Archives of Virology最新文献

Kuchijirosho virus (KJV) infects the brain of the tiger puffer, Takifugu rubripes, causing lethal disease in cultured populations. Next-generation sequencing identified eight RNA genome segments encoding proteins of 562, 498, 454, 369, 370, 164, 207, and 83 amino acids. BLAST analysis showed that segment 1 encodes a polymerase basic protein 1 (PB1)-like RNA-dependent RNA polymerase homologous to those of members of the family Amnoonviridae. Segment 5 encodes a protein that shows similarity to envelope proteins with two predicted transmembrane domains, suggesting a function as an envelope glycoprotein. The remaining segments could not be annotated due to the limited homology of their encoded proteins to known proteins. These findings indicate that KJV represents a novel lineage within the family Amnoonviridae.

Plum pox virus (PPV) is a serious viral threat to stone fruit trees worldwide. Wild Prunus species including American plum (Prunus americana) can serve as sources of inoculum. High-throughput sequencing was used to characterize PPV populations in American plum and peach after aphid inoculation and after two cycles of cold-induced dormancy (CID). A significant decrease in the number of sequence variations in the PPV genome was observed after CID in American plum, but not in peach. Seventeen were identified as unique to American plum, while eight were unique to peach. These findings provide insight into the genetic diversity of PPV in a potential reservoir host.

Artemisia argyi is a significant medicinal plant in China. To date, no viruses have been reported to infect A. argyi. In this study, using the RNA-seq technique, we identified a novel marafivirus in A. argyi plants showing leaf mottle and albinism symptoms, which we have tentatively named “Artemisia argyi albinism-associated virus” (AAAaV). The AAAaV genome is a positive-sense single-stranded RNA with a length of 6749 nt, excluding the poly(A) tail, containing a single open reading frame (ORF) encoding a large polyprotein. Phylogenetic analysis based on the full-length genome and polyprotein amino acid sequences revealed that AAAaV is related to members of the genus Marafivirus of the family Tymoviridae. The polyprotein of AAAaV shares 33.68-38.14% amino acid sequence identity with those of 12 closely related marafiviruses and contains five conserved domains that are characteristic of members of this genus. This discovery expands our knowledge of marafivirus diversity, host range, and viruses capable of infecting A. argyi.

Klebsiella pneumoniae is a significant pathogen responsible for a range of infections, including pneumonia, urinary tract infections, and sepsis, in both human and veterinary medicine. The extracellular polysaccharide produced by this bacterium forms a capsule that protects the cell from immune responses and external influences, complicating treatment. The World Health Organization has placed this pathogen into the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) of pathogens that require special attention due to their resistance to multiple drugs, and hypermucoid K. pneumoniae strains with prevalent capsular types (e.g., K1 and K2) have been extensively studied. However, rare capsular types that are less well-characterised can still pose significant challenges. In the present study, we isolated a K. pneumoniae strain with capsular type K14, which is associated with antibiotic-resistant urogenital infections in felines, from a veterinary clinic. We successfully isolated and characterised three bacteriophages that exhibit rapid adsorption to and efficient lysis of the bacterium. All three phages demonstrated strictly lytic behavior and proved effective in degrading the extracellular polysaccharide capsule of the pathogen. We have modelled the receptor-binding proteins of these phages, which exhibit depolymerising activity. These proteins were produced in recombinant form, and experimental evidence has demonstrated their capacity to cleave the polysaccharide associated with the K14 capsular type. Furthermore, the chemical structure of the resulting cleavage products was determined. All three phages have been thoroughly characterised and show potential for application in combating multidrug-resistant K. pneumoniae.

Using unbiased high-throughput sequencing for metagenomic screening of viruses in diseased tomato plants, we identified a viral complex that includes viruses previously reported in tomato crops on La Réunion Island as well as a novel polerovirus, tentatively named "tomato necrotic yellowing virus" (ToNYV, proposed species, "Polerovirus ToNYV"). Molecular characterization and phylogenetic analysis revealed that ToNYV is closely related to two recently described poleroviruses from Africa and the Middle East, one of which is transmitted by the whitefly Bemisia tabaci, a trait uncommon among poleroviruses. Our transmission experiments demonstrated that ToNYV is also transmitted by B. tabaci and is prevalent across major tomato-growing regions of La Réunion. These findings highlight the value of metagenomic virome analysis in diseased plants for identifying novel viruses potentially involved in emerging plant diseases, either individually or as components of viral complexes.

A novel double-stranded RNA (dsRNA) virus was discovered in Valeriana jatamansi Jones plants showing brown necrotic stripe symptoms in Kunming, Yunnan Province. This virus was tentatively designated as "Valeriana jatamansi cryptic virus 2" (VJCV2), with GenBank accession numbers PP482523 and PP482524. The complete genome sequence of VJCV2 was determined using metatranscriptomic sequencing and Sanger sequencing. The genome of VJCV2 comprises two dsRNA segments dsRNA1 (PP482523, 2,463 bp) and dsRNA2 (PP482524, 2,170 bp). dsRNA1 is predicted to encode an RNA-dependent RNA polymerase (RdRp) containing 742 amino acids, and dsRNA2 is predicted to encode a coat protein (CP) with a molecular weight of 75.2 kDa. Multiple sequence alignments revealed that the RdRp and CP encoded by VJCV2 shared a high degree of amino acid sequence similarity with numerous members of the genus Betapartitivirus. Specifically, the RdRp and CP of VJCV2 share the most sequence similarity with dill cryptic virus 2 (77.88% identity in the RdRp and 71.17% in the CP), closely followed by cannabis cryptic virus (77.66% identity in the RdRp and 68.50% in the CP). Phylogenetic trees constructed based on RdRp and CP sequences showed that VJCV2 and its closest relatives clustered independently within the genus Betapartitivirus, and VJCV2 formed a separate small branch together with dill cryptic virus 2 and cannabis cryptic virus. These results indicated that VJCV2 should be classified as a novel member of the genus Betapartitivirus in the family Partitiviridae. This is the first report of a betapartitivirus infecting V. jatamansi.

A potyvirus (isolate AMLV-CQ) infecting culantro (Eryngium foetidum L.) imported from Vietnam was identified by RT-PCR. The complete genome sequence of AMLV-CQ was determined to be 9,549 nucleotides in length. It contains a large open reading frame encoding a 3,082-amino-acid putative polyprotein, flanked by 5´ and 3´ untranslated regions (UTRs) of 77 and 226 nt, respectively. AMLV-CQ is closely related to five other completely sequenced potyviruses, sharing 68-69% nucleotide and 69-70% amino acid sequence identity. However, the coat protein (CP) gene shares 89% nucleotide and 93% amino acid sequence identity with that of a partially sequenced potyvirus, Ammi majus latent virus (isolate AMLV-WF17). These results suggest that AMLV-CQ and AMLV-WF17 are isolates of the same species. To our knowledge, this is the first report of a complete genome sequence of an AMLV isolate, and culantro was identified as a new natural host for this virus. In addition, a one-step RT-PCR assay was developed that provides a rapid, robust, and highly sensitive approach for the detection of AMLV.

Human adenovirus (HAdV), a leading cause of pediatric acute respiratory infections (ARIs), exhibited altered transmission patterns during the period of time in which COVID-19 nonpharmaceutical interventions (NPIs) were being applied. In this study, we investigated the molecular and clinical characteristics of pediatric HAdV infections in Hangzhou across two epidemiological phases: the 2022 group (March 2022–February 2023), representing a period of strict NPIs with initial post-policy adjustment, and the 2023 group (March 2023-February 2024), reflecting resumption of normal social activities. The retrospective analysis included 55,772 children (aged 0–16 years) with respiratory infections from the Children's Hospital of Zhejiang University School of Medicine. HAdV was detected via PCR‒capillary electrophoresis. Hexon gene sequencing and phylogenetic analysis were performed on 105 randomly selected HAdV-positive samples. In the 2022 group, the positivity rate of HAdV was 4.12% (579/14,049), whereas in the 2023 group, it was 3.59% (1,497/41,723). The peak HAdV infection rate occurred in May 2022 (6.39%, 61/955) and November 2022 (5.32%, 102/1,918). A sustained epidemic trend emerged after Oct. 2023, with a 6.08% (230/3,785) rate occurring in February 2024. HAdV-positive children were predominantly aged 3–6 years (P < 0.001), with no significant difference in the proportion of male and female patients (P > 0.05). The primary coinfections involved Mycoplasma pneumoniae. Pneumonia was the most common clinical diagnosis. Phylogenetic analysis classified 92.6% of the circulating strains as HAdV-B, with a small proportion of HAdV-C. These results offer vital evidence for optimizing the prevention and control of pediatric HAdV infections.

The corn leafhopper Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae) is a major pest of corn in the Americas, transmitting pathogens that cause corn stunt disease. Using high-throughput sequencing and PCR-based assays, we identified and characterized two novel large-genome pestiviruses (LGPs), chicharrita del maiz pestivirus 1 (ChMPV1) and 2 (ChMPV2), from D. maidis populations collected in Texas, Oklahoma, Missouri, and Iowa. Genome analysis revealed long polyproteins with conserved "Pestiviridae" domains, and virus incidence varied geographically (0–43%). Phylogenetic analysis placed both viruses within the newly proposed family "Pestiviridae". These findings expand the known insect virome and provide tools for future studies on insect virus–vector–plant pathogen interactions.

Feline coronavirus (FCoV) has two biotypes: feline enteric coronavirus (FECV), which typically causes mild intestinal infections, and feline infectious peritonitis virus (FIPV), a virulent form associated with a fatal systemic and infectious disease in cats, known as feline infectious peritonitis (FIP). The differentiation between FECV and FIPV has been linked to specific mutations, most notably M1058L and S1060A, in the spike (S) protein. These mutations are believed to enhance macrophage tropism and facilitate systemic dissemination. However, the precise contribution of these mutations to FIPV virulence remains uncertain, as they have also been reported in non-FIP cases. Here, we report three FIP-positive cases (3/20; 15%) in domestic cats in Hanoi, Vietnam, in which the virus carried the M1058L mutation, while none had the S1060A substitution. These findings contribute to the ongoing debate regarding the role of spike protein mutations in FIP pathogenesis and underscore the need for continued genomic surveillance. Further research is needed to elucidate the molecular determinants involved in the FECV-to-FIPV transition, with potential implications for improving diagnosis, treatment, and prevention strategies for feline infectious peritonitis.