1
|
Lawaju BR, Yan G, Whitworth J. Development of a Droplet Digital PCR Assay for Detection and Quantification of Stubby Root Nematode, Paratrichodorus allius, in Soil. Plant Dis 2023; 107:3344-3353. [PMID: 37115564 DOI: 10.1094/pdis-03-23-0439-sr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The stubby root nematode Paratrichodorus allius is an important plant-parasitic nematode species within the Trichodoridae family. It can directly harm the plants by feeding on the roots or indirectly by transmitting Tobacco rattle virus. These nematodes are mostly diagnosed either by traditional microscopic methods or a polymerase chain reaction (PCR)-based method. Droplet digital PCR (ddPCR) is a novel PCR technique which is sensitive and precise in quantifying DNA templates of the test samples. In this study, we developed a ddPCR assay to detect and quantify P. allius in soil. The specificity and sensitivity of the assay was first determined using P. allius nematode DNA or DNA from sterilized soil artificially inoculated with P. allius, and the assay was used to quantify P. allius populations in field soils. The assay did not detect nematodes other than P. allius, thus showing high specificity. It was able to detect P. allius equivalent to a 0.01 and 0.02 portion of a single nematode in soil DNA and nematode DNA extracts, respectively. Highly linear relationships between DNA copy numbers from ddPCR and serial dilutions of known concentrations were observed with DNA from P. allius nematodes (R2 = 0.9842) and from artificially infested soil (R2 = 0.9464). The P. allius populations from field soils determined by ddPCR were highly correlated with traditional microscopic counts (R2 = 0.7963). To our knowledge, this is the first report of applying ddPCR to detect and quantify stubby root nematode in soil. The results of this study support the potentiality of a ddPCR assay as a new research tool in diagnostics of plant-parasitic nematodes.
Collapse
Affiliation(s)
- Bisho Ram Lawaju
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108
| | - Guiping Yan
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108
| | - Jonathan Whitworth
- Small Grains and Potato Germplasm Research Unit, USDA-ARS, Aberdeen, ID 83210
| |
Collapse
|
2
|
Baltrušis P, Höglund J. Digital PCR: modern solution to parasite diagnostics and population trait genetics. Parasit Vectors 2023; 16:143. [PMID: 37098569 PMCID: PMC10131454 DOI: 10.1186/s13071-023-05756-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 03/23/2023] [Indexed: 04/27/2023] Open
Abstract
The use of polymerase chain reaction (PCR)-based diagnostic approaches has steadily increased in the field of parasitology in recent decades. The most recent large-scale technological modification of the PCR formula, also known as third-generation PCR, came in the form of digital PCR (dPCR). Currently, the most common form of dPCR on the market is digital droplet PCR (ddPCR). Unlike quantitative real-time PCR (qPCR), the digital format allows for highly sensitive, absolute quantification of nucleic acid targets and does not require external standards to be included in the developed assays. Dividing each sample into thousands of compartments and using statistical models also eliminates the need for technical replicates. With unprecedented sensitivity and enforcement of binary endpoint reactions, ddPCR not only allows the use of tiny sample volumes (especially important when working with limited amounts of DNA) but also minimises the impact of variations in amplification efficiency and the presence of inhibitors. As ddPCR is characterised by excellent features such as high throughput, sensitivity and robust quantification, it is widely used as a diagnostic tool in clinical microbiology. Due to recent advances, both the theoretical background and the practical, current applications related to the quantification of nucleic acids of eukaryotic parasites need to be updated. In this review, we present the basics of this technology (particularly useful for new users) and consolidate recent advances in the field with a focus on applications to the study of helminths and protozoan parasites.
Collapse
Affiliation(s)
- Paulius Baltrušis
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Johan Höglund
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| |
Collapse
|
3
|
Rinaldi L, Krücken J, Martinez-Valladares M, Pepe P, Maurelli MP, de Queiroz C, Castilla Gómez de Agüero V, Wang T, Cringoli G, Charlier J, Gilleard JS, von Samson-Himmelstjerna G. Advances in diagnosis of gastrointestinal nematodes in livestock and companion animals. Adv Parasitol 2022; 118:85-176. [PMID: 36088084 DOI: 10.1016/bs.apar.2022.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Diagnosis of gastrointestinal nematodes in livestock and companion animals has been neglected for years and there has been an historical underinvestment in the development and improvement of diagnostic tools, undermining the undoubted utility of surveillance and control programmes. However, a new impetus by the scientific community and the quickening pace of technological innovations, are promoting a renaissance of interest in developing diagnostic capacity for nematode infections in veterinary parasitology. A cross-cutting priority for diagnostic tools is the development of pen-side tests and associated decision support tools that rapidly inform on the levels of infection and morbidity. This includes development of scalable, parasite detection using artificial intelligence for automated counting of parasitic elements and research towards establishing biomarkers using innovative molecular and proteomic methods. The aim of this review is to assess the state-of-the-art in the diagnosis of helminth infections in livestock and companion animals and presents the current advances of diagnostic methods for intestinal parasites harnessing (i) automated methods for copromicroscopy based on artificial intelligence, (ii) immunodiagnosis, and (iii) molecular- and proteome-based approaches. Regardless of the method used, multiple factors need to be considered before diagnostics test results can be interpreted in terms of control decisions. Guidelines on how to apply diagnostics and how to interpret test results in different animal species are increasingly requested and some were recently made available in veterinary parasitology for the different domestic species.
Collapse
Affiliation(s)
- Laura Rinaldi
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy.
| | - J Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
| | - M Martinez-Valladares
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, León, Spain
| | - P Pepe
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | - M P Maurelli
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | - C de Queiroz
- Faculty of Veterinary Medicine, 3331 Hospital Drive, Host-Parasite Interactions (HPI) Program University of Calgary, Calgary, Alberta, Canada; Faculty of Veterinary Medicine, St Georges University, Grenada
| | - V Castilla Gómez de Agüero
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, León, Spain
| | - T Wang
- Kreavet, Kruibeke, Belgium
| | - Giuseppe Cringoli
- Department of Veterinary Medicine and Animal Production, University of Naples "Federico II", Naples, Italy
| | | | - J S Gilleard
- Faculty of Veterinary Medicine, 3331 Hospital Drive, Host-Parasite Interactions (HPI) Program University of Calgary, Calgary, Alberta, Canada
| | - G von Samson-Himmelstjerna
- Institute for Parasitology and Tropical Veterinary Medicine, Veterinary Centre for Resistance Research, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
4
|
Mancusi A, Giordano A, Bosco A, Girardi S, Proroga YTR, Morena L, Pinto R, Sarnelli P, Cringoli G, Rinaldi L, Capuano F, Maurelli MP. Development of a droplet digital polymerase chain reaction tool for the detection of Toxoplasma gondii in meat samples. Parasitol Res 2022; 121:1467-1473. [PMID: 35230549 PMCID: PMC8993784 DOI: 10.1007/s00436-022-07477-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/22/2022] [Indexed: 12/14/2022]
Abstract
Toxoplasmosis is a zoonotic disease caused by the protozoan parasite Toxoplasma gondii. Infection in humans has usually been related to the consumption of raw, undercooked or cured meat. The aim of this study was to develop a droplet digital polymerase chain reaction (ddPCR)-based assay for the detection and quantification of T. gondii in meat samples. To optimize the ddPCR, T.gondii reference DNA aliquots at five known concentrations: 8000 cg/µl, 800 cg/µl, 80 cg/µl, 8 cg/µl were used. Moreover, results obtained by ddPCR and quantitative PCR (qPCR) were compared using 80 known samples (40 positive and 40 negative), as well as 171 unknown diaphragm tissue samples collected at slaughterhouses. The ddPCR showed a sensitivity of 97.5% and a specificity of 100%, with a detection limit of 8 genomic copy/µl of T. gondii. A nearly perfect agreement (κ = 0.85) was found between results obtained by ddPCR and qPCR for both positive and negative known samples analysed. On the 171 diaphragm tissue samples from field, 7.6% resulted positive by ddPCR and only 1.2% by qPCR. Therefore, this innovative method could be very useful for the detection of T. gondii in meat samples, aiming to prevent human infections.
Collapse
Affiliation(s)
- Andrea Mancusi
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, NA), Italy
| | - Angela Giordano
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, NA), Italy
| | - Antonio Bosco
- Unit of Parasitology and Parasitic Diseases, Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, Naples, Italy
| | - Santa Girardi
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, NA), Italy
| | | | - Luigi Morena
- Centro Di Riferimento Regionale Sanità Animale (CReSan), Salerno, Italy
| | - Renato Pinto
- UOD Prevenzione E Sanità Pubblica Veterinaria Regione Campania, Naples, Italy
| | - Paolo Sarnelli
- UOD Prevenzione E Sanità Pubblica Veterinaria Regione Campania, Naples, Italy
| | - Giuseppe Cringoli
- Unit of Parasitology and Parasitic Diseases, Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, Naples, Italy
- Centro Di Riferimento Regionale Sanità Animale (CReSan), Salerno, Italy
| | - Laura Rinaldi
- Unit of Parasitology and Parasitic Diseases, Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, Naples, Italy
- Centro Di Riferimento Regionale Sanità Animale (CReSan), Salerno, Italy
| | - Federico Capuano
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, NA), Italy
| | - Maria Paola Maurelli
- Unit of Parasitology and Parasitic Diseases, Department of Veterinary Medicine and Animal Production, University of Naples Federico II, CREMOPAR, Naples, Italy.
| |
Collapse
|
5
|
Sahu R, Vishnuraj MR, Srinivas C, Dadimi B, Megha GK, Pollumahanti N, Malik SS, Vaithiyanathan S, Rawool DB, Barbuddhe SB. Development and comparative evaluation of droplet digital PCR and quantitative PCR for the detection and quantification of Chlamydia psittaci. J Microbiol Methods 2021; 190:106318. [PMID: 34592374 DOI: 10.1016/j.mimet.2021.106318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/28/2021] [Accepted: 08/29/2021] [Indexed: 10/20/2022]
Abstract
Chlamydia psittaci is a zoonotic pathogen mainly transmitted by psittacine birds and poultry. The low shedding rate of the pathogen in the apparently healthy birds and human clinical cases may result in false-negative results. In the present study, a droplet digital PCR (ddPCR) assay was developed and compared with optimized quantitative PCR (qPCR) for the detection of C. psittaci from the clinical samples. The ddPCR assay was found to be comparatively more sensitive than the qPCR, wherein the limit of detection (LOD) of ddPCR was upto 2.4 copies of the DNA template, whereas, the qPCR could detect upto 38 copies of the DNA template in the reaction mixture. Overall, the developed ddPCR assay was found to be robust, specific, and could reliably quantify up to 17.8 copies of the DNA template. Finally, the applicability of the developed ddPCR assay was tested by screening the field samples (n = 124), comprising lung tissues from dead poultry and feral birds; pooled faecal samples from the free-living birds, commercial and backyard poultry farms; pharyngeal and cloacal swabs collected from the duck farms. Of these, a total of seven samples were found to be positive by the ddPCR, whereas, three samples could be detected as positive using the qPCR. The developed ddPCR could serve as a reliable screening tool, particularly in those clinical samples wherein the shedding of C. psittaci is substantially very low.
Collapse
Affiliation(s)
- Radhakrishna Sahu
- ICAR-National Research Centre on Meat, Chengicherla, Hyderabad 500092, India; Department of Veterinary Public Health, ICAR- Indian Veterinary Research Institute, Izatnagar 243122, India
| | - M R Vishnuraj
- ICAR-National Research Centre on Meat, Chengicherla, Hyderabad 500092, India
| | - Ch Srinivas
- ICAR-National Research Centre on Meat, Chengicherla, Hyderabad 500092, India
| | - Bhargavi Dadimi
- Department of Veterinary Public Health, ICAR- Indian Veterinary Research Institute, Izatnagar 243122, India
| | - G K Megha
- Department of Veterinary Public Health, ICAR- Indian Veterinary Research Institute, Izatnagar 243122, India
| | | | - Satyaveer S Malik
- Department of Veterinary Public Health, ICAR- Indian Veterinary Research Institute, Izatnagar 243122, India
| | - S Vaithiyanathan
- ICAR-National Research Centre on Meat, Chengicherla, Hyderabad 500092, India
| | - Deepak B Rawool
- ICAR-National Research Centre on Meat, Chengicherla, Hyderabad 500092, India
| | | |
Collapse
|