Complete genome sequences of four torque teno virus (TTV) (family Anelloviridae) isolates were obtained from the feces of two raccoon dogs (Nyctereutes procyonoides) and two red foxes (Vulpes vulpes) in Gifu Prefecture, Japan. The ORF1 nucleotide sequences of these four viruses, named Raccoon dog_Fe_1, Raccoon dog_Fe_2, Fox_Fe_1, and Fox_Fe_2, were different from those of known TTVs but similar to those of TTVs derived from masked palm civet_Pl-TTV9-1 (59.8 %), masked palm civet_Pl-TTV3 (56.7%), masked palm civet_Pl-TTV9-2 (70.6 %), and crab-eating fox_LV23 strain (64.7 %), respectively, indicating that Raccoon dog_Fe_1, Raccoon dog_Fe_2, and Fox_Fe_2 represent new species. Phylogenetic analysis based on amino acid sequences of the ORF1 protein revealed that Fox_Fe_1 and Fox_Fe_2 clustered together with crab-eating fox_LV23 from Brazil and were distinct from viruses from domestic dogs. Furthermore, Raccoon dog_Fe_2 did not belong to any canine animal TTVs cluster. In contrast, Raccoon dog_Fe_1 clustered together with pampas fox_LV13, and these viruses were distant from other canid animal TTVs. Therefore, wild-canid TTVs formed several distinct clusters even at different geological locations such as Brazil and Japan.

Porcine epidemic diarrhea virus (PEDV) is the primary pathogen responsible for highly contagious intestinal infections in pigs, which results in significant economic losses to the global animal husbandry industry. PEDV is an enveloped virus that enters cells via endocytosis, a process that is dependent on the binding of the viral surface S protein to a receptor on the host cell membrane. This results in a series of biomechanical alterations that drive the fusion of the viral and host cell membranes. These alterations stabilise the binding of the virus to the receptor and also affect the tension and the curvature of the plasma membrane and the formation of endocytic vesicles. A comprehensive understanding of the mechanism by which PEDV enters cells and the biomechanical changes that accompany this process is of paramount importance for the development of PEDV inhibitors, vaccines, and disease prevention and control strategies. Here, we review the general mechanism of PEDV entry, the biomechanical phenomena that occur during endocytosis, and the potential applications of biomechanics in antiviral therapy. It is anticipated that by gaining insight into these mechanisms, novel approaches to regulating viral entry pathways through mechanical interference, vaccine development, and antiviral drug design can be explored.

Arboviruses are viruses that are transmitted by arthropods such as mosquitoes, ticks, and flies, and most of them are RNA viruses. Vector-borne transmission occurs when an infected arthropod bites a vertebrate host, allowing the virus to enter the bloodstream and initiate infection. Arboviruses are known to cause significant morbidity and mortality in mammals, and at least a hundred of them have been identified as human pathogens. In this review, we provide an updated overview of four prominent arboviruses that are present in Southeast Asia (SEA): dengue virus (DENV), Japanese encephalitis virus (JEV), Zika virus (ZIKV), and chikungunya virus (CHIKV). The epidemiology and pathogenesis of these viruses and the currently used methods for diagnosis, prevention, and treatment of arbovirus infections are discussed in detail. Finally, we summarise the concerns and future considerations for combating these dangerous pathogens.

The aims of this study were to assess the adjuvant properties of an MF59-like adjuvant containing yeast-derived squalene (MF59-like YD) in a cell-based quadrivalent influenza vaccine (QIV) and to investigate the potential mechanisms of action. MF59-like adjuvants containing either yeast-derived or shark-derived squalene were incorporated into QIV formulations. Antigen-specific immune responses in mouse serum were evaluated via enzyme-linked immunosorbent assays (ELISAs), hemagglutination inhibition (HI) assays, and microneutralization (MN) assays. The effects and mechanisms of action of the adjuvants were further analyzed by analyzing mouse spleen germinal center (GC) cell activation via flow cytometry. MF59-like YD significantly increased the humoral immune responses induced by QIVs in mice, in particular, the titers of HI and MN antibodies against homologous and heterologous virus subtypes. Mechanistically, MF59-like YD increased the immune response to influenza vaccines by activating T follicular helper (Tfh) and B cells in the GC. Given the greater availability of yeast-derived squalene and the finding that its adjuvant efficacy was comparable to that of shark-derived squalene, we propose that the MF59-like YD adjuvant is a promising alternative adjuvant for future influenza vaccines.

Grapevine geminivirus A (GGVA) is a recently identified DNA virus that infects grapevine, but its pathogenicity is not well studied. Previously, we investigated the pathogenicity of the new GGVA isolate QN (GGVAQN) on grapevine 'Red Globe' plants. In this study, grapevine 'Red Globe' and 'Summer Black' plants were inoculated with GGVAQN and grown without artificial control of temperature and light, and all of them exhibited upward leaf curling. This symptom was also found in field-grown grapevine 'Shine Muscat' plants infected with multiple grapevine viruses, including GGVA (isolate SM) (2,905 nt, sharing 97.69% genome sequence identity with GGVAQN), and in the upper developed leaves of previously GGVAQN-inoculated 'Red Globe' plants one week after they were moved from artificial to natural lighting. The upward leaf curling symptom was similar to that observed previously in Nicotiana benthamiana plants inoculated with GGVAQN, in field-grown grapevine 'Queen Nina' plants, and in in vitro-grown grapevine 'Marselan' plantlets, from which GGVAQN and GGVAML isolates with identical genome sequences were obtained. In addition to upward leaf curling, malformation, chlorosis, and necrosis symptoms were also observed on all GGVAQN-inoculated 'Red Globe' and 'Summer Black' plants. The findings presented here suggest that GGVAQN is closely associated with severe foliar symptoms in grapevine 'Red Globe' and 'Summer Black' cultivars and emphasize the need to control the virus.

The pattern recognition receptors (PRRs) participating in the innate immune response to Tembusu virus (TMUV) were investigated using duck embryo fibroblasts (DEFs). TMUV infection induced significant upregulation of RIG-I and MDA5 and strong IFN-α, IFN-β, IL-6, and Mx responses. Overexpression of RIG-I or MDA5 resulted in increased IFN-α, IFN-β, IL-6, and Mx expression and decreased TMUV replication. Conversely, knockdown of RIG-I or MDA5 resulted in decreased IFN-α, IFN-β, IL-6, and Mx expression and increased TMUV replication. These findings demonstrate that RIG-I and MDA5 are essential sensors in the innate immune defense against TMUV, orchestrating cytokine production and restricting viral replication.

Human non-polio enteroviruses (NPEVs) cause a wide range of illnesses such as hand, foot, and mouth disease (HFMD), herpangina, and aseptic meningitis. In this study, we investigated the incidence of NPEV infections in the Ural Federal District and Western Siberia, Russia, from 2019 to 2023 in patients with various NPEV-associated diseases, identified the main circulating genotypes in 2023, and analyzed their epidemiological characteristics. A total of 384 samples that tested positive by polymerase chain reaction (PCR) for NPEVs were genotyped by semi-nested PCR specific for the VP1 gene. A total of 20 genotypes were identified among the patients in this study, with enterovirus A accounting for 57.2% of all typed samples, enterovirus B accounting for 41%, and enterovirus C accounting for 1.8%. Coxsackievirus A6 (CVA6) was the most common genotype in HFMD cases. Echovirus 30 (E30) was predominant in aseptic meningitis patients, and coxsackievirus A2 was primarily associated with herpangina. Phylogenetic analysis showed that most of the CVA6 strains identified in this study displayed a close genetic relationship to strains that circulated in China, while E30 genotypes circulating in the studied region belonged to subgenotype V. Laboratory-based monitoring and epidemiological surveillance for genetic changes and evolutionary studies are necessary for improving prevention and clinical care.

Here, we isolated two novel mycoviruses coinfecting the fugus Colletotrichum karstii, which were designated as "Colletotrichum karstii mitovirus 1" (CkMV1) and "Colletotrichum karstii mitovirus 2" (CkMV2). The length of the complete genome of CkMV1 is 2,441 nucleotides, and that of CkMV2 is 2,391 nucleotides. Both contain a single open reading frame (ORF) that encodes an RNA-dependent RNA polymerase (RdRp). BLAST searches showed that the amino acids (aa) sequences of CkMV1 and CkMV2 had the highest amino acid sequence identity of 35.41% and 52.37% to the RdRp of Pleurotus pulmonarius duamitovirus 1 and Fusarium oxysporum f. sp. cubense mitovirus 4, respectively. Phylogenetic analysis based on RdRp sequences revealed that CkMV1 grouped with members of the genus Duamitovirus and that CkMV2 grouped with members of the genus Unuamitovirus, both within the family Mitoviridae.

With the widespread prevalence of Kaposi’s sarcoma-associated herpesvirus (KSHV) globally, particularly in sub-Saharan Africa and the Mediterranean region, the open reading frame (ORF) K1 gene, a key gene for distinguishing different subtypes of KSHV, has been extensively studied for its diversity and sequence variations. In this study, we collected K1 gene sequences representing subtypes of KSHV worldwide in order to assess the global distribution of KSHV subtypes and to investigate the recombination and selection history of KSHV. Recombination and gene flow analysis indicated a minimum average recombination rate of 0.41 per site for the K1 gene. Recombination analysis indicated that 11 major recombination events had occurred, predominantly in subtypes A and C, while subtype B showed minimal involvement in recombination processes, consistent with the gene flow analysis. Using tip-dating methods, we estimated that the most recent common ancestor of KSHV emerged in the 12th century, while the currently globally prevalent subtypes appeared within the past three centuries. Its recent origin and rapid evolution indicate that KSHV is now undergoing strong selection and is in the process of adaptation.

In this study, we analysed the outcomes of 1165 symptomatic patients infected with the SARS-CoV-2 Omicron BA.2 variant and their response to Sinovac-CoronaVac vaccination. We assessed the effectiveness of vaccination against adverse outcomes (severe, critical, or fatal cases). Of these patients, 504 (43.3%) were men, the median age was 71 years, and 391 patients (66.4%) had received the Sinovac-CoronaVac COVID-19 vaccine (Sino Pharma, Beijing, China). The percentages of severe, critical, and fatal cases were 3.9%, 2.8%, and 3.7%, respectively, with significantly lower rates among vaccinated patients (2.8% vs. 14.2%; adjusted odds ratio [aOR], 0.306; 95% confidence interval [95% CI], 0.129-0.727). Age ≥ 70 years and a CRP level > 8 mg/L were independent predictors of an adverse outcome. Out of 630 patients aged ≥ 70 years, 107 (17.0%) were vaccinated. Seven vaccinated patients (6.5%) and 94 unvaccinated patients (18.0%) experienced adverse outcomes. Multivariate analysis indicated that vaccination (OR, 0.401; 95% CI 0.162-0.991) and CRP levels > 8 mg/L (OR, 3.262; 95% CI 1.754-6.067) were independently associated with adverse outcomes in patients aged ≥ 70 years. Inactivated vaccines were effective against symptomatic and severe COVID-19. Even in symptomatic Omicron infections, full vaccination with inactivated vaccines significantly reduced the number of adverse cases, especially in patients aged ≥ 70 years. Systemic inflammation (as measured by the CRP level) was independently correlated with adverse outcomes in patients infected with Omicron BA.2.