https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/5 2026-10-23T01:03:06Z https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/999 Integrative omics reveals candidate drug-repurposing targets in Tritrichomonas foetus Dąbrowska, Joanna; Kochanowski, Maciej; Sroka, Jacek Background Feline tritrichomonosis is a globally distributed chronic large-bowel diarrhoea of cats caused by the flagellated protozoan Tritrichomonas foetus. The only drug with demonstrated clinical efficacy is the off-label 5-nitroimidazole ronidazole, which has a narrow therapeutic window and against which clinical resistance has now been documented across three continents. The last comprehensive in silico drug-target prioritisation for T. foetus was published a decade ago and proposed 113 candidates based on homology to ChEMBL alone; the genomic and pharmacological landscape has since changed substantially, but no integrative reanalysis has been undertaken. Results Starting from the predicted proteome of strain K (25030 proteins), an integrative subtractive pipeline combining filtering against the feline host proteome, three pharmacological reference data- bases, essential-gene resources from three model eukaryotes, and the PHI-base virulence reference re- turned 433 priority candidates. Application of the same pipeline to the chromosome-scale strain KV-1 assembly yielded 436 candidates, with 66% cross-strain recovery as reciprocal best hits. Gene-level expression analysis showed that 82.7% of priority candidates were actively transcribed in the feline isolate G10/1, and a proof-of-concept docking screen against three top-ranked candidates recovered internally consistent, structure-based affinity rankings that await experimental validation. Nine of the ten most highly expressed candidates correspond to a protein family with clinically advanced small- molecule inhibitors; the tenth, a Rab4B GTPase, belongs to the broader, pharmacologically tractable Ras/GTPase superfamily but has no Rab4B-specific inhibitor characterised to date. Conclusions This work provides a substantially expanded and cross-validated drug-target landscape for T. foetus. Nine of the ten most highly expressed priority candidates fall into protein families for which clinically advanced small-molecule inhibitors are already available, namely Hsp70 and Hsp90 chaperones, the CDC48/p97 AAA+ ATPase, the ubiquitin-proteasome pathway, and serine/threonine kinases; the tenth, a Rab4B GTPase, belongs to the broader Ras/GTPase superfamily but has no Rab4B-specific inhibitor characterised to date. Together they offer an immediate opportunity for drug-repurposing studies in feline tritrichomonosis, a disease that lacks any approved therapy and against which off-label ronidazole resistance is increasingly documented. 2026-01-01T00:00:00Z https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/998 Effects of Experimental Infection with Lagovirus europaeus GI.1 and GI.2 on the Fecal Microbiota of Rabbits: New Insights into Virus–Host Microbiota Associations Hukowska-Szematowicz, Beata; Fitzner, Andrzej; Mazgaj, Szymon; Dybus, Andrzej; Kulig, Hanna; Shih-Hsiang Hsiao, Felix; Kosik-Bogacka, Danuta; Li, Yi-Hung; Yu, Yu-Hsiang Lagovirus europaeus GI.1 (RHDV) and GI.2 (RHDV2), the causative agents of rabbit hemorrhagic disease (RHD), are highly virulent pathogens of the European rabbit; however, their impact on the host fecal microbiota remains poorly understood. Previous field studies have suggested an association between the fecal microbiota and RHDV2 epidemiology in wild rabbits, highlighting the need for studies under controlled experimental conditions. To address this knowledge gap, we investigated the effects of experimental infection with L. europaeus GI.1 and GI.2 on the fecal microbiota of rabbits. Eighteen rabbits were assigned to three groups: an uninfected control group and two groups experimentally infected with L. europaeus GI.1 or GI.2 (n = 6 per group). Fecal microbiota composition was characterized by high-throughput sequencing of the V3–V4 region of the 16S rRNA gene using the HiSeq 2500 platform (Illumina). Rabbits infected with either genotype developed clinical signs consistent with RHD. No significant differences in alpha and beta diversity were observed. However, selective taxonomic shifts were detected, particularly in the GI.2 group, in which the relative abundance of Firmicutes was significantly higher and that of Bacteroidota significantly lower than in the control group. The abundance of Muribaculaceae was lower in both infected groups, whereas Sporosarcina reached its highest abundance in the GI.2 group. Correlation analysis revealed associations between selected bacterial taxa and clinical parameters. Muribaculaceae abundance was positively correlated with survival time and negatively correlated with lethargy and diarrhea, whereas Sporosarcina showed the opposite pattern, with positive correlations with lethargy and diarrhea and a negative correlation with survival time. Our findings indicate that experimental infection with L. europaeus GI.1 and GI.2 was not associated with a global restructuring of the fecal microbiota but rather with selective changes in the abundance of specific bacterial taxa, some of which were associated with viral genotype and the clinical course of infection. To our knowledge, this is the first controlled experimental study to directly compare the effects of L. europaeus GI.1 and GI.2 infection on the rabbit fecal microbiota. This study extends previous field observations by providing experimental evidence and offers new insights into the associations between L. europaeus infection and the host fecal microbiota during RHD. 2026-01-01T00:00:00Z https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/997 Liquid chromatography-tandem mass spectrometry analysis of pyrrolizidine alkaloids in Polish honey Kowalczyk, Ewelina Pyrrolizidine alkaloids (PAs) are among the most widespread naturally occurring toxins. Since they are primarily produced by flowering plants, there is a high likelihood of their transfer into honey. Given the toxic properties of PAs, their presence in honey can significantly compromise the safety of the product. Therefore, monitoring the occurrence of PAs in honey is essential. Material and Methods: A total of 65 honey samples collected in Poland were analysed for the presence of 42 PAs. The samples included multifloral, acacia, rapeseed and forest honeys. Pyrrolizidine alkaloids were quantified using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Results: Quantifiable amounts of PAs were detected in 10 of the honey samples. At least one of the monitored PAs was present in 39 samples, although most were below the method’s limit of quantification. The highest concentration observed was 46.9 μg/kg. Conclusion: A newly validated LC-MS/MS method was successfully applied to determine PAs in honey from Poland. Most of the analysed samples were free of the monitored PAs, confirming the general safety of Polish honey 2026-01-01T00:00:00Z https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/996 Pathogenesis and Host Response to A3B4 and A3B2 Infectious Bursal Disease Virus Strains in Chickens Pikuła, Anna; Lisowska, Anna; Opolska, Justyna; Kubiś, Piotr Recently, the identification of novel reassortants of infectious bursal disease (IBD) virus (IBDV) was reported. Interestingly, these strains competed with the previously dominant A3B2 lineage, becoming the prevalent lineage in Poland and disseminating to other countries in Europe. However, the specific virulence properties that facilitate their spreading were not elucidated. In this study, we compared the pathogenesis of the A3B4 Bug/03 and A3B2 75/11 IBDV strains in specific-pathogen-free (SPF) chickens, integrating viral replication dynamics, tissue tropism, immunosuppressive effects and host transcriptional responses. Both strains replicated efficiently in lymphoid and non-lymphoid tissues, with peak viral loads in the bursa of Fabricius. While the A3B2 75/11 strain exhibited higher viral RNA levels at early time points, the A3B4 Bug/03 strain persisted longer in multiple tissues. Notably, the A3B4 Bug/03 strain induced earlier bursal atrophy despite comparable viral loads at 4 dpi, and was associated with heteroge- neous growth performance, reflecting uneven flock development. Transcriptomic analysis revealed distinct host response profiles between strains. Infection with the A3B4 virus was characterised by the enrichment of metabolic and translational pathways, indicating cellular adaptation and metabolic reprogramming. In contrast, the A3B2 75/11 strain triggered a strong activation of immune and inflammatory pathways, including cytokine and chemokine signalling. Collectively, these findings demonstrate that IBDV pathogenicity is not solely determined by viral replication, but is critically shaped by host response mechanisms. The ability of A3B4 strains to modulate host pathways and persist in infected birds likely contributes to their epidemiological success and facilitates their continued spread in poultry populations. 2026-01-01T00:00:00Z