Veterinary parasitology最新文献

{"title":"Impacts of targeted selective treatment on performance, nematode faecal egg counts and anthelmintic use in sheep: A meta-analysis","authors":"Adam D. Hayward,&nbsp;Fiona Kenyon","doi":"10.1016/j.vetpar.2026.110696","DOIUrl":"10.1016/j.vetpar.2026.110696","url":null,"abstract":"<div><div>Gastrointestinal nematode (GIN) infections of ruminant livestock have traditionally been controlled through regular, “suppressive”, treatment with anthelmintic drugs, but this has resulted in the evolution of anthelmintic resistance and reduced efficacy. There is now a critical need to reduce anthelmintic use to maintain anthelmintic efficacy by creating refugia where susceptible GIN reside. Targeted selective treatment (TST) strategies only treat animals that need it, ensuring animals affected by GIN maintain their performance, while animals unaffected by GIN are not treated unnecessarily. TST is generally agreed to reduce anthelmintic use without drastically reducing animal performance or increasing GIN faecal egg count (FEC), but there is considerable variation in results reported by studies comparing TST with other strategies. To explore the effectiveness of TST and identify factors affecting previous results, we applied meta-analysis to data collected from 20 studies comparing TST to other strategies. Overall, TST was associated with a statistically significant, but small, reduction in animal performance, no effect on worm FEC, and 50 % lower anthelmintic use. Experimental design affected study outcome: basing treatment decisions on body condition scores resulted in less favourable outcomes compared to other methods. Meanwhile, TST was associated with negligible reductions in performance compared to “suppressive” treatment, and although FEC was increased slightly in the TST group, anthelmintic use was reduced by around two-thirds. Differences between TST and “strategic” treatments were smaller, but TST still reduced anthelmintic use by 25 %. Overall, the results support the use of TST to reduce anthelmintic use while maintaining efficacy and animal performance.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110696"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic anticoccidial effects of pomegranate peel extract and probiotics against Eimeria tenella via mitigating inflammation and restoring gut microbiota","authors":"Weimei Wang ,&nbsp;Xiaobin Yi ,&nbsp;Yu Han ,&nbsp;Ping Feng ,&nbsp;Ruonan Bo ,&nbsp;Mingjiang Liu ,&nbsp;Jingui Li","doi":"10.1016/j.vetpar.2026.110693","DOIUrl":"10.1016/j.vetpar.2026.110693","url":null,"abstract":"<div><div><em>Eimeria tenella</em> (<em>E. tenella</em>)<em>,</em> a pathogenic protozoan parasite, poses a significant threat to the global poultry industry due to its severe impact on intestinal health and growth performance. Given the limitations of conventional anticoccidial drugs, such as the development of drug resistance and chemical residues, it is imperative to explore natural alternative strategies for effective control. In this study, we evaluated the synergistic anti-coccidial effect of pomegranate peel extract (PPE) and Bacillus subtilis (BS). PPE exhibits antioxidant and anti-inflammatory properties, whereas BS, contributes to maintaining intestinal microbial balance. Broiler chickens were challenged with <em>E. tenella</em> and treated with 400 mg/kg PPE in feed and 400 mg/L BS in drinking water, using diclazuril (DIC) as a positive control. The results demonstrated that the PPE+BS combination significantly alleviated cecal lesions, reduced oocyst it mainly parasitizes on the mucosa of the cecum output and mortality, lowered organ indices, suppressed inflammatory responses, and restored body weight gain. The anti-coccidial index (ACI) reached 163, indicating moderate efficacy. Gut microbiota analysis revealed that PPE+BS restored microbial homeostasis by increasing the abundance of Firmicutes, reducing <em>Escherichia coli</em> and <em>Enterococcus</em>, and restoring Micrococcus to levels comparable to uninfected controls. To further explore the potential of the intestinal probiotics, <em>Lactobacillus salivarius</em> (LS) and <em>Lactobacillus curvatus</em> (LC), isolated and identified from chicken feces, achieved comparable anti-coccidial efficacy when combined with PPE, confirming the role of specific probiotics in the observed synergy. In conclusion, the combination of PPE and BS represents an effective and sustainable strategy for controlling avian coccidiosis, primarily through modulation of the gut microbiota and enrichment of beneficial probiotics.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110693"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145967044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Arthrobotrys flagrans concentration, predatory activity, and efficacy in a commercial product","authors":"Maria Vitória Lamóglia Bastos Ferreira ,&nbsp;Edna Barcelos Alves ,&nbsp;Caroline Bittencourt Miranda ,&nbsp;Vanessa Cola Thomazini ,&nbsp;Ricardo Augusto Mendonça Vieira ,&nbsp;Luis Fonseca Matos ,&nbsp;Clóvis de Paula Santos","doi":"10.1016/j.vetpar.2026.110705","DOIUrl":"10.1016/j.vetpar.2026.110705","url":null,"abstract":"<div><div>Gastrointestinal nematodes pose a major threat to livestock health and productivity, and the growing inefficacy of commercial anthelmintics highlights the need for alternative control methods. This study evaluated BioVerm®, a Brazilian commercial product (BCP) based on the nematophagous fungus <em>Arthrobotrys flagrans</em>, using three criteria: chlamydospore count per gram (CCG), predatory activity, and efficacy in reducing infective larvae (L3). CCG was quantified using a Neubauer chamber. Predatory activity was assessed by inoculating <em>Panagrellus</em> spp. in Petri dishes. Efficacy was evaluated through coprocultures treated or not with (BCP), including post-gastrointestinal tract analysis using sheep feces. Three commercial batches were tested. The mean CCG ranged from 8333 to 12,500, significantly below the 5 × 10⁵ spores per gram stated on the label. Fungal growth was observed in only one batch, and high contamination was found in another. No significant reduction in L3 counts was detected in either <em>in vitro</em> or <em>in vivo</em> assays. These results indicate low fungal viability and support the urgent need for quality control measures to ensure BCP efficacy.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110705"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization and validation of a TaqMan real-time PCR for the detection of Heterobilharzia americana in dog feces","authors":"Francis Aduku ,&nbsp;Jody L. Gookin ,&nbsp;Jan S. Suchodolski ,&nbsp;Lea J. Poellmann ,&nbsp;Joe L. Luksovsky ,&nbsp;Guilherme G. Verocai ,&nbsp;Luis Fernando da Costa Medina ,&nbsp;Mike Hong ,&nbsp;Kathleen M. Aicher","doi":"10.1016/j.vetpar.2026.110712","DOIUrl":"10.1016/j.vetpar.2026.110712","url":null,"abstract":"<div><div><em>Heterobilharzia americana</em> is a trematode parasite that causes canine schistosomiasis, a disease capable of causing significant morbidity and mortality in dogs. Reliable diagnosis is essential for limiting disease progression. This study aimed to optimize and validate a previously developed TaqMan qPCR assay for detection of <em>H. americana</em> DNA in feces. The assay targets a highly repetitive non-coding DNA sequence located across multiple loci within the <em>H. americana</em> genome. PCR optimization involved gradient thermocycling and serial dilutions to refine annealing temperature and efficiency. PCR products were cloned and sequenced to confirm target specificity. Analytical sensitivity was assessed using serial two-fold dilutions of <em>H. americana</em> eggs spiked into feces and matrix-free samples, with PCR detection across replicates. Diagnostic sensitivity was assessed in 111 fecal samples from infected dogs using fecal sedimentation as gold standard. Analytical and diagnostic specificities were assessed by testing 54 fecal samples containing non-target parasites and 100 fecal samples from <em>H. americana</em>-uninfected dogs<em>,</em> respectively. Target specificity was confirmed by BLAST. Assay efficiency was 107 %. Matrix-dependent analytical sensitivity was 3 eggs/g feces (100 % replicates) and 1.5 eggs/g feces (60 % replicates); matrix-free sensitivity was 3 eggs/mL in saline. Diagnostic sensitivity was 98.2 % (95 % CI: 93.7–99.8 %). Both analytical and diagnostic specificities were 100 % (95 % CI: 93.6–100 % and 96.4–100 %, respectively). The assay demonstrated low intra-assay and inter-assay variability and minimal inter-operator variability across the dilution range tested. These findings support the optimized TaqMan qPCR assay as a highly sensitive and specific tool for detecting <em>H. americana</em> DNA in dog feces.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110712"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146114347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A recombinant adeno-associated virus expressing Eimeria stiedai HSP70 proteins exhibited a promising efficacy against rabbit coccidiosis","authors":"Chaofan Li ,&nbsp;Chuanmin Li ,&nbsp;Yahuan Li ,&nbsp;Zhenzhen Liu,&nbsp;Xu Zhang,&nbsp;Hongyu Wang,&nbsp;Pengtao Gong,&nbsp;Nan Zhang,&nbsp;He Li,&nbsp;Xin Li,&nbsp;Jianhua Li,&nbsp;Xiaocen Wang","doi":"10.1016/j.vetpar.2026.110692","DOIUrl":"10.1016/j.vetpar.2026.110692","url":null,"abstract":"<div><div><em>Eimeria stiedai</em> is a critical protozoan that colonizes in rabbit hepatocytes and cholangiocytes, causing severe hepatic coccidiosis and substantial economic loss in the rabbit industry. However, there are no effective vaccines against <em>E. stiedai</em> infection. In this study, the recombinant <em>E. stiedai</em> heat shock protein 70 (r<em>Es</em>HSP70) was produced via a prokaryotic expression system, and its polyclonal antibody was prepared. Immunofluorescence analysis demonstrated that <em>Es</em>HSP70 localized predominantly in the cytoplasm and enriched around the nucleus of sporozoites, while in merozoites it was distributed in the cytoplasm, displaying a peripheral and apical distribution pattern. Functional blocking assays demonstrated that anti-<em>Es</em>HSP70 polyclonal antibody significantly inhibited sporozoites invasion in primary rabbit hepatocytes, suggesting a potential role for <em>Es</em>HSP70 in this process. Furthermore, a recombinant adeno-associated virus serotype 9-ZsGreen1 expressing <em>Es</em>HSP70 (rAAV-ZsGreen1-<em>Es</em>HSP70) was successfully packaged and purified. The recombinant virus particles was observed by transmission electron microscopy (TEM) as 20 nm hexagonal structures, with a titer exceeding 1.0 × 10¹³ vg/mL. The recombinant viruses could infect 293 T cells and express EsHSP70 proteins. Immunization with recombinant rAAV-ZsGreen1-EsHSP70 significantly elevated the levels of specific IgG antibody, IL-2, IL-10, and IFN-γ, with reduced oocyst shedding by 69.8 %, alleviated liver lesion, resulting in an anticoccidial index (ACI) of 169.48. In conclusion, these results indicated that rAAV-ZsGreen1-<em>Es</em>HSP70 conferred a promising protective efficacy against <em>E. stiedai</em> infection, thereby providing valuable insights for the development of rabbit coccidiosis vaccines.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110692"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proteomic profiling of Ascaridia galli reveals sex- and stage-specific protein signatures","authors":"Anna Sophia Feix ,&nbsp;Maibritt Mardahl ,&nbsp;Johan Palmfeldt ,&nbsp;Rikke Brødsgaard Kjærup ,&nbsp;Tina Sørensen Dalgaard","doi":"10.1016/j.vetpar.2026.110707","DOIUrl":"10.1016/j.vetpar.2026.110707","url":null,"abstract":"<div><div><em>Ascaridia galli</em> is one of the most prevalent intestinal nematodes of domesticated chickens and the primary cause of avian ascaridiasis, a globally important disease in poultry production. Infection rates often reach 70–90 % in free-range systems due to its direct life cycle and efficient environmental transmission. Despite its impact, the molecular mechanisms governing <em>A. galli</em> host-parasite interactions remain poorly understood. <em>A. galli</em> belongs to Clade III nematodes, which include several species of major veterinary importance. Comparative genomic studies Clade III-nematodes have revealed expansions in gene families associated with key parasitic traits such as immune modulation, tissue migration, and adaptation to host environments. Proteomics provides a powerful approach for characterizing these processes by identifying proteins essential for development, metabolism, reproduction, and host interaction. However, current knowledge is based almost exclusively on mammalian-infecting species, and no developmental proteome has previously been mapped for <em>A. galli.</em> By profiling protein expression across life stages, this study produces the first proteomic dataset for <em>A. galli</em>. In total, 852 worm proteins were identified. Of these, 452 proteins were shared across female adults, male adults, and larvae, while each group also displayed distinct protein sets. Male worms shared a substantial subset of 327 proteins with females but not larvae, while larvae and females shared 18 proteins. These findings demonstrate that protein expression in parasitic nematodes is strongly sex-specific, with males typically expressing proteins linked to spermatogenesis and motility, and females expressing vitellogenins and lipid-binding proteins.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110707"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing in vitro cultivation of Haemonchus contortus larvae: Comparative assessment of growth conditions","authors":"Kyriánová Iveta Angela ,&nbsp;Bieliková Lucia ,&nbsp;Pytelková Jana ,&nbsp;Pachulová Klára ,&nbsp;Vacek Vojtěch ,&nbsp;Fišerová Natálie ,&nbsp;Vadlejch Jaroslav ,&nbsp;Dvořák Jan","doi":"10.1016/j.vetpar.2026.110711","DOIUrl":"10.1016/j.vetpar.2026.110711","url":null,"abstract":"<div><div><em>Haemonchus contortus,</em> a highly pathogenic nematode of small ruminants, causes substantial economic losses worldwide. The transition from the infective third-stage larva (L₃) to the metabolically active fourth-stage larva (L₄) is critical for parasite survival, as L₄ larvae initiate blood-feeding within the host. This study aimed to optimize <em>in vitro</em> cultivation conditions for L₄ larvae and evaluate their metabolic activity, providing a basis for future research on parasite biology and anthelmintic development. We systematically tested six culture media (BME, DMEM, IMDM, RPMI 1640, M199, LB broth; LB without FBS) supplemented with antibiotics including gentamicin (significantly improved L₄ development: 85 % vs 70 % without, p &lt; 0.05) to determine optimal L₃-to-L₄ conditions. Larval survival was assessed by motility under inverted microscopy; L₄ development by exsheathment, body thickening (600–800 μm), and genital primordium visibility. To assess metabolic status, we probed proteolytic activity, which represents a key function of blood-feeding larvae. A fluorogenic peptide substrate was employed to detect significant cysteine protease activity, serving as a marker of a competent digestive system. These findings establish a refined methodology for <em>in vitro</em> cultivation of L₄ larvae and highlight their suitability for functional studies and drug screening. By optimizing culture conditions and demonstrating active proteolysis, this study provides a valuable platform for investigating stage-specific parasite biology and identifying novel therapeutic targets.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110711"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of an indirect ELISA and an immunochromatographic test method for early detection of Haemonchus contortus infection in sheep","authors":"Xueqiu Chen ,&nbsp;Lingyun Mou ,&nbsp;Manqin Deng ,&nbsp;Jingju Zhang ,&nbsp;Jiaming Yu ,&nbsp;Jianfang Li ,&nbsp;Hongli Zhang ,&nbsp;Guangxu Ma ,&nbsp;Yi Yang ,&nbsp;Aifang Du","doi":"10.1016/j.vetpar.2026.110703","DOIUrl":"10.1016/j.vetpar.2026.110703","url":null,"abstract":"<div><div>Haemonchosis, caused by the parasitic nematode <em>Haemonchus contortus</em>, poses a significant global threat to small ruminant health and productivity. Current diagnostic methods, such as fecal egg flotation, cannot detect early-stage or latent infections, hindering timely intervention. Building on prior identification of the secreted BPTI/Kunitz inhibitor domain-containing protein SPI-I8 as a key <em>H. contortus</em> antigen released during initial infection, we developed two diagnostic methods using recombinant <em>Hc</em>-SPI-I8B (r<em>Hc</em>-SPI-I8B). First, an indirect ELISA with r<em>Hc</em>-SPI-I8B as the coating antigen demonstrated detection of <em>H. contortus</em> infection in sheep as early as 10 days post-infection (dpi), with a sensitivity of 1:200. Concurrently, an immunochromatographic test (ICT) was established by conjugating r<em>Hc</em>-SPI-I8B with 20 nm gold particles, achieving a sensitivity of 1:40, detecting antibodies at 11 dpi, and remaining effective beyond 100 dpi. Both methods exhibited high specificity, showing no cross-reactivity with positive sera of <em>Echinococcus granulosus</em>, <em>Fasciola hepatica</em>, or <em>Fasciola gigantica</em>. Additionally, they showed high stability and reproducibility (inter-/intra-assay CV &lt;10 % for ELISA). Both approaches provide efficient tools for early diagnosis of haemonchosis.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110703"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to \"Development of a novel multiplex PCR assay for the specific identification of Toxocara canis, Toxocara cati and Toxascaris leonina in dogs and cats\" [Vet. Parasitol. 343 (2026) 110709].","authors":"Xiaoqing Ding, Shaobing Wan, Junting Yu, Pei Zhou, Shoujun Li","doi":"10.1016/j.vetpar.2026.110754","DOIUrl":"https://doi.org/10.1016/j.vetpar.2026.110754","url":null,"abstract":"","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":" ","pages":"110754"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147610194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fasciola gigantica: Ultrastructure and cytochemistry of tegumental secretory activity and extracellular vesicle formation in juvenile flukes migrating in mouse liver","authors":"R.E.B. Hanna ,&nbsp;G.P. Brennan ,&nbsp;M.W. Robinson ,&nbsp;P.-E. Kajugu ,&nbsp;J.M. Quinn ,&nbsp;C.E. Bennett","doi":"10.1016/j.vetpar.2026.110694","DOIUrl":"10.1016/j.vetpar.2026.110694","url":null,"abstract":"<div><div><em>Fasciola gigantica</em>, the predominant cause of fasciolosis in tropical regions, is a major cause of economic loss to the global farming community and is also recognised as a significant human pathogen. The surface tegument of the fluke, situated as it is at the host-parasite interface, is a metabolically active and highly dynamic secretory organ mainly concerned with ensuring the survival of the parasite in a hostile immunological and physiochemical environment. The period of migration of the juvenile fluke through the hepatic parenchyma of the host is critical in establishing a mutually sustainable host-parasite relationship, but due to technical difficulties has been inadequately investigated. Here, the tegument of migrating juvenile <em>F. gigantica</em> collected from the hepatic parenchyma of experimentally infected mice 4 and 7 weeks after infection was examined by conventional transmission electron microscopy (TEM) and by cytochemistry using the periodic acid-thiocarbohydrazine-osmium (PATCO) and Ruthenium Red methods. T1 secretory bodies in the surface syncytium maintain the surface glycocalyx by exocytosis in response to sloughing of immunocomplex as the fluke encounters the effectors of host immunity. Their bounding plasma membranes engender a superficial zone of microvilli which appear to give rise to detached tubules and extracellular vesicles. These may have a role in host-parasite communication and immunomodulation. T2 secretory bodies in the tegument contain stable glycoprotein, and their main contribution may be to preadapt the apical surface for changes in the physicochemical environment when the fluke enters the bile ducts. A novel type of tegumental cell, termed T3, has been described in the sub-syncytial zone. T3 secretory bodies may contribute to the syncytial proteome or spine formation in the growing juvenile flukes. The surface secretory activity in migrating juvenile flukes may offer a battery of stage-specific soluble and membrane-associated molecular products with potential for therapeutic exploitation.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110694"},"PeriodicalIF":2.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}