Coxsackievirus B2 (CVB2) is a member of the enterovirus group known to induce a spectrum of illnesses, from mild to severe. In the summer of 2022, an unusual outbreak of enteroviral central nervous system (CNS) infections occurred that was attributed to CVB2. Cerebrospinal fluid (CSF) samples collected from patients in 2015-2022 were tested for enterovirus via RT-PCR, followed by Sanger sequencing for positive cases. CVB2 samples were further sequenced in the P1 region using NGS. A total of 30 CSF samples were identified as CVB2, with 60% of these cases occurring between June and August 2022. The 2022 CVB2 variants were associated with severe clinical symptoms, including encephalitis (50%) and ataxia (27.8%). Samples from 2015 to 2020 were also included due to the absence of these symptoms. Phylogenetic analysis revealed that CVB2 strains from 2019 to 2020 were also distinct from those obtained in 2022. Amino acid analysis of the capsid proteins VP1, VP2, and VP3 identified three unique substitutions with potential antigenic significance in the 2022 variant: S67A in VP2, and T93A and E274D in VP1. These substitutions were not present in earlier strains or reported in the literature, suggesting they may influence the virus's virulence. The clinical observations from this study highlight new patterns of CVB2 infection in the CNS that had not been previously observed. Additionally, it identifies unique genetic changes in the 2022 CVB2 variant that may account for the increased virulence seen in the 2022 outbreak. However, further analysis is required to validate this assumption.

The variola virus, the causative agent of smallpox, has claimed more human lives than all other infectious diseases combined. Consequently, any epidemiological event involving related viruses (orthopoxviruses) triggers significant concern, as was the case with the pandemic rise of monkeypox virus (MPXV), the causative agent of monkeypox in 2022-2023. Smallpox vaccines, based on vaccinia virus antigens, are expected to provide cross-protection against MPXV. Studying the general seroprevalence of orthopoxviruses in populations worldwide is crucial for estimating susceptibility, risks, and the need for vaccination campaigns. In this study, we aimed to evaluate the seroprevalence of antibodies capable of recognizing MPXV in a Brazilian population and assess the potential for cross-protection from previous smallpox vaccinations. We analyzed demographic data, vaccination records, and serum levels of anti-MPXV IgG measured by enzyme-linked immunosorbent assay (ELISA) in 319 volunteers from Barreiras, Bahia, Brazil. Our main findings show that the numbers of volunteers with serum samples recognizing MPXV in ELISA, as well as their serum levels of anti-MPXV IgG, did not differ significantly according to gender or address type. However, both male and female elderly volunteers exhibited significantly higher concentrations of anti-MPXV IgG than adults, youth, and children. These results suggest that the elderly may benefit from a cross-reactive immune response due to previous smallpox vaccinations, whereas adults, youth, and children appear susceptible to MPXV. Further investigations involving other populations are necessary to assess the necessity of vaccinating potentially vulnerable groups.

Our objective was to evaluate the ramifications of the 2019 coronavirus disease (COVID-19) pandemic on the microbial profile and antimicrobial resistance patterns of bacteria isolated from cerebrospinal fluid (CSF) specimens of patients with bacterial meningitis. We conducted a retrospective analysis of laboratory results and clinical records about positive CSF cultures reported by the SPARSS network from 2017 to 2023. The study covered three distinct periods: January 2017 to December 2019 (before the COVID-19 pandemic), January 2020 to December 2022 (during the COVID-19 pandemic), and January 2023 to December 2023 (after the COVID-19 pandemic), with a total of 5793 CSF isolates collected. Notably, the proportion of male patients (61.3%) was higher than that of females. After COVID-19, we observed a notable shift in the seasonal peak of CSF pathogens, with a delay of approximately 3 months. Remarkable alterations were evident in both pediatric and adult CSF isolate profiles. In children, the predominant pathogens included coagulase-negative Staphylococcus (CoNS), Streptococcus pneumonia, and Escherichia coli. Notably. After COVID-19, there was a significant decrease in the proportion of CoNS (p = 0.0039) and a notable increase in E. coli (p = 0.0067). In adults, the top three pathogens were CoNS, Acinetobacter baumannii, and Klebsiella pneumoniae. After the pandemic, we observed a significant reduction in the prevalence of A. baumannii (p = 0.0059), while the proportions of K. pneumoniae, Pseudomonas aeruginosa, Enterobacter cloacae, and Enterococcus faecalis increased significantly (p < 0.05). Additionally, among multidrug-resistant bacteria, the detection rate of carbapenem-resistant E. coli escalated (p = 0.0375). Antimicrobial susceptibility analysis indicated a declining trend in resistance rates for CoNS and A. baumannii to certain antibiotics following the pandemic. Conversely, resistance to imipenem in A. baumannii increased. In conclusion, the COVID-19 pandemic has significantly influenced the composition, antimicrobial resistance patterns, and epidemiological dynamics of CSF-isolated bacteria in Shandong province. To effectively address these changes, ongoing and dynamic surveillance of pathogen trends and antimicrobial resistance rate is essential.

The evolution of SARS-CoV-2, which limits public control and treatment, seems to have occurred through multiple mechanisms, including recombination of cocirculating strains in hosts. However, insufficient experimental data have been obtained after coinfection. Therefore, we investigated the emergence of variants after coinfection with parental SARS-CoV-2 and the SARS-CoV-2 Delta. We found that fewer (approximately 50%) mutations accumulated in Calu-3 cells than in other cells after serial passaging. Previously, we established a long-term replication mouse model by infecting Calu-3 cell-derived xenograft tumors with SARS-CoV-2. Here, we utilized our model to investigate the outcome after coinfection. More diverse viral mutations, along with multiple high-frequency simultaneous mutations, were discovered in the tumors than during cell passaging. Viral isolates from the tumors showed no cytopathic effects and formed much smaller plaques. Phylogenetic analysis suggested that the genetic makeup of the variants remained largely the same as that of parental SARS-CoV-2 rather than the SARS-CoV-2 Delta. Viral challenge revealed that the isolates were less lethal than the parental SARS-CoV-2 and SARS-CoV-2 Delta strains. These findings suggest that parental SARS-CoV-2 predominates over the SARS-CoV-2 Delta when coinfected, but the SARS-CoV-2 Delta contributes to the evolution of parental SARS-CoV-2 variants toward better host adaptation without recombination.

HPV viral E6 and E7 onco-proteins play a well-known role in carcinogenesis. Host genomic alterations also play a key role in the development of HPV-related oropharyngeal cancer and have been under-recognized. We describe a case series of 6 metastatic/locoregionally recurrent HPVOPSCC patients with FGFR alterations. HPVOPSCC presents with distinct pattern of spread both temporally and sites of recurrence compared to  non-HPV-related oropharyngeal cancer. Identification and reporting of genomic alterations in HPV are crucial to the understanding of disease biology and could aid in development of novel therapeutics for these patients. In addition, use of circulating tumor DNA may lead to early detection and supplement imaging in the follow up of these patients. Loco-regional treatments may also play a key role in the management of metastatic HPV OPSCC depending on the pattern of presentation. Our case series highlights all these novelties that could lead to better treatment outcomes.

Influenza virus is a major respiratory viral pathogen responsible for the deaths of hundreds of thousands worldwide each year. Current vaccines provide protection primarily by inducing strain-specific antibody responses with the requirement of a match between vaccine strains and circulating strains. It has been suggested that anti-influenza T-cell responses, in addition to antibody responses may provide the broadest protection against different flu strains. Therefore, to address this urgent need, it is desirable to develop a vaccine candidate with an ability to induce balanced adaptive immunity including cell mediated immune responses. Here, we explored the potential of VC2, a well-characterized Herpes Simplex Virus type 1 vaccine vector, as a live attenuated influenza vaccine candidate. We generated a recombinant VC2 virus expressing the influenza A hemagglutinin protein. We show that this virus is capable of generating potent and specific anti-influenza humoral and cell-mediated immune responses. We further show that a single vaccination with the VC2-derived influenza vaccine protects mice from lethal challenge with influenza virus. Our data support the continued development of VC2-derived influenza vaccines for protection of human populations from both seasonal and pandemic strains of influenza. Finally, our results support the potential of VC2-derived vaccines as a platform for the rapid development of vaccines against emerging and established pathogens, particularly respiratory pathogens.

Exactly why human infection of avian influenza A virus H7N9 causes more severe disease in the elderly remains elusive. In this study, we found that H7N9 PB1-F2 is a pathogenic factor in 15-18-month-old BALB/C mice (aged mice) but not in 6-8-week-old young adult mice (young mice). Recombinant influenza A virus with H7N9 PB1-F2-knockout was less pathogenic in aged mice as indicated with delayed weight loss. In contrast, survival of young mice infected with this virus was diminished. Furthermore, tissue damage, inflammation, proinflammatory cytokine and 2'3'-cGAMP production in the lung were less pronounced in infected aged mice despite no change in viral titer. cGAS is known to produce 2'3'-cGAMP to boost proinflammatory cytokine expression through STING-NF-κB signaling. We found that H7N9 PB1-F2 promoted interferon β (IFNβ) and chemokine gene expression in cultured cells through the mitochondrial DNA-cGAS-STING-NF-κB pathway. H7N9 PB1-F2 formed protein aggregate and caused mitochondrial cristae collapse, complex V-dependent electron transport dysfunction, reverse electron transfer-dependent oxidized mitochondrial DNA release to the cytoplasm and activation of cGAS-STING-NF-κB signaling. PB1-F2 N57 truncation, which is frequently observed in human circulating strains, mitigated H7N9 PB1-F2-mediated mitochondrial dysfunction and cGAS activation. In addition, we found that PB1-F2 of pathogenic avian influenza viruses triggered more robust cGAS activation than their human-adapted descendants. Our findings provide one explanation to age-dependent pathogenesis of H7N9 infection.

A helicase-primase inhibitor, amenamevir (ASP2151), is the active pharmaceutical ingredient of a drug for the herpes zoster that is caused by reactivation of varicella-zoster virus (VZV). Here we report a new amenamevir-resistant VZV isolated under the selection pressure of amenamevir. The resistant virus has a nonsynonymous mutation K350N in the helicase gene ORF55. A recombinant virus artificially constructed harboring the ORF55 K350N also acquired amenamevir resistance, and thus the single amino-acid substitution in helicase is revealed to be responsible for the resistance. We observed that the drug-resistant virus and the ORF55 K350N recombinant virus have high resistance to amenamevir, as the EC values in a plaque reduction assay were > 100 μM, while the two viruses remained susceptible to the nucleoside analog drug acyclovir. No defect in viral growth was observed for these resistant viruses in a plaque size assay in human malignant melanoma cells. However, defect in plaque formation was observed from resistant virus in human fetal lung fibroblast cells, showing that the growth of the resistant virus is dependent on the cell type. We observed that the single amino-acid substitution in the helicase induces amenamevir resistance, confirming the importance of the helicase in amenamevir's inhibition of virus growth. Our findings highlight the importance of regulating the clinical use of amenamevir to minimize the risk of the emergence of helicase K350N mutation, especially in the long-term use of amenamevir by immunosuppressed patients.

Natural killer (NK) cells play a pivotal role in the immune response against viral infections, including SARS-CoV-2. However, our understanding of memory NK cell responses in the context of SARS-CoV-2 remains limited. To address this, we investigated the memory-like response of NK cells to SARS-CoV-2 peptides, presented by autologous cells. Blood samples from 45 donors underwent analysis for SARS-CoV-2 IgG antibodies, categorizing them into four groups based on the antibody kind and level. NK cells from SARS-CoV-2-experienced donors demonstrated enhanced degranulation and activation levels, IFNγ production and proliferative potential in response to SARS-CoV-2 peptides. Investigation of highly proliferating NK cells demonstrated the formation of distinct clusters depending on the SARS-CoV-2 peptide supplementation and the donor group. RNA sequencing revealed differential gene expression patterns, highlighting metabolism, protein transport, and immune response genes. Notably, KIR2DS4 expression correlated with enhanced IFNγ production, degranulation and proliferation levels, suggesting a role in SARS-CoV-2 recognition. Collectively, these findings provide detailed insights into antigen-specific NK cell responses to SARS-CoV-2 peptides, indicating potential mechanisms underlying NK cell activation in antiviral immunity.

Hepatitis B virus reactivation (HBVr) can be a serious clinical complication that has not been fully characterized in terms of the drugs associated with this adverse effect. Leveraging the expansive data available in the FDA Adverse Event Reporting System (FAERS) and the Japanese Adverse Drug Event Report (JADER) databases, we conducted a retrospective analysis to identify drugs significantly linked to HBVr using three disproportionality analyses. Our study identified 44 drugs associated with HBVr, of which 35 did not have warnings in their product labels. The majority of these drugs were antineoplastic and immunomodulating agents, with a tendency for early occurrence of HBVr, particularly among antineoplastic agents and systemic corticosteroids. Additionally, entecavir, tenofovir disoproxil and tenofovir alafenamide demonstrated better safety profiles in preventing HBVr. These findings enhance our understanding of the demographic characteristics of patients at risk for HBVr, the drugs that pose a high risk for HBVr, the timing of such events, and the appropriate preventive medications. This knowledge contributes to the development of better prevention and treatment strategies, ultimately optimizing patient outcomes.

Recurrent respiratory papillomatosis (RRP) is caused by human papillomaviruses (HPV) 6 and 11, but the role of their genomic variants in the disease's clinical course is unclear. This study investigated whether long-term persistence of a particular HPV genotype, subtype or genomic variant influences the RRP clinical course. HPV genotyping was performed in paired baseline and follow-up RRP laryngeal tissue specimens of 59 patients. HPV6 and HPV11 genomic variants were determined in paired tissue specimens taken at least 10 years apart in 20 selected patients. HPV was identified in 58/59 patients, most commonly HPV6 (40/58), followed by HPV11 (17/58). The most prevalent HPV genomic variant was HPV11 A2. HPV6 A and HPV6 B1 were most frequent in aggressive RRP. In all patients, identical HPV genomic variants were identified in both paired specimens. RRP results from a long-term infection with the same HPV genomic variant that can be identified decades after disease onset. We report the longest duration of genetically confirmed persistent HPV infection in peer-reviewed literature, during a 44-year interval in a patient with HPB6 B1. This study suggests that infection with a particular HPV genotype, subtype, or genomic variant does not significantly influence the clinical course of RRP.

Elucidating the detailed features of emerging SARS-CoV-2 strains both in vitro and in vivo is indispensable for the development of effective vaccines or drugs against viral infection. We thoroughly characterized the virological and pathogenic features of eight different pandemic SARS-CoV-2 strains, from the WT strain to current circulating sublineage EG.5.1, both in vitro and in vivo. Besides detailed virological features observed in Vero E6 cells, the Omicron variants, from BA.1 to EG.5.1, exhibited enhanced infectious effects to upper respiratory tract in K18 human angiotensin-converting enzyme (ACE2) (K18 hACE2) transgenic mice. Both XBB.1.9.1 and EG.5.1 presented stronger tropism to brain, which could be the main reason for the increased lethal effects on mice. In addition, the pathogenesis comparisons among all these viruses in C57BL/6JGpt mice indicated that Omicron variant BA.1 and two new sublineages XBB.1.9.1 and EG.5.1 possessed dual tropisms to both human and mice, which were further confirmed by subsequent bioinformatic analyses and actual affinity comparison between viral RBDs and mouse or human receptor ACE2. Furthermore, the immunocompromised BKS-db mice were found to be more susceptible to Omicron strains compared to C57BL/6JGpt mice, which revealed that viral infectivity was determined by both its affinity to the host receptor and host immunocompetence. Thus, this study not only contributes to a systematic understanding of the pathogenic features of SARS-CoV-2 in mice, but also provides new insights to combat potential future surges of new SARS-CoV-2 variants.

This study aims to explore the epidemiological characteristics of neuro-specific antibodies (ns-Ab) induced by different viral infections within the central nervous system (CNS). Additionally, it seeks to compare the autoimmune effects following several typical viral infections in CNS. We conduct a retrospective study to compare and analyze the prevalence trends of ns-Ab in patients with different viral infections. Additionally, evaluate the intensity of CNS inflammatory responses postviral infection by correlating clinical characteristics and laboratory findings, and briefly demonstrate the immune effects in CNS following various viral infections. This study retrospectively collected data from 1037 patients hospitalized with suspected CNS infections. A total of 654 patients (63.1%) were included in the final analysis. A higher proportion of patients with pathogens present in their cerebrospinal fluid (CSF) (114 out of 332, 34.3%) tested positive for ns-Ab compared to those without pathogens (70 out of 322, 21.7%) (p = 0.0004). Specifically, the screening rate for ns-Ab in patients with CNS viral infections (83 out of 165, 50.3%) and the prevalence of ns-Ab (27 out of 83, 32.5%) were significantly higher than in those with other pathogen infections (p < 0.0001 and p = 0.016, respectively). Among these, human herpesvirus 7 (HHV7) patients had the highest detection rate of ns-Ab during the disease course (11 out of 26, 42.3%), but exhibited infection characteristics distinctly different from those of herpes simplex virus 1 (HSV1). Viral infections significantly promote the development of autoimmune responses in CNS. The production of ns-Ab and the subsequent autoimmune response vary across different viral infections. There is a strong statistical correlation between HHV7 and the presence of ns-Ab, suggesting that HHV7 may serve as an early indicator of secondary autoimmune response following CNS infections.

Tick-borne encephalitis virus (TBEV) can cause life-threatening central nervous system infection. Changes in cerebrospinal fluid (CSF) metabolites may reflect critical aspects of host responses and end-organ damage in neuro infection and neuroinflammation. In this study, we applied an untargeted metabolomics screen of CSF samples to investigate the metabolites profile and explore biomarkers for TBEV infection. By analyzing CSF samples from 77 patients with TBEV infection and 23 without TBEV infection, tryptophan metabolism and Citrate cycle were found to be the top important metabolic pathways in differentiating the control and case groups; acetoacetate, 5'-deoxy-5'-(methylthio)-adenosine, 3-methyl-2-oxobutanoic acid, and so forth. were identified to be metabolic biomarkers (| FC|> 1, VIP > 1, FDR < 0.05) in CSF and clearly separated the TBEV infection from the noninfected samples. Moreover, four metabolites were identified to be associated with fatal outcome, including kynurenic acid, 5-hydroxyindole-3-acetic acid, DL-tryptophan, indole-3-acrylic acid, demonstrating the potential predictive biomarkers for severe TBEV infection. This study explored the metabolic profile of TBEV infection in CSF samples and identified candidate biomarkers for TBEV infection, which might be useful in target screening for differential diagnosis and therapeutic inter-vention.