Search Results (1,936)

Mammarenaviruses are enveloped, ambisense, single-stranded RNA viruses capable of causing fatal hemorrhagic fevers and severe neurological disorders in humans. Although muroid rodents have historically been recognized as the primary reservoirs for major pathogens like Lassa virus, recent surveillance has revealed a significant expansion of their host range. This review aims to synthesize current global data regarding the epidemiology of mammarenaviruses in conventional reservoirs and the emergence of novel arenaviruses in non-traditional mammalian hosts. To achieve this, we comprehensively analyzed recent molecular and metagenomic surveillance data, evolutionary studies, and epidemiological reports published worldwide. Key discoveries include Wenzhou virus in Asian house shrews, Plateau Pika virus in plateau pikas, and an independent, geographically clustered of hedgehog-associated arenaviruses across Europe. Ultimately, this review underscores the global distribution of these pathogens and the critical need for continued, multi-host surveillance worldwide. Full article

Avian influenza is a highly contagious viral disease affecting domestic and wild birds, caused by influenza A viruses of the family Orthomyxoviridae. Continuous genetic surveillance is essential for monitoring viral evolution and identifying molecular determinants associated with pathogenicity and host adaptation. In this study, the PB1 and PB2 polymerase genes of highly pathogenic avian influenza (HPAI) H5N1 viruses detected in Romania between 2017 and 2024 were genetically characterized. A total of 18 organ samples collected from domestic and wild birds in several Romanian counties were analyzed by real-time RT-PCR, followed by conventional RT-PCR, Sanger sequencing, mutational analysis, and phylogenetic reconstruction. High-quality sequence data were obtained for six PB1 and eight PB2 gene fragments. Sequence analysis revealed a high degree of conservation within the PB1 gene, particularly across regions involved in viral replication, indicating strong evolutionary constraints. In contrast, the PB2 gene exhibited several amino acid substitutions, including changes at positions 464 and 678 in selected isolates. Notably, all analyzed strains lacked the mammalian adaptation marker E627K. Phylogenetic analysis clustered the Romanian isolates within Eurasian H5N1 lineages and demonstrated close genetic relationships with contemporary strains circulating in Eastern Europe and Russia. These findings highlight the genetic stability of PB1, the ongoing diversification of PB2, and the importance of continuous molecular surveillance for the early detection of viral variants with potential implications for host adaptation and zoonotic risk. Full article

Emerging viral variants can affect both commercial insect production and wild insect populations, highlighting the need to identify molecular features associated with viral host range. TdNV-Korea, isolated from the Korean rhinoceros beetle Allomyrina dichotoma (syn. Trypoxylus dichotomus), represents a Korean isolate within the Oryctes rhinoceros nudivirus (OrNV) lineage associated with infection of a non-Oryctes scarab host. To define candidate features associated with host-range variation, we compared the sequence and predicted structural properties of viral entry factors across OrNV-related isolates using sequence analysis, structural modeling, and electrostatic surface analysis. The major capsid protein VP39 was highly conserved and served as a comparative baseline, whereas the per os infectivity factors GP106 and GP126 showed greater divergence despite their expected constraints during oral entry. GP106 retained an invariant chitin-binding domain, with substitutions restricted to a peripheral C-terminal region, whereas GP126 concentrated most substitutions within a predicted disordered interdomain segment associated with a localized electrostatic shift on a candidate host-interaction surface. Because functional assays were not performed, these findings should be interpreted as a hypothesis-generating model in which two entry factors follow contrasting modes of sequence change. GP126, and secondarily, the GP106 C-terminal region are prioritized for future experimental validation of nudivirus host-range determinants. Full article

Cuticular wax metabolites on leaf surfaces function as chemical interfaces that modulate the pre-penetration development of phytopathogenic fungi. However, the specific monomeric constituents in grapevine leaf wax that regulate conidial germination and host recognition by grapevine powdery mildew caused by Erysiphe necator remain elusive. Here, we compared leaf cuticular wax characteristics between four susceptible Vitis vinifera cultivars and three resistant Chinese wild Vitis accessions. Scanning electron microscopy coupled with gravimetric analysis revealed that susceptible V. vinifera cultivars exhibited lower wax loads and lamellar crystals, whereas resistant Chinese wild Vitis accessions displayed higher wax accumulation with granular or blocky crystals. Gas chromatography–mass spectrometry profiling further demonstrated divergent compositional patterns: primary alcohols predominated among susceptible V. vinifera cultivars, while aldehydes and alkanes were enriched in resistant Chinese wild Vitis accessions. Paradoxically, in vitro conidial germination assays showed that wax extracts from all grapevines significantly promoted En. NAFU1 conidial germination, indicating that resistance in Chinese wild Vitis accessions is independent of direct wax-mediated inhibition of spore germination. Bioassays of representative monomers revealed that n-triacontane suppressed germination at high concentrations, whereas n-dotriacontanol and stearic acid stimulated it. Collectively, these findings demonstrate that specific cuticular wax monomers exert distinct biological effects on En. NAFU1 conidial germination. Given the ubiquitous presence and concentration-dependent stimulatory activity of stearic acid, we hypothesize that this monomer serves as a conserved chemical cue enabling initial host recognition by En. NAFU1, whereas the differential susceptibility among grapevine genotypes is governed by downstream physical and induced defense mechanisms rather than by variation in stearic acid levels. Full article

Intestinal dysbiosis is a hallmark of both inflammatory bowel conditions and colorectal cancer, yet the mechanisms by which inflammatory mediators alter microbial communities and may contribute to tumor development remain poorly understood. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine involved in innate immunity and the progression of inflammatory and neoplastic disorders. In this study, sequencing of the microbial 16S rRNA gene was performed to characterize the fecal microbiota profiles of wild-type (WT) and MIF-knockout (MIF-KO) BALB/c mice subjected to AOM/DSS-induced colitis-associated colorectal cancer (CAC). CAC induction resulted in marked microbial shifts, including increases in Muribaculaceae and Bacteroidota, in both WT and MIF-KO mice. Notably, MIF-KO CAC mice developed more severe disease compared with WT CAC mice. Furthermore, FMT experiments revealed that the fecal microbiota from MIF-KO donors was associated with increased tumor burden in WT recipients under CAC-inducing conditions compared with that in recipients colonized with WT-derived microbiota. Together, these findings suggest that MIF deficiency is associated with gut microbiota remodeling during CAC and support a potential relationship between the MIF-dependent host context, microbial composition and colorectal cancer severity. Full article

Ornamental flora is often appreciated for its aesthetic and recreational value, overlooking its ecological functions. This study provides the first comprehensive assessment of ecosystem services and disservices delivered by cultivated ornamental plants across all the islands of the circum-Sicilian archipelago. We surveyed the vascular flora characterizing each island, compiling a checklist of 402 taxa. For each taxon, we recorded biological traits, beneficial services (e.g., wildlife food, human food, habitat provision, beekeeping, erosion control, green fencing, and medicinal interest), and disservices (naturalization, toxicity to humans, pets, or livestock, and allergenicity). The island of Ustica hosts the highest number of taxa (217), followed by the island of Lipari (213), while the islands of Marettimo (95) and Alicudi (96) are the poorest. Remarkably, 329 taxa are potential sources of medicine, 326 provide wildlife habitats, 299 are of beekeeping interest, 218 are suitable for living fences, 212 contribute to erosion control, 192 supply fruits for wild birds, 130 human food, and 86 livestock forage. Spatial analysis of ornamental flora reveals that the island of Favignana has the highest proportional cover (11%) with moderate clustering, the islands of Ustica and Panarea display more dispersed, larger patches, and the islands of Lipari and Salina show strongly aggregated small patches. These results demonstrate that ornamental plants perform substantial regulatory and provisioning services, and their spatial arrangement further modulates ecological outcomes. Full article

Molecular microbiology has revolutionized our understanding of the complex host-associated microbiomes required for normative development and physiology. Horses and other members of the family Equidae are particularly reliant on the early maturation and lifelong maintenance of an unusually rich hindgut microbiome for optimal digestion and overall health and performance. Research on the equine gut microbiome has accelerated in the past several years, necessitating a renewed appraisal of the field. The present work is a comprehensive and critical review of the literature regarding the bacterial gastrointestinal microbiome of horses. First, the developmental trajectory of the foal gut microbiome is discussed, followed by descriptions of the taxonomic membership of the core equine gut microbiome, its primary functions and effects on host physiology, and intrinsic and extrinsic factors that shape the equine microbiome during health, with a focus on diet and supplements. Next, evidence supporting adverse effects on the equine gut microbiome of gastrointestinal conditions including colic and colitis, extraintestinal conditions including obesity and laminitis, and pharmacological interventions including antibiotics and non-steroidal anti-inflammatory drugs is summarized. Lastly, clinical and experimental research investigating the effects of treatments targeting the gut microbiome of horses, including probiotics, prebiotics, and fecal microbiome transfer, is critically examined. Conclusions summarize the connection between natural (i.e., wild) equine behavior and the health of the equine gut microbiome and the impacts of human management. Full article

Retroviruses induce immunosuppression in their infected hosts. This phenomenon is well described for the immunodeficiency viruses, with human immunodeficiency virus type 1 (HIV-1) representing the best-studied example, but it also occurs in other retroviral infections. Immunosuppressive properties were first characterized in murine leukemia viruses (MuLV). Additional well-studied examples include feline leukemia virus (FeLV) and koala retrovirus (KoRV). Investigations into the mechanisms underlying retrovirus-induced immunosuppression revealed that not only inactivated viral particles but also their purified transmembrane (TM) envelope proteins exhibit immunosuppressive activity. However, in certain retroviral infections, additional viral proteins contribute to the immunosuppression in vivo. Within the TM envelope proteins, a highly conserved region—designated the immunosuppressive (isu) domain—was identified. Synthetic peptides corresponding to this domain suppress a wide range of in vitro immune responses, possibly by regulating Ras-Raf-MEK-MAPK and PI3K-AKT-mTOR pathways. They modulate cytokine release and alter gene expression in immune cells, mirroring the activity of the corresponding TM envelope protein. Mutations in the sequence abrogate the effect. Numerous TM envelope proteins have demonstrated immunosuppressive activity in vivo in a tumor rejection model, and mutations within the isu domain also abrogate this function. These studies have important implications for reproduction, particularly through the immunosuppressive syncytins in the placenta, for tumor development, where similar mechanisms may protect cancer cells from the host immune system, and for vaccine development and xenotransplantation. Notably, immunization with TM envelope proteins carrying mutations in the isu domain elicits stronger immune responses compared with the wild-type proteins. Finally, the potential of retroviral TM envelope proteins to protect xenotransplants from immune rejection will be discussed. Full article

Ilyonectria is a common soil-inhabiting fungal genus that comprises numerous plant phytopathogenic species capable of infecting a wide array of crops, medicinal herbs, and horticultural plants. However, the lack of a reliable and efficient genetic transformation method has severely hindered the elucidation of the pathogenic mechanisms of Ilyonectria pathogens. In this study, we established an efficient protoplast-mediated genetic transformation method for two dominant Panax root rot pathogens, I. robusta and I. vredehoekensis. Key parameters governing high-quality protoplast preparation, including mycelium culture time, enzyme composition, osmotic stabilizer type, digestion speed, and digestion time, were systematically optimized. Subsequently, orthogonal experiments were conducted to optimize the PEG-CaCl₂-mediated transformation conditions and to screen regeneration media for protoplasts. The optimal enzymatic system is composed of 20 mg/mL driselase and 10 mg/mL lysing enzyme, with 0.7 M NaCl as the osmotic stabilizer. Under these conditions, high-viability and high-quality protoplasts were obtained from I. vredehoekensis after 3 h of digestion at 150 rpm, and from I. robusta after 2 h of digestion at 100 rpm, yielding 5.52 × 10⁷ CFU/mL and 5.75 × 10⁷ CFU/mL protoplasts, respectively. Efficient transformation was achieved using a mannitol-prepared STC buffer mediated by 40% PEG4000. PCR and fluorescence microscopy verified positive transformants. Additionally, pathogenicity assays showed no significant differences in virulence between the transformed and wild-type strains, suggesting that the transformation procedure did not alter virulence. To the best of our knowledge, this is the first study to successfully establish genetic transformation methods for I. robusta and I. vredehoekensis, providing an essential technical platform for functional gene analysis, pathogenicity studies, and host–pathogen interaction research. In addition, the optimized transformation strategy may serve as a valuable reference for studies on other Ilyonectria species. Full article

Campylobacter jejuni (C. jejuni) is a prevalent zoonotic pathogen that poses a significant threat to global public health, causing gastroenteritis with symptoms ranging from mild diarrhea to severe complications, and is widely distributed among various animal hosts, including poultry, livestock, and wild birds. Among these, wild birds, characterized by their exceptional species diversity, high mobility, and long-distance migratory behavior, are capable of disseminating infectious agents across geographic regions and ecological settings. However, wild birds are increasingly recognized as potential carriers, research on C. jejuni in these hosts remains nascent and fragmented, and a unified understanding has yet to emerge. Therefore, this review synthesizes current knowledge on the prevalence patterns, key determinants, and genetic and transmission characteristics of wild bird origin C. jejuni, aiming to provide a foundation for subsequent in-depth evaluation of the public health significance of C. jejuni derived from wild birds. Full article

The dissemination of antibiotic resistance genes (ARGs) in riverine ecosystems poses a pressing public health threat, while the mechanisms governing the assembly of the gut resistome in wild fish remain poorly elucidated. This study aimed to elucidate the distributional patterns of ARGs across multiple environmental compartments and to identify factors associated with their variation, particularly the contributions of mobile genetic elements (MGEs) and metal resistance genes (MRGs) to gut resistome variation. Metagenomic sequencing was conducted on 60 samples, comprising water, sediment, and gut contents from three wild fish species (Megalobrama terminalis, Aristichthys nobilis, and Coilia nasus) with distinct feeding habits, collected from four reaches of the Qiantang River basin. A total of 305 ARG subtypes belonging to 23 classes were identified. ARG composition differed significantly across environmental media and host species (permutational multivariate analysis of variance, PERMANOVA; p < 0.01), with host species identity as the primary structuring factor. Variance partitioning analysis (VPA) revealed that MGEs independently explained the largest fraction of ARG variation in A. nobilis (33.8%, p = 0.006), whereas MRGs dominated in C. nasus (33.3%, p = 0.005); in M. terminalis, MGEs and MRGs together accounted for 47.9% of the variation. Metagenomic assembly recovered 2622 ARG-carrying contigs, of which 28.3% (743) were predicted as plasmid sequences; physical co-localization among ARGs, MGEs, and MRGs was detected on both chromosomes and plasmids. Metagenomic binning validated the physical co-localization of ARG-MGE-MRG modules in genera such as Morganella and Burkholderia at the genome level, while plasmid-borne high-risk ARGs were identified in Aeromonas. Risk ranking further revealed significant enrichment of Rank II potentially high-risk ARGs (e.g., mcr-7.1, blaZ) in fish guts, carried by potential pathogens. These findings suggest that horizontal gene transfer involving MGEs and co-selection related to MRGs are closely associated with the fish gut resistome composition in a manner dependent on host ecology, providing a scientific basis for shifting riverine resistance management from concentration-based control toward the interruption of dissemination pathways. Full article

Strawberries, as an important economic crop, are widely planted worldwide. Fusarium oxysporum, belonging to FOSC (Fusarium oxysporum species complex), is widely present in plants. Among them, Fusarium oxysporum f. sp. fragariae (Fof) is one of the most important pathogens on strawberry and has pathogenic specificity toward strawberry hosts. In recent years, diseases caused by Fof have seriously threatened the strawberry industry. Secreted in Xylem (SIX) genes play important and different roles in F. oxysporum. In this study, we knocked out SIX9 in Fof to analyze its functions. The mycelial growth rate of ΔFofSIX9 was significantly lower than that of the wild type, but the difference in spore production was not significant. The pathogenicity of ΔFofSIX9 toward four different representative strawberry varieties was significantly reduced, manifested by the decrease in the severity of plant wilt, root rot, and crown rot. In addition, compared to the wild type, the activities of superoxide dismutase (SOD) and catalase (CAT) in ΔFofSIX9-infected plants were significantly increased, while the content of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and superoxide anion (O₂⁻) were significantly decreased. So ∆FofSIX9 could reduce the pathogenicity of the wild type by affecting the host plant’s defense response against infection of Fof. Full article

Background: While vaccines are designed to elicit targeted immune responses, in some cases, the immunogenic molecules employed can inherently interact with broader host cellular pathways as a secondary consequence. This phenomenon can be exemplified by COVID-19 vaccines. COVID-19 vaccines, including mRNA platforms, use the SARS-CoV-2 spike protein as an immunogen to induce the production of neutralizing antibodies. The spike protein binds the ACE2 (angiotensin-converting enzyme 2) receptor on human cells, mediating viral entry and infection. ACE2 is widely expressed across multiple tissues and is a key component of the renin–angiotensin–aldosterone system (RAAS) that acts as a homeostatic regulator of systemic and local blood flow, blood pressure, cardiac function, fluid balance and immunity. Some studies have proposed the interaction between the spike protein and ACE2 as a possible contributing factor to rare adverse effects observed following COVID-19 vaccination, including myocarditis, pericarditis, thrombosis, and reported alterations in blood pressure, though these mechanisms remain to be fully elucidated. Objectives: As a proof-of-concept approach in vaccine antigen development, we engineered SARS-CoV-2 spike mutants with impaired binding to the host receptor ACE2. Methods: By rational design, we produced and validated in vitro and in vivo spike point mutants that do not effectively bind ACE2. Results: The engineered spike mutants do not effectively bind the human entry receptor ACE2 while retaining the immunogenic properties equal to or better than the wild type spike and thus generate a protective response in animals when used as a vaccination agent. Conclusions: By establishing a straightforward molecular strategy for rational vaccine design, this work demonstrates the feasibility of limiting specific antigen–host receptor interactions while maintaining immunogenicity. This approach may be applicable to future vaccination strategies where antigen interaction with host cells could potentially interfere with physiological pathways. Full article

Hepatospora eriocheir is a microsporidian parasite of the Chinese mitten crab Eriocheir sinensis, an invasive decapod now widely distributed in European inland and coastal waters. Although the host is common across much of Europe, confirmed European records of H. eriocheir have remained scarce and, until now, have not included the Baltic Sea region. In this study, 15 adult E. sinensis collected from the Vistula Lagoon, southern Baltic Sea, were examined using gross pathological assessment, wet-mount microscopy, histopathology, PCR amplification, Sanger sequencing, and phylogenetic analyses of parasite SSU rRNA and host COI sequences. Hepatopancreatic alterations were observed in several individuals, ranging from pale discolouration and friability to loss of normal tissue organisation. Spores were detected in fresh squash preparations from affected tissue, and histology revealed epithelial disruption, intratubular spore accumulation, and necrotic changes consistent with progressive microsporidian infection. Molecular screening confirmed H. eriocheir in 60.0% of crabs, with positive cases occurring in both females and males. The parasite sequences formed a single, well-supported clade and were highly similar to previously reported H. eriocheir sequences from the United Kingdom and China. Host COI sequences represented three mitochondrial haplotypes, indicating that the infection occurred across more than one host mitochondrial haplotype background. These findings constitute the first record of H. eriocheir in E. sinensis from the Baltic Sea and support the hypothesis that infected crabs reaching the Vistula Lagoon are connected with the wider North Sea invasion system rather than an isolated Baltic lineage. Full article

Wild and synanthropic birds harbour a diverse range of yeasts, including species of recognised clinical relevance. Given their close interaction with human activities, these birds represent a valuable source for investigating environmental yeasts and assessing the performance of identification methods. We investigated yeasts recovered from cloacal and crop samples of birds from Gran Canaria and compared routine identification methods with molecular sequencing. Twenty-four isolates were examined by biochemical profiling (API ID32C) and MALDI-TOF MS. Molecular identification based on ITS sequencing was carried out only for the sixteen isolates for which the two routine methods yielded discordant results, allowing resolution of their taxonomic identification. Phenotypic and proteomic methods showed limited agreement at the species level (8/24; 33.3%), with 16 discordant identifications resolved by sequencing. Pigeon isolates were dominated by members of the Kazachstania telluris complex, chiefly K. bovina (11/24; 45.8%), while partridges yielded taxa of clinical importance, including Candida parapsilosis and Pichia kudriavzevii (formerly Candida krusei). Rhodotorula mucilaginosa, Debaryomyces spp., and Saccharomyces cerevisiae were also detected. Comparative tests confirmed significant host-associated differences in species distribution (p < 0.05), and Cohen’s kappa indicated substantial agreement between API and MALDI-TOF at the genus level when benchmarked against ITS (κ = 0.71), although concordance was lower at the species level. In conclusion, these findings strengthen the case for integrating sequencing into diagnostic workflows, highlight the potential One Health relevance of yeast carriage by wild birds, and underscore the need for targeted surveillance at urban and game-handling interfaces where human exposure is likely. Full article