scholarly journals Development of a Loop-Mediated Isothermal Amplification Assay for Rapid Detection ofTrichosporon asahiiin Experimental and Clinical Samples

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jianfeng Zhou ◽  
Yong Liao ◽  
Haitao Li ◽  
Xuelian Lu ◽  
Xiufeng Han ◽  
...  
Keyword(s):  
Lamp Assay ◽  
Isothermal Amplification ◽  
Clinical Samples ◽  
Rrna Gene ◽  
Intergenic Spacers ◽  
Loop Mediated Isothermal Amplification ◽  
Detection And Identification ◽  
Deep Mycosis ◽  
Pathogen Dna ◽  
Species Specific

Invasive trichosporonosis is a deep mycosis found mainly in immunocompromised hosts, and the major pathogen isTrichosporon asahii. We detected the species-specific intergenic spacers (IGS) of rRNA gene ofT. asahiiusing a loop-mediated isothermal amplification (LAMP) assay in 15 isolates with 3 different visualization methods, including SYBR green detection, gel electrophoresis, and turbidimetric methods. The LAMP assay displayed superior rapidity to other traditional methods in the detection time; that is, only 1 h was needed for detection and identification of the pathogen DNA. Furthermore, the detection limit of the LAMP assay was more sensitive than the PCR assay. We also successfully detect the presence ofT. asahiiin samples from experimentally infected mice and samples from patients with invasive trichosporonosis caused byT. asahii, suggesting that this method may become useful in clinical applications in the near future.

scholarly journals Development of a Multiplex Loop-Mediated Isothermal Amplification Assay for Diagnosis of Plasmodium spp., Plasmodium falciparum and Plasmodium vivax

Diagnostics ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1950
Author(s):  
Woong Sik Jang ◽  
Da Hye Lim ◽  
YoungLan Choe ◽  
Hyunseul Jee ◽  
Kyung Chul Moon ◽  
...  
Keyword(s):  
Internal Control ◽  
Point Of Care ◽  
Lamp Assay ◽  
18S Rrna Gene ◽  
Isothermal Amplification ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Clinical Samples ◽  
Rrna Gene ◽  
Loop Mediated Isothermal Amplification

Malaria, caused by the parasite Plasmodium and transmitted by mosquitoes, is an epidemic that mainly occurs in tropical and subtropical regions. As treatments differ across species of malarial parasites, there is a need to develop rapid diagnostic methods to differentiate malarial species. Herein, we developed a multiplex malaria Pan/Pf/Pv/actin beta loop-mediated isothermal amplification (LAMP) to diagnose Plasmodium spp., P. falciparum, and P. vivax, as well as the internal control (IC), within 40 min. The detection limits of the multiplex malaria Pan/Pf/Pv/IC LAMP were 1 × 102, 1 × 102, 1 × 102, and 1 × 103 copies/µL for four vectors, including the 18S rRNA gene (Plasmodium spp.), lactate dehydrogenase gene (P. falciparum), 16S rRNA gene (P. vivax), and human actin beta gene (IC), respectively. The performance of the LAMP assay was compared and evaluated by evaluating 208 clinical samples (118 positive and 90 negative samples) with the commercial RealStar® Malaria S&T PCR Kit 1.0. The developed multiplex malaria Pan/Pf/Pv/IC LAMP assay showed comparable sensitivity (100%) and specificity (100%) with the commercial RealStar® Malaria S&T PCR Kit 1.0 (100%). These results suggest that the multiplex malaria Pan/Pf/Pv/IC LAMP could be used as a point-of-care molecular diagnostic test for malaria.

scholarly journals Novel Multiplex and Loop-Mediated Isothermal Amplification (LAMP) Assays for Rapid Species and Mating-Type Identification of Oculimacula acuformis and O. yallundae (Causal Agents of Cereal Eyespot), and Application for Detection of Ascospore Dispersal and in planta Use

2020 ◽  
Author(s):  
Kevin M. King ◽  
Gavin J. Eyres ◽  
Jon West ◽  
Clara Siraf ◽  
Pavel Matusinsky ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Mating Type ◽  
Field Experiments ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
In Planta ◽  
Loop Mediated Isothermal Amplification ◽  
Multiplex Pcr Assay ◽  
Species Specific ◽  
Oculimacula Acuformis

Eyespot, caused by the related fungal pathogens Oculimacula acuformis (OA) and O. yallundae (OY), is an important cereal stem-base disease in temperate parts of the world. Both species are dispersed mainly by splash-dispersed conidia but are also known to undergo sexual reproduction yielding apothecia containing ascospores. Field diagnosis of eyespot can be challenging with other pathogens causing similar symptoms, which complicates eyespot management strategies. Differences between OA and OY (e.g. host pathogenicity and fungicide sensitivity) require that both be targeted for effective disease management. Here, we develop and apply two molecular methods for species-specific and mating-type (MAT1-1 or MAT1-2) discrimination of OA and OY isolates. First, a multiplex PCR-based diagnostic assay targeting the MAT idiomorph region was developed allowing simultaneous determination of both species and mating type. This multiplex-PCR assay was successfully applied to type a global collection of isolates. Second, the development of loop-mediated isothermal amplification (LAMP) assays targeting beta-tubulin sequences is described, which allow fast (<9 min) species-specific discrimination of global OA and OY isolates. The LAMP assay can detect very small amounts of target DNA (1 pg) and was successfully applied in planta. In addition, mating-type specific LAMP assays were also developed for rapid (<12 min) genotyping of OA and OY isolates. Finally, the multiplex PCR-based diagnostic was applied, in conjunction with spore trapping in field experiments, to provide evidence of the wind dispersal of ascospores from a diseased crop. The results indicate an important role of the sexual cycle in the dispersal of eyespot.

scholarly journals Rapid and Extraction-Free Detection of SARS-CoV-2 from Saliva by Colorimetric Reverse-Transcription Loop-Mediated Isothermal Amplification

2020 ◽  
Author(s):  
Matthew A Lalli ◽  
Joshua S Langmade ◽  
Xuhua Chen ◽  
Catrina C Fronick ◽  
Christopher S Sawyer ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Limit Of Detection ◽  
Colorimetric Assay ◽  
Quantitative Polymerase Chain Reaction ◽  
Rna Extraction ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
Clinical Samples ◽  
Viral Detection ◽  
Loop Mediated Isothermal Amplification

Abstract Background Rapid, reliable, and widespread testing is required to curtail the ongoing COVID-19 pandemic. Current gold-standard nucleic acid tests are hampered by supply shortages in critical reagents including nasal swabs, RNA extraction kits, personal protective equipment, instrumentation, and labor. Methods To overcome these challenges, we developed a rapid colorimetric assay using reverse-transcription loop-mediated isothermal amplification (RT-LAMP) optimized on human saliva samples without an RNA purification step. We describe the optimization of saliva pretreatment protocols to enable analytically sensitive viral detection by RT-LAMP. We optimized the RT-LAMP reaction conditions and implemented high-throughput unbiased methods for assay interpretation. We tested whether saliva pretreatment could also enable viral detection by conventional reverse-transcription quantitative polymerase chain reaction (RT-qPCR). Finally, we validated these assays on clinical samples. Results The optimized saliva pretreatment protocol enabled analytically sensitive extraction-free detection of SARS-CoV-2 from saliva by colorimetric RT-LAMP or RT-qPCR. In simulated samples, the optimized RT-LAMP assay had a limit of detection of 59 (95% confidence interval: 44–104) particle copies per reaction. We highlighted the flexibility of LAMP assay implementation using 3 readouts: naked-eye colorimetry, spectrophotometry, and real-time fluorescence. In a set of 30 clinical saliva samples, colorimetric RT-LAMP and RT-qPCR assays performed directly on pretreated saliva samples without RNA extraction had accuracies greater than 90%. Conclusions Rapid and extraction-free detection of SARS-CoV-2 from saliva by colorimetric RT-LAMP is a simple, sensitive, and cost-effective approach with broad potential to expand diagnostic testing for the virus causing COVID-19.

scholarly journals Development of an in-house loop-mediated isothermal amplification (LAMP) assay for detection of Mycobacterium tuberculosis and evaluation in sputum samples of Nepalese patients

2008 ◽  
Vol 57 (4) ◽  
pp. 439-443 ◽  
Author(s):  
Basu Dev Pandey ◽  
Ajay Poudel ◽  
Tomoko Yoda ◽  
Aki Tamaru ◽  
Naozumi Oda ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Lamp Assay ◽  
High Sensitivity ◽  
Isothermal Amplification ◽  
Nucleic Acid Amplification ◽  
Lamp Method ◽  
Rrna Gene ◽  
Predictive Values ◽  
Loop Mediated Isothermal Amplification ◽  
System A

A number of nucleic acid amplification assays (NAAs) have been employed to detect tubercle bacilli in clinical specimens for tuberculosis (TB) diagnosis. Among these, loop-mediated isothermal amplification (LAMP) is an NAA possessing superior isothermal reaction characteristics. In the present study, a set of six specific primers targeting the Mycobacterium tuberculosis 16S rRNA gene with high sensitivity was selected and a LAMP system (MTB-LAMP) was developed. Using this system, a total of 200 sputum samples from Nepalese patients were investigated. The sensitivity of MTB-LAMP in culture-positive samples was 100 % (96/96), and the specificity in culture-negative samples was 94.2 % (98/104, 95 % confidence interval 90.5–97.9 %). The positive and negative predictive values of MTB-LAMP were 94.1 and 100 %, respectively. These results indicate that this MTB-LAMP method may prove to be a powerful tool for the early diagnosis of TB.

scholarly journals Field Verification of an African Swine Fever Virus Loop-Mediated Isothermal Amplification (LAMP) Assay during an Outbreak in Timor-Leste

Viruses ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1444
Author(s):  
Peter T. Mee ◽  
Shani Wong ◽  
Kim J. O’Riley ◽  
Felisiano da Conceição ◽  
Joanita Bendita da Costa Jong ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Lamp Assay ◽  
Fever Virus ◽  
Isothermal Amplification ◽  
Clinical Samples ◽  
Loop Mediated Isothermal Amplification ◽  
Field Verification ◽  
Extraction Step ◽  
Timor Leste

Recent outbreaks of African swine fever virus (ASFV) have seen the movement of this virus into multiple new regions with devastating impact. Many of these outbreaks are occurring in remote, or resource-limited areas, that do not have access to molecular laboratories. Loop-mediated isothermal amplification (LAMP) is a rapid point of care test that can overcome a range of inhibitors. We outline further development of a real-time ASFV LAMP, including field verification during an outbreak in Timor-Leste. To increase field applicability, the extraction step was removed and an internal amplification control (IAC) was implemented. Assay performance was assessed in six different sample matrices and verified for a range of clinical samples. A LAMP detection limit of 400 copies/rxn was determined based on synthetic positive control spikes. A colourmetric LAMP assay was also assessed on serum samples. Comparison of the LAMP assay to a quantitative polymerase chain reaction (qPCR) was performed on clinical ASFV samples, using both serum and oral/rectal swabs, with a substantial level of agreement observed. The further verification of the ASFV LAMP assay, removal of extraction step, implementation of an IAC and the assessment of a range of sample matrix, further support the use of this assay for rapid in-field detection of ASFV.

scholarly journals Development of a Loop-mediated isothermal amplification (LAMP) technique for specific and early detection of Mycobacterium leprae in clinical samples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nupur Garg ◽  
Upasana Sahu ◽  
Sudeshna Kar ◽  
Farhan J. Ahmad
Keyword(s):  
Early Detection ◽  
Mycobacterium Leprae ◽  
Negative Control ◽  
Rapid Diagnosis ◽  
Isothermal Amplification ◽  
Detection Methods ◽  
Diagnostic Tools ◽  
Clinical Samples ◽  
Rrna Gene ◽  
Loop Mediated Isothermal Amplification

AbstractLeprosy, a progressive, mutilating and highly stigmatized disease caused by Mycobacterium leprae (ML), continues to prevail in the developing world. This is due to the absence of rapid, specific and sensitive diagnostic tools for its early detection since the disease gets notified only with the advent of physical scarring in patients. This study reports the development of a Loop-mediated isothermal amplification (LAMP) technique for fast, sensitive and specific amplification of 16S rRNA gene of ML DNA for early detection of leprosy in resource-limited areas. Various parameters were optimized to obtain robust and reliable amplification of ML DNA. Blind clinical validation studies were performed which showed that this technique had complete concurrence with conventional techniques. Total absence of amplification of negative control DNA confirmed the specificity of this test. Various visual detection methods viz. colorimetric, turbidity differentiation and bridge flocculation were standardized to establish easy-to-read and rapid diagnosis. This technique eliminates the lack of accuracy and sensitivity in skin smear tests in patients and the requirement for expensive lab equipments and trained technicians. The technique holds promise for further expansion and has the potential to cater to the unmet needs of society for a cheap, highly-sensitive and robust rapid diagnosis of ML.

Visual and Real-Time Event-Specific Loop-Mediated Isothermal Amplification Based Detection Assays for Bt Cotton Events MON531 and MON15985

2015 ◽  
Vol 98 (5) ◽  
pp. 1207-1214 ◽  
Author(s):  
Gurinder Jit Randhawa ◽  
Rashmi Chhabra ◽  
Rajesh K Bhoge ◽  
Monika Singh
Keyword(s):  
Real Time ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
Bt Cotton ◽  
Loop Mediated Isothermal Amplification ◽  
Commercial Cultivation ◽  
Detection And Identification ◽  
Cotton Seeds ◽  
Gm Detection ◽  
Time Loop

Abstract Bt cotton events MON531 and MON15985 are authorized for commercial cultivation in more than 18 countries. In India, four Bt cotton events have been commercialized; more than 95% of total area under genetically modified (GM) cotton cultivation comprises events MON531 and MON15985. The present study reports on the development of efficient event-specific visual and real-time loop-mediated isothermal amplification (LAMP) assays for detection and identification of cotton events MON531 and MON15985. Efficiency of LAMP assays was compared with conventional and real-time PCR assays. Real-time LAMP assay was found time-efficient and most sensitive, detecting up to two target copies within 35 min. The developed real-time LAMP assays, when combined with efficient DNA extraction kit/protocol, may facilitate onsite GM detection to check authenticity of Bt cotton seeds.

scholarly journals Evaluation of Loop Mediated Isothermal Amplification (LAMP) for Diagnosis of Plasmodium falciparum in Wad Medani City, Gezira State, Sudan

2019 ◽  
pp. 1-7
Author(s):  
M. Y. Mohamed ◽  
A. D. Abakar ◽  
B. A. Talha ◽  
Salah Eldin G. Elzaki ◽  
Y. A. Mohammed ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Falciparum Malaria ◽  
Diagnostic Performance ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
Teaching Hospitals ◽  
Molecular Technique ◽  
Rrna Gene ◽  
Predictive Values ◽  
Loop Mediated Isothermal Amplification

Plasmodium falciparum considered as the most serious form of species causes malaria compared with other species. Diagnosis of falciparum malaria in Sudan remain a major problem, the laboratory diagnosis depends solely on microscopy and RDTs. Loop mediated isothermal amplification (LAMP) assay is a molecular technique done in isothermal temperature using simple, inexpensive instruments for detection of falciparum malaria. The aim of the study is to evaluate the diagnostic performance of loop mediated isothermal amplification (LAMP) assay for detection of P. falciparum and compare with microscopic detection. A cross sectional hospital based study conducted on 220 blood samples collected from participants suspected to have falciparum malaria attending Wad Medani Teaching Hospitals and 26 healthy participants during the period November 2018 to January 2019. Thick blood films were done and used for P. falciparum detection. The extracted DNA by TE buffer was amplified by LAMP assay targeting 18S rRNA gene. Data were analyzed using Medical calculator (MedCalc) programs (V. 16). The results showed that the sensitivity, specificity, positive predictive value, negative predictive values were 99.1%, 84.6%, 53.2%, 99.8% respectively. Validation of LAMP diagnostic performance revealed that area under the curve is 0.919, while Weighted Kappa is 0.866. The study concluded that the LAMP assay had the identical diagnostic performance compared with microscopy in diagnosis of Plasmodium falciparum malaria. This gives a relative effortlessness application of LAMP assay in Sudan after availing the required logistics.

scholarly journals A Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

2020 ◽  
Vol 21 (8) ◽  
pp. 2826 ◽  
Author(s):  
Renfei Lu ◽  
Xiuming Wu ◽  
Zhenzhou Wan ◽  
Yingxue Li ◽  
Xia Jin ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Limit Of Detection ◽  
Lamp Assay ◽  
Isothermal Amplification ◽  
Qpcr Assay ◽  
N Gene ◽  
Clinical Samples ◽  
Loop Mediated Isothermal Amplification ◽  
Specificity And Sensitivity

COVID-19 has become a major global public health burden, currently causing a rapidly growing number of infections and significant morbidity and mortality around the world. Early detection with fast and sensitive assays and timely intervention are crucial for interrupting the spread of the COVID-19 virus (SARS-CoV-2). Using a mismatch-tolerant amplification technique, we developed a simple, rapid, sensitive and visual reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for SARS-CoV-2 detection based on its N gene. The assay has a high specificity and sensitivity, and robust reproducibility, and its results can be monitored using a real-time PCR machine or visualized via colorimetric change from red to yellow. The limit of detection (LOD) of the assay is 118.6 copies of SARS-CoV-2 RNA per 25 μL reaction. The reaction can be completed within 30 min for real-time fluorescence monitoring, or 40 min for visual detection when the template input is more than 200 copies per 25 μL reaction. To evaluate the viability of the assay, a comparison between the RT-LAMP and a commercial RT-qPCR assay was made using 56 clinical samples. The SARS-CoV-2 RT-LAMP assay showed perfect agreement in detection with the RT-qPCR assay. The newly-developed SARS-CoV-2 RT-LAMP assay is a simple and rapid method for COVID-19 surveillance.

First report on optimization of loop-mediated isothermal amplification (LAMP) for the diagnosis of Babesia felis

2017 ◽  
Author(s):  
Muhammad Awais Salim ◽  
Raheela Akhtar ◽  
Muhammad Lateef ◽  
Imran Rashid ◽  
Harron Akbar ◽  
...  
Keyword(s):  
Lamp Assay ◽  
Cost Effective ◽  
Conventional Polymerase Chain Reaction ◽  
18S Rrna Gene ◽  
Isothermal Amplification ◽  
Rrna Gene ◽  
Chain Reaction ◽  
Loop Mediated Isothermal Amplification ◽  
Polymerase Chain ◽  
Effective Diagnosis

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.

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