scholarly journals Loop-Mediated Isothermal Amplification (LAMP) for the Diagnosis of Zika Virus: A Review

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 19 ◽  
Author(s):  
Severino Jefferson Ribeiro da Silva ◽  
Keith Pardee ◽  
Lindomar Pena
Keyword(s):  
Zika Virus ◽  
Molecular System ◽  
Point Of Care ◽  
Low Cost ◽  
Quantitative Polymerase Chain Reaction ◽  
High Specificity ◽  
Isothermal Amplification ◽  
Loop Mediated Isothermal Amplification ◽  
Freeze Dried ◽  
Polymerase Chain

The recent outbreak of Zika virus (ZIKV) in the Americas and its devastating developmental and neurological manifestations has prompted the development of field-based diagnostics that are rapid, reliable, handheld, specific, sensitive, and inexpensive. The gold standard molecular method for lab-based diagnosis of ZIKV, from either patient samples or insect vectors, is reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The method, however, is costly and requires lab-based equipment and expertise, which severely limits its use as a point-of-care (POC) tool in resource-poor settings. Moreover, given the lack of antivirals or approved vaccines for ZIKV infection, a POC diagnostic test is urgently needed for the early detection of new outbreaks and to adequately manage patients. Loop-mediated isothermal amplification (LAMP) is a compelling alternative to RT-qPCR for ZIKV and other arboviruses. This low-cost molecular system can be freeze-dried for distribution and exhibits high specificity, sensitivity, and efficiency. A growing body of evidence suggests that LAMP assays can provide greater accessibility to much-needed diagnostics for ZIKV infections, especially in developing countries where the ZIKV is now endemic. This review summarizes the different LAMP methods that have been developed for the virus and summarizes their features, advantages, and limitations.

scholarly journals Loop-Mediated Isothermal Amplification as Point-of-Care Diagnosis for Neglected Parasitic Infections

2020 ◽  
Vol 21 (21) ◽  
pp. 7981
Author(s):  
Catalina Avendaño ◽  
Manuel Alfonso Patarroyo
Keyword(s):  
Neglected Tropical Diseases ◽  
Point Of Care ◽  
Low Cost ◽  
High Specificity ◽  
World Health Organisation ◽  
Isothermal Amplification ◽  
World Health ◽  
Parasitic Infections ◽  
River Blindness ◽  
Loop Mediated Isothermal Amplification

The World Health Organisation (WHO) has placed twenty diseases into a group known as neglected tropical diseases (NTDs), twelve of them being parasitic diseases: Chagas’ disease, cysticercosis/taeniasis, echinococcosis, food-borne trematodiasis, human African trypanosomiasis (sleeping sickness), leishmaniasis, lymphatic filariasis, onchocerciasis (river blindness), schistosomiasis, soil-transmitted helminthiasis (ascariasis, hookworm, trichuriasis), guinea-worm and scabies. Such diseases affect millions of people in developing countries where one of the main problems concerning the control of these diseases is diagnosis-based due to the most affected areas usually being far from laboratories having suitable infrastructure and/or being equipped with sophisticated equipment. Advances have been made during the last two decades regarding standardising and introducing techniques enabling diagnoses to be made in remote places, i.e., the loop-mediated isothermal amplification (LAMP) technique. This technique’s advantages include being able to perform it using simple equipment, diagnosis made directly in the field, low cost of each test and the technique’s high specificity. Using this technique could thus contribute toward neglected parasite infection (NPI) control and eradication programmes. This review describes the advances made to date regarding LAMP tests, as it has been found that even though several studies have been conducted concerning most NPI, information is scarce for others.

scholarly journals Loop Mediated Isothermal Amplification: Principles and Applications in Plant Virology

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 461 ◽  
Author(s):  
Stefano Panno ◽  
Slavica Matić ◽  
Antonio Tiberini ◽  
Andrea Giovanni Caruso ◽  
Patrizia Bella ◽  
...  
Keyword(s):  
Plant Protection ◽  
Point Of Care ◽  
Low Cost ◽  
Isothermal Amplification ◽  
Nucleic Acid Amplification ◽  
Plant Virology ◽  
Food Industries ◽  
Loop Mediated Isothermal Amplification ◽  
Application Fields ◽  
Agriculture And Food

In the last decades, the evolution of molecular diagnosis methods has generated different advanced tools, like loop-mediated isothermal amplification (LAMP). Currently, it is a well-established technique, applied in different fields, such as the medicine, agriculture, and food industries, owing to its simplicity, specificity, rapidity, and low-cost efforts. LAMP is a nucleic acid amplification under isothermal conditions, which is highly compatible with point-of-care (POC) analysis and has the potential to improve the diagnosis in plant protection. The great advantages of LAMP have led to several upgrades in order to implement the technique. In this review, the authors provide an overview reporting in detail the different LAMP steps, focusing on designing and main characteristics of the primer set, different methods of result visualization, evolution and different application fields, reporting in detail LAMP application in plant virology, and the main advantages of the use of this technique.

scholarly journals Loop-Mediated Isothermal Amplification (LAMP) as a Promising Point-of-Care Diagnostic Strategy in Avian Virus Research

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 76
Author(s):  
Faiz Padzil ◽  
Abdul Razak Mariatulqabtiah ◽  
Wen Siang Tan ◽  
Kok Lian Ho ◽  
Nurulfiza Mat Isa ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Nucleic Acid ◽  
Point Of Care ◽  
Rolling Circle Amplification ◽  
Isothermal Amplification ◽  
Screening Methods ◽  
Diagnostic Strategy ◽  
Chain Reaction ◽  
Loop Mediated Isothermal Amplification ◽  
Polymerase Chain

Over the years, development of molecular diagnostics has evolved significantly in the detection of pathogens within humans and their surroundings. Researchers have discovered new species and strains of viruses, while mitigating the viral infections that occur, owing to the accessibility of nucleic acid screening methods such as polymerase chain reaction (PCR), qualitative (real-time) polymerase chain reaction (qPCR) and reverse-transcription qPCR (RT-qPCR). While such molecular detection methods are widely utilized as the benchmark, the invention of isothermal amplifications has also emerged as a reliable tool to improvise on-field diagnosis without dependence on thermocyclers. Among the established isothermal amplification technologies are loop-mediated isothermal amplification (LAMP), recombinant polymerase amplification (RPA), strand displacement activity (SDA), nucleic acid sequence-based amplification (NASBA), helicase-dependent amplification (HDA) and rolling circle amplification (RCA). This review highlights the past research on and future prospects of LAMP, its principles and applications as a promising point-of-care diagnostic method against avian viruses.

scholarly journals Comparative analysis of loop-mediated isothermal amplification (LAMP)-based assays for rapid detection of SARS-CoV-2 genes

2020 ◽  
Author(s):  
Daniel Urrutia-Cabrera ◽  
Roxanne Hsiang-Chi Liou ◽  
Jianxiong Chan ◽  
Sandy Shen-Chi Hung ◽  
Alex W Hewitt ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Reaction Time ◽  
False Positive ◽  
Point Of Care ◽  
Low Cost ◽  
Isothermal Amplification ◽  
Fluorescent Detection ◽  
Experimental Conditions ◽  
Diagnostic Laboratory ◽  
Loop Mediated Isothermal Amplification

AbstractThe COVID-19 pandemic caused by SARS-CoV-2 has infected millions worldwide and there is an urgent need to increase our diagnostic capacity to identify infected cases. Although RT-qPCR remains the gold standard for SARS-CoV-2 detection, this method requires specialised equipment in a diagnostic laboratory and has a long turn-around time to process the samples. To address this, several groups have recently reported development of loop-mediated isothermal amplification (LAMP) as a simple, low cost and rapid method for SARS-CoV-2 detection. Herein we present a comparative analysis of three LAMP-based assays that target different regions of the SARS-CoV-2: ORF1ab RdRP, ORF1ab nsp3 and Gene N. We perform a detailed assessment of their sensitivity, kinetics and false positive rates for SARS-CoV-2 diagnostics in LAMP or RT-LAMP reactions, using colorimetric or fluorescent detection. Our results independently validate that all three assays can detect SARS-CoV-2 in 30 minutes, with robust accuracy at detecting as little as 1000 RNA copies and the results can be visualised simply by color changes. We also note the shortcomings of these LAMP-based assays, including variable results with shorter reaction time or lower load of SARS-CoV-2, and false positive results in some experimental conditions. Overall for RT-LAMP detection, the ORF1ab RdRP and ORF1ab nsp3 assays have higher sensitivity and faster kinetics for detection, whereas the Gene N assay exhibits no false positives in 30 minutes reaction time. This study provides validation of the performance of LAMP-based assays for SARS-CoV-2 detection, which have important implications in development of point-of-care diagnostic for SARS-CoV-2.

scholarly journals Detecting SARS-CoV-2 at point of care: preliminary data comparing loop-mediated isothermal amplification (LAMP) to polymerase chain reaction (PCR)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Marc F. Österdahl ◽  
Karla A. Lee ◽  
Mary Ni Lochlainn ◽  
Stuart Wilson ◽  
Sam Douthwaite ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcription ◽  
Predictive Value ◽  
Point Of Care ◽  
Isothermal Amplification ◽  
Service Improvement ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Loop Mediated Isothermal Amplification ◽  
Polymerase Chain

Abstract Background A cost effective and efficient diagnostic tool for COVID-19 as near to the point of care (PoC) as possible would be a game changer in the current pandemic. We tested reverse transcription loop mediated isothermal amplification (RT-LAMP), a method which can produce results in under 30 min, alongside standard methods in a real-life clinical setting. Methods This prospective service improvement project piloted an RT-LAMP method on nasal and pharyngeal swabs on 21 residents of a high dependency care home, with two index COVID-19 cases, and compared it to multiplex tandem reverse transcription polymerase chain reaction (RT-PCR). We recorded vital signs of patients to correlate clinical and laboratory information and calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of a single swab using RT-LAMP compared with the current standard, RT-PCR, as per Standards for Reporting Diagnostic Accuracy Studies (STARD) guidelines. Results The novel method accurately detected 8/10 RT-PCR positive cases and identified a further 3 positive cases. Eight further cases were negative using both methods. Using repeated RT-PCR as a “gold standard”, the sensitivity and specificity of a single novel test were 80 and 73% respectively. PPV was 73% and NPV was 83%. Incorporating retesting of low signal RT-LAMP positives improved the specificity to 100%. We also speculate that hypothermia may be a significant early clinical sign of COVID-19. Conclusions RT-LAMP testing for SARS-CoV-2 was found to be promising, fast and to work equivalently to RT-PCR methods. RT-LAMP has the potential to transform COVID-19 detection, bringing rapid and accurate testing to the PoC. RT-LAMP could be deployed in mobile community testing units, care homes and hospitals to detect disease early and prevent spread.

Advances in loop-mediated isothermal amplification: integrated with several point-of-care diagnostic methods

2014 ◽  
Vol 6 (19) ◽  
pp. 7585-7589 ◽  
Author(s):  
Pin Gong ◽  
Taotao Zhang ◽  
Fuxin Chen ◽  
Lan Wang ◽  
Sai Jin ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Point Of Care ◽  
Low Cost ◽  
Isothermal Amplification ◽  
Diagnostic Methods ◽  
Diagnostic Systems ◽  
Loop Mediated Isothermal Amplification

Recent outbreaks linked to pathogenic bacteria heighten the need to develop rapid, sensitive, portable and low-cost pathogen diagnostic systems.

scholarly journals Development of a novel loop-mediated isothermal amplification assay for rapid detection of Mycobacterium leprae in clinical samples

2021 ◽  
Vol 0 ◽  
pp. 1-7
Author(s):  
Shweta Joshi ◽  
Vanila Sharma ◽  
V. Ramesh ◽  
Ruchi Singh ◽  
Poonam Salotra
Keyword(s):  
Polymerase Chain Reaction ◽  
Confidence Interval ◽  
Quantitative Polymerase Chain Reaction ◽  
Mycobacterium Leprae ◽  
Isothermal Amplification ◽  
Chain Reaction ◽  
Assay Sensitivity ◽  
Loop Mediated Isothermal Amplification ◽  
Amplification Assay ◽  
Polymerase Chain

Background: Sensitive and definitive diagnostic tests are required for timely treatment of leprosy and to control its transmission. Aim: In the present study, we report the development of loop-mediated isothermal amplification assay using six primers targeting the RLEP gene sequence uniquely present in Mycobacterium leprae. Methods: Tissue punch samples (n = 50) and slit aspirates (n = 50) from confirmed cases of leprosy (M. leprae positive by quantitative polymerase chain reaction), reporting at the Department of Dermatology, Safdarjung Hospital, New Delhi, were analyzed using newly developed closed tube loop-mediated isothermal amplification assay. The sensitivity and specificity; positive predictive value, negative predictive value and accuracy were calculated using MedCalc statistical software. Results: The loop-mediated isothermal amplification assay specifically amplified M. leprae genomic DNA with an analytical sensitivity of 100 fg. About 47 Out of the 50 quantitative polymerase chain reactions confirmed M. leprae positive tissue samples, 47 were positive by loop-mediated isothermal amplification assay (sensitivity 94%; 95% confidence interval 83.5%–98.8%) while only 31/50 were positive by histopathology (sensitivity 62%; 95% confidence interval 47.2%–75.4%). Using slit aspirate samples of these 50 patients, 42 were positive by both quantitative polymerase chain reaction and loop-mediated isothermal amplification assay (sensitivity 84%; 95% confidence interval 70.9%–92.8%) while only 23/50 (sensitivity 46%; 95% confidence interval 31.8%–60.7%) were positive by microscopy. Limitations: In the present study, the leprosy patient cohort was not uniform, as it comprised of a lower number of paucibacillary cases (22%) compared to multibacillary (78%) cases. Conclusion: Loop-mediated isothermal amplification assay established here provides a rapid and accurate diagnostic test for leprosy in terms of sensitivity and specificity. The assay is simple to perform in comparison with other molecular techniques (polymerase chain reaction/quantitative polymerase chain reaction) and has potential for field applicability.

scholarly journals Zika virus lateral flow assays using reverse transcription-loop-mediated isothermal amplification

RSC Advances ◽  
2021 ◽  
Vol 11 (29) ◽  
pp. 17800-17808
Author(s):  
Gna Ahn ◽  
SeonHyung Lee ◽  
Se Hee Lee ◽  
Yun Hee Baek ◽  
Min-Suk Song ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Zika Virus ◽  
Detection Method ◽  
Point Of Care ◽  
Lateral Flow ◽  
Isothermal Amplification ◽  
Independent Point ◽  
Loop Mediated Isothermal Amplification ◽  
Lateral Flow Assays ◽  
Point Of Care Detection

Our study suggest that ZIKV RT-LAMP combined with LFA could serve as a rapid, accurate, and independent point-of-care detection method for ZIKV outbreaks.

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