scholarly journals Using a Loop-Mediated Isothermal Amplification (LAMP) Assay and Direct DNA Extraction Method from Wood for Rapid Detection of Verticillium dahliae in Olive Trees

2017 ◽  
Vol 14 (2) ◽  
pp. 727-734
Author(s):  
Saba Aslani ◽  
Ghasemali Garoosi ◽  
Hossein Jafary

ABSTRACT: Verticillium wilt, which is caused by the fungus Verticillium dahliae, is one of the most important olive diseases worldwide. There are many ways to extract DNA from plant pathogenic fungi and from plant tissues for molecular-based diagnostic assays. LAMP is a new and sensitive molecular-based technique used for detection of plant pathogenic agents with minimum requirements needed. In this study, we tried to achieve a simple, cost effective and efficient method of DNA extraction from both Verticillium dahliae fungus and from infected wood samples in order to run a loop-mediated isothermal amplification (LAMP) assay. Efficiency of three DNA isolation methods from both mycelia and infected wood samples was evaluated. For this purpose, wood samples from infected olive trees were collected from Tarom region in Zanjan province and the samples were cultured on the media. The fungus was isolated and identified as V. dahliae based on morphological features. Then the genomic DNA was extracted using traditional CTAB method, fast NaOH method and direct isolation method from infected wood samples. After assessment of the quality and the quantity of the extracted DNA samples, a LAMP assay was ran using specific primer pairs and the DNA templates extracted using three different methods. In spite of the significant differences in the quantity of DNA samples, LAMP assay could successfully detect the fungus in all samples. The improved direct isolation of the DNA of V. dahlia from infected wood, followed by a LAMP assay could considerably shortened the detection process of the fungus and hence is a suitable method for screening of olive trees and saplings against Verticillium wilt disease.

2017 ◽  
Vol 07 (03) ◽  
pp. 042-048
Author(s):  
Gunimala Chakraborty ◽  
Indrani Karunasagar ◽  
Anirban Chakraborty

AbstractDelivery of quality healthcare in case of an infectious disease depends on how efficiently and how quickly the responsible pathogens are detected from the samples. Molecular methods can detect the presence of pathogens in a rapid and sensitive manner. Over the years, a number of such assays have been developed. However, these methods, although highly reliable and efficient, require use of expensive equipment, reagents, and trained personnel. Therefore, development of molecular assays that are simple, rapid, cost-effective, yet sensitive, is highly warranted to ensure efficient management or treatment strategies. Loop-mediated isothermal amplification (LAMP), a technique invented in the year 2000, is a novel method that amplifies DNA at isothermal conditions. Since its invention, this technique has been one of the most extensively used molecular diagnostic tools in the field of diagnostics offering rapid, accurate and cost-effective diagnosis of infectious diseases. Using the LAMP principle, many commercial kits have been developed in the last decade for a variety of human pathogens including bacteria, viruses and parasites. Currently LAMP assay is being considered as an effective diagnostic tool for use in developing countries because of its simple working protocol, allowing even an onsite application. The focus of this review is to describe the salient features of this technique the current status of development of LAMP assays with an emphasis on the pathogens of clinical significance.


Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 972 ◽  
Author(s):  
Mohammed A. Rohaim ◽  
Emily Clayton ◽  
Irem Sahin ◽  
Julianne Vilela ◽  
Manar E. Khalifa ◽  
...  

Until vaccines and effective therapeutics become available, the practical solution to transit safely out of the current coronavirus disease 19 (CoVID-19) lockdown may include the implementation of an effective testing, tracing and tracking system. However, this requires a reliable and clinically validated diagnostic platform for the sensitive and specific identification of SARS-CoV-2. Here, we report on the development of a de novo, high-resolution and comparative genomics guided reverse-transcribed loop-mediated isothermal amplification (LAMP) assay. To further enhance the assay performance and to remove any subjectivity associated with operator interpretation of results, we engineered a novel hand-held smart diagnostic device. The robust diagnostic device was further furnished with automated image acquisition and processing algorithms and the collated data was processed through artificial intelligence (AI) pipelines to further reduce the assay run time and the subjectivity of the colorimetric LAMP detection. This advanced AI algorithm-implemented LAMP (ai-LAMP) assay, targeting the RNA-dependent RNA polymerase gene, showed high analytical sensitivity and specificity for SARS-CoV-2. A total of ~200 coronavirus disease (CoVID-19)-suspected NHS patient samples were tested using the platform and it was shown to be reliable, highly specific and significantly more sensitive than the current gold standard qRT-PCR. Therefore, this system could provide an efficient and cost-effective platform to detect SARS-CoV-2 in resource-limited laboratories.


2020 ◽  
Author(s):  
Mohammed A Rohaim ◽  
Emily Clayton ◽  
Irem Sahin ◽  
Julianne Vilela ◽  
Manar E Khalifa ◽  
...  

Until vaccines and effective therapeutics become available, the practical way to transit safely out of the current lockdown may include the implementation of an effective testing, tracing and tracking system. However, this requires a reliable and clinically validated diagnostic platform for the sensitive and specific identification of SARS-CoV-2. Here, we report on the development of a de novo, high-resolution and comparative genomics guided reverse-transcribed loop-mediated isothermal amplification (LAMP) assay. To further enhance the assay performance and to remove any subjectivity associated with operator interpretation of result, we engineered a novel hand-held smart diagnostic device. The robust diagnostic device was further furnished with automated image acquisition and processing algorithms, and the collated data was processed through artificial intelligence (AI) pipelines to further reduce the assay run time and the subjectivity of the colorimetric LAMP detection. This advanced AI algorithm-implemented LAMP (ai-LAMP) assay, targeting the RNA-dependent RNA polymerase gene, showed high analytical sensitivity and specificity for SARS-CoV-2. A total of ~200 coronavirus disease (CoVID-19)-suspected patient samples were tested using the platform and it was shown to be reliable, highly specific and significantly more sensitive than the current gold standard qRT-PCR. The system could provide an efficient and cost-effective platform to detect SARS-CoV-2 in resource-limited laboratories.


Author(s):  
Muhammad Awais Salim ◽  
Raheela Akhtar ◽  
Muhammad Lateef ◽  
Imran Rashid ◽  
Harron Akbar ◽  
...  

The objective of present study was to optimize loop mediated isothermal amplification (LAMP) assay for the diagnosis of Babesia felis in cats. LAMP primers were designed recognizing four sections of 18SribosomalRNA (18S rRNA) gene of B. felis. The blood samples of cats microscopically positive for Babesia felis were further used to extract deoxyribo neuclic acid (DNA) and the reaction mixture of 25 µL was standardized at 63°C temperature for 1 hour. LAMP assay provided more positive samples than conventional polymerase chain reaction (PCR). The prevalence of B. felis was also determined in cats using this optimized LAMP assay and it was found that the prevalence was more in younger cats as compare to adults. The application of LAMP can be helpful in rapid, reliable and cost effective diagnosis of B. felis in field.


2018 ◽  
Vol 17 (3) ◽  
pp. 402-410 ◽  
Author(s):  
Nurul Izzati Hamzan ◽  
Fatin Hazwani Fauzi ◽  
Haslina Taib ◽  
Suharni Mohamad

Background: Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans are two main causative agents associated with periodontitis, an inflammatory reaction of tissues around the teeth. The aim of this study was to develop and evaluate the loop-mediated isothermal amplification (LAMP) assay for simple and rapid detection of P. gingivalis and A. actinomycetemcomitans.Methods: A total of ten subgingival plaque and saliva samples were evaluated to detect the presence of both bacteria by LAMP and PCR assays. Two sets of six primers each were designed to amplify pepO and dam gene. The LAMP assay was carried out using a Loopamp DNA amplification kit in 25 μl volumes. The reaction mixture was incubated at 65oC for 60 minutes and terminated at 80oC for 5 minutes in heating block. The amplification reactions were visualized using naked eye detection and by agarose gel electrophoresis. The sensitivity of the LAMP assay was investigated ranging from 10 μg to 100fg of P. gingivalis(ATCC 33327) and A. actinomycetemcomitans (ATCC 33384).Results: The lowest detection limit of both LAMP and PCR methods were 1 ng and 10 ng of DNA, respectively. When crude template of subgingival plaques were used, P. gingivalisand A. actinomycetemcomitans were tested80% (8/10) and 60% (6/10) positive respectively through LAMP detection. Whereas by PCR, P. gingivaliswas tested 40% (4/10) positive and no significant detection rate for A. actinomycetemcomitans. When a crude template of saliva was used, P. gingivalisand A. actinomycetemcomitans were tested 70% (7/10) and 30% (3/10) positive respectively through LAMP detection. Whereas, when using PCR, there was no significant detection rate for P. gingivalisand A. actinomycetemcomitans.Conclusion: The LAMP assay using a crude template offers greater advantage as it is simple, rapid and cost-effective to detect periodontal pathogens.Bangladesh Journal of Medical Science Vol.17(3) 2018 p.402-410


2020 ◽  
Vol 66 (1) ◽  
pp. 17-24
Author(s):  
Chengzhong Lan ◽  
Jinai Yao ◽  
Xiujuan Yang ◽  
Hongchun Ruan ◽  
Deyi Yu ◽  
...  

Anthracnose of guava, caused by the fungus Colletotrichum gloeosporioides, is a major factor limiting worldwide guava production. Timely and accurate detection of the pathogen is important in developing a disease management strategy. Herein, a loop-mediated isothermal amplification (LAMP) assay for the specific and sensitive detection of C. gloeosporioides was developed using primers targeting the β-tubulin 2 (TUB2) gene. The optimal reaction conditions were 64 °C for 60 min. The specificity of the method was tested against C. gloeosporioides isolates, Colletotrichum spp. isolates, and isolates of other genera. Positive results were obtained only in the presence of C. gloeosporioides, whereas no cross-reaction was observed for other species. The detection limit of the LAMP assay was 10 fg of genomic DNA in a 25 μL reaction. The LAMP assay successfully detected C. gloeosporioides in guava fruit collected in the field. The results indicate that the developed LAMP assay is a simple, cost-effective, rapid, highly sensitive, and specific tool for the diagnosis of guava anthracnose caused by C. gloeosporioides and could be useful for disease management.


2014 ◽  
Vol 63 (2) ◽  
pp. 248-251 ◽  
Author(s):  
Yuta Aizawa ◽  
Tomohiro Oishi ◽  
Shinya Tsukano ◽  
Tetsuo Taguchi ◽  
Akihiko Saitoh

Loop-mediated isothermal amplification (LAMP) is a cost-effective and rapid method for identifying Mycoplasma pneumoniae (MP). We investigated the utility of the LAMP assay in diagnosing MP pneumonia among children in a clinical setting. In this prospective study, the cause of community-acquired pneumonia was evaluated in 111 patients for whom MP was the suspected pathogen. All participants were patients at a city hospital in Japan between April 2012 and September 2012. Throat swabs for the LAMP assay were obtained at admission, and paired serum samples to measure antibody titres to MP by particle agglutination were obtained at admission and during convalescence. Overall, 45 of 111 (41 %) patients had a fourfold or greater increase in MP titres and received a diagnosis of MP pneumonia. Among them, 43 (96 %) patients (median age, 9 years) were positive on the LAMP assay and had a fourfold or greater increase in MP titres. The median interval from fever onset to collection of throat swabs was 7 days (range, 4–10 days). As compared with paired serum titres, the LAMP assay enabled quicker diagnosis of MP (median interval, 13 vs. 7 days), thereby allowing early initiation of appropriate antimicrobial therapy.


2021 ◽  
Author(s):  
Anish Khan ◽  
Ekta Kamra ◽  
Raj Singh ◽  
Vikrant Sharma ◽  
Vishwajeet Singh ◽  
...  

Aim: Diagnosis of osteoarticular tuberculosis (OATB) is quite challenging and there is an urgent need to design a prompt and precise diagnostic test. Methods: We developed a multi-targeted loop-mediated isothermal amplification (LAMP) assay using mpt64 (Rv1980c) and pstS1 (Rv0934) targets for the detection of Mycobacterium tuberculosis in OATB patients. Results: The sensitivities of 100 and 82.4% were obtained in confirmed (n = 10) and suspected (n = 57) OATB cases, respectively by multi-targeted LAMP with a specificity of 96.9% (n = 33). Moreover, the sensitivities attained by multi-targeted LAMP in total OATB cases were significantly higher (p < 0.05–0.01) than multiplex-PCR ( mpt64 +  pstS1) and GeneXpert assay. Conclusion: Our LAMP is simple, reliable and cost-effective method, which may develop into an attractive diagnostic kit for early detection of OATB cases.


Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2187
Author(s):  
Paulina Rajko-Nenow ◽  
Emma L. A. Howson ◽  
Duncan Clark ◽  
Natasha Hilton ◽  
Aruna Ambagala ◽  
...  

Epizootic haemorragic disease (EHD) is an important disease of white-tailed deer and can cause a bluetongue-like illness in cattle. A definitive diagnosis of EHD relies on molecular assays such as real-time RT-qPCR or conventional PCR. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a cost-effective, specific, and sensitive technique that provides an alternative to RT-qPCR. We designed two sets of specific primers targeting segment-9 of the EHD virus genome to enable the detection of western and eastern topotypes, and evaluated their performance in singleplex and multiplex formats using cell culture isolates (n = 43), field specimens (n = 20), and a proficiency panel (n = 10). The limit of detection of the eastern and western RT-LAMP assays was estimated as ~24.36 CT and as ~29.37 CT in relation to real-time RT-qPCR, respectively, indicating a greater sensitivity of the western topotype singleplex RT-LAMP. The sensitivity of the western topotype RT-LAMP assay, relative to the RT-qPCR assay, was 72.2%, indicating that it could be theoretically used to detect viraemic cervines and bovines. For the first time, an RT-LAMP assay was developed for the rapid detection of the EHD virus that could be used as either a field test or high throughput screening tool in established laboratories to control the spread of EHD.


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