1
|
Jamwal VL, Kumar N, Bhat R, Jamwal PS, Singh K, Dogra S, Kulkarni A, Bhadra B, Shukla MR, Saran S, Dasgupta S, Vishwakarma RA, Gandhi SG. Optimization and validation of RT-LAMP assay for diagnosis of SARS-CoV2 including the globally dominant Delta variant. Virol J 2021; 18:178. [PMID: 34461941 PMCID: PMC8404189 DOI: 10.1186/s12985-021-01642-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/12/2021] [Indexed: 01/12/2023] Open
Abstract
Background Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19 pandemic, has infected more than 179 million people worldwide. Testing of infected individuals is crucial for identification and isolation, thereby preventing further spread of the disease. Presently, Taqman™ Reverse Transcription Real Time PCR is considered gold standard, and is the most common technique used for molecular testing of COVID-19, though it requires sophisticated equipments, expertise and is also relatively expensive. Objective Development and optimization of an alternate molecular testing method for the diagnosis of COVID-19, through a two step Reverse Transcription Loop-mediated isothermal AMPlification (RT-LAMP). Results Primers for LAMP were carefully designed for discrimination from other closely related human pathogenic coronaviruses. Care was also taken that primer binding sites are present in conserved regions of SARS-CoV2. Our analysis shows that the primer binding sites are well conserved in all the variants of concern (VOC) and variants of interest (VOI), notified by World Health Organization (WHO). These lineages include B.1.1.7, B.1.351, P.1, B.1.617.2, B.1.427/B.1.429, P.2, B.1.525, P.3, B.1.526 and B.1.617.1. Various DNA polymerases with strand displacement activity were evaluated and conditions were optimized for LAMP amplification and visualization. Different LAMP primer sets were also evaluated using synthetic templates as well as patient samples. Conclusion In a double blind study, the RT-LAMP assay was validated on more than 150 patient samples at two different sites. The RT-LAMP assay appeared to be 89.2% accurate when compared to the Taqman™ rt-RT-PCR assay. Supplementary Information The online version contains supplementary material available at 10.1186/s12985-021-01642-9.
Collapse
Affiliation(s)
- Vijay Lakshmi Jamwal
- CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Natish Kumar
- CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India
| | - Rahul Bhat
- CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Piyush Singh Jamwal
- CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India
| | - Kaurab Singh
- Higher Education Department, Union Territory of Jammu and Kashmir, Jammu, India
| | - Sandeep Dogra
- Department of Microbiology, Government Medical College, Jammu, 180001, India
| | - Abhishek Kulkarni
- A2O - Biology, Reliance Technology Group, Reliance Industries Limited, RCP, Navi Mumbai, 400701, India
| | - Bhaskar Bhadra
- A2O - Biology, Reliance Technology Group, Reliance Industries Limited, RCP, Navi Mumbai, 400701, India
| | - Manish R Shukla
- A2O - Biology, Reliance Technology Group, Reliance Industries Limited, RCP, Navi Mumbai, 400701, India
| | - Saurabh Saran
- CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Santanu Dasgupta
- A2O - Biology, Reliance Technology Group, Reliance Industries Limited, RCP, Navi Mumbai, 400701, India
| | - Ram A Vishwakarma
- CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India
| | - Sumit G Gandhi
- CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India. .,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| |
Collapse
|