Maximum biosafety level laboratories, also known as Biosafety Level 4 (BSL-4) laboratories are pivotal to advancing basic research and technological innovation for preventing and treating infections caused by maximum biosafety level pathogens. Herein, we conduct a bibliometric analysis to identify global research trends and hotspots in this field, with the aim of guiding future scientific strategy and fostering international collaboration. A total of 604 relevant English publications (1980–2025) from the Web of Science Core Collection were analyzed using CiteSpace, VOSviewer, and the bibliometrix R package. The results delineate a two-phase growth pattern: annual publication output transitioned from a prolonged period of slow growth to a sustained high-output plateau following the 2014–2016 Ebola epidemic. Ebola virus is the most frequently studied pathogen, while the Journal of Infectious Diseases is the most prolific journal. Keyword analysis revealed an evolution in research focus from basic research towards applied medical countermeasures, with current priorities centered on evaluating the safety and efficacy of vaccines. The United States emerged as the dominant force, producing the leading institutions, core researchers, and maintained a robust collaborative network with partners like Canada and Germany that significantly outpaced Asian countries. This concentration of research effort, observed within our pathogen cohort, underscores the need for more balanced global cooperation focused on a wider spectrum of maximum biosafety level pathogens.

Background Ticks are the second most significant vector of human pathogens worldwide, with 911 documented species globally and a broad distributed across China. Currently, over 160 tick-borne viruses (TBVs) have been identified, several of which pose substantial threats to human health, such as Dabie bandavirus, Jingmen tick virus, Alongshan virus, Songling virus, Beiji nairovirus, and Langya henipavirus, raising increasing global attention. Despite their significance, the diversity of TBVs in Beijing remains poorly characterized. Methods In this study, we conducted metagenomic sequencing on tick samples collected from Mentougou District, Beijing. The obtained reads were subjected to quality control, de novo assembly, and viral sequence identification, followed by phylogenetic and evolutionary analyses. Results Our results identified 19 distinct viral species spanning 12 families, including Hepelivirales, Solemoviridae,Mymonaviridae, Nodaviridae,Permutotetraviridae, Phenuiviridae,Rhabdoviridae, Tombusviridae,Totiviridae, Peribunyaviridae,Flaviviridae, Nodaviridae,Tymoviridae, Tombusviridae. Among these, six novel viruses from five virus families were discovered. A potential pathogen, Tick jingmen-like virus, was also detected in the selected pathogens. These findings underscore the remarkable diversity of RNA viruses harbored by ticks in Mentougou District. Conclusions Our research findings reveal a previously unrecognized diversity of tick-borne viruses in the Mentougou District, Beijing, and provide essential baseline data for informing future surveillance strategies and guiding prevention and control of tick-borne diseases in the Beijing metropolitan area.

ObjectivesTo evaluate the immune persistence and cross-immune response of elderly individuals after Omicron BA.5 infections.MethodThe neutralizing antibodies against WT, BA.5, XBB.1 and EG.5 strains were analyzed. The T/B-cell subsets’ responses were tested through intracellular cytokine staining and flow cytometry.ResultsThe neutralizing antibodies titers against WT and BA.5 strain, remaining high level for at least 6 months, were higher than that of both XBB.1 and EG.5 variants. The neutralizing antibodies of WT, BA.5, XBB.1, and EG.5 strains in the elderly were slightly lower than those in middle-age. The memory B cells decreased rapidly in the elderly, and Tfh, Th17 cells of the elderly continued to increase for only 3 months, while Tfh and Th17 cells increased in the middle-aged for over 6 months. For the elderly, after peptide stimulation, unswitched/switched memory B cells decreased, while double negative B cells displayed higher proliferation. The proportions of both naïve and Temra cells in CD4+ and CD8+ T cells declined, whereas those of Tcm and Tem cells elevated. In the meantime, both CD69+ and CD38+ T cells decreased, but the frequencies of PD-1+ and CTLA-4+ of CD4+ and CD8+ T cells showed an increasing trend. The proportions of PD-1+ and CTLA-4+ cells also increased in older people with long COVID symptoms at 3m post-infection.ConclusionsOmicron BA.5 infection induced lower neutralizing antibodies against XBB.1 and EG.5 variant. The decrease of memory B cells, CD69+ and CD38+T cells, as well as the increase of PD-1+, CTLA-4+ of CD4+/CD8+T cells and double negative B cells, indicate that sustained immune responses against BA.5 infection may wane more rapidly in elderly populations.

ObjectiveTo understand the epidemiology and evolutionary characteristics of human adenovirus (HAdV) infecting children in Yancheng, China, during the winter of 2023-2024.MethodsHAdV-positive throat swab samples were collected from pediatric patients in Yancheng. The Hexon, Penton base, and Fiber genes were amplified and sequenced for typing and phylogenetic analysis of HAdV.Results170 HAdV-positive samples were collected and identified from children with acute respiratory infection (ARI) in Yancheng. A total of 133 samples were successfully amplified and sequenced for Hexon, Penton base, and Fiber genes. Phylogenetic analysis showed that HAdV-B3 was the dominant circulating strain, and two strains of B21, one strain of C1 and one strain of C5 were also identified.ConclusionDuring the winter of 2023-2024, HAdV infecting children in Yancheng was mainly the B3 type.

IntroductionSeasonal human coronavirus NL63 (HCoV-NL63) is a frequently encountered virus linked to mild upper respiratory infections. However, its potential to cause more severe or widespread disease remains an area of concern. This study aimed to investigate a rare localized epidemic of HCoV-NL63-induced respiratory infections among pediatric patients in Guilin, China, and to understand the viral subtype distribution and genetic characteristics.MethodsIn this study, 83 pediatric patients hospitalized with acute respiratory infections and positive for HCoV-NL63 were enrolled. Molecular analysis was conducted to identify the viral subgenotypes and to assess genetic variations in the receptor-binding domain of the spiking protein.ResultsAmong the 83 HCoV-NL63-positive children, three subgenotypes were identified: C4, C3, and B. Notably, 21 cases exhibited a previously unreported subtype, C4. Analysis of the C4 subtype revealed a unique amino acid mutation (I507L) in the receptor-binding domain of the spiking protein, which was also observed in the previously reported C3 genotype. This mutation may suggest potential increases in viral transmissibility and pathogenicity.DiscussionThe findings of this study highlight the rapid mutation dynamics of HCoV-NL63 and its potential for increased virulence and epidemic transmission. The presence of a unique mutation in the C4 subtype, shared with the C3 genotype, raises concerns about the virus’s evolving nature and its potential public health implications. This research contributes valuable insights into the understanding of HCoV-NL63’s epidemiology and pathogenesis, which is crucial for effective disease prevention and control strategies. Future studies are needed to further investigate the biological significance of the observed mutation and its potential impact on the virus’s transmissibility and pathogenicity.

The symptoms of children infected with SARS-CoV-2 are mainly asymptomatic, mild, moderate, and a few severe cases. To understand the immune response characteristics of children infected with SARS-COV-2 who do not develop severe cases, 82 children infected with the SARS-CoV-2 delta strain were recruited in this study. Our results showed that high levels of IgG, IgM, and neutralization antibodies appeared in children infected with SARS-CoV-2. SARS-CoV-2 induced upregulation of both pro-inflammatory factors including TNF-α and anti-inflammatory factors including IL-4 and IL-13 in the children, even IL-10. The expression of INF-α in infected children also showed a significant increase compared to healthy children. However, IL-6, one of the important inflammatory factors, did not show an increase in infected children. It is worth noting that a large number of chemokines reduced in the SARS-CoV-2-infected children. Subsequently, TCR Repertoire, TCRβ bias, and preferential usage were analyzed on data of TCR next-generation sequencing from 8 SARS-CoV-2-infected children and 8 healthy controls. We found a significant decrease in TCR clonal diversity and a significant increase in TCR clonal expansion in SARS-CoV-2-infected children compared to healthy children. The most frequent V and J genes in SARS-CoV-2 children were TRBV28 and TRBJ2-1. The most frequently VβJ gene pairing in SARS-CoV-2 infected children was TRBV20-1-TRBJ2-1. The strong antiviral antibody levels, low expression of key pro-inflammatory factors, significant elevation of anti-inflammatory factors, and downregulation of many chemokines jointly determine that SARS-CoV-2-infected children rarely develop severe cases. Overall, our findings shed a light on the immune response of non-severe children infected with SARS-CoV-2.

In August 2023, the National Health Science and Education Commission of the National Health Commission issued Notice No.24[2023], officially releasing the " Catalogue of Pathogenic Microorganisms Transmitted to Human Beings". This is to better implement the relevant regulations of the Biosafety Law of the People′s Republic of China and the Biosafety Management Regulations for Pathogenic Microbial Laboratories. With the continuous emergence of new pathogenic microorganisms, updated understanding of existing pathogenic microorganisms, and deepening laboratory biosafety research, the original " List of Pathogenic Microorganisms Transmitted from Human Beings" cannot meet the needs, so the " Catalogue of Pathogenic Microorganisms Transmitted from Human Beings" has been issued. This article aims to provide a detailed interpretation of the virus section of the Catalogue, including its background, principles, processes, and main content, in order to facilitate a better understanding of the Catalogue.

Viral myocarditis (VMC) is a common disease characterized by cardiac inflammation. AC-73, an inhibitor of CD147, disrupts the dimerization of CD147, which participates in the regulation of inflammation. To explore whether AC-73 could alleviate cardiac inflammation induced by CVB3, mice were injected intraperitoneally with AC-73 on the fourth day post-infection (dpi) and sacrificed on the seventh dpi. Pathological changes in the myocardium, T cell activation or differentiation, and expression of cytokines were analyzed using H&E staining, flow cytometry, fluorescence staining and multiplex immunoassay. The results showed that AC-73 alleviated cardiac pathological injury and downregulated the percentage of CD45+CD3+ T cells in the CVB3-infected mice. The administration of AC-73 reduced the percentage of activated CD4+ and CD8+ T cells (CD69+ and/or CD38+) in the spleen, while the percentage of CD4+ T cell subsets in the spleen was not changed in the CVB3-infected mice. In addition, the infiltration of activated T cells (CD69+) and macrophages (F4/80+) in the myocardium also decreased after the AC-73 treatment. The results also showed that AC-73 inhibited the release of many cytokines and chemokines in the plasma of the CVB3-infected mice. In conclusion, AC-73 mitigated CVB3-induced myocarditis by inhibiting the activation of T cells and the recruitment of immune cells to the heart. Thus, CD147 may be a therapeutic target for virus-induced cardiac inflammation.

SARS-CoV-2, the causative agent of COVID-19, emerged in December 2019. Its origins remain uncertain. It has been reported that a number of the early human cases had a history of contact with the Huanan Seafood Market. Here we present the results of surveillance for SARS-CoV-2 within the market. From January 1st 2020, after closure of the market, 923 samples were collected from the environment. From 18th January, 457 samples were collected from 18 species of animals, comprising of unsold contents of refrigerators and freezers, swabs from stray animals, and the contents of a fish tank. Using RT-qPCR, SARS-CoV-2 was detected in 73 environmental samples, but none of the animal samples. Three live viruses were successfully isolated. The viruses from the market shared nucleotide identity of 99.99% to 100% with the human isolate HCoV-19/Wuhan/IVDC-HB-01/2019. SARS-CoV-2 lineage A (8782T and 28144C) was found in an environmental sample. RNA-seq analysis of SARS-CoV-2 positive and negative environmental samples showed an abundance of different vertebrate genera at the market. In summary, this study provides information about the distribution and prevalence of SARS-CoV-2 in the Huanan Seafood Market during the early stages of the COVID-19 outbreak.

This study determined the global genetic diversity and transmission dynamics of enterovirus B83 (EV-B83) and proposed future disease surveillance directions. Blood samples were collected from a patient with viral myocarditis, and viral isolation was performed. The complete genome sequence of the viral isolate was obtained using Sanger sequencing. A dataset of 15 sequences (from three continents) that had sufficient time signals for Bayesian phylogenetic analysis was set up, and the genetic diversity and transmission dynamics of global EV-B83 were analyzed using bioinformatics methods, including evolutionary dynamics, recombination event analysis, and phylogeographic analysis. Here, we report the complete genome sequence of an EV-B83 strain (S17/YN/CHN/2004) isolated from a patient with acute viral myocarditis in Yunnan Province, China. All 15 EV-B83 strains clustered together in a phylogenetic tree, confirming the classification of these isolates as a single EV type, and the predicted time for the most recent common ancestor appeared in 1998. Recombinant signals were detected in the 5’-untranslated region and 2A–3D coding regions of the S17 genome. The phylogeographic analysis revealed multiple intercontinental transmission routes of EV-B83. This study indicates that EV-B83 is globally distributed. Our findings add to the publicly available EV-B83 genomic sequence data and deepen our understanding of EV-B83 epidemiology.

Thirty-six strains of 10 RNA viruses belonging to 4 viral families, including 3 viruses of Iflaviridae , 4 viruses of Phenuiviridae , 2 viruses of Nairoviridae , and 1 virus of Chuviridae , were identified from five tick species in Qingdao, China. A diversity of tick-borne viruses from hares and hedgehogs in Qingdao was found in this study.

Objective:A mouse model of pancreatitis induced by coxsackievirus B3 (CVB3) was established. The pathological change of pancreas and the infiltration of Th17/Treg cells were observed.Methods:The BALB/c mice were inoculated intraperitoneally with CVB3 to induce acute viral pancreatitis model. Then the pathological changes of pancreas were observed by HE staining; the viral RNA load and relative expression of cytokines (IFN-γ, IL-6 and IL-17) mRNA were detected by q-PCR; the proportion of infiltrated CD45 + CD3 + T cells, CD4 + and CD8 + T cells, Th17 and Treg cells in the pancreas was determined by flow cytometry. Results:Three days after CVB3 infection, the viral RNA load in pancreas was the highest (0.96±0.18) and gradually decreased with prolongation of infection. Compared with the 3 dpi group, the viral RNA load in pancreas was decreased (0.96±0.18 vs. 0.62±0.14) at 7 dpi, but there was no statistically significant difference. In addition, the infiltration of immune cell in pancreas increased significantly after 7dpi and the pathological score >2. The percent of infiltrated Th17 cells (1.05±0.21 vs. 22.13±5.79) and Treg cells (3.11±0.78 vs. 8.25±1.30) among CD4 + T cells significantly increased after infection (P<0.05), and the Th17/Treg also increased (P<0.01). Compared with the control group, the relative mRNA expression of IFN-γ (1.05±0.23 vs. 672.6±47.67), IL-6 (1.00±0.38 vs. 68.28±4.57), and IL-17 (1.01±0.11 vs. 54.15±7.94) in pancreas increased at 7 days after CVB3 infection ( P<0.01). Conclusions:The infiltration of Th17/Treg cells and the expression of related cytokines related cytokines IL-6 and IL-17 mRNA were upregulated in pancreas, which promoted the process of CVB3-induced pancreatitis.

Objective:To analyze the association of respiratory syncytial virus infection with meteorological factors and to predict and explain the trends.Methods:Data of cases with severe acute respiratory infections in hospitalized children in Xuzhou City were collected from 2015-2021. Respiratory syncytial virus (RSV) was detected by real-time fluorescence polymerase chain reaction. The result were statistically analyzed using SPSS 26.0 software, including constructing a negative binomial regression model to explore meteorological factors that impact RSV detection and a multivariate time series model to predict its epidemiological trend from 2020 to 2021.Results:A total of 1 663 samples of children with severe acute respiratory infections were collected from 2015to 2021, of which 218 (13.1%) were positive for RSV. Seasonal effects on RSV detection were evident: there was a 1-year cycle with a peak in winter (December-February) and a trough in summer (June-August). The negative binomial regression analysis showed that monthly mean temperature, monthly mean relative humidity, and monthly total sunshine hours may influenced RSV detection. The prediction result of the time series model with sunshine hours as the covariate showed that the prediction was better for 2020, and the actual values were close to the predicted values. The expected trends in 2021 were consistent, but the actual values were higher than predicted.Conclusions:Monthly mean temperature, monthly mean relative humidity, and monthly total sunshine hours may influence RSV detection in the Xuzhou region.A prediction model can be built using data from 2015-2019, where deviations in the predicted values for 2021, reflecting that disease prevalence is multifactorial correlated, suggest a possible rise in RSV prevalence in the future.

Objective:This study aimed to identify internal ribosome entry sites (IRESs) in the open reading frame (ORF) of the Coxsackievirus B3 (CVB3) genome.Methods:The sequences of P1, P2, or P3 of the CVB3 genome or the truncated sequences from each antithymocyte globulin (ATG) to the end of the P1, P2, or P3 gene were inserted into the pEGFP-N1 vector. After transfection, possible IRES-dependent green fluorescent protein (GFP)-fused proteins were detected by anti-GFP western blotting. The sequences of possible IRESs were inserted into specific Fluc/Rluc bicistronic vectors, in which the potential IRESs were determined according to the Fluc/Rluc activity ratio. Expression of Fluc and Rluc mRNA of the bicistronic vector was detected by RT-qPCR.Results:After transfection of full length or truncated sequences of the P1, P2, or P3 plasmids, six GFP-fused protein bands in P1, six bands in P2 and nine bands in P3 were detected through western blotting. Two IRESs in VP2 (1461-1646 nt) and VP1 (2784-2983 nt) of P1; one IRES in 2C (4119-4564 nt) of P2; and two IRESs in 3C (5634-5834 nt) and 3D (6870-7087 nt) of P3 were identified according to Fluc/Rluc activity ratio. The cryptic promoter was also excluded by RT-qPCR.Conclusion:Five IRESs are present in the CVB3 coding region.

Objective:To analyze the epidemiological characteristics and genotypes of human rhinovirus (HRV) in patients with upper respiratory tract infection in Qingdao in the winter of 2020.Methods:Throat swab samples were collected from 101 patients with upper respiratory tract infection in Qingdao from November 2020 to January 2021. Quantitative PCR was used to detect 15 common respiratory viruses in the samples. HRV-positive samples were further analyzed with RT-PCR to amplify and sequence HRV VP4/VP2 gene. A phylogenetic tree was constructed based on the sequencing results and homology analysis was conducted.Results:Six common respiratory viruses were detected in the 101 patients. Thirty-four cases (34/101, 33.66%) were single pathogen infection and two cases were multiple infection (2/101, 1.98%). The positive rate of HRV was the highest (21.78%, 22/101). Twenty HRV VP4/VP2 sequences were successfully amplified. Phylogenetic analysis showed that there were 16 strains of HRV-A subtype and four strains of HRV-C subtype and 14 serotypes were involved.Conclusions:HRV was one of the leading viral pathogens causing upper respiratory tract infection in Qingdao in the winter of 2020 and the predominant subtype was HRV-A.

Objective:To Isolate and identify human rhinovirus (HRV) in hospitalized children with pneumonia in Qingdao in 2020.Methods:A total of 98 throat swab samples were collected from hospitalized children with pneumonia in 2020. Common respiratory viruses were screened through RT-qPCR. The HRV positive samples were inoculated into H1-HeLa cells. Viruses with typical cytopathic effect (CPE) were identified by HRV specific RT-PCR. Subsequently, sequences of HRV-VP4/VP2 gene were used to construct phylogenetic trees and analyze homology with sequences of reference strains through MEGA software.Results:Among 98 hospitalized children with pneumonia, 11 samples were HRV positive in 98 throat swab samples. After the typical CPE appeared in HeLa cells, two strains of HRV were identified by specific RT-PCR. The HRV-A28 and HRV-A58 were confirmed by comparison and analysis of VP4/VP2 sequence. Phylogenetic tree found that the isolated HRV-A28 strain was genetically close to strains of Singapore in 2011, of Tunisia in 2017, and Kenya in 2017. The isolated HRV-A58 strain was genetically close to the strains of Australia in 2009, Venezuela in 2011, Mongolia in 2011, and the United States in 2014.Conclusions:The HRV-A28 and HRV-A58 strains were isolated from the throat swabs of children patients with pneumonia in Qingdao.

In the present study we investigated the changes in miRNA levels inhuman rhinovirus 16 (HRV16)-infected cells. A small RNA deep sequencing experiment was performed through next-generation sequencing. In total, 53 differentially expressed miRNAs were confirmed by RT-qPCR, including 37 known miRNAs and 16 novel miRNAs. Interaction networks between differentially expressed miRNAs and their targets were established by mirDIP and Navigator. The prediction results showed that QKI, NFAT5, BNC2, CELF2, LCOR, MBNL2, MTMR3, NFIB, PPARGC1A, RSBN1, TRPS1, WDR26, and ZNF148, which are associated with cellular differentiation and transcriptional regulation, were recognized by 12, 11, or 9 miRNAs. Many correlations were observed between transcriptional or post-transcriptional regulation of an miRNA and the expression levels of its target genes in HRV16-infected H1-HeLa cells.

Objective. To detect viral load in human cytomegalovirus (HCMV) infection children after hematopoietic stem cell transplant (HSCT) by chip digital PCR (cdPCR). Methods. The plasmid pUC57-UL83 containing the HCMV-UL83 gene and HCMV AD169 strain were used to evaluate the sensitivity of cdPCR. Either HSV-1, HSV-2, VZV, EBV, HHV-6, or HHV-7 was used to evaluate the specificity of HCMV cdPCR. The cdPCR was compared with quantitative PCR (qPCR) by detecting HCMV infection in 125 children's whole blood samples following HSCT. Results. The limit of detection (LOD) of HCMV cdPCR was 103 copies/ml and the qPCR LOD was 297 copies/ml for plasmid pUC57-UL83. The result of HCMV cdPCR was 146 copies/ml for the HCMV AD169 strain, indicating that the sensitivity of cdPCR was higher than that of qPCR. There is no cross-reaction between HCMV cdPCR and other herpes viruses. The incidence of HCMV infection was 30.40% in 125 children following HSCT by cdPCR. The range of the HCMV viral load was from 107 copies/ml to 6600 copies/ml by cdPCR. Conclusions. cdPCR is more sensitive than qPCR for detecting HCMV viral load. Furthermore, the cdPCR could be used to detect the viral load of HCMV infection before or after HSCT in children.

As an alternative mechanism for cap-dependent (m7GpppN) translation, internal ribosome entry site (IRES)-dependent translation has been observed in the 5' untranslated regions (5' UTR) and coding regions of a number of viral and eukaryotic mRNAs. In this study, a series of 5' terminal truncated structural protein genes that were fused with GFP was used to screen for potential IRESs, and IRESs were identified using a bicistronic luciferase vector or GFP expression vector possessing a hairpin structure. Our results revealed that a putative IRES was located between nt 1982 and 2281 in the VP3 coding region of the human rhinovirus 16 (HRV16) genomes. We also demonstrated that effective IRES-initiated protein expression in vitro did not occur through splicing sites or cryptic promoters. We confirmed that thapsigargin (TG), an inducer of endoplasmic reticulum stress (ERS), facilitated increased IRES activity in a dose-dependent manner. Additionally, the secondary structure of the IRES was predicted online using the RNAfold web server.

Objectives: This study assessed the incidence and resistance of Mycoplasma pneumoniae (MP) in children in Qingdao, China, in 2019. Methods: We detected MP infection in 78 pharyngeal swabs from children with pneumonia by qPCR. The RepMP4 element in the P1 adhesin gene, domain V of the 23S rRNA gene, and the L4/L22 ribosomal pro-teins were amplified by nested PCR. Evolutionary analysis was conducted based on the P1 gene sequence. Resistance mutations in domain V of the 23S rRNA gene and L4/L22 ribosomal proteins were analysed. Results: The incidence of MP infection in children with pneumonia was 59.0% (46/78). The mean duration of MP infection was longer than that of non-MP infection. According to P1 gene sequencing of 21 samples, 12 (57.1%) were type 1 and 9 (42.9%) were type 2. Drug resistance mutations A2063G in domain V of 23S rRNA gene and T508C in L22 were identified from all sequenced MP. However, mutations at positions 2064 and 2617 were not found in this study. C162A mutation appeared in most type 2 samples. A430G mutation appeared in one type 1 sample and in several type 2 samples. T279C mutation in L22 was mostly found in type 2 samples. Conclusion: The incidence of MP infection was 59.0% in children with pneumonia in Qingdao in 2019. Type 1 MP infection was slightly more common than type 2, indicating that the genotype of MP is grad-ually shifting from type 1 to type 2. Macrolide resistance mutation A2063G could be detected in all sequenced MP. (c) 2021 The Author(s). Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )