scholarly journals Real-time loop-mediated isothermal amplification for rapid detection of Enterocytozoon hepatopenaei

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5993 ◽  
Author(s):  
Shao-Xin Cai ◽  
Fan-De Kong ◽  
Shu-Fei Xu ◽  
Cui-Luan Yao

Background Enterocytozoon hepatopenaei (EHP) is a newly emerged microsporidian parasite that causes retarded shrimp growth in many countries. But there are no effective approaches to control this disease to date. The EHP could be an immune risk factor for increased dissemination of other diseases. Further, EHP infection involves the absence of obvious clinical signs and it is difficult to identify the pathogen through visual examination, increasing the risk of disease dissemination. It is urgent and necessary to develop a specific, rapid and sensitive EHP-infected shrimp diagnostic method to detect this parasite. In the present study, we developed and evaluated a rapid real-time loop-mediated isothermal amplification (real-time LAMP) for detection of EHP. Methods A rapid and efficient real-time LAMP method for the detection of EHP has been developed. Newly emerged EHP pathogens in China were collected and used as the sample, and three sets of specificity and sensitivity primers were designed. Three other aquatic pathogens were used as templates to test the specificity of the real-time LAMP assay. Also, we compared the real-time LAMP with the conventional LAMP by the serial dilutions of EHP DNA and their amplification curves. Application of real-time LAMP was carried out with clinical samples. Results Positive products were amplified only from EHP, but not from other tested species, EHP was detected from the clinical samples, suggesting a high specificity of this method. The final results of this assay were available within less than 45 min, and the initial amplification curve was observed at about 6 min. We found that the amplification with an exponential of sixfold dilutions of EHP DNA demonstrated a specific positive signal by the real-time LAMP, but not for the LAMP amplicons from the visual inspection. The real-time LAMP amplification curves demonstrated a higher slope than the conventional LAMP. Discussion In this study, pathogen virulence impacts have been increased in aquaculture and continuous observation was predominantly focused on EHP. The present study confirmed that the real-time LAMP assay is a promising and convenient method for the rapid identification of EHP in less time and cost. Its application greatly aids in the detection, surveillance, and prevention of EHP.

2011 ◽  
Vol 47 (No. 4) ◽  
pp. 140-148 ◽  
Author(s):  
N. Rostamkhani ◽  
A. Haghnazari ◽  
M. Tohidfar ◽  
A. Moradi

In an attempt to speed up the process of screening of transgenic cotton (G. hirsutum L.) plants, a visual and rapid loop-mediated isothermal amplification (LAMP) assay was adopted. Genomic DNA was extracted from fresh leaf tissues of T<sub>2</sub> transgenic cotton containing chitinase (chi) and cry1A(b) genes. Detection of genes of interest was performed by polymerase chain reaction (PCR), LAMP and real-time PCR methods. In LAMP assay the amplification was performed after 30 min at 65&deg;C when loop primers were involved in the reaction. The involvement of loop primers decreased the time needed for amplification. By testing serial tenfold dilutions (10<sup>&ndash;1</sup> to 10<sup>&ndash;8</sup>) of the genes of interest, the detection sensitivity of LAMP was found to be 100-fold higher than that of PCR. The rapid DNA extraction method and LAMP assay can be performed within 30 min and the derived LAMP products can be directly observed as visually detectable based on turbidity in the reaction tube. The accuracy of LAMP method in the screening of transgenes was confirmed by PCR and real-time PCR. The developed method was efficient, rapid and sensitive in the screening of cotton transgenic plants. This method can be applied to any other crops.


2015 ◽  
Vol 12 (4) ◽  
pp. 5963-5966 ◽  
Author(s):  
CHAO ZHANG ◽  
JUANLI ZHU ◽  
JIANGCUN YANG ◽  
YINSHENG WAN ◽  
TING MA ◽  
...  

2015 ◽  
Vol 98 (5) ◽  
pp. 1207-1214 ◽  
Author(s):  
Gurinder Jit Randhawa ◽  
Rashmi Chhabra ◽  
Rajesh K Bhoge ◽  
Monika Singh

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.


2020 ◽  
Vol 21 (8) ◽  
pp. 2826 ◽  
Author(s):  
Renfei Lu ◽  
Xiuming Wu ◽  
Zhenzhou Wan ◽  
Yingxue Li ◽  
Xia Jin ◽  
...  

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.


2017 ◽  
Vol 100 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Xinyue Zhang ◽  
Guojie Xu ◽  
Huaqi Tang ◽  
Yanpeng Li ◽  
Chunsheng Liu

Abstract Fungi of the Alternaria genus are associated with allergic diseases, with Alternaria alternata being one of the most prevalent species. A. alternata has been frequently reported as the etiologic agent of hypersensitivity pneumonitis, allergic rhinosinusitis, bronchial asthma,and other diseases. In this study, we developed a loop-mediated isothermal amplification (LAMP) assay and a real-time PCR assay to detect low levels of A. alternata in herbal tea samples. The LAMP assay can detect as little as 3 pg/μL of A. alternata genomic DNA with high specificity. In addition, both the LAMP assay and the real-time PCR assay can be used for quantification of A. alternata. Although the newly developed LAMP assay is more rapid and specific in A. alternata identification, the real-time PCR assay is more precise in quantitation analysis.


2017 ◽  
Vol 61 (4) ◽  
pp. 439-444 ◽  
Author(s):  
Syed Ehtisham-ul-Haque ◽  
Madiha Kiran ◽  
Usman Waheed ◽  
Muhammad Younus

AbstractIntroduction:Mycoplasma gallisepticum is considered the most pathogenic and economically significant avian Mycoplasma spp. for the worldwide poultry industry. The aim of this study was to develop a novel and sensitive real-time loop-mediated isothermal amplification (LAMP) assay based on the amplification of its mgc2 gene sequence for its rapid molecular detection in poultry.Material and Methods: Blood samples from 300 broiler and layer chickens were screened using a rapid serum agglutination (RSA) test. A real-time LAMP reaction was conducted with seropositive swab samples at 60°C for 90 min in an ESEQuant tube scanner using 6-carboxyfluorescein as the reporting dye.Results: The sensitivity of the developed assay was 10 fg/μL of DNA. The assay was found 100% specific, showing no cross-reactivity with other avian Mycoplasma species. The proportion found of the positive samples by the real-time LAMP was 58%. In comparison, the RSA was found to detect 52% of positive cases.Conclusion: The mgc2 real-time LAMP emerged as a more sensitive and accurate method for molecular detection of M. gallisepticum than RSA. Robustness and precision give it applicability as a potential field diagnostic tool for M. gallisepticum control. The study will be beneficial in reducing economic losses that M. gallisepticum inflicts on the poultry industry. This is the first reported development of a real-time LAMP assay based on the amplification of the mgc2 gene sequence using an ESEQuant tube scanner for galline M. gallisepticum detection.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244753
Author(s):  
Jeeyong Kim ◽  
Borae G. Park ◽  
Da Hye Lim ◽  
Woong Sik Jang ◽  
Jeonghun Nam ◽  
...  

Introduction The rapid and accurate diagnosis of tuberculosis (TB) is important to reduce morbidity and mortality rates and risk of transmission. Therefore, molecular detection methods such as a real-time PCR–based assay for Mycobacterium tuberculosis (MTB) have been commonly used for diagnosis of TB. Loop-mediated isothermal amplification (LAMP) assay was believed to be a simple, quick, and cost-effective isothermal nucleic acid amplification diagnostic test for infectious diseases. In this study, we designed an in-house multiplex LAMP assay for the differential detection of MTB and non-tuberculosis mycobacterium (NTM), and evaluated the assay using clinical samples. Material and methods For the multiplex LAMP assay, two sets of specific primers were designed: the first one was specific for IS6110 genes of MTB, and the second one was universal for rpoB genes of mycobacterium species including NTM. MTB was confirmed with a positive reaction with both primer sets, and NTM was identified with a positive reaction by only the second primer set without a MTB-specific reaction. Total 333 clinical samples were analyzed to evaluate the multiplex LAMP assay. Clinical samples were composed of 195 positive samples (72 MTB and 123NTM) and 138 negative samples. All samples were confirmed positivity or negativity by real-time PCR for MTB and NTM. Analytical sensitivity and specificity were evaluated for the multiplex LAMP assay in comparison with acid fast bacilli staining and the culture method. Results Of 123 NTM samples, 121 were identified as NTM and 72/72 MTB were identified as MTB by the multiplex LAMP assay. False negative reactions were seen only in two NTM positive samples with co-infection of Candida spp. All 138 negative samples were identified as negative for MTB and NTM. Analytical sensitivity of the multiplex LAMP assay was 100% (72/72) for MTB, and 98.4% (121/123) for NTM. And the specificity of assay was 100% (138/138) for all. Conclusions Our newly designed multiplex LAMP assay for MTB and NTM showed relatively good sensitivity in comparison with previously published data to detect isolated MTB. This multiplex LAMP assay is expected to become a useful tool for detecting and differentiating MTB from NTM rapidly at an acceptable sensitivity.


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