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Povzetek: Diatom blooms influence carbon cycling through organic matter production and its deposition or remineralization – processes mediated by the microbial community. Viruses can influence diatom bloom dynamics and even terminate blooms, yet interactions between diatoms, their viruses, and associated bacteria remain poorly resolved. Here, we examined how infection of the toxigenic diatom Pseudo-nitzschia galaxiae by its ssRNA virus PnGalRNAV reshapes host physiology, microbiome structure, and organic-matter processing in non-axenic batch cultures. Using epi-fluorescence microscopy, 16S rRNA amplicon sequencing, and metatranscriptomics, we linked microbial composition, localisation, and functional activity during viral lysis. Infection rapidly collapsed diatom growth and induced a senescence-like host state, with broad repression of photosynthesis, silicon metabolism, and core biosynthetic pathways, alongside induction of heat-shock and other stress-related genes. Concurrently, phycosphere-associated bacteria declined, detritosphere-associated bacteria increased, and community composition shifted from Marinobacter (Gammaproteobacteria) dominated, towards Flavobacteriaceae (Bacteroidetes) dominated, especially by Polaribacter. In non-infected controls Alphaproteobacteria proved to benefit from the stable healthy phycospheres with a distinct DOM pool. Bacterial metatranscriptomes showed significant upregulation of polysaccharide-degradation-associated genes in infected cultures, indicating active utilisation of lysis-derived diatom glycans. Similar compositional and metabolic profiles in infected cultures and later-stage senescent controls suggest infection accelerated senescence-associated microbial processes. Overall, viral lysis converted a productive diatom culture into a detrital, DOM-rich environment that selects for specialised polysaccharide degraders, redirects carbon through the viral shunt and may accelerate nutrient recycling in coastal systems. Extending this approach to natural microbial communities and diverse diatom–virus systems will help determine whether these mechanisms are broadly conserved.
Ključne besede: diatoms, virus, bacteria, Pseudo-nitzschia, shunt, senescence, microbiome, phycosphere
Objavljeno v DiRROS: 10.08.2026; Ogledov: 204; Prenosov: 216
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Povzetek: Introduction: Monkeypox virus (MPXV), typically endemic in West and Central Africa, has raised global concern due to the recent outbreak in several non-endemic countries with human-to-human transmission. Here we present a comprehensive analysis of MPXV genomes from Slovenia. Methods: Two real-time polymerase chain reaction (RT-PCR) assays for Orthopoxvirus (OPV) and MPXV genes were used for laboratory confirmation of mpox. Complete MPXV genomic sequences were obtained using nanopore long reads and Illumina technology. Phylogenetic analyses compared the Slovenian MPXV sequences with the global sequences. Results: A total of 49 laboratory-confirmed mpox cases were diagnosed in Slovenia in 2022, mainly affecting males under 40. In 48 cases, a complete genome sequence was obtained and phylogenetic analysis revealed five distinct lineages (B.1, B.1.14, B.1.2, B.1.3, and A.2.1), with B.1 and B.1.3 dominating, suggesting multiple introductions into Slovenia. Genome analysis revealed significant divergence from the reference MPXV-M5312_HM12_Rivers. Conclusions: The genetic diversity observed in the Slovenian MPXV sequences sheds light on the complex dynamics of the 2022 mpox outbreak and highlights the need for further research to understand the impact of mutations on MPXV functional characteristics and their role in the evolution and diversification of current lineages.
Ključne besede: monkeypox virus, B.1 lineage, phylogenomic analysis, orthopoxvirus, viral genome surveillance
Objavljeno v DiRROS: 03.08.2026; Ogledov: 234; Prenosov: 85
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Povzetek: Molluscum contagiosum virus (MOCV) is an important human pathogen causing a high disease burden worldwide. It is the last exclusively human-infecting poxvirus still circulating in its natural reservoir-a valuable model of poxviral evolution. Unfortunately, MOCV remains neglected, and little is known about its evolutionary history and circulating genomic variants, especially in non-privileged countries. The design weaknesses of available MOCV detection/genotyping assays surfaced with recent accumulation of abundant sequence information: all existing MOCV assays fail at accurate genotyping and capturing sub-genotype level diversity. Because complete MOCV genome characterization is an expensive and labor-intensive task, it makes sense to prioritize samples for whole-genome sequencing by diversity triage screening. To meet this demand, we developed a novel assay for accurate MOCV detection and genotyping, and comprehensive sub-genotype qualification to the level of phylogenetic groups (PGs). The assay included a novel set of oligonucleotide primers and probes, and it was implemented using digital polymerase chain reaction (dPCR). It offers sensitive, specific, and accurate detection, genotyping (MOCV1-MOCV3), and PG qualification (PG1-6) of MOCV DNA from clinical samples. The novel dPCR assay is suitable for MOCV diversity triage screening and prioritization of samples for complete MOCV genome characterization.
Ključne besede: Molluscum contagiosum, Molluscum contagiosum virus, digital PCR, diversity screening, molecular diagnostics, sample prioritization triage
Objavljeno v DiRROS: 12.06.2026; Ogledov: 249; Prenosov: 195
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Povzetek: The emergence of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants poses a challenge to current therapies and emphasises the need for targets that are less susceptible to mutation. The SARS-CoV-2 envelope protein (Epro) is a highly conserved viroporin and is of central importance to the viral life cycle, yet it remains underexplored as a therapeutic target. In this study, we have identified and characterised a novel lead candidate (LC) − (S)-N-(2-((1S,3S,5S,7S)-adamantan-2-yl)ethyl)-2-(butylamino)-3-(1H-indol-3-yl)propanamide − for inhibition of the SARS-CoV-2 Epro ion channel using combined in silico and in vitro approaches. Molecular dynamics (MD) simulations showed that LC forms stable complexes at the N-terminal vestibule, with key interactions at GLU8, THR9, THR11, ASN15, and LEU18, and a calculated binding affinity higher than that of the reference compound rimantadine within the applied MD/molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) framework. Results of in vitro experiments indicated that LC inhibits the model coronavirus murine hepatitis virus at late stages of the viral cycle. Activity under co-treatment conditions further suggests a direct virucidal effect or interference with early entry stages; an EC50 of approximately 12 μM was within the same micromolar range as those observed for the reference Epro inhibitors 5-(N,N-hexamethylene)amiloride and rimantadine. Quantitative PCR experiments showed delayed RNA replication in LC-treated infected cells, while light and transmission electron microscopy displayed the reduced release of virions and prevention of cell lysis. These results emphasise the central role of the Epro ion channel in the coronavirus life cycle and present LC as a promising candidate for the further development of novel coronavirus inhibitors.
Ključne besede: SARS-CoV-2 envelope protein, viroporin, ion channel blockers, molecular docking, molecular dynamics simulations, drug discovery, murine hepatitis virus, in vitro
Objavljeno v DiRROS: 11.06.2026; Ogledov: 325; Prenosov: 348
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Povzetek: Objectives − Most viral respiratory tract infections (VRTI) are seasonal diseases and frequently severely affect public health by causing seasonal epidemics and pandemics, also in newborns. The objective of this study was to analyse the relation of meteorological factors to the occurrence of neonatal VRTI and to estimate their predictive role for VRTI seasonality. Patients and methods − The retrospective observational cohort study enrolled 228 newborns (56% male and 29% preterm) aged up to 44 postmenstrual weeks, hospitalized due to acute VRTI between January 2015 and December 2020 in the central Slovenian region. The meteorological data for the same geographical region and time period were assessed, and correlation, multiple regression and cut-off values were analysed. Results − A typical seasonal distribution of VRTI from December to March was observed and the large majority of cases were due to respiratory syncytial virus (RSV) infection. Low air temperature, high relative humidity, shorter daily solar radiation and increased cloud cover were associated with an increased risk of neonatal, either RSV or non-RSV VRTI. Conclusions − Meteorological factors, particularly air temperature and relative humidity, were associated with neonatal VRTI occurrence in the temperate climate of central Slovenia. The average daily air temperature below 4.9 and 3.8 °C could predict the onset of the VRTI and RSV VRTI season, respectively. These factors could be used as real-time predictive warning, especially for RSV season onset and the need to begin RSV immunoprophylaxis in vulnerable newborns.
Ključne besede: respiratory tract infections, newborn, respiratory syncytial virus
Objavljeno v DiRROS: 04.06.2026; Ogledov: 330; Prenosov: 214
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