Establishment and preliminary evaluation of a fluorescent recombinase-aided amplification/CRISPR-Cas12a system for rapid detection of Plasmodium falciparum
10.16250/j.32.1374.2022240
- VernacularTitle:荧光重组酶聚合酶扩增/CRISPR-Cas12a快速检测 恶性疟原虫方法的建立与初步评价
- Author:
Weiyi HUANG
1
;
Huagui WEI
1
;
Chunfang WANG
2
;
Junli WANG
1
;
Liying CHEN
1
;
Weizhong CHEN
3
;
Yaqun LIU
4
;
Yuzhong ZHENG
1
,
5
;
Min LIN
1
,
5
Author Information
1. School of Laboratory Medicine, Youjiang Medical University for Nationalities, Baise, Guangxi 533000, China
2. Department of Laboratory Medicine, The Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi 533000, China
3. Department of Laboratory Medicine, Chaozhou People’s Hospital Affiliated to Shantou University, Chaozhou, Guangdong 521000, China
4. College of Life Science and Food Engineering, Hanshan Normal University, Chaozhou, Guangdong 521000, China
5. College of Life Science and Food Engineering, Hanshan Normal University, Chaozhou, Guangdong 521000, China
- Publication Type:Journal Article
- Keywords:
Plasmodium falciparum;
Recombinase-aided amplification;
CRISPR-Cas12a;
Detection efficiency
- From:
Chinese Journal of Schistosomiasis Control
2023;35(1):38-43
- CountryChina
- Language:Chinese
-
Abstract:
Objective To establish a fluorescent assay for rapid detection of Plasmodium falciparum based on recombinaseaided amplification (RAA) and CRISPR-Cas12a system,and to preliminarily evaluate the diagnostic efficiency of this system.. Methods The 18S ribosomal RNA (rRNA) gene of P. falciparum was selected as the target sequence, and three pairs of RAA primers and CRISPR-derived RNA (crRNA) were designed and synthesized. The optimal combination of RAA primers and crRNA was screened and the reaction conditions of the system were optimized to create a fluorescent RAA/CRISPR-Cas12a system. The plasmid containing 18S rRNA gene of the P. falciparum strain 3D7 was generated, and diluted into concentrations of 1 000, 100, 10, 1 copy/μL for the fluorescent RAA/CRISPR-Cas12a assay, and its sensitivity was evaluated. The genomic DNA from P. vivax, P. malariae, P. ovum, hepatitis B virus, human immunodeficiency virus and Treponema pallidum was employed as templates for the fluorescent RAA/CRISPR-Cas12a assay, and its specificity was evaluated. Fifty malaria clinical samples were subjected to the fluorescent RAA/CRISPR-Cas12a assay and nested PCR assay, and the consistency between two assays was compared. In addition, P. falciparum strain 3D7 was cultured in vitro. Then, the culture was diluted into blood samples with parasite densities of 1 000, 500, 200, 50, 10 parasites/μL with healthy volunteers’ O-positive red blood cells for the RAA/CRISPR-Cas12a assay, and the detection efficiency was tested. Results The Pf-F3/Pf-R3/crRNA2 combination, 2.5 μL as the addition amount of B buffer, 40 min as the RAA reaction time, 37 °C as the reaction temperature of the CRISPR-Cas12a system were employed to establish the fluorescent RAA/CRISPR-Cas12a system. Such a system was effective to detect the plasmid containing 18S rRNA gene of the P. falciparum strain 3D7 at a concentration of 1 copy/μL, and presented fluorescent signals for detection of P. falciparum, but failed to detect P. ovum, P. malariae, P. vivax, T. pallidum, hepatitis B virus or human immunodeficiency virus. The fluorescent RAA/CRISPR-Cas12a system and nested PCR assay showed completely consistent results for detection of 50 malaria clinical samples (kappa = 1.0, P < 0.001). Following 6-day in vitro culture of the P. falciparum strain 3D7, 10 mL cultures were generated and the fluorescent RAA/CRISPR-Cas12a system showed the minimal detection limit of 50 parasites/μL. Conclusion The fluorescent RAA/CRISPR-Cas12a system is rapid, sensitive and specific for detection of P. falciparum, which shows promising value for rapid detection and risk monitoring of P. falciparum.
