Rapid On-Site Detection Method for White Spot Syndrome Virus Using Recombinase Polymerase Amplification Combined With Lateral Flow Test Strip Technology

Rapid and specific detection of Enterococcus faecium with an isothermal amplification and lateral flow strip combined method

Enterococcus faecium is responsible for a highly contagious, drug-resistant nosocomial infection that often causes serious illness. In this study, a rapid and sensitive RPA-LFS (recombinase polymerase amplification-lateral flow strip) method for the detection of E. faecium was established based on specific primers and probes designed using the ddl gene. To verify the specificity and sensitivity of the method, 26 specific strains and 100-106 CFU/μL E. faecium were selected for detection. The results show that the proposed method can specifically detect E. faecium, and the minimum detection limit is 100 CFU/μL. To compare the clinical application of the method with qPCR, 181 clinical samples were collected for testing. RPA-LFS and qPCR had the same practical applicability, and 61 parts of E. faecium were detected in 183 clinical samples. The methods developed in this study not only have the advantages of rapid sensitivity and specificity but also meet the needs of remote areas with scarce medical resources.

A recombinase polymerase amplification and Pyrococcus furiosus Argonaute combined method for ultra-sensitive detection of white spot syndrome virus in shrimp

White spot disease (WSD) in shrimp is an acute infectious disease caused by white spot syndrome virus (WSSV). WSD has seriously threatened the security of shrimp farming, causing huge economic losses worldwide. As there is currently no effective treatment for WSD, developing early detection technologies for WSSV is of great significance for the prevention. In this study, we have established a detection method for WSSV using a combination of recombinase polymerase amplification (RPA) and Pyrococcus furiosus Argonaute (PfAgo). We have achieved a detection sensitivity of single copy per reaction, which is more sensitive than the previously reported detection methods. Additionally, we have demonstrated high specificity. The entire detection process can be completed within 75 min without the need for precise thermal cyclers, making it suitable for on-site testing. The fluorescence signal generated by the reaction can be quantified using a portable fluorescence detector or observed with the naked eye under a blue light background. This study provides an ultrasensitive on-site detection method for WSSV in shrimp aquaculture and expands the application of PfAgo in the field of aquatic disease diagnosis.

Advances in the application of recombinase-aided amplification combined with CRISPR-Cas technology in quick detection of pathogenic microbes

The rapid diagnosis of pathogenic infections plays a vital role in disease prevention, control, and public health safety. Recombinase-aided amplification (RAA) is an innovative isothermal nucleic acid amplification technology capable of fast DNA or RNA amplification at low temperatures. RAA offers advantages such as simplicity, speed, precision, energy efficiency, and convenient operation. This technology relies on four essential components: recombinase, single-stranded DNA-binding protein (SSB), DNA polymerase, and deoxyribonucleoside triphosphates, which collectively replace the laborious thermal cycling process of traditional polymerase chain reaction (PCR). In recent years, the CRISPR-Cas (clustered regularly interspaced short palindromic repeats-associated proteins) system, a groundbreaking genome engineering tool, has garnered widespread attention across biotechnology, agriculture, and medicine. Increasingly, researchers have integrated the recombinase polymerase amplification system (or RAA system) with CRISPR technology, enabling more convenient and intuitive determination of detection results. This integration has significantly expanded the application of RAA in pathogen detection. The step-by-step operation of these two systems has been successfully employed for molecular diagnosis of pathogenic microbes, while the single-tube one-step method holds promise for efficient pathogen detection. This paper provides a comprehensive review of RAA combined with CRISPR-Cas and its applications in pathogen detection, aiming to serve as a valuable reference for further research in related fields.