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Richins T, Houghton K, Barratt J, H. Sapp SG, Peterson A, Qvarnstrom Y. Comparison of two novel one-tube nested real-time qPCR assays to detect human-infecting Cyclospora spp. Microbiol Spectr 2023; 11:e0138823. [PMID: 37819113 PMCID: PMC10715049 DOI: 10.1128/spectrum.01388-23] [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: 03/30/2023] [Accepted: 09/01/2023] [Indexed: 10/13/2023] Open
Abstract
IMPORTANCE Human-infecting Cyclospora spp. cause gastrointestinal distress among healthy individuals contributing to morbidity and putting stress on the economics of countries and companies in the form of produce recalls. Accessible and easy-to-use diagnostic tools available to a wide variety of laboratories would aid in the early detection of possible outbreaks of cyclosporiasis. This, in turn, will assist in the timely traceback investigation to the suspected source of an outbreak by informing the smallest possible recall and protecting consumers from contaminated produce. This manuscript describes two novel detection methods with improved performance for the causative agents of cyclosporiasis when compared to the currently used 18S assay.
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Affiliation(s)
- Travis Richins
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Parasitic Disease Branch, Atlanta, USA
- Oak Ridge Associated Universities, Oak Ridge, Tennessee, USA
| | | | - Joel Barratt
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Parasitic Disease Branch, Atlanta, USA
- Oak Ridge Associated Universities, Oak Ridge, Tennessee, USA
| | - Sarah G. H. Sapp
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Parasitic Disease Branch, Atlanta, USA
| | - Anna Peterson
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Parasitic Disease Branch, Atlanta, USA
- Oak Ridge Associated Universities, Oak Ridge, Tennessee, USA
| | - Yvonne Qvarnstrom
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Parasitic Disease Branch, Atlanta, USA
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Santana BN, Ferrari ED, Nakamura AA, Silva GSD, Meireles MV. Validation of a one-tube nested real-time PCR assay for the detection of Cryptosporidium spp. in avian fecal samples. REVISTA BRASILEIRA DE PARASITOLOGIA VETERINARIA = BRAZILIAN JOURNAL OF VETERINARY PARASITOLOGY : ORGAO OFICIAL DO COLEGIO BRASILEIRO DE PARASITOLOGIA VETERINARIA 2022; 31:e000522. [PMID: 35320826 PMCID: PMC9901886 DOI: 10.1590/s1984-29612022017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 02/21/2022] [Indexed: 11/22/2022]
Abstract
The aim of this study was to validate a one-tube nested real-time PCR assay followed by genetic sequencing to detect and identify Cryptosporidium species and genotypes in birds. A total of 443 genomic DNA extracted from avian fecal samples were analyzed by one-tube nested real-time PCR and conventional nested PCR. By one-tube nested real-time PCR, 90/443 (20.3%) samples were positive for Cryptosporidium spp. In contrast, 36/443 (8.1%) samples were positive for Cryptosporidium spp. by conventional nested PCR. The analytical sensitivity test showed that one-tube nested real-time PCR detects approximately 0.5 oocyst (2 sporozoites) per reaction. An evaluation of analytical specificity did not reveal amplification of microorganisms that commonly present nonspecific amplification with primers used for the diagnosis of Cryptosporidium spp. The repeatability analysis showed the same result in 27 out of 30 samples (90%). As for the reproducibility of one-tube nested real-time PCR, 24 of the 30 samples examined (80%) showed the same result. All the 90 samples amplified by one-tube real-time nested PCR were successfully sequenced, leading to the identification of C. baileyi, C. galli, C. meleagridis, C. proventriculi, and Cryptosporidium avian genotype I. Genetic sequencing of conventional nested PCR amplicons was successful in 10/36 (27.8%) of positive samples.
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Affiliation(s)
- Bruna Nicoleti Santana
- Faculdade de Medicina Veterinária, Universidade Estadual Paulista - UNESP, Araçatuba, SP, Brasil
| | - Elis Domingos Ferrari
- Faculdade de Medicina Veterinária, Universidade Estadual Paulista - UNESP, Araçatuba, SP, Brasil
| | - Alex Akira Nakamura
- Faculdade de Medicina Veterinária, Universidade Estadual Paulista - UNESP, Araçatuba, SP, Brasil
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O'Leary JK, Sleator RD, Lucey B. Cryptosporidium spp. diagnosis and research in the 21 st century. Food Waterborne Parasitol 2021; 24:e00131. [PMID: 34471706 PMCID: PMC8390533 DOI: 10.1016/j.fawpar.2021.e00131] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/06/2021] [Accepted: 08/17/2021] [Indexed: 01/01/2023] Open
Abstract
The protozoan parasite Cryptosporidium has emerged as a leading cause of diarrhoeal illness worldwide, posing a significant threat to young children and immunocompromised patients. While endemic in the vast majority of developing countries, Cryptosporidium also has the potential to cause waterborne epidemics and large scale outbreaks in both developing and developed nations. Anthroponontic and zoonotic transmission routes are well defined, with the ingestion of faecally contaminated food and water supplies a common source of infection. Microscopy, the current diagnostic mainstay, is considered by many to be suboptimal. This has prompted a shift towards alternative diagnostic techniques in the advent of the molecular era. Molecular methods, particularly PCR, are gaining traction in a diagnostic capacity over microscopy in the diagnosis of cryptosporidiosis, given the laborious and often tedious nature of the latter. Until now, developments in the field of Cryptosporidium detection and research have been somewhat hampered by the intractable nature of this parasite. However, recent advances in the field have taken the tentative first steps towards bringing Cryptosporidium research into the 21st century. Herein, we provide a review of these advances.
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Affiliation(s)
- Jennifer K. O'Leary
- Department of Biological Sciences, Munster Technological University, Bishopstown Campus, Cork, Ireland
| | - Roy D. Sleator
- Department of Biological Sciences, Munster Technological University, Bishopstown Campus, Cork, Ireland
| | - Brigid Lucey
- Department of Biological Sciences, Munster Technological University, Bishopstown Campus, Cork, Ireland
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Koutsoumanis K, Allende A, Alvarez-Ordóñez A, Bolton D, Bover-Cid S, Chemaly M, Davies R, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Cacciò S, Chalmers R, Deplazes P, Devleesschauwer B, Innes E, Romig T, van der Giessen J, Hempen M, Van der Stede Y, Robertson L. Public health risks associated with food-borne parasites. EFSA J 2018; 16:e05495. [PMID: 32625781 PMCID: PMC7009631 DOI: 10.2903/j.efsa.2018.5495] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Parasites are important food‐borne pathogens. Their complex lifecycles, varied transmission routes, and prolonged periods between infection and symptoms mean that the public health burden and relative importance of different transmission routes are often difficult to assess. Furthermore, there are challenges in detection and diagnostics, and variations in reporting. A Europe‐focused ranking exercise, using multicriteria decision analysis, identified potentially food‐borne parasites of importance, and that are currently not routinely controlled in food. These are Cryptosporidium spp., Toxoplasma gondii and Echinococcus spp. Infection with these parasites in humans and animals, or their occurrence in food, is not notifiable in all Member States. This Opinion reviews current methods for detection, identification and tracing of these parasites in relevant foods, reviews literature on food‐borne pathways, examines information on their occurrence and persistence in foods, and investigates possible control measures along the food chain. The differences between these three parasites are substantial, but for all there is a paucity of well‐established, standardised, validated methods that can be applied across the range of relevant foods. Furthermore, the prolonged period between infection and clinical symptoms (from several days for Cryptosporidium to years for Echinococcus spp.) means that source attribution studies are very difficult. Nevertheless, our knowledge of the domestic animal lifecycle (involving dogs and livestock) for Echinoccocus granulosus means that this parasite is controllable. For Echinococcus multilocularis, for which the lifecycle involves wildlife (foxes and rodents), control would be expensive and complicated, but could be achieved in targeted areas with sufficient commitment and resources. Quantitative risk assessments have been described for Toxoplasma in meat. However, for T. gondii and Cryptosporidium as faecal contaminants, development of validated detection methods, including survival/infectivity assays and consensus molecular typing protocols, are required for the development of quantitative risk assessments and efficient control measures.
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An overview of methods/techniques for the detection of Cryptosporidium in food samples. Parasitol Res 2018; 117:629-653. [PMID: 29350281 DOI: 10.1007/s00436-017-5735-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 12/26/2017] [Indexed: 11/27/2022]
Abstract
Cryptosporidium is one of the most important parasitic protozoa of concern within the food production industry, worldwide. This review describes the evolution and its development, and it monitors the methodology that has been used for Cryptosporidium in food material since 1984, when the first publication appeared regarding the detection of Cryptosporidium parvum in food materials. The methods that are currently being used for the detection of Cryptosporidium oocysts in food material (mainly vegetables) and all of the other available published methods are discussed in this review. Generating more consistent and reliable data should lead to a better understanding of the occurrence, transport and fate of the oocysts in food material. Improvements in monitoring and developing effective methodology, along with food security, offer more practical possibilities for both the developed and developing worlds.
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Koloren Z, Ayaz E. Genotyping of Cryptosporidium spp. in environmental water in Turkey. Acta Parasitol 2016; 61:671-679. [PMID: 27787219 DOI: 10.1515/ap-2016-0094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 05/23/2016] [Indexed: 11/15/2022]
Abstract
This research was undertaken to study the molecular detection and characterization of Cryptosporidium spp. in environmental water sources at Samsun and Giresun Provinces of The Black Sea in Turkey. Two-hundred forty and one-hundred eighty environmental samples were collected from a total of twenty and twenty-five sampling sites of Giresun and Samsun Provinces. One hundred twenty untreated drinking water samples were also detected for Cryptosporidium spp. in both investigated areas. 101 (%42), 92 (%38.3) of 240 and 74 (41.1%), 70 (38.8%) of 180 environmental samples have been found positive for Cryptosporidium spp. by Loop mediated isothermal amplification (LAMP) targeting the S-adenosyl-L-methionine synthetase (SAM) gene and nested PCR targeting small subunit (SSU)rRNA gene in Samsun and Giresun Provinces, respectively. Of the tested untreated drinking water samples collected from the investigated area, one sample was positive for Cryptosporidium spp. Six and twelve samples were clearly sequenced for the Cryptosporidium (SSU)rRNA gene among the highest positive samples selected from each of the twenty and twenty-five sampling sites of Giresun and Samsun Provinces, respectively. Genetic characterization of Cryptosporidium isolates from water samples represented Cryptosporidium bovis for five samples, Cryptosporidium parvum for six samples and one sample for Cryptosporidium felis in Samsun Province, where C. parvum for five samples and C. bovis for one sample were sequenced in Giresun Province. According to accessible information sources, this is the first research about genotyping of Cryptosporidium spp. in water samples collected from Samsun and Giresun Provinces of Turkey.
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Chow NA, Griffin DW, Barker BM, Loparev VN, Litvintseva AP. Molecular detection of airborne Coccidioides in Tucson, Arizona. Med Mycol 2016; 54:584-92. [PMID: 27143633 DOI: 10.1093/mmy/myw022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 02/03/2016] [Indexed: 11/12/2022] Open
Abstract
Environmental surveillance of the soil-dwelling fungus Coccidioides is essential for the prevention of Valley fever, a disease primarily caused by inhalation of the arthroconidia. Methods for collecting and detecting Coccidioides in soil samples are currently in use by several laboratories; however, a method utilizing current air sampling technologies has not been formally demonstrated for the capture of airborne arthroconidia. In this study, we collected air/dust samples at two sites (Site A and Site B) in the endemic region of Tucson, Arizona, and tested a variety of air samplers and membrane matrices. We then employed a single-tube nested qPCR assay for molecular detection. At both sites, numerous soil samples (n = 10 at Site A and n = 24 at Site B) were collected and Coccidioides was detected in two samples (20%) at Site A and in eight samples (33%) at Site B. Of the 25 air/dust samples collected at both sites using five different air sampling methods, we detected Coccidioides in three samples from site B. All three samples were collected using a high-volume sampler with glass-fiber filters. In this report, we describe these methods and propose the use of these air sampling and molecular detection strategies for environmental surveillance of Coccidioides.
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Affiliation(s)
- Nancy A Chow
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Dale W Griffin
- US Geological Survey, Coastal and Marine Science Center, St. Petersburg, Florida
| | - Bridget M Barker
- Division of Pathogen Genomics, Translational Genomics Research Institute, Flagstaff, Arizona Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, Arizona Valley Fever Center for Excellence, University of Arizona, Tucson, Arizona
| | - Vladimir N Loparev
- Biotechnology Core Facility Branch, Centers for Disease Control and Prevention, Atlanta, GA
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Genotyping of Cryptosporidium Species and Their Clinical Manifestations in Patients with Renal Transplantation and Human Immunodeficiency Virus Infection. J Pathog 2016; 2016:2623602. [PMID: 26981284 PMCID: PMC4769749 DOI: 10.1155/2016/2623602] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 12/27/2015] [Indexed: 01/10/2023] Open
Abstract
In the present study we aimed to determine (i) frequency of Cryptosporidium species among patients with renal transplantation (RT) and human immunodeficiency virus (HIV) infection and (ii) relationship of the nature, severity, and duration of symptoms with different species and load of Cryptosporidium. Stool samples from 70 (42 RT and 28 HIV) and 140 immunocompromised patients with and without cryptosporidiosis by modified Kinyoun's staining were subjected to qPCR-melting curve analysis for identification of parasite species. qPCR detected one microscopically negative sample to be positive for cryptosporidiosis. C. hominis, C. parvum, and mixed infection were detected in 50/71 (70.4%), 19/71 (26.8%), and 2/71 (2.8%) patients, respectively. Patients with cryptosporidiosis had higher stool frequency (median, IQR: 4, 3–6/d versus 3, 2–4/d; P = 0.017) and watery stool (52/71 [73%] versus 64/139 [46%]; P = 0.003). Parasite load (median, IQR: Log10 6.37 (5.65–7.12), Log10 5.81 (4.26–6.65); P = 0.046) and nausea/vomiting (29/50 [58%] versus 5/19 [26%]; P = 0.032) were more frequent with C. hominis than with C. parvum infection. Thus, Cryptosporidium spp. (mainly C. hominis) is a common cause of diarrhoea in RT and HIV patients.
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Adamska M, Sawczuk M, Kolodziejczyk L, Skotarczak B. Assessment of molecular methods as a tool for detecting pathogenic protozoa isolated from water bodies. JOURNAL OF WATER AND HEALTH 2015; 13:953-959. [PMID: 26608757 DOI: 10.2166/wh.2015.077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Several species belong to the Cryptosporidium and Giardia genus, the main parasitic protozoa occurring in water, but only some of them are infectious to humans. We investigated the occurrence of Cryptosporidium and Giardia and identified their species in the water samples collected from natural water bodies in north-western Poland. A total of 600 samples from water bodies used for bathing, sewage discharge, as drinking water sources and watering places for animals were screened. The samples were collected during a 3-year period in each of the four seasons and filtered using Filta-Max (IDEXX Laboratories, USA). Genomic DNA was extracted from all samples and used as a target sequence for polymerase chain reaction (PCR) and TaqMan real-time PCR, as well as for reverse line blotting (RLB) methods. PCR methods seem to be more sensitive to detect Giardia and Cryptosporidium DNA in water samples than RLB methods. All PCR products were sequenced and three were identified as C. parvum and four as G. intestinalis. The overall prevalence of C. parvum (0.5%) and G. intestinalis (0.6%) in the samples suggests that the risk of Cryptosporidium and Giardia infections in north-western Poland is minimal.
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Affiliation(s)
- M Adamska
- Department of Genetics, Szczecin University, Felczaka 3c, 71-412 Szczecin, Poland E-mail:
| | - M Sawczuk
- Department of Genetics, Szczecin University, Felczaka 3c, 71-412 Szczecin, Poland E-mail:
| | - L Kolodziejczyk
- Chair and Department of Biology and Medical Parasitology, Pomeranian Medical University, Szczecin, Poland
| | - B Skotarczak
- Department of Genetics, Szczecin University, Felczaka 3c, 71-412 Szczecin, Poland E-mail:
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Nurminen N, Juuti R, Oikarinen S, Fan YM, Lehto KM, Mangani C, Maleta K, Ashorn P, Hyöty H. High-throughput multiplex quantitative polymerase chain reaction method for Giardia lamblia and Cryptosporidium species detection in stool samples. Am J Trop Med Hyg 2015; 92:1222-6. [PMID: 25918202 DOI: 10.4269/ajtmh.15-0054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 02/27/2015] [Indexed: 11/07/2022] Open
Abstract
Giardia lamblia and Cryptosporidium species belong to a complex group of pathogens that cause diseases hampering development and socioeconomic improvements in the developing countries. Both pathogens are recognized as significant causes of diarrhea and nutritional disorders. However, further studies are needed to clarify the role of parasitic infections, especially asymptomatic infections in malnutrition and stunting. We developed a high-throughput multiplex quantitative polymerase chain reaction (qPCR) method for G. lamblia and Cryptosporidium spp. detection in stool samples. The sensitivity and specificity of the method were ensured by analyzing confirmed positive samples acquired from diagnostics laboratories and participating in an external quality control round. Its capability to detect asymptomatic G. lamblia and Cryptosporidium spp. infections was confirmed by analyzing stool samples collected from 44 asymptomatic 6-month-old infants living in an endemic region in Malawi. Of these, five samples were found to be positive for G. lamblia and two for Cryptosporidium spp. In conclusion, the developed method is suitable for large-scale studies evaluating the occurrence of G. lamblia and Cryptosporidium spp. in endemic regions and for clinical diagnostics of these infections.
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Affiliation(s)
- Noora Nurminen
- Department of Virology, School of Medicine, University of Tampere, Finland; Department for International Health, School of Medicine, University of Tampere, Finland; School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland
| | - Rosa Juuti
- Department of Virology, School of Medicine, University of Tampere, Finland; Department for International Health, School of Medicine, University of Tampere, Finland; School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland
| | - Sami Oikarinen
- Department of Virology, School of Medicine, University of Tampere, Finland; Department for International Health, School of Medicine, University of Tampere, Finland; School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland
| | - Yue-Mei Fan
- Department of Virology, School of Medicine, University of Tampere, Finland; Department for International Health, School of Medicine, University of Tampere, Finland; School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland
| | - Kirsi-Maarit Lehto
- Department of Virology, School of Medicine, University of Tampere, Finland; Department for International Health, School of Medicine, University of Tampere, Finland; School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland
| | - Charles Mangani
- Department of Virology, School of Medicine, University of Tampere, Finland; Department for International Health, School of Medicine, University of Tampere, Finland; School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland
| | - Kenneth Maleta
- Department of Virology, School of Medicine, University of Tampere, Finland; Department for International Health, School of Medicine, University of Tampere, Finland; School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland
| | - Per Ashorn
- Department of Virology, School of Medicine, University of Tampere, Finland; Department for International Health, School of Medicine, University of Tampere, Finland; School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland
| | - Heikki Hyöty
- Department of Virology, School of Medicine, University of Tampere, Finland; Department for International Health, School of Medicine, University of Tampere, Finland; School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi; Department of Pediatrics, Tampere University Hospital, Tampere, Finland; Fimlab Laboratories, Pirkanmaa Hospital District, Tampere, Finland
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Optimization of single-tube nested PCR for the diagnosis of visceral leishmaniasis. Exp Parasitol 2013; 134:206-10. [PMID: 23507078 DOI: 10.1016/j.exppara.2013.03.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 03/01/2013] [Accepted: 03/02/2013] [Indexed: 12/25/2022]
Abstract
Conventional nested PCR is a very sensitive and specific method for the diagnosis of visceral leishmaniasis. However, this type of PCR is notorious for contamination problems related to the processing of the product between the first and the second PCR steps. In order to have a PCR method that is just as efficient but without the risk of contamination, we attempted the optimization of a single-tube nested PCR (STNPCR) method. During the first and the second PCR steps, we used the small subunit of ribosomal RNA (ssu rRNA) and the ribosomal internal transcribed spacer (ITS) as targets, respectively. The performances of STNPCR and nested PCR in detecting the DNA of Leishmania chagasi were compared. In the case of STNPCR, the inner primers were immobilized on the interior of the tube cap by means of adsorption microtubes and then were solubilized before the second reaction. This procedure eliminated the need to open the microtube, which could have led to false-positive results through cross-contamination. The detection limit for the purified L. chagasi DNA was 1 fg by using nested PCR and 10 fg by using STNPCR. We also tested the specificity of the system against other parasites, and observed that Trypanosoma cruzi DNA was amplified with a detection limit of up to 1 pg. This study not only presents a promising tool for the diagnosis of visceral leishmaniasis, but also provides a new tool for the diagnosis of Chagas disease, either in mono-infection by T. cruzi or in co-infection with Leishmania spp.
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Costa J, Mafra I, Kuchta T, Oliveira MBPP. Single-tube nested real-time PCR as a new highly sensitive approach to trace hazelnut. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:8103-10. [PMID: 22849792 DOI: 10.1021/jf302898z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Hazelnut is one of the most commonly consumed tree nuts, being largely used by the food industry in a wide variety of processed foods. However, it is a source of allergens capable of inducing mild to severe allergic reactions in sensitized individuals. Hence, the development of highly sensitive methodologies for hazelnut traceability is essential. In this work, we developed a novel technique for hazelnut detection based on a single-tube nested real-time PCR system. The system presents high specificity and sensitivity, enabling a relative limit of detection of 50 mg/kg of hazelnut in wheat material and an absolute limit of detection of 0.5 pg of hazelnut DNA (1 DNA copy). Its application to processed food samples was successfully achieved, detecting trace amounts of hazelnut in chocolate down to 60 mg/kg. These results highlight the adequacy of the technique for the specific detection and semiquantitation of hazelnut as potential hidden allergens in foods.
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Affiliation(s)
- Joana Costa
- REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, Portugal
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Homem CG, Nakamura AA, Silva DC, Teixeira WFP, Coelho WMD, Meireles MV. Real-time PCR assay targeting the actin gene for the detection of Cryptosporidium parvum in calf fecal samples. Parasitol Res 2011; 110:1741-5. [DOI: 10.1007/s00436-011-2694-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 10/07/2011] [Indexed: 10/16/2022]
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Bergerová E, Brežná B, Kuchta T. A novel method with improved sensitivity for the detection of peanuts based upon single-tube nested real-time polymerase chain reaction. Eur Food Res Technol 2011. [DOI: 10.1007/s00217-011-1484-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Minarovičová J, Lopašovská J, Valík Ľ, Kuchta T. A Method for the Detection of Cryptosporidium parvum Oocysts in Milk Based on Microfiltration and Real-Time Polymerase Chain Reaction. FOOD ANAL METHOD 2010. [DOI: 10.1007/s12161-010-9141-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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