Changsheng He | Search PubMed

PubMed2026

Repeated Cross-Sectional Surveillance and ORF5-Based Molecular Epidemiology of Porcine Reproductive and Respiratory Syndrome Virus in Anhui Province, China, 2019-2024.

Porcine reproductive and respiratory syndrome virus (PRRSV) remains a major threat to swine production, and its circulation after the African swine fever outbreak requires continued surveillance. This study investigated the temporal, regional, and genetic characteristics of PRRSV in Anhui Province from September 2019 to November 2024. Ten rounds of repeated cross-sectional surveillance were conducted at 147 slaughterhouses and 21 rendering plants. Tissue samples were collected by random, cluster, or risk-based sampling, pooled in groups of five, and tested by RT-qPCR. Representative positive samples with Ct values < 25 underwent ORF5 amplification, Sanger sequencing, and phylogenetic analysis. A total of 994 site visits yielded 18,733 tissue samples. No positive samples were detected in autumn 2020 or spring 2021, whereas PRRSV was detected again from autumn 2021 and subsequently fluctuated. The highest site-level positivity was 41.18% in autumn 2023, and the highest estimated individual-level positivity was 4.66% in spring 2023. Regional differences were statistically significant, with the highest site-level positivity in northern Anhui, and pooled-sample positivity was higher in rendering plants than in slaughterhouses. All 24 ORF5 sequences belonged to PRRSV-2 and mainly clustered with NADC30-like, NADC34-like, or MLV/classical strains. These findings demonstrate temporal fluctuations and lineage coexistence, supporting continued multisource surveillance and broader genomic and antigenic evaluation.

NADC30-like↗

PubMed2025

Sensitive and Visualized Detection of Hantavirus Using CRISPR/Cas12a Based on AutoCORDSv2 Design.

In recent years, detection technologies based on the CRISPR/Cas12a method have been extensively utilized in the fields of nucleic acid, enzyme, and macromolecule detection, thereby reinforcing their significant role in the detection landscape. Enhancing the simplicity of design, efficiency, and automation of the CRISPR/Cas12a detection system is essential for advancing its application in diagnostics. Recently, we developed an automated CRISPR/Cas12a design system named AutoCORDSv2. This system can process published genomic sequences of pathogenic bacteria in a high-throughput manner and automatically generate conserved and highly specific crRNA sequences, along with primer sequences for target amplification. This capability facilitates the specific and precise design of the CRISPR/Cas12a detection system. In this study, crRNAs targeting the Hantaan virus (HTNV) and Seoul virus (SEOV), as well as RT-PCR primers and RT-RPA primers, were designed using AutoCORDSv2. The experimental results demonstrated that the CRISPR/Cas12a system, automatically designed by AutoCORDSv2, was specific for the detection of both the HTNV and SEOV, with no cross-reactivity observed with other pathogens. The detection sensitivity reached 6 copies/μL (equivalent to 111 copies per amplification reaction), whether measured by a microplate reader or directly observed with the naked eye. The detection results for 50 samples were consistent with those obtained from commercial RT-qPCR kits, indicating high precision. Furthermore, the CRISPR/Cas12a system designed by AutoCORDSv2 can also be utilized for the development of a single-tube detection system with a sensitivity of 42 copies per reaction. This system combined with a 5-min extraction step and RT-RPA, further underscoring its potential for application.

CRISPR-Cas Systems↗