Molecular epidemiology and antimicrobial resistance of Vibrio parahaemolyticus isolates from the Pearl River Delta region, China.

The Pearl River Delta (PRD) region in southern China is a densely populated area and a hotspot for Vibrio parahaemolyticus infections. However, systematic research on this pathogen, particularly comparing clinical and environmental strains, remains limited. This study analyzed the molecular epidemiology and antimicrobial resistance of 200 V.

Expression and immunogenicity of non-structural protein 8 of porcine epidemic diarrhea virus.

The non-structural protein (nsp) 8 of the porcine epidemic diarrhea virus (PEDV) is highly stable across different PEDV strains and plays an important role in PEDV virulence. In current study, nsp8 prokaryotic expression vectors were constructed based on parental vectors pMAL-c2x-maltose binding protein (MBP) and pET-28a (+). Subsequently, the optimization of expression conditions in , including induced temperature, time and isopropyl β-D-thiogalactopyranoside concentration were performed to obtain a stable expression of MBP-nsp8 and nsp8.

A photocontrolled one-pot isothermal amplification and CRISPR-Cas12a assay for rapid detection of SARS-CoV-2 Omicron variants.

CRISPR-Cas technology has widely been applied to detect single-nucleotide mutation and is considered as the next generation of molecular diagnostics. We previously reported the combination of nucleic acid amplification (NAA) and CRISPR-Cas12a system to distinguish major severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. However, the mixture of NAA and CRISPR-Cas12a reagents in one tube could interfere with the efficiency of NAA and CRISPR-Cas12a cleavage, which in turn affects the detection sensitivity.

Serological investigation on the prevalence of poliovirus in Guangdong province: A cross-sectional study.

In 2019, we conducted a cross-sectional study for polio virus seroprevalence in Guangdong province, China. We assessed the positivity rates of poliomyelitis NA and GMT in serum across various demographic groups, and the current findings were compared with pre-switch data from 2014. Using multistage random sampling method, four counties/districts were randomly selected per city, and within each, one general hospital and two township hospitals were chosen.

[Rapid detection and genotyping of SARS-CoV-2 Omicron BA.4/5 variants using a RT-PCR and CRISPR-Cas12a-based assay].

Objective: To establish a rapid detection and genotyping method for SARS-CoV-2 Omicron BA.4/5 variants using CRISPPR-Cas12a gene editing technology.

Methods: We combined reverse transcription-polymerase chain reaction (RT-PCR) and CRISPR gene editing technology and designed a specific CRISPPR RNA (crRNA) with suboptimal protospacer adjacent motifs (PAM) for rapid detection and genotyping of SARS- CoV-2 Omicron BA.

[Genomic epidemiology of from acute diarrheal patients in Shenzhen City from 2013 to 2021].

To characterize the prevalence and genomic epidemiology of from acute diarrheal patients in Shenzhen City from 2013 to 2021. Based on the Shenzhen Infectious Diarrhea Surveillance System, acute diarrheal patients were actively monitored in sentinel hospitals from 2013 to 2021. Whole-genome sequencing (WGS) of isolates was performed, and the genomic population structure, serotypes, virulence genes and multilocus sequence typing were analyzed.

[Establishment and preliminary application of quantitative real-time PCR assay for the detection of SARS-CoV-2 subgenomic nucleocapsid RNA].

To establish a rapid and specific quantitative real-time PCR (qPCR) method for the detection of SARS-CoV-2 subgenomic nucleocapsid RNA (SgN) in patients with COVID-19 or environmental samples. The qPCR assay was established by designing specific primers and TaqMan probe based on the SARS-CoV-2 genomic sequence in Global Initiative of Sharing All Influenza Data (GISAID) database. The reaction conditions were optimized by using different annealing temperature, different primers and probe concentrations and the standard curve was established.

Immunogenicity analysis of the E. coli expressed structural protein VP1 of persistent infection foot-and-mouth disease virus.

The persistent infection of FMDV in cloven hoofed animals has made the epidemic prevention and control more difficult. VP1 is the main immunogenic protein and first candidate of vaccine development for FMDV prevention. However, the mutation of VP1 in host cell with persistent infection FMDV (PI-FMDV) caused the change of its immunogenicity.

Development and Characterization of a Genetically Stable Infectious Clone for a Genotype I Isolate of Dengue Virus Serotype 1.

Dengue virus (DENV) is primarily transmitted by the bite of an infected mosquito of and , and symptoms caused may range from mild dengue fever to severe dengue hemorrhagic fever and dengue shock syndrome. Reverse genetic system represents a valuable tool for the study of DENV virology, infection, pathogenesis, etc. Here, we generated and characterized an eukaryotic-activated full-length infectious cDNA clone for a DENV serotype 1 (DENV-1) isolate, D19044, collected in 2019.

Exosomal microRNA expression profiles derived from A549 human lung cells in response to influenza A/H1N1pdm09 infection.

Exosomes participate in intercellular communication by shuttling various small molecules from donor to recipient cells. We aimed to examine the role of exosomes and exosomal miRNAs in influenza virus infection. The results showed that influenza A/H1N1pdm09 infection could promote A549 cells to secrete exosomes, while blocking the generation of exosomes reduced viral RNA production.

Combination of Isothermal Recombinase-Aided Amplification and CRISPR-Cas12a-Mediated Assay for Rapid Detection of Major Severe Acute Respiratory Syndrome Coronavirus 2 Variants of Concern.

Coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 variants is a new and unsolved threat; therefore, it is an urgent and unmet need to develop a simple and rapid method for detecting and tracking SARS-CoV-2 variants. The spike gene of SARS-CoV-2 was amplified by isothermal recombinase-aided amplification (RAA) followed by the cleavage of CRISPR-Cas12a in which five allele-specific crRNAs and two Omicron-specific crRNAs were designed to detect and distinguish major SARS-CoV-2 variants of concerns (VOCs), including alpha, beta, delta variants, and Omicron sublineages BA.1 and BA.

[Progress in research of 2019-nCoV Omicron variant].

2019-nCoV Omicron (B.1.1.

PBPK Modeling on Organs-on-Chips: An Overview of Recent Advancements.

Organ-on-a-chip (OoC) is a new and promising technology, which aims to improve the efficiency of drug development and realize personalized medicine by simulating environment . Physiologically based pharmacokinetic (PBPK) modeling is believed to have the advantage of better reflecting the absorption, distribution, metabolism and excretion process of drugs than traditional compartmental or non-compartmental pharmacokinetic models. The combination of PBPK modeling and organ-on-a-chip is believed to provide a strong new tool for new drug development and have the potential to replace animal testing.

[Epidemiological and etiological characteristics of strains causing foodborne disease outbreaks in Guangdong Province from 2017 to 2020].

To study the epidemiological and pathogenic characteristics of isolated from outbreaks cases in Guangdong Province, 2017-2020. Epidemiological characteristics of 87 outbreak events caused by were analyzed. Strains were serotyped, and then analyzed by pulsed-field gel electrophoresis (PFGE).

[Identification and analysis of 2 strains in Guangdong Province].

To identify and analyze two strains of in Guangdong Province by combining whole genome sequencing with traditional detection methods. The was isolated from Guangzhou in 2010 and Zhuhai in 2020 respectively. Isolates were identified by API Coryne strips and MALDI-TOF-MS.

Detection of Major SARS-CoV-2 Variants of Concern in Clinical Samples via CRISPR-Cas12a-Mediated Mutation-Specific Assay.

: Emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants pose a great threat and burden to global public health. Here, we evaluated a clustered regularly interspaced short palindromic repeat-associated enzyme 12a (CRISPR-Cas12a)-based method for detecting major SARS-CoV-2 variants of concern (VOCs) in SARS-CoV-2 positive clinical samples. : Allele-specific CRISPR RNAs (crRNAs) targeting the signature mutations in the spike protein of SARS-CoV-2 are designed.

Rapid detection and tracking of Omicron variant of SARS-CoV-2 using CRISPR-Cas12a-based assay.

Background: The newly emerged SARS-CoV-2 variant of concern (VOC) Omicron is spreading quickly worldwide, which manifests an urgent need of simple and rapid assay to detect and diagnose Omicron infection and track its spread.

Methods: To design allele-specific CRISPR RNAs (crRNAs) targeting the signature mutations in the spike protein of Omicron variant, and to develop a CRISPR-Cas12a-based assay to specifically detect Omicron variant.

Results: Our system showed a low limit of detection of 2 copies per reaction for the plasmid DNA of Omicron variant, and could readily detect Omicron variant in 5 laboratory-confirmed clinical samples and distinguish them from 57 SARS-CoV-2 positive clinical samples (4 virus isolates and 53 oropharyngeal swab specimens) infected with wild-type (N = 8) and the variants of Alpha (N = 17), Beta (N = 17) and Delta (N = 15).

Simultaneous quantification of hepatitis A virus and norovirus genogroup I and II by triplex droplet digital PCR.

The representative enteric viruses responsible for global foodborne outbreaks that have become an essential concern for health authorities are Norovirus (NoV) and Hepatitis A virus (HAV). Droplet digital PCR (ddPCR) has recently emerged as an alternative platform for virus quantification due to its high precision, ultra-sensitivity, and lack of a standard curve need. Using a ratio-based probe-mixing strategy, we established a triplex ddPCR method to detect norovirus genogroup I (GI), genogroup II (GII), and HAV in food, drinking water, and faecal samples.

Dengue Fever Outbreaks Caused by Varied Serotype Dengue Virus - Guangdong Province, China, 2019.

Dengue fever (DF) outbreaks affect hundreds of millions of people worldwide and have increased significantly in Guangdong Province in 2019. This paper described briefly DF outbreaks were attributed to several types of dengue virus (DENV) including DENV-1, DENV-2, and DENV-3 in 2019 in Guangdong, tracked the sources of viruses through phylogenetic analysis and epidemiological investigation, and primarily revealed the epidemiological links among the outbreaks. The introduction of DENV from DF endemic areas increased pressure on the prevention and control of DF in Guangdong.

Misdiagnosis of scrub typhus as hemorrhagic fever with renal syndrome and potential co-infection of both diseases in patients in Shandong Province, China, 2013-2014.

Background: Scrub typhus, caused by Orientia tsutsugamushi, an obligate intracellular gram-negative bacterium, along with hemorrhagic fever with renal syndrome (HFRS), caused by hantaviruses, are natural-focus infectious diseases prevalent in Shandong Province, China. Both diseases have similar clinical manifestations in certain disease stages and similar epidemic seasons, which has caused difficulties for physicians in distinguishing them. The aim of this study was to investigate whether misdiagnosis of scrub typhus as HFRS occurred in patients in Shandong Province.

SFTSV Infection Induced Interleukin-1β Secretion Through NLRP3 Inflammasome Activation.

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging tick-borne virus that causes hemorrhagic fever. Previous studies showed that SFTSV-infected patients exhibited elevated levels of pro-inflammatory cytokines like interleukin-1β (IL-1β), indicating that SFTSV infection may activate inflammasomes. However, the detailed mechanism remains poorly understood.