surfaces can dramatically boost the specificity of the detection system, but can also yield reproducibility problems and increased complexity. Several nanobiosensor architectures based on mechanical devices, optical resonators, functionalized nanoparticles, nanowires, nanotubes, and nanofibers have been demonstrated in the lab. As nanobiosensor technology becomes more refined and reliable, it is likely it will eventually make its way from the lab to the clinic, where future lab-on-a-chip devices incorporating an array of nanobiosensors could be used for rapid screening of a wide variety of analytes at low cost using small samples of patient material.
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Affiliation(s)
- Leon M Bellan
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Odiwuor SOC, Saad AA, De Doncker S, Maes I, Laurent T, El Safi S, Mbuchi M, Büscher P, Dujardin JC, Van der Auwera G. Universal PCR assays for the differential detection of all Old World Leishmania species. Eur J Clin Microbiol Infect Dis 2010; 30:209-18. [PMID: 20936316 DOI: 10.1007/s10096-010-1071-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Accepted: 09/19/2010] [Indexed: 12/01/2022]
Abstract
For the epidemiological monitoring and clinical case management of leishmaniasis, determination of the causative Leishmania species gains importance. Current assays for the Old World often suffer from drawbacks in terms of validation on a geographically representative sample set and the ability to recognize all species complexes. We want to contribute to standardized species typing for Old World leishmaniasis. We determined the ribosomal DNA internal transcribed spacer 1 sequence of 24 strains or isolates, and validated four species-specific polymerase chain reactions (PCRs) amplifying this target. They discriminate L. aethiopica, L. tropica, L. major, and the L. donovani complex, use the same cycling conditions, and include an internal amplification control. Our PCRs amplify 0.1 pg of Leishmania DNA, while being 100% specific for species identification on an extensive panel of geographically representative strains and isolates. Similar results were obtained in an endemic reference laboratory in Kenya. Species could also be identified in clinical specimens. The presented PCRs require only agarose gel detection, and have several other advantages over many existing assays. We outline potential problems, suggest concrete solutions for transferring the technique to other settings, and deliver the proof-of-principle for analyzing clinical samples.
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Affiliation(s)
- S Ogado Ceasar Odiwuor
- Department of Parasitology, Institute of Tropical Medicine Antwerp, Nationalestraat 155, 2000, Antwerp, Belgium
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Sethi S, Murphy TF, Klingman KL. Diagnosis, epidemiology and pathogenesis of bacterial infections in the molecular era. Mol Pathol 2010; 49:M1-7. [PMID: 16696037 PMCID: PMC408009 DOI: 10.1136/mp.49.1.m1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- S Sethi
- Division of Pulmonary and Critical Care Medicine, State University of New York at Buffalo
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Marra NM, Chiuso-Minicucci F, Machado GC, Zorzella-Pezavento SFG, França TGD, Ishikawa LLW, Amarante AFT, Sartori A, Amarante MRV. Faecal examination and PCR to detect Strongyloides venezuelensis in experimentally infected Lewis rats. Mem Inst Oswaldo Cruz 2010; 105:57-61. [PMID: 20209330 DOI: 10.1590/s0074-02762010000100008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 12/18/2009] [Indexed: 11/22/2022] Open
Abstract
More sensitive methodologies are necessary to improve strongyloidiasis diagnosis. This study compared the sensitivities of the McMaster modified technique and polymerase chain reaction (PCR) assays, both performed in faecal samples. Lewis rats were subcutaneously infected with 4,000, 400 or 40 infective third-stage larvae, considered as high, moderate or low infection, respectively. Seven days later, they were euthanized to count adult nematodes recovered from the small intestine. Stool samples were used to count the number of eggs per gram (EPG) of faeces and to detect parasite DNA by PCR performed with a species and a genus primer pair. The sensitivity of these assays depended upon parasite burden and the primer specificity. All assays presented 100% sensitivity at the highest parasite load. In the moderate infection, EPG and PCR with the genus primer maintained 100% specificity, whereas PCR sensitivity with the species primer decreased to 77.7%. In low infection, the sensitivity was 60% for EPG, 0% for PCR with the species primer and 90% for PCR done with the genus primer. Together, these results suggest that PCR with a genus primer can be a very sensitive methodology to detect Strongyloides venezuelensisin faeces of Lewis rats infected with very low parasite burden.
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Affiliation(s)
- Nelson Mendes Marra
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, SP, Brasil, 18618-000
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Meeus I, de Graaf DC, Jans K, Smagghe G. Multiplex PCR detection of slowly-evolving trypanosomatids and neogregarines in bumblebees using broad-range primers. J Appl Microbiol 2009; 109:107-15. [PMID: 20015206 DOI: 10.1111/j.1365-2672.2009.04635.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS The aims of this study were to design universal markers for different protozoan parasites of Bombus spp. based on the phylogenetic position of two important bumblebee parasites Crithidia bombi and Apicystis bombi. METHODS AND RESULTS Standard PCR and extraction techniques were used to amplify and sequence 18S rDNA. Phylogenetic analysis of the rDNA was performed in order to predict the parasite range of the primers. CONCLUSIONS Crithidia bombi phylogenetically clusters with the trypanosomatids with slowly-evolving SSU-rRNA sequences (SE), while A. bombi is the closest sister group of Mattesia. A multiplex was designed containing an internal control and two broad-range primer pairs, detecting C. bombi and other SE trypanosomatids and also A. bombi and other neogregarines. SIGNIFICANCE AND IMPACT OF THE STUDY Sequence data generated will further improve the current systematics of insect trypanosomatids and gregarines that remain troublesome. Broad-range markers for bumblebee parasites are necessary tools enabling the screening of commercially imported colonies and thus controlling their worldwide distribution and to discover related emerging parasites.
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Affiliation(s)
- I Meeus
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Alfonso Y, Fraga J, Jiménez N, Fonseca C, Dorta-Contreras AJ, Cox R, Capó V, Bandera F, Pomier O, Ginorio D. Detection of Toxoplasma gondii in cerebrospinal fluid from AIDS patients by nested PCR and rapid identification of type I allele at B1 gene by RFLP analysis. Exp Parasitol 2009; 122:203-7. [DOI: 10.1016/j.exppara.2009.03.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 03/02/2009] [Accepted: 03/16/2009] [Indexed: 10/21/2022]
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Alfonso Y, Fraga J, Fonseca C, Jiménez N, Pinillos T, Dorta-Contreras AJ, Cox R, Capó V, Pomier O, Bandera F, Ginorio D. Molecular diagnosis of Toxoplasma gondii infection in cerebrospinal fluid from AIDS patients. Cerebrospinal Fluid Res 2009; 6:2. [PMID: 19267913 PMCID: PMC2657107 DOI: 10.1186/1743-8454-6-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Accepted: 03/06/2009] [Indexed: 12/02/2022] Open
Abstract
Background Toxoplasmic encephalitis (TE) is one of the most common opportunistic infections in immunocompromised patients. In Cuba, despite the highly active antiretroviral therapy, TE is still the most important cause of cerebral mass lesions in patients infected with the human immunodeficiency virus (HIV). The detection of Toxoplasma gondii by PCR may facilitate the diagnosis and follow-up of TE in acquired immunodeficiency syndrome (AIDS) patients by direct identification of parasite DNA in clinical samples. The aim of the present study was to evaluate a rapid PCR method using the B1 gene to detect T. gondii in cerebrospinal fluid (CSF) samples from patients with suspected TE. Methods CSF samples from AIDS and HIV-negative patients were analyzed. Patients were divided into two groups according to the Centre for Disease Control and Prevention (CDC) criteria for AIDS-related TE: AIDS patients with suspected neurotoxoplasmosis and AIDS and HIV-negative patients with other confirmed neurological diseases but no suspicions of TE. Predictive values, diagnostic accuracy, sensitivity and specificity of the PCR B1 method were calculated. Results The results obtained from 190 patients showed that this assay has a good sensitivity and specificity (83.3% and 95.7%, respectively) for the diagnosis of TE in AIDS patients. Conclusion PCR using the B1 gene and B22/B23 set of primers is a single, rapid and reliable method that may be valuable for discrimination between toxoplasmosis and other central nervous system (CNS) diseases.
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Affiliation(s)
- Yenisey Alfonso
- Parasitology Department, Institute of Tropical Medicine 'Pedro Kourí', PO Box 601, Marianao 13, Ciudad de La Habana, Cuba.
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Abstract
Echinococcosis is a human disease caused by the larval form of Taenia echinococcus, which lives in the gut of the dog, wild canides and other carnivorous animals which represent the definitive hosts and involves as intermediate hosts both domestic and wild animals. Humans become accidental intermediate hosts by ingesting Taenia eggs. The main species pathogenic for man are E granulosus causing cystic echinococcosis with worldwide distribution and endemic in sheep and cattle breeding countries, and E multilocularis causing alveolar echinococcosis, with preferential distribution in the northern hemisphere. After ingestion of contaminated food, hexacanth embryos migrate by the portal system to liver and later lung, brain and other tissues. Symptoms are related to both cyst location and size. E granulosus infection of the central nervous system (CNS) may be primary or secondary and has been estimated to be low (2%). Sharply demarcated, spherical and intraparenchymal, cysts may reach a large size causing neurological symptoms. Spilling of cyst fluid due to trauma or surgery may trigger anaphylaxis as well as disseminated infection. Host reaction is minimal in the brain but a foreign giant cell reaction may develop. E multilocularis develops within the liver as a rapid invasive pseudomalignant growth and may metastasize to the CNS, where estimated incidence reaches 5%. Hydatid antigens induce an immune reaction in the host which is helpful for the diagnosis. DNA probes and PCR may be applied to differentiate between Echinococcus spp. Although the host develops an immunological protection from reinfection, the parasite evades host immune attack. A wide range of evasion mechanisms have been advanced, including a barrier for host cells due to hydatid cyst laminated cuticle, polyclonal activation of lymphocytes by parasite soluble antigens, and depression of host cell immune responses. Chronic stimulation of the host by cyst fluid antigens leads to increased specific IgG4 production, which might act as blocking antibodies against anaphlaxis suggestive of host response immunomodulation.
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Affiliation(s)
- A L Taratuto
- Department of Neuropathology, Raul Carrea Institute for Neurological Research, Buenos Aires, Argentina
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The detection and quantification of a digenean infection in the snail host with special emphasis on Fasciola sp. Parasitol Res 2008; 103:735-44. [DOI: 10.1007/s00436-008-1086-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Accepted: 06/05/2008] [Indexed: 10/21/2022]
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Mens PF, van Amerongen A, Sawa P, Kager PA, Schallig HDFH. Molecular diagnosis of malaria in the field: development of a novel 1-step nucleic acid lateral flow immunoassay for the detection of all 4 human Plasmodium spp. and its evaluation in Mbita, Kenya. Diagn Microbiol Infect Dis 2008; 61:421-7. [PMID: 18455349 DOI: 10.1016/j.diagmicrobio.2008.03.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 03/14/2008] [Accepted: 03/18/2008] [Indexed: 10/22/2022]
Abstract
Microscopy is frequently used for malaria diagnosis, but at low parasitemia, it becomes less sensitive and time consuming. Molecular tools allow for specific/sensitive diagnosis, but current formats, such as polymerase chain reaction (PCR) combined with gel electrophoresis and real-time PCR assays, are difficult to implement in resource-poor settings. Development of a simple, fast, sensitive, and specific detection system, nucleic acid lateral flow immunoassay (NALFIA) for amplified pan-Plasmodium PCR products, is described. The NALFIA lower detection limit is 0.3 to 3 parasites/microL, 10-fold more sensitive than gel electrophoresis analysis. Evaluating 650 clinically suspected malaria cases with the pan-Plasmodium assay under field conditions (rural Kenya) revealed that NALFIA detected more positives than microscopy (agreement, 95%; kappa value = 0.85), and there was an excellent agreement between gel electrophoresis and NALFIA (98.5%; kappa value = 0.96). In conclusion, NALFIA is more sensitive than microscopy and a good alternative to detect PCR products while circumventing using electricity or expensive equipment, making NALFIA the 1st step toward molecular field diagnosis.
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Affiliation(s)
- Petra F Mens
- Koninklijk Instituut voor de Tropen (KIT)/Royal Tropical Institute, KIT Biomedical Research, 1105 AZ Amsterdam, The Netherlands.
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Young ND, Dyková I, Nowak BF, Morrison RN. Development of a diagnostic PCR to detect Neoparamoeba perurans, agent of amoebic gill disease. JOURNAL OF FISH DISEASES 2008; 31:285-295. [PMID: 18353020 DOI: 10.1111/j.1365-2761.2008.00903.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The recent description of Neoparamoeba perurans as an aetiological agent of amoebic gill disease (AGD) advanced our understanding of the condition and has forced a re-evaluation of methods used for the diagnosis of AGD. Currently, there are no tools available that are both specific for N. perurans and suitable for a routine diagnostic procedure. Therefore, in this study we describe an assay to detect N. perurans. The assay, which utilizes PCR to amplify the N. perurans 18S rRNA gene, was shown to be specific and highly sensitive. Neoparamoeba perurans was detected in both gill samples and primary isolates of non-cultured gill-derived amoebae obtained during necropsy or biopsy from AGD-affected Atlantic salmon, Salmo salar L. The PCR-based assay provides a simple, flexible tool that will be a useful addition to the diagnostic repertoire for AGD. It may also be used for the genotypic screening of trophozoites during culture and could facilitate further epidemiological and ecological studies of AGD.
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Affiliation(s)
- N D Young
- School of Aquaculture, Tasmanian Aquaculture and Fisheries Institute, University of Tasmania and Aquafin CRC, Launceston, Tasmania, Australia
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Schuster H, Agada FO, Anderson AR, Jackson RS, Blair D, McGann H, Kelly G. Otitis media and a neck lump--current diagnostic challenges for Paragonimus-like trematode infections. J Infect 2006; 54:e103-6. [PMID: 16824610 DOI: 10.1016/j.jinf.2006.05.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Revised: 05/20/2006] [Accepted: 05/22/2006] [Indexed: 10/24/2022]
Abstract
A 29 year-old Nigerian studying in the UK presented with a neck lump and otitis media. Paragonimus-like trematode eggs were found in the neck lump aspirate. Morphologically these eggs resembled Paragonimus uterobilateralis or Achillurbainia congolensis. We favoured the diagnosis of achillurbainiasis over extrapulmonary paragonimiasis on the basis of clinical features and because we could not amplify DNA sequences using PCR primers specific for Paragonimus species. We discuss current diagnostic challenges for this rare parasitic infection.
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Affiliation(s)
- H Schuster
- Microbiology Department, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, UK
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Nogueira YL, Galati EAB. Reproduction of Leishmania (Leishmania ) infantum chagasi in conditioned cell culture growth medium. Rev Inst Med Trop Sao Paulo 2006; 48:147-50. [PMID: 16847504 DOI: 10.1590/s0036-46652006000300006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Leishmanias can be produced by inoculation in conditioned McCoy cell culture growth medium (CGM). Leishmania (Leishmania) infantum chagasi (100 parasites) grown in NNN medium was inoculated in 2.5 mL CGM, kept in plates (24 wells) and its multiplication was observed for five days (120 hours). After day 5, the medium was saturated with the flagellate forms of the parasite (promastigotes). The reproduction of the leishmanias was observed every 24 hours and the number of parasites was calculated by counting the parasites in a drop of 10 µ L and photomicrographied. So the number of Leishmanias was adjusted to 1 mL volume. The advantage of the technique by isolation of Leishmania in CGM demonstrated in this study is its low cost and high efficacy even with a small quantity of parasites (10² promastigotes) used as inoculum. Additionally, isolation of the leishmania can be obtained together with an increase in their density (180 times) as observed by growth kinetics, within a shorter time. These results justify the use of this low-cost technique for the isolation and investigation of the behavior and multiplication of Leishmania both in vertebrates and invertebrates, besides offering means of obtaining antigens, whether whole antigens (leishmanias) or the soluble antigens produced by the parasites which may be useful for the production of new diagnostic kits.
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Affiliation(s)
- Yeda L Nogueira
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Avc. Dr. Arnaldo 715, 01246-902 São Paulo, SP, Brasil.
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Francino O, Altet L, Sánchez-Robert E, Rodriguez A, Solano-Gallego L, Alberola J, Ferrer L, Sánchez A, Roura X. Advantages of real-time PCR assay for diagnosis and monitoring of canine leishmaniosis. Vet Parasitol 2006; 137:214-21. [PMID: 16473467 DOI: 10.1016/j.vetpar.2006.01.011] [Citation(s) in RCA: 276] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Revised: 12/23/2005] [Accepted: 01/10/2006] [Indexed: 11/27/2022]
Abstract
The aim of the present study is to highlight the advantages of real-time quantitative PCR intended to aid in the diagnosis and monitoring of canine leishmaniosis. Diagnosis of canine leishmaniosis is extremely challenging, especially in endemic areas, due to the diverse and non-specific clinical manifestations, and due to the high seroprevalence rate in sub-clinical dogs. Veterinarian clinicians are usually confronted with cases that are compatible with the disease, and with several diagnostic tests, sometimes with contradictory results. We have developed a new TaqMan assay, targeting the kinetoplast, applied to 44 samples of bone marrow aspirate or peripheral blood. The dynamic range of detection of Leishmania DNA was established in 7 logs and the limit of detection is 0.001 parasites in the PCR reaction. At the time of diagnosis parasitemia ranges from less than 1 to 10(7)parasites/ml. The ability to quantify the parasite burden allowed: (i) to elucidate the status of positive dogs by conventional PCR, although larger studies are necessary to clarify the dividing line between infection and disease, (ii) to estimate the kinetics of the parasite load and the different response to the treatment in a follow-up and (iii) to validate blood as less invasive sample for qPCR. The continuous data provided by real-time qPCR could solve the dilemma for the clinician managing cases of canine leishmaniosis by differentiating between Leishmania-infected dogs or dogs with active disease of leishmaniosis.
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Affiliation(s)
- O Francino
- Servei Veterinari de Genètica Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Colombo FA, Vidal JE, Penalva de Oliveira AC, Hernandez AV, Bonasser-Filho F, Nogueira RS, Focaccia R, Pereira-Chioccola VL. Diagnosis of cerebral toxoplasmosis in AIDS patients in Brazil: importance of molecular and immunological methods using peripheral blood samples. J Clin Microbiol 2005; 43:5044-7. [PMID: 16207959 PMCID: PMC1248484 DOI: 10.1128/jcm.43.10.5044-5047.2005] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cerebral toxoplasmosis is the most common cerebral focal lesion in AIDS and still accounts for high morbidity and mortality in Brazil. Its occurrence is more frequent in patients with low CD4(+) T-cell counts. It is directly related to the prevalence of anti-Toxoplasma gondii antibodies in the population. Therefore, it is important to evaluate sensitive, less invasive, and rapid diagnostic tests. We evaluated the value of PCR using peripheral blood samples on the diagnosis of cerebral toxoplasmosis and whether its association with immunological assays can contribute to a timely diagnosis. We prospectively analyzed blood samples from 192 AIDS patients divided into two groups. The first group was composed of samples from 64 patients with cerebral toxoplasmosis diagnosed by clinical and radiological features. The second group was composed of samples from 128 patients with other opportunistic diseases. Blood collection from patients with cerebral toxoplasmosis was done before or on the third day of anti-toxoplasma therapy. PCR for T. gondii, indirect immunofluorescence, enzyme-linked immunosorbent assay, and an avidity test for toxoplasmosis were performed on all samples. The PCR sensitivity and specificity for diagnosis of cerebral toxoplasmosis in blood were 80% and 98%, respectively. Patients with cerebral toxoplasmosis (89%) presented higher titers of anti-T. gondii IgG antibodies than patients with other diseases (57%) (P<0.001). These findings suggest the clinical value of the use of both PCR and high titers of anti-T. gondii IgG antibodies for the diagnosis of cerebral toxoplasmosis. This strategy may prevent more invasive approaches.
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Affiliation(s)
- Fabio A Colombo
- Department of Parasitology, Instituto Adolfo Lutz, São Paulo, SP, Brazil
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Gontijo CMF, Melo MN. Leishmaniose visceral no Brasil: quadro atual, desafios e perspectivas. REVISTA BRASILEIRA DE EPIDEMIOLOGIA 2004. [DOI: 10.1590/s1415-790x2004000300011] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
No Brasil, a importância da leishmaniose visceral reside não somente na sua alta incidência e ampla distribuição, mas também na possibilidade de assumir formas graves e letais quando associada ao quadro de má nutrição e infecções concomitantes. A crescente urbanização da doença ocorrida nos últimos 20 anos coloca em pauta a discussão das estratégias de controle empregadas. Neste artigo foram analisados os principais aspectos biológicos, ambientais e sociais que influenciaram no processo de expansão e urbanização dos focos da doença. Os métodos disponíveis para o diagnóstico e tratamento não apresentam a eficácia e aplicabilidade desejadas, embora avanços promissores tenham sido alcançados com as pesquisas de novos testes diagnósticos e drogas terapêuticas. As medidas de controle da doença até agora implementadas foram incapazes de eliminar a transmissão e impedir a ocorrência de novas epidemias. É feita uma breve análise destas medidas e dos desafios a serem enfrentados. A prevenção da doença nos cães através da imunoprofilaxia aparece como uma alternativa para o controle. Uma nova vacina para cães, já testada em campo, está sendo industrializada e será comercializada no Brasil a partir de 2004. Apesar da existência de inúmeros estudos sobre a leishmaniose visceral humana e canina, muitas lacunas ainda precisam ser preenchidas.
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Shaw EI, Moura H, Woolfitt AR, Ospina M, Thompson HA, Barr JR. Identification of Biomarkers of Whole Coxiella burnetii Phase I by MALDI-TOF Mass Spectrometry. Anal Chem 2004; 76:4017-22. [PMID: 15253637 DOI: 10.1021/ac030364k] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) specific biomarkers have been shown to be an effective tool for identifying microorganisms. In this study, we demonstrate the feasibility of using this technique to detect the obligate intracellular bacterium Coxiella burnetii, a category B bioterrorism agent. Specific biomarkers were detected in C. burnetii Nine Mile phase I (NMI) strain purified from embryonated egg yolk sac preparations. Whole organisms were applied directly to the MALDI target. MALDI-TOF MS analysis of C. burnetii NMI grown and purified at different times and places revealed a group of unique, characteristic, and reproducible spectral markers in the mass range of 1000-25000 Da. Statistical analysis of the averaged centroided masses uncovered at least 24 peptides or biomarkers. Three biomarkers observed in the MALDI-TOF MS spectrum consistently matched proteins that had been previously described in C. burnetii, one of them being the small cell variant protein A. MALDI-TOF MS analysis of whole organisms represents a sensitive and specific option for characterizing C. burnetii isolates, especially when coupled with antigen capture techniques. The method also has potential for several applications in basic microbial research, including regulation of gene expression.
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Affiliation(s)
- Edward I Shaw
- Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA.
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Deniau M, Cañavate C, Faraut-Gambarelli F, Marty P. The biological diagnosis of leishmaniasis in HIV-infected patients. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2004; 97 Suppl 1:115-33. [PMID: 14678639 DOI: 10.1179/000349803225002598] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This review emphasises the particular difficulties encountered in confirming a suspected case of cutaneous or visceral leishmaniasis when that case is co-infected with HIV. HIV infection appears to have a more profound impact on the development of visceral leishmaniasis than on the evolution of the purely cutaneous disease. The various techniques available for immunological, parasitological and molecular diagnosis are presented and evaluated. The value of serodiagnosis for the detection of antileishmanial antibodies is in part dependent on the antigens used. Western blots may have a use not only in diagnosis but also in predicting the cases of HIV infection that are at most risk of developing symptomatic leishmaniasis. The presence of leishmanial parasites may still only be demonstrated incontrovertibly by the microscopical examination of smears or the culture of blood or biopsy samples. The use of cultures not only permits diagnosis but also detailed study of the parasites. The potential use of PCR in diagnosis is explored and related to other possible tests. A recommended, standardized procedure for the diagnosis of leishmaniasis in HIV-infected patients is presented.
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Affiliation(s)
- M Deniau
- Service de Parasitologie-Mycologie, UMR BIPAR 956, Hôpital Henri Mondor, Avenue du Général de Lattre de Tassigny, 94010 Créteil, France.
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Lobo TT, Feijó G, Carvalho SE, Costa PL, Chagas C, Xavier J, Simoes-Barbosa A. A comparative evaluation of the Papanicolaou test for the diagnosis of trichomoniasis. Sex Transm Dis 2003; 30:694-9. [PMID: 12972792 DOI: 10.1097/01.olq.0000079525.04451.05] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Trichomoniasis is the most prevalent nonviral sexually transmitted disease in humans worldwide. In addition to its pathologic implications, trichomoniasis is a risk factor for the transmission of the HIV and is associated with reproductive complications in females. Diagnosis of the disease is problematic due to inadequate accuracy of current diagnostic methods. Recently developed DNA-based techniques for detection of Trichomonas vaginalis seem to be promising alternatives. GOAL The goal of this study was to evaluate the accuracy of the Papanicolaou test for the diagnosis of trichomoniasis by comparing polymerase chain reaction (PCR) with other current diagnostic methods. STUDY DESIGN A total of 1008 cervicovaginal swab specimens from a randomized population attending a gynecological service were analyzed in this study. In addition to current diagnostic methods, two sets of specific primers were used for PCR detection of T vaginalis in the cervicovaginal DNA samples, with a PCR quality control. Different examiners conducted PCR and Papanicolaou analyses in a double-blind trial. RESULTS The prevalence of trichomoniasis in this population was 6%. A considerable number of diagnostic results of the Papanicolaou test were false negative or false positive. Compared with PCR, specificity of the Papanicolaou test was 97.6%, whereas sensitivity was only 60.7%. The positive predictive value of the Papanicolaou smear was 61.7%. These results suggest that irregularly shaped parasites without clearly defined nuclei and flagella and bacteria-induced focal cytolysis limit the ability of the Papanicolaou test to detect T vaginalis. CONCLUSION The Papanicolaou test, the most readily available cytologic method for screening sexually transmitted pathogens and cellular abnormalities in most developing countries, is inadequate for the diagnosis of trichomoniasis due to its inherent limitations. However, PCR is a highly sensitive and specific test for the diagnosis of trichomoniasis.
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Affiliation(s)
- Tatiana T Lobo
- Program of Genomic Sciences and Molecular Biotechnology, Universidade Católica de Brasília, Brasília DF, Brazil
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Kho WG, Chung JY, Sim EJ, Kim MY, Kim DW, Jongwutiwes S, Tanabe K. A multiplex polymerase chain reaction for a differential diagnosis of Plasmodium falciparum and Plasmodium vivax. Parasitol Int 2003; 52:229-36. [PMID: 14550478 DOI: 10.1016/s1383-5769(03)00028-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A multiplex PCR was designed for the differential diagnosis of the two parasite species by targeting the 18S rRNA gene with a set of primer combinations, amplifying DNA fragments of 1451-bp and 833-bp for P. falciparum and P. vivax, respectively. The sensitivity of this PCR test was high, as minimal as 0.1 parasite per one microliter of blood sample and a minimum of four copies of the target gene could be detected. For the diagnosis of mixed infection of two Plasmodium spp., there were no apparent competition or cross-reaction between the majority and minority Plasmodium species. The multiplex PCR was evaluated on 210 clinical samples and 60 normal controls. The PCR test yielded highly concordant results with microscopic examination, with the only one exception of a mixed (P. falciparum plus P. vivax) infection case, which was diagnosed as a single infection of P. falciparum by microscopy. We propose that the multiplex PCR is a sensitive, specific, and rapid tool that can serve as a useful differential diagnostic tool for detecting P. falciparum and P. vivax.
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MESH Headings
- Animals
- Base Sequence
- DNA, Protozoan/analysis
- DNA, Ribosomal/analysis
- Diagnosis, Differential
- Humans
- Malaria, Falciparum/diagnosis
- Malaria, Falciparum/parasitology
- Malaria, Vivax/diagnosis
- Malaria, Vivax/parasitology
- Molecular Sequence Data
- Plasmodium falciparum/classification
- Plasmodium falciparum/genetics
- Plasmodium falciparum/isolation & purification
- Plasmodium vivax/classification
- Plasmodium vivax/genetics
- Plasmodium vivax/isolation & purification
- Polymerase Chain Reaction/methods
- RNA, Ribosomal, 18S/genetics
- Sensitivity and Specificity
- Sequence Analysis, DNA
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Affiliation(s)
- Weon-Gyu Kho
- Institute of Malariology and Department of Parasitology, Inje University College of Medicine, Pusan 614-735, South Korea.
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Vasuki V, Hoti SL, Sadanandane C, Jambulingam P. A simple and rapid DNA extraction method for the detection of Wuchereria bancrofti infection in the vector mosquito, Culex quinquefasciatus by Ssp I PCR assay. Acta Trop 2003; 86:109-14. [PMID: 12711110 DOI: 10.1016/s0001-706x(02)00267-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A simple, rapid and inexpensive method for the extraction of DNA from filarial vector, Culex quinquefasciatus, useful in Ssp I PCR assay for xenomonitoring of infection with Wuchereria bancrofti is presented. The DNA extracted by this method was found suitable for PCR detection of W. bancrofti infection in pools of 10-30 mosquitoes. The PCR assay employing the simplified DNA extraction method was evaluated for its sensitivity on field caught Cx. quinquefasciatus, in comparison with the conventional dissection and microscopy technique. When assayed on dissection washings of vector mosquitoes the PCR assay detected 45 pools out of 49 dissection positive pools as positive for infection and hence found to be less sensitive than the conventional technique. The reason for detecting four dissection positive pools as negatives by the PCR assay may be due to the loss of a few numbers of parasites (1-3) present in these pools during the transfer of washings of dissected mosquitoes. The PCR assay detected ten out of 72 dissection negative pools as positives, while it did not detect any of the 62 known negative (laboratory reared, uninfected) mosquito pools as positives. When 38 pools (10 mosquitoes/pool) of intact mosquitoes were assessed for infection by each method, the infection rates obtained by the two methods were almost similar (3.35 and 3.01%, respectively, for conventional method and PCR assay). The results thus show that the DNA extraction method, which is simple, rapid, safe and inexpensive, is efficient to generate DNA from vector mosquitoes useful in PCR assay and hence has potential application in xenomonitoring.
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Affiliation(s)
- V Vasuki
- Vector Control Research Centre (ICMR), Medical Complex, Indira Nagar, 600 006 Pondicherry, India.
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Yera H, Tzen M, Dupouy-Camet J. Molecular biology for detection and characterization of protozoan infections in humans. Eur J Protistol 2003. [DOI: 10.1078/0932-4739-00017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
Toxoplasmosis is an anthropozoonotic disease endemic world-wide, caused by the apicomplexan Toxoplasma gondii. Although the course of infection is generally benign, it can cause significant morbidity and mortality in the developing fetus and in immunocompromised individuals. Biological diagnosis classically relies upon serology and direct detection of the parasite by inoculation to laboratory animals. In the past decade, the use of the polymerase chain reaction (PCR) has made a significant improvement in both the prenatal diagnosis of congenital toxoplasmosis and the detection of acute disease in the immunocompromised patient. Nevertheless, like many 'in-house' PCR assays, the PCR-Toxoplasma suffers from lack of standardization and variable performance according to the laboratory. A wide variety of primers has been used in different assays, but few comparative tests have been performed. Moreover, in contrast to other parasitic diseases, PCR-Toxoplasma has not yet attained a sufficient level of sensitivity, regardless of the clinical condition considered. These drawbacks are discussed, together with the undoubted gain that PCR has brought to this difficult diagnosis.
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Affiliation(s)
- Patrick Bastien
- CNRS UMR 5093 Gènome des Protozoaires Parasites, Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire, Faculté de Médecine, 163 Rue A. Broussonet, 34090 Montpellier, France.
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