Objective: To explore the characteristics of viral infections in children with diarrhea in Beijing from 2018 to 2022. Methods: Real-time PCR and enzyme-linked immunosorbent assay were used to detect viral nucleic acid of Norovirus (NoV), Sappovirus (SaV), Astrovirus (AstV), Enteric Adenovirus (AdV) or antigen of Rotavirus (RV) in 748 stool samples collected from Beijing Capital Institute of Pediatrics from January 2018 to December 2021. Subsequently, the reverse transcription PCR or PCR method was used to amplify the target gene of the positive samples after the initial screening, followed by sequencing, genotyping and evolution analysis, so as to obtain the characteristics of these viruses. Phylogenetic analysis was performed using Mega 6.0. Results: From 2018 to 2021, the overall detection rate of the above five common viruses was 37.6%(281/748)in children under 5 years old in Beijing. NoV, Enteric AdV and RV were still the top three diarrhea-related viruses, followed by AstV and SaV, accounting for 41.6%, 29.2%, 27.8%, 8.9% and 7.5%, respectively. The detection rate of co-infections with two or three diarrhea-related viruses was 4.7% (35/748). From the perspective of annual distribution, the detection rate of Enteric AdV was the highest in 2021, while NoV was predominant in the other 4 years. From the perspective of genetic characteristics, NoV was predominant by GⅡ.4, and after the first detection of GⅡ.4[P16] in 2020, it occupied the first two gene groups together with GⅡ.4[P31]. Although the predominant RV was G9P[8], the rare epidemic strain G8P[8] was first detected in 2021. The predominant genotypes of Enteric AdV and AstV were Ad41 and HAstV-1. SaV was sporadic spread with a low detection rate. Conclusion: Among the diarrhea-related viruses infected children under 5 years of age in Beijing, the predominant strains of NoV and RV have changed and new sub-genotypes have been detected for the first time, while the predominant strains of AstV and Enteric AdV are relatively stable.
Child, Preschool ; Humans ; Infant ; Beijing/epidemiology* ; Diarrhea/epidemiology* ; Feces ; Norovirus/genetics* ; Phylogeny ; Rotavirus/genetics* ; Virus Diseases/epidemiology* ; Viruses/genetics*

Porcine epidemic diarrhea virus (PEDV) is a highly pathogenic virus that can cause acute intestinal infectious diseases in both piglets and fattening pigs. The virus encodes at least 16 non-structural proteins, including nsp9, which has been shown to bind to single-stranded RNA. However, its function and mechanism remain unclear. In this study, we aimed to identify potential host proteins that interact with PEDV nsp9 using immunoprecipitation combined with mass spectrometry. The interactions were then confirmed by co-immunoprecipitation (Co-IP) and confocal laser scanning fluorescence techniques. The results showed that nsp9 interacts with HSPA8, Tollip, HSPA9 and TOMM70. Among them, overexpression of HSPA8 resulted in caused first upregulated and then down-regulated expression of nsp9, and promoted the proliferation of PEDV. Overexpression of Tollip significantly upregulated the expression of nsp9 and inhibited the proliferation of PEDV. Overexpression of TOMM70 significantly reduced the expression of nsp9, but did not show significant effect on the proliferation of PEDV. Overexpression of HSPA9 did not show significant effect on the expression of nsp9 and the proliferation of PEDV. These findings may facilitate further investigating the role of nsp9-interacting proteins in PEDV infection.
Animals ; Swine ; Porcine epidemic diarrhea virus/genetics* ; Virus Replication ; Proteins ; Swine Diseases

DNA ; Hepatitis B virus/genetics* ; Humans ; Immunosuppression Therapy ; Skin Diseases

Rice stripe virus (RSV) transmitted by the small brown planthopper causes severe rice yield losses in Asian countries. Although viral nuclear entry promotes viral replication in host cells, whether this phenomenon occurs in vector cells remains unknown. Therefore, in this study, we systematically evaluated the presence and roles of RSV in the nuclei of vector insect cells. We observed that the nucleocapsid protein (NP) and viral genomic RNAs were partially transported into vector cell nuclei by utilizing the importin α nuclear transport system. When blocking NP nuclear localization, cytoplasmic RSV accumulation significantly increased. In the vector cell nuclei, NP bound the transcription factor YY1 and affected its positive regulation to FAIM. Subsequently, decreased FAIM expression triggered an antiviral caspase-dependent apoptotic reaction. Our results reveal that viral nuclear entry induces completely different immune effects in vector and host cells, providing new insights into the balance between viral load and the immunity pressure in vector insects.
Animals ; Cell Nucleus ; Hemiptera/metabolism* ; Insect Vectors/genetics* ; Insecta ; Nucleocapsid Proteins/metabolism* ; Oryza ; Plant Diseases ; Tenuivirus/metabolism* ; Virus Replication

To investigate whether the engineered Lactobacillus plantarum expressing the porcine epidemic diarrhea virus (PEDV) S1 gene can protect animals against PEDV, guinea pigs were fed with recombinant L. plantarum containing plasmid PVE5523-S1, with a dose of 2×10⁸ CFU/piece, three times a day, at 14 days intervals. Guinea pigs fed with wild type L. plantarum and the engineered L. plantarum containing empty plasmid pVE5523 were used as negative controls. For positive control, another group of guinea pigs were injected with live vaccine for porcine epidemic diarrhea and porcine infectious gastroenteritis (HB08+ZJ08) by intramuscular injection, with a dose of 0.2 mL/piece, three times a day, at 14 days intervals. Blood samples were collected from the hearts of the four groups of guinea pigs at 0 d, 7 d, 14 d, 24 d, 31 d, 41 d and 48 d, respectively, and serum samples were isolated for antibody detection and neutralization test analysis by enzyme-linked immunosorbent assay (ELISA). The spleens of guinea pigs were also aseptically collected to perform spleen cells proliferation assay. The results showed that the engineered bacteria could stimulate the production of secretory antibody sIgA and specific neutralizing antibody, and stimulate the increase of IL-4 and IFN-γ, as well as the proliferation of spleen cells. These results indicated that the engineered L. plantarum containing PEDV S1 induced specific immunity toward PEDV in guinea pigs, which laid a foundation for subsequent oral vaccine development.
Animals ; Antibodies, Viral ; Coronavirus Infections/veterinary* ; Guinea Pigs ; Lactobacillus plantarum/genetics* ; Porcine epidemic diarrhea virus/genetics* ; Swine ; Swine Diseases ; Viral Vaccines/genetics*

Viral myocarditis (VMC) is a disease characterized by inflammation of myocardial cells caused by viral infection. Since the pathogenesis mechanism of VMC has not been fully elucidated, the diagnosis and treatment of this disease remains extremely challenging. Non-coding RNAs (ncRNAs) are a class of RNAs that do not encode proteins. An increasing number of studies have shown that ncRNAs are involved in regulating the occurrence and development of VMC, thus providing potential new targets for the treatment and diagnosis of VMC. This review summarizes the possible roles of ncRNAs in the pathogenesis and diagnosis of VMC revealed recently.
Coxsackievirus Infections ; Enterovirus B, Human ; Humans ; Inflammation ; Myocarditis/genetics* ; Virus Diseases/genetics*

The aim of this study was to develop a blocking enzyme-linked immunosorbent assay (bELISA) based on a biotinylated nanobody target the S1 protein of porcine epidemic diarrhea virus (PEDV) for detecting the anti-PEDV antibodies and evaluating the immune effect of the vaccine. The gene encoding the single-domain antibody sdAb3 target the PEDV S1 protein was amplified and the Avitag sequence was fused at its 3'-end. The PCR product was cloned into the expression vector pET-21b for expression and purification of the sdAb3-Avitag protein. The purified sdAb3-Avitag fusion protein was biotinylated and its activity was determined. Using the recombinant S1 protein as a coating antigen, a bELISA was established and optimized. Serum samples were tested in parallel by the bELISA and a commercial kit. The recombinant vector pET21b-sdAb3-Avitag was constructed to express the tagged sdAb3. After induction for expression, the biotin-labeled sdAb3 (sdAb3-Biotin) with high purity and good activity was obtained. For the optimized bELISA, the coating concentration of the S1 protein was 200 ng/well, the serum dilution was 1:2 and incubated for 2 h, the dilution ratio of the biotinylated sdAb3 was 1:8 000 and incubated for 30 min, the dilution of the enzyme-labeled antibody was 1:5 000 and incubated for 30 min. The bELISA had no cross reaction with the sera of major porcine viruses including transmissible gastroenteritis virus, porcine reproductive and respiratory syndrome virus and showed good specificity and reproducibility. For a total of 54 porcine serum samples tested, the overall compliance rate of the bELISA with a commercial kit was 92.56%. This study developed a rapid and reliable bELISA method, which can be used for serosurveillance and vaccine evaluation for PEDV.
Animals ; Antibodies, Viral ; Coronavirus Infections/veterinary* ; Enzyme-Linked Immunosorbent Assay ; Porcine epidemic diarrhea virus/genetics* ; Reproducibility of Results ; Sensitivity and Specificity ; Single-Domain Antibodies ; Swine ; Swine Diseases

A large number of viruses have been found to be associated with ocular diseases, including human adenovirus, human herpesvirus (HHV), human T lymphotropic virus type-1 (HTLV-1), and newly emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This group of diseases is prone to be misdiagnosed or missed diagnosis, resulting in serious tissue and visual damage. Etiological diagnosis is a powerful auxiliary mean to diagnose the ocular diseases associated with human adenovirus, herpes simplex virus 1 and varicella-zoster virus, and it provides the leading diagnosis evidence of infections with herpes simplex virus 2, Epstein-Barr virus, cytomegalovirus, HHV-6/7, HHV-8, HTLV-1 and SARS-CoV-2. Virus isolation, immunoassay and genetic diagnosis are usually used for etiologic diagnosis. For genetic diagnosis, the PCR technique is the most important approach because of its advantages of rapid detection, convenient operation, high sensitivity and high specificity.
COVID-19 ; Coronavirus Infections/virology* ; DNA, Viral/genetics* ; Eye Diseases/virology* ; Humans ; Pandemics ; Pneumonia, Viral/virology* ; Research/trends* ; Virus Diseases/virology*

To achieve uniform soluble expression of multiple proteins in the same Escherichia coli strain, and simplify the process steps of antigen production in genetic engineering subunit multivalent vaccine, we co-expressed three avian virus proteins including the fowl adenovirus serotype 4 (FAdV-4) Fiber-2 protein, infectious bursal disease virus (IBDV) VP2 protein and egg-drop syndrome virus (EDSV) Fiber protein in E. coli BL21(DE3) cells after optimization of gene codon, promoter, and tandem expression order. The purified proteins were analyzed by Western blotting and agar gel precipitation (AGP). The content of the three proteins were well-proportioned after co-expression and the purity of the purified proteins were more than 80%. Western blotting analysis and AGP experiment results show that all the three co-expression proteins had immunoreactivity and antigenicity. It is the first time to achieve the three different avian virus antigens co-expression and co-purification, which simplified the process of antigen production and laid a foundation for the development of genetic engineering subunit multivalent vaccine.
Animals ; Antigens, Viral/genetics* ; Biological Assay ; Chickens/immunology* ; Escherichia coli/genetics* ; Infectious bursal disease virus/immunology* ; Poultry Diseases ; Vaccines, Synthetic/isolation & purification* ; Viral Structural Proteins/immunology* ; Viral Vaccines/immunology*

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was found initially in Wuhan, China in early December 2019. The pandemic has spread to 216 countries and regions, infecting more than 23310 000 people and causing over 800 000 deaths globally by Aug. 24, 2020, according to World Health Organization (https://www.who.int/emergencies/diseases/ novel-coronavirus-2019). Fever, cough, and dyspnea are the three common symptoms of the condition, whereas the conventional transmission route for SARS-CoV-2 is through droplets entering the respiratory tract. To date, infection control measures for COVID-19 have been focusing on the involvement of the respiratory system. However, ignoring potential faecal transmission and the gastrointestinal involvement of SARS-CoV-2 may result in mistakes in attempts to control the pandemic.
Betacoronavirus/isolation & purification* ; COVID-19 ; China/epidemiology* ; Coronavirus Infections/virology* ; Environmental Microbiology ; Feces/virology* ; Gastrointestinal Diseases/virology* ; Humans ; Models, Biological ; Pandemics ; Pneumonia, Viral/virology* ; RNA, Viral/genetics* ; SARS-CoV-2 ; Virus Shedding