Abstract: The sporadic outbreaks of human mpox diseases in the nearly twenty years have seriously influenced the public health and economic. Though the reservoirs of mpox virus (MPXV) are mainly rodents, it could spill over to humans by direct contact and cause self-limiting infection with the symptom of lymphadenopathy and rash on the skin. Since the first case reported outside Africa in the USA at the beginning of this century in America, MPXV has been gradually prevalent globally and become an increasing public threat. With the advancing technology of viral detection and gene sequencing, many novel poxviruses were detected which enriched the variety of Poxviridae family. In this review, we provide a comprehensive overview on the latest classification, host spectrum, genome feature, pathogenicity and the evolution of MPXV and other poxviruses. This information will promote our understanding of the phylogenetic relationship and infectious transmission of pathogenic poxviruses and contribute to future viral researches and disease control.  

Key words: poxvirus; pathogenicity; taxonomy; host; evolution

CLC number: R373.9                     Document code: A                 DOI：10.3969/j.issn.1007-7146.2023.06.001

 

Abstract: Coronaviruses (CoV) are enveloped viruses that possess a positive-sense single-stranded RNA genome 27～32 kb in length, belonging to the Coronaviridae family, the Nidovirales order. In recent years, coronaviruses have posed a great threat to human life and health. For example, in 2002 and 2012, severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) emerged and caused panic, respectiverly. In particular, a novel coronavirus designated as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in 2019, has been epidemic so far worldwidely, seriously endangering human health and social order and arousing attention. So far, SARS-CoV-2 has evolved several variants. At present, the epidemic types are mainly Omicron family strains, and accompanying other variant strains. Meanwhile, SARS-CoV-2 is still in constant variation. Nowadays, the epidemic situation prevention and control of our country has entered the stage of “category B disease” with normalization prevention and control, whereas SARS-CoV-2 will still be an important public health issue in the future. In this review, the key mutations of various major strains of SARS-CoV-2 Omicron and their relationship with virus infectivity, pathogenicity, immune escape ability, and other characteristics were summarized, which can provide reference for the systematic understanding of SARS-CoV-2 evolution, transmission, and epidemic status.

Key words: SARS-CoV-2; S protein; variation; infection and disease; immune escape 

（Acta Laser Biology Sinica, 2023, 32(6): 492-501）

 

Abstract: Frequent viral epidemics in recent years urge the development of efficient and convenient techniques for virus detection and antiviral drugs development. As the most popular gene-editing tools, engineered systems based on clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas) possess high specificity and efficiency in nucleic acid targeting and cleavage, which have also been widely used in virological research and medical practice. This review briefly introduces the features of three most commonly used CRISPR/Cas systems, including Cas9, Cas12 and Cas13, and comprehensively concludes their application in virus detection and antiviral therapeutics. For virus detection, Cas9 enhances the sensitivity and accuracy of biosensor detection by combining it with biosensors such as fluorescent sensors, electrochemical sensors, and lateral flow chromatography. As for Cas12 and Cas13, multiple technologies have been developed to detect DNA and RNA viruses based on their trans-cleavage activity, such as SHERLOCK and DETECTR. As CRISPR/Cas-based antiviral techniques, Cas9 has been employed to cleave viral DNA, including genomes of DNA viruses and intermediate DNA of retroviruses, while Cas13 has been used to target viral RNA, including genomes of RNA viruses and viral mRNA. Although CRISPR/Cas systems have shown multiple advantages in sensitivity, efficiency and convenience, they still bear some limitations, such as off-target effect, immunogenicity and carcinogenicity. In summary, this manuscript provides an overview of current progress in the application of different CRISPR/Cas systems as promising tools in virus detection and antiviral therapy.

Key words: CRISPR/Cas system; virus detection; antiviral therapy; biosensor

CLC number: Q789                        Document code: A                DOI：10.3969/j.issn.1007-7146.2023.06.003

Abstract: Bacterial diseases of fish pose a serious threat to the development of fish breeding industry, and the abuse of antibiotics and the emergence of drug resistance of pathogenic bacteria have a serious impact on the yield of fish breeding, the quality of aquatic products and the breeding environment. In order to promote the development of healthy fish breeding industry, it is urgent to innovate the green prevention and control technology of fish diseases. As a natural and non-residual bacterial killer, phage has the characteristics of strong specificity and high lysis efficiency. Using phage to treat bacterial diseases of fish will be an important technical approach. This paper reviews the important resource mining of phages, the mechanism of action in the prevention and control of bacterial diseases in fish and its application prospects, and puts forward measures to speed up the research of phage treatment technology in the field of healthy aquaculture of fish, which is of great significance for healthy aquaculture of fish.

Key words: fish farming; phage therapy; bacterial diseases; bacterial killer; green prevention and control technology

（Acta Laser Biology Sinica, 2023, 32(6): 517-524）

 

Abstract: In order to study the molecular mechanism of tobacco vein mottling virus (TVMV) infection of Nicotiana benthamiana, this study established a TVMV transcriptome database, excavated disease-resistant genes, metabolic and signaling pathways, and used the Illumina Novaseq 6000 high-throughput sequencing platform to perform transcriptome sequencing and bioinformatics analysis Nicotiana benthamiana infected with TVMV. We used software such as R package: edge R to analyze differentially expressed genes related to disease resistance, and conducted gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis on differentially expressed genes in the KEGG. A total of 4 593 differentially expressed genes were obtained based on the transcriptome sequencing results of TVMV infection, among which the 3 564 genes were up-regulated and 1 029 genes were down-regulated. A total of 10 differentially expressed genes related to disease resistance were screened, 6 were up-regulated and 4 were down-regulated. A total of 50 functional groups have been annotated in the GO database in three categories: biological processes, cell components and molecular functions. Among them, in the third class of molecular functions, the differentially expressed genes involved in protein binding function and ATP binding function were most significant, there were 501 and 453 differential genes, respectively. KEGG was enriched in 20 pathways, annotation to ribosome pathway has the highest degree of differential gene enrichment. 307 differentially expressed genes were more significant. Protein binding, ATP binding, ribosome, eukaryotic ribosome biological reaction, DNA replication and other pathways may play an important role in the regulation of TVMV. The analysis of differentially expressed genes screened in transcriptome has laid an important foundation for further research on the resistance of Nicotiana benthamiana to TVMV virus.

Key words: tobacco vein mottle virus; transcriptome; KEGG pathway; Nicotiana benthamiana; bioinformatics analysis

（Acta Laser Biology Sinica, 2023, 32(6): 525-536）

Abstract: To investigate the common characteristics of mammalian virus co-receptors, this study collected 277 pairs of viral co-receptor combinations based on the data from ViralReceptor database. We investigated the structural, functional, evolutionary and tissue expression characteristics of mammalian virus co-receptors and compared them with combinations of viral receptors derived from different mammalian viruses, as well as randomly selected human proteins. The results showed that in comparison to other protein pairs, mammalian virus co-receptors exhibited higher functional similarity, higher ratio of interaction in the host protein interaction network, and higher co-expression levels in common human tissues. This study demonstrates that mammalian virus co-receptors share common features such as functionality, expression, and interaction, with the expectation that these findings will provide a reference for the discovery and identification of virus receptors.

Key words: mammalian virus; bioinformatic; virus co-receptor; virus receptor; human protein combination

（Acta Laser Biology Sinica, 2023, 32(6): 537-547）

Abstract: Hepatitis E virus (HEV) harbored by small mammals in Dali City, Yunnan Province was investigated. The samples were detected by nested RT-PCR and whole genomes were sequenced by high-throughput sequencing in the positive HEV samples. Bioinformatics was analyzed by the soft-wares of MEGA-X, BESTv1.10.4 and Geneious. A total of 114 small mammals from 6 genera and 7 species were screened in this study. The positivity rate of HEV in Norway rat (Rattus norvegicus) was 8.00% (2/25), and the whole genome of one HEV strain of No. DL147 was obtained, which was the HEV-C1 genotype, and had the highest homology to HEV in the serum of a patient with hepatitis E in Hong Kong, with a nucleotide level of 95.21%. The earliest divergence between the two strains was about 2003. The study confirmed the presence of HEV-C1 infection in Norway rat in Dali City, Yunnan Province, which is highly homologous to the recently reported human emerging HEV and has a relatively recent phylogenetic relationship， and it is instructive for prevention and control of hepatitis E.

 Key words: hepatitis E virus；zoonosis; rodents; genetic analysis; high throughput sequencing

（Acta Laser Biology Sinica, 2023, 32(6): 548-553）

Abstract: In order to detect African swine fever virus (ASFV) quickly by ordinary PCR, In this study, we established a common PCR method for ASFV B646L and F778R dual genes by two pairs of specific primers which were designed based on the target sequences of ASFV B646L and F778R genes respectively. And its specificity, sensitivity and reproducibility were tested. It showed that the optimal combination of PCR system (25.0 μL system) was Pfu enzyme 0.2 μL, 10×Reaction Buffer 2.5 μL, 2.5 mmol/L dNTP Mixture 2.5 μL, B646L upstream primer and B646L downstream primer were 1.5 μL, F778R upstream primer, F778R downstream primer each 0.5 μL, DNA template 1.0 μL, annealing temperature 57℃, annealing time 30 s. The method was only used for specific amplification of ASFV B646L and F778R genes, without cross-reaction. The lower limits of detection of positive plasmid B646L and F778R were 7.2×107 copies/μL and 1.5×106 copies/μL. The test repeatability is good. This study has important value for improving the accuracy, specificity and efficiency of clinical diagnosis of ASFV, and provides reliable technical support for rapid detection of ASFV.

Key words: African swine fever; multiplex PCR; B646L gene; F778R gene; quick detection

（Acta Laser Biology Sinica, 2023, 32(6): 554-560）

Abstract: Influenza viruses spread through the respiratory tract among humans，and it is particularly important to enhance the mucosal immunity against the viruses by vaccination， However，influenza vaccines，which are now mainly inactivated vaccines and  inoculated by intramuscular injection，can hardly induce mucosal immunity. In this study，mucosal immunization of mice with H7N9 inactivated influenza vaccine was explored. In order to enhance effectiveness of the vaccine through  intranasal route，phospholipids and cholesterol，whose properties are similar to those of pulmonary surfactants (PS)，were used to prepare PS-biomimetic liposomes，and then resiquimod (R848)， a small-molecule compound， was encapsulated within the bionic PS liposomes using thin-film dispersion method to form a novel mucosal adjuvant. BALB/c mice were immunized intranasally with H7N9 influenza inactivated vaccine mixed with PS-R848. The immunological indicators and protective effects post challenge were detected. Compared with the vaccine plus R848，the vaccine plus PS-R848 induced in mice significantly increased serum immunoglobulin G (IgG) antibody，IgG1 and IgG2a subclass  antibody titers，haemagglutination inhibition (HI) titers，and lung secretory IgA titers，and also significantly increased secretion amounts of interferon-γ (IFN-γ)，interleukin-2 (IL-2) and IL-4 cytokines. After the lethal homologous virus attack，mice in vaccine plus PS-R848 group survived 100%，with significantly reduced lung residual virus titer and the maximum weight loss rate，compared to the vaccine alone group. The results indicated that PS-biomimetic liposomes encapsulating R848 could be used as a mucosal adjuvant to effectively enhance the immune efficacy of inactivated influenza virus vaccines.

Key words: influenza virus；inactivated vaccine；liposome；pulmonary surfactant；mucosal immunization

（Acta Laser Biology Sinica, 2023, 32(6): 561-568）

Abstract: To analyze the detection of group A rotavirus (RVA) in the diarrheal patients of Zhuhai City and its correlation with patient gender, age, and infection timing. Fecal specimens were collected from patients with diarrhea in Zhuhai Center for Maternal and Child Health Care from January 2019 to December 2022 and were tested for RVA antigen using antigen test kit. Statistical analysis of the results was performed using SPSS 20.0. Among the 11 385 fecal samples collected, with an overall RVA detection rate of 9.170% (1 044/11 385), and no significant difference in gender distribution (P>0.05). RVA was detected in all age groups, with the highest positive rate of 9.962% (369/3 704) in infants (29 days to <1 year), significantly higher than those in school-age children (6 to <12 years) and adults (≥18 years) (P<0.01). There were no significant differences in the positive rate of RVA among children under 6 years old (P>0.05). RVA infections occurred throughout the year, with the highest positive rate of 15.456% (117/757) in February. The positive rate of RVA in February was significantly higher than that in other months except for January, March, and May (P<0.01). Seasonally, the positive rate of 11.666% (341/2 923) was the highest in spring, which was significantly higher than that in summer and autumn (P<0.01). The study showed that RVA infection in Zhuhai from 2019 to 2022 exhibited obvious seasonal and population distribution characteristics. It is necessary to strengthen the prevention and control of RVA in children under 6 years old in late winter and early spring. This study is helpful to better understand transmission characteristics and rules of RVA in Zhuhai, and provide scientific basis for the prevention and control of RVA in this area.

Key words: infectious diarrhea; group A rotavirus; epidemiological characteristics; positive rate of infants and young children; epidemiological analysis

（Acta Laser Biology Sinica, 2023, 32(6): 569-576）