https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/5 Mon, 09 Nov 2026 11:33:05 GMT 2026-11-09T11:33:05Z https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/1007 Prolonged persistence of chloramphenicol residues in chicken feathers: implications for retrospective exposure detection Śniegocki, Tomasz; Łebkowska-Wieruszewska, Beata; Giorgi, Mario; Krajewska, Weronika; Samorek, Elżbieta; Poźniak, Błażej Chloramphenicol (CAP) is a prohibited antimicrobial and its detection is important for residue monitoring programmes. This study compared CAP depletion in different types of chicken feathers, plasma, liver and muscle following experimental exposure (approximately 18–25 mg kg⁻¹ body weight day⁻¹ for 7 days). A QuEChERS-based LC–MS/MS method was developed and validated for CAP determination in feathers, plasma, liver and muscle. Apparent recoveries ranged from 90.3% to 97.2%, within-laboratory reproducibility ranged from 6.3% to 9.4%, and the decision limit (CCα) was 0.10 μg kg⁻¹ for all matrices. The highest CAP concentrations one day after treatment withdrawal were observed in plasma (2493 μg kg−1) and tail feathers (2460 μg kg−1). CAP concentrations in plasma, liver and muscle remained above CCα through day 14 after treatment withdrawal but were below CCα from day 21 onward, whereas concentrations in all four analysed feather types (wings, tail, neck and legs) remained above CCα throughout the 28-day observation period. At the final sampling point (49 days of age), the highest CAP concentration was observed in wing feathers (84 μg kg−1). Depletion analysis indicated prolonged persistence of CAP in feathers, particularly in wing and neck feathers. These results support the potential use of feathers as a matrix for retrospective assessment of CAP exposure in poultry. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/1007 2026-01-01T00:00:00Z https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/1006 Hybrid QuEChERS–Micro-Solid Phase Extraction for the Determination of Chloramphenicol in Honey by HPLC-MS/MS: Method Validation and Matrix-Effect Assessment Śniegocki, Tomasz; Samorek, Elżbieta; Krajewska, Weronika An HPLC-MS/MS method combining modified QuEChERS-based extraction with micro- solid-phase extraction (MSPE) using C18P-PVDF microspin filters was developed and validated for chloramphenicol (CAP) determination in honey. At validation levels of 0.10, 0.15, and 0.30 μg kg−1 , apparent recoveries ranged from 102.1% to 105.1%, repeatability (RSDr) from 4.5% to 9.5%, and within-laboratory reproducibility (RSDwR) from 6.0% to 12.5%. The decision limit (CCα) was 0.123 μg kg−1 , below the reference point for action of 0.15 μg kg−1 , while the estimated limit of detection (LOD; not experimentally verified) was 0.01 μg kg−1 .. Matrix-effect assessment across 20 honey samples showed responses within the 80–120% range for the proposed procedure and the SPE and QuEChERS comparators. No CAP was detected in the authentic honey samples. The developed workflow provides a practical, validated alternative for routine CAP determination in honey. Thu, 01 Jan 2026 00:00:00 GMT https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/1006 2026-01-01T00:00:00Z https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/1005 Hepatospora eriocheir infection affects the fitness of adult Chinese mitten crabs in their non-native range Keirsebelik, Heleen; Ewers, Christine; Opinion, April Grace; Stachnik, Magdalena; Normant-Saremba, Monika; Poma, Giulia; Bosschaerts, Stijn; De Boeck, Gudrun; Schoelynck, Jonas For many invasive crustaceans, including the Chinese mitten crab (Eriocheir sinensis), the prevalence and impact of parasites in their introduced range remain largely unexplored. The microsporidium Hepatospora eriocheir was recently detected in mitten crabs across Europe, yet little is known about its physiological effects on its host. In this study, the influence of H. eriocheir infection on physiological biomarkers in adult mitten crabs collected from rivers in Germany and Belgium was experimentally investigated. We assessed metabolic rates (routine and maximum metabolic rate, aerobic scope), haemolymph glucose and lactate levels, and lipid content in the hepatopancreas. Infection prevalence reached 27% in adult mitten crabs from the Belgian population and 38% in individuals from the German population. Infected individuals showed a significantly reduced maximum metabolic rate and aerobic scope, while the routine metabolic rate remained unaffected. Glucose levels were lower in infected crabs both at rest and post-exercise, which indicates that energy reserves have dropped, whereas lactate levels showed no significant difference. The lipid content in the hepatopancreas was reduced, likely due to direct exploitation of host resources by the parasite and damage to hepatopancreatic tissue. Together, these patterns indicate an impaired energy metabolism, which may hamper energetically demanding activities such as migration and reproduction. The Chinese mitten crab is a catadromous species, and as the examined crabs were at the life stage when they commence a long-distance migration for their single reproductive event, infection by H. eriocheir may compromise their ability to complete this migration and successfully reproduce. Fri, 01 Jan 2027 00:00:00 GMT https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/1005 2027-01-01T00:00:00Z https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/1004 Conserved Hepatospora eriocheir Sequences in Chinese Mitten Crabs from Poland, Germany and Belgium: A Comparative Molecular Study Stachnik, Magdalena; Normant-Saremba, Monika; Ewers, Christine; Keirsebelik, Heleen; Schoelynck, Jonas Hepatospora eriocheir is an obligate intracellular microsporidian associated with the Chinese mitten crab, Eriocheir sinensis, an important aquaculture species in Asia and an invasive species in Europe. We investigated parasite sequence variation in crabs from three Eu- ropean regions: the Vistula Lagoon in the Baltic Sea (Poland) and the Elbe and Scheldt catchments draining into the North Sea (Germany and Belgium). Among 57 crabs examined, 26 infections were confirmed by small subunit ribosomal RNA (SSU rRNA) sequencing, including 17 newly identified infections among 42 specimens collected in 2022. The parasite groups comprised 13 Polish, eight German and five Belgian infections. Their SSU rRNA sequences were identical across a 794-position shared core, and all 26 newly generated arginyl-tRNA synthetase (ArgRS) sequences were identical across 624 nucleotides and matched the British reference KU695717. Both parasite gene fragments were identical across four host mitochondrial cytochrome c oxidase subunit I (COI) haplotypes; the Eriocheir japonica-associated haplotype was detected only in Belgian crabs in this sample. The study provides the first specimen-linked, sequence-confirmed molecular characterisation of in- fections in the sampled German and Belgian crab populations, together with new Polish infections from 2022 and a comparative two-locus reference dataset. The repeated Baltic detection, combined with shared Polish–German host COI haplotypes and existing evidence of North Sea–Baltic connectivity, is consistent with the arrival of infected migrating crabs, although the parasite’s precise source remains unresolved Thu, 01 Jan 2026 00:00:00 GMT https://dspace.piwet.pulawy.pl/xmlui/handle/123456789/1004 2026-01-01T00:00:00Z