Pub Date : 2025-12-29DOI: 10.1016/j.vetpar.2025.110684
Xialian Bu , Yulong Liu , Xianqi Peng , Lei Huang , Weisong Ma , Jing Chen , Chen Niu , Xiaofeng Shan , Jiayun Yao
Species of Gyrodactylus are common monogenean ectoparasites infecting both freshwater and marine fish. Their rapid proliferation and high transmissibility make them a serious threat to aquaculture. Current chemical treatments have drawbacks of drug residues and high resistance, requiring the discovery of safe and environmentally friendly alternatives. In this study, anthelmintic efficacy against Gyrodactylus kobayashii of eight herbal medicines was evaluated. One of the components bakuchiol from Psoralea corylifolia showed the best anthelmintic efficacy. The in vitro assays showed a positive correlation between bakuchiol concentrations and the mortality of G. kobayashii, with 100 % mortality at 8 mg/L and 1 h exposure. The in vivo anthelmintic efficiency also exhibited a concentration-dependent relationship, treatment with bakuchiol at 6 mg/L for 48 h resulted in 100 % mortality. The EC50 and EC90 values after 48 h exposure were 2.93 and 5.17 mg/L, respectively. Besides, the result of acute toxicity test showed its safety in goldfish, with the 96 h LC50 value of 45.85 mg/L. Additionally, the results of scanning electron microscopy and transmission electron microscopy showed that bakuchiol induced severe ultrastructural damage to G. kobayashii, including tegument disruption, mitochondria swelling, and myofilaments reduction. Histopathological analysis indicated that G. kobayashii were detached from gills of goldfish after bakuchiol exposure. Overall, these findings demonstrated the potential of bakuchiol as an alternative treatment for controlling gyrodactylid infections.
{"title":"Comparative efficacy of herbal extracts and separately bakuchiol against the monogenean parasite Gyrodactylus kobayashii in goldfish","authors":"Xialian Bu , Yulong Liu , Xianqi Peng , Lei Huang , Weisong Ma , Jing Chen , Chen Niu , Xiaofeng Shan , Jiayun Yao","doi":"10.1016/j.vetpar.2025.110684","DOIUrl":"10.1016/j.vetpar.2025.110684","url":null,"abstract":"<div><div>Species of <em>Gyrodactylus</em> are common monogenean ectoparasites infecting both freshwater and marine fish. Their rapid proliferation and high transmissibility make them a serious threat to aquaculture. Current chemical treatments have drawbacks of drug residues and high resistance, requiring the discovery of safe and environmentally friendly alternatives. In this study, anthelmintic efficacy against <em>Gyrodactylus kobayashii</em> of eight herbal medicines was evaluated. One of the components bakuchiol from <em>Psoralea corylifolia</em> showed the best anthelmintic efficacy. The <em>in vitro</em> assays showed a positive correlation between bakuchiol concentrations and the mortality of <em>G. kobayashii</em>, with 100 % mortality at 8 mg/L and 1 h exposure. The <em>in vivo</em> anthelmintic efficiency also exhibited a concentration-dependent relationship, treatment with bakuchiol at 6 mg/L for 48 h resulted in 100 % mortality. The EC<sub>50</sub> and EC<sub>90</sub> values after 48 h exposure were 2.93 and 5.17 mg/L, respectively. Besides, the result of acute toxicity test showed its safety in goldfish, with the 96 h LC<sub>50</sub> value of 45.85 mg/L. Additionally, the results of scanning electron microscopy and transmission electron microscopy showed that bakuchiol induced severe ultrastructural damage to <em>G. kobayashii</em>, including tegument disruption, mitochondria swelling, and myofilaments reduction. Histopathological analysis indicated that <em>G. kobayashii</em> were detached from gills of goldfish after bakuchiol exposure. Overall, these findings demonstrated the potential of bakuchiol as an alternative treatment for controlling gyrodactylid infections.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"342 ","pages":"Article 110684"},"PeriodicalIF":2.2,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883618","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}
Pub Date : 2025-12-27DOI: 10.1016/j.vetpar.2025.110683
Esma Kozan , Büşra Karpuz Ağören , Mahmut Sinan Erez , Ferhat Fatih Karaman , Mevlüt Akdağ , Mustafa Abdullah Yılmaz , Oguz Cakir , Abbas Tarhan , Esra Küpeli Akkol
The increasing resistance of gastrointestinal nematodes (GINs) to conventional anthelmintic drugs has intensified the search for alternatives. This study evaluated the anthelmintic efficacy of Avena sativa L. seed extracts using in vitro and in silico approaches against GINs of sheep. Aqueous (AS–H₂O) and n-hexane (AS–n-hexane) extracts prepared from A. sativa seeds were tested against GINs using egg hatch and larval motility inhibition assays. Both extracts demonstrated clear dose-dependent ovicidal activity, achieving 100 % egg hatch inhibition at concentrations ≥ 12.5 mg/mL, while lower concentrations (6.25–1.5625 mg/mL) produced partial but substantial inhibition. Nonlinear four-parameter logistic modelling yielded EC₅₀ values of 2.16 mg/mL for AS–H₂O and 3.14 mg/mL for AS–n-hexane, indicating greater ovicidal potency of the aqueous extract. The AS–H₂O extract exhibited superior anthelmintic activity, with a 24 h mortality rate of 81.33 % and an LC₅₀ value of 3.62 mg/mL, compared to 74.66 % and 6.24 mg/mL for the AS–n-hexane extract. LC–MS/MS analysis of AS–H₂O extract identified six phenolic compounds: fumaric acid, (−)-quinic acid, protocatechuic acid, protocatechuic aldehyde, naringenin, and apigenin. Molecular docking revealed strong binding affinities of these compounds—particularly naringenin (−8.4 kcal/mol)—to the colchicine-binding site of β-tubulin, a key antiparasitic target. These findings highlight the potential of A. sativa seed extracts, especially the aqueous form, as natural and sustainable anthelmintic agents for parasite control in livestock.
{"title":"In vitro anthelmintic activity of Avena sativa seed extracts against sheep gastrointestinal nematodes: Phytochemical and in silico insights","authors":"Esma Kozan , Büşra Karpuz Ağören , Mahmut Sinan Erez , Ferhat Fatih Karaman , Mevlüt Akdağ , Mustafa Abdullah Yılmaz , Oguz Cakir , Abbas Tarhan , Esra Küpeli Akkol","doi":"10.1016/j.vetpar.2025.110683","DOIUrl":"10.1016/j.vetpar.2025.110683","url":null,"abstract":"<div><div>The increasing resistance of gastrointestinal nematodes (GINs) to conventional anthelmintic drugs has intensified the search for alternatives. This study evaluated the anthelmintic efficacy of <em>Avena sativa</em> L. seed extracts using <em>in vitro</em> and <em>in silico</em> approaches against GINs of sheep. Aqueous (AS–H₂O) and <em>n</em>-hexane (AS–<em>n</em>-hexane) extracts prepared from <em>A. sativa</em> seeds were tested against GINs using egg hatch and larval motility inhibition assays. Both extracts demonstrated clear dose-dependent ovicidal activity, achieving 100 % egg hatch inhibition at concentrations ≥ 12.5 mg/mL, while lower concentrations (6.25–1.5625 mg/mL) produced partial but substantial inhibition. Nonlinear four-parameter logistic modelling yielded EC₅₀ values of 2.16 mg/mL for AS–H₂O and 3.14 mg/mL for AS–n-hexane, indicating greater ovicidal potency of the aqueous extract. The AS–H₂O extract exhibited superior anthelmintic activity, with a 24 h mortality rate of 81.33 % and an LC₅₀ value of 3.62 mg/mL, compared to 74.66 % and 6.24 mg/mL for the AS–<em>n</em>-hexane extract. LC–MS/MS analysis of AS–H₂O extract identified six phenolic compounds: fumaric acid, (−)-quinic acid, protocatechuic acid, protocatechuic aldehyde, naringenin, and apigenin. Molecular docking revealed strong binding affinities of these compounds—particularly naringenin (−8.4 kcal/mol)—to the colchicine-binding site of β-tubulin, a key antiparasitic target. These findings highlight the potential of <em>A. sativa</em> seed extracts, especially the aqueous form, as natural and sustainable anthelmintic agents for parasite control in livestock.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"343 ","pages":"Article 110683"},"PeriodicalIF":2.2,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915346","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}
The current study aimed to investigate the pharmacokinetic/pharmacodynamic (PK/PD) relationship of five macrocyclic lactone (MLs) formulations, three 1 % formulations (ivermectin, doramectin and moxidectin) and two long-acting 3.15 % products (ivermectin and doramectin), against sheep experimentally infested with resistant Psoroptes ovis under standardized doses. Thirty naïve Merino sheep were experimentally infested and randomly assigned to five treatment groups (n = 6). Baseline mite counts were not used to block animals during group allocation. The three 1 % formulations of ivermectin (IVM), doramectin (DRM), and moxidectin (MXD), were administered off-label at a dose of 0.5–0.6 mg/kg on days 0 and 7, subcutaneously. The long-acting 3.15 % formulations were subcutaneously administered once at their approved doses of 1.05 mg/kg (IVM 3.15 %) and 1.26 mg/kg (DRM 3.15 %). Plasma drug concentrations and mite counts were assessed between 0 and 35 days post-treatment. Conventional 1 % formulations produced higher peak plasma concentrations than long-acting formulations, although the latter showed greater persistence, similar to that observed with repeated MXD 1 %. DRM 1 % showed greater systemic exposure compared to 3.15 % long acting formulations and IVM 1 %. Significant reductions in mite counts were observed by day 7 with DRM 1 %, and by day 14 with IVM 1 % and MXD 1 %. In contrast, long-acting formulations showed delayed responses, with significant reductions only by day 21. Only DRM 1 % and MXD 1 % achieved 100 % efficacy. PK/PD indices established for ML-resistant P. ovis were calculated as the ratio between peak plasma concentration (Cmax) and the minimal inhibitory concentration (MIC) values of 15 and 30 ng/mL (Cmax/MIC), as well as the ratios between the area under the concentration–time curve (AUC) and the same MIC values (AUC/MIC). The Cmax/MIC ratio observed for 1 % formulations were significantly higher compared to those obtained with the long-acting formulations at both MIC levels. For the AUC/MIC parameter, the 1 % formulations exhibited significantly higher values compared to the long-acting formulations for the MIC 30 ng/mL.These findings suggest that both the magnitude and duration of MLs in plasma are critical for efficacy against P. ovis.
{"title":"Integrated pharmacokinetic–pharmacodynamic analysis of macrocyclic lactones in sheep infested with resistant Psoroptes ovis","authors":"Rodolfo Herrera , Victoria Miró , Adrián Lifschitz , Marcela Larroza","doi":"10.1016/j.vetpar.2025.110681","DOIUrl":"10.1016/j.vetpar.2025.110681","url":null,"abstract":"<div><div>The current study aimed to investigate the pharmacokinetic/pharmacodynamic (PK/PD) relationship of five macrocyclic lactone (MLs) formulations, three 1 % formulations (ivermectin, doramectin and moxidectin) and two long-acting 3.15 % products (ivermectin and doramectin), against sheep experimentally infested with resistant <em>Psoroptes ovis</em> under standardized doses. Thirty naïve Merino sheep were experimentally infested and randomly assigned to five treatment groups (n = 6). Baseline mite counts were not used to block animals during group allocation. The three 1 % formulations of ivermectin (IVM), doramectin (DRM), and moxidectin (MXD), were administered off-label at a dose of 0.5–0.6 mg/kg on days 0 and 7, subcutaneously. The long-acting 3.15 % formulations were subcutaneously administered once at their approved doses of 1.05 mg/kg (IVM 3.15 %) and 1.26 mg/kg (DRM 3.15 %). Plasma drug concentrations and mite counts were assessed between 0 and 35 days post-treatment. Conventional 1 % formulations produced higher peak plasma concentrations than long-acting formulations, although the latter showed greater persistence, similar to that observed with repeated MXD 1 %. DRM 1 % showed greater systemic exposure compared to 3.15 % long acting formulations and IVM 1 %. Significant reductions in mite counts were observed by day 7 with DRM 1 %, and by day 14 with IVM 1 % and MXD 1 %. In contrast, long-acting formulations showed delayed responses, with significant reductions only by day 21. Only DRM 1 % and MXD 1 % achieved 100 % efficacy. PK/PD indices established for ML-resistant <em>P. ovis</em> were calculated as the ratio between peak plasma concentration (Cmax) and the minimal inhibitory concentration (MIC) values of 15 and 30 ng/mL (Cmax/MIC), as well as the ratios between the area under the concentration–time curve (AUC) and the same MIC values (AUC/MIC). The Cmax/MIC ratio observed for 1 % formulations were significantly higher compared to those obtained with the long-acting formulations at both MIC levels. For the AUC/MIC parameter, the 1 % formulations exhibited significantly higher values compared to the long-acting formulations for the MIC 30 ng/mL.These findings suggest that both the magnitude and duration of MLs in plasma are critical for efficacy against <em>P. ovis</em>.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"342 ","pages":"Article 110681"},"PeriodicalIF":2.2,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145865844","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}
Pub Date : 2025-12-23DOI: 10.1016/j.vetpar.2025.110680
Maria Carolina A. Serpa , Jonas Moraes-Filho , Isabella P. Pesenato , Gabrielle R. de Andrade , Thiago F. Martins , Igor S. Silito , Lina C. Binder , Marcos Amaku , Marcelo B. Labruna
Rhipicephalus linnaei is the most important tick infesting dogs in urban areas of many tropical and subtropical regions of the world, where it can complete its life cycle within human dwellings. This study evaluated the role of veterinary facilities (hospitals, clinics, pet shops) and green areas (parks, public squares) as sources of dispersal of R. linnaei to households. During February 2021-September 2023, we visited 34 veterinary facilities and 51 green areas within São Paulo city. In each facility we inspected the internal premises (waiting/reception, inpatient and exam rooms) for the presence of ticks in cracks, holes and crevices in the structures. When ticks were found, they were collected and taken to laboratory for identification and molecular testing for Ehrlichia canis. Epidemiological information was obtained from each facility via a questionnaire. In the 51 green areas, all with high daily frequency of visiting dogs, the search for ticks was carried out by cloth dragging (60 min/area) and dry ice traps (10 or 11/area). Overall, 12 (37.5 %) veterinary facilities reported seeing ticks at least once in the premises, and 28 (87.5 %) facilities reported seeing ticks on dogs at least once. During our visits, R. linnaei ticks were found on the premises of five (15.6 %) facilities, significantly associated with the high number of animals treated per day. All developmental stages of R. linnaei (including eggs, ticks at premolting period, ovipositing females, and nymphal exuvia) were found in the veterinary facilities, suggesting that this tick species was able to complete its life cycle within the facility. Ticks from three facilities were found infected by E. canis. In the green areas, ticks were collected from six (11.8 %) areas and were all identified as Amblyomma spp. The results of this study support the hypothesis that veterinary facilities are an important source of acquisition and dispersal of the R. linnaei tick among dogs in urban areas. The results also serve as a basis for invalidating the widespread popular belief that, in urban areas, dogs are infested with ticks only when they frequent green areas.
{"title":"The possibility of the brown dog tick (Rhipicephalus linnaei) dispersing through veterinary facilities in urban areas","authors":"Maria Carolina A. Serpa , Jonas Moraes-Filho , Isabella P. Pesenato , Gabrielle R. de Andrade , Thiago F. Martins , Igor S. Silito , Lina C. Binder , Marcos Amaku , Marcelo B. Labruna","doi":"10.1016/j.vetpar.2025.110680","DOIUrl":"10.1016/j.vetpar.2025.110680","url":null,"abstract":"<div><div><em>Rhipicephalus linnaei</em> is the most important tick infesting dogs in urban areas of many tropical and subtropical regions of the world, where it can complete its life cycle within human dwellings. This study evaluated the role of veterinary facilities (hospitals, clinics, pet shops) and green areas (parks, public squares) as sources of dispersal of <em>R. linnaei</em> to households. During February 2021-September 2023, we visited 34 veterinary facilities and 51 green areas within São Paulo city. In each facility we inspected the internal premises (waiting/reception, inpatient and exam rooms) for the presence of ticks in cracks, holes and crevices in the structures. When ticks were found, they were collected and taken to laboratory for identification and molecular testing for <em>Ehrlichia canis.</em> Epidemiological information was obtained from each facility via a questionnaire. In the 51 green areas, all with high daily frequency of visiting dogs, the search for ticks was carried out by cloth dragging (60 min/area) and dry ice traps (10 or 11/area). Overall, 12 (37.5 %) veterinary facilities reported seeing ticks at least once in the premises, and 28 (87.5 %) facilities reported seeing ticks on dogs at least once. During our visits, <em>R. linnaei</em> ticks were found on the premises of five (15.6 %) facilities, significantly associated with the high number of animals treated per day. All developmental stages of <em>R. linnaei</em> (including eggs, ticks at premolting period, ovipositing females, and nymphal exuvia) were found in the veterinary facilities, suggesting that this tick species was able to complete its life cycle within the facility. Ticks from three facilities were found infected by <em>E. canis.</em> In the green areas, ticks were collected from six (11.8 %) areas and were all identified as <em>Amblyomma</em> spp. The results of this study support the hypothesis that veterinary facilities are an important source of acquisition and dispersal of the <em>R. linnaei</em> tick among dogs in urban areas. The results also serve as a basis for invalidating the widespread popular belief that, in urban areas, dogs are infested with ticks only when they frequent green areas.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"342 ","pages":"Article 110680"},"PeriodicalIF":2.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145879080","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}
Pub Date : 2025-12-23DOI: 10.1016/j.vetpar.2025.110679
Muhammad Farhab , Yu-Guo Yuan
Toxoplasma gondii is an obligate intracellular apicomplexan parasite whose motility, host cell invasion, and egress are powered by a unique actomyosin system. Unlike canonical actins that form stable filaments, T. gondii actin (TgACT1) is highly dynamic, existing predominantly in a monomeric state. This review traces the lifecycle of TgACT1, from nucleation to capping, to elucidate how the parasite harnesses rapid cytoskeletal turnover for gliding motility. This review discusses how TgACT1’s intrinsic properties—including isodesmic polymerization, rapid subunit turnover, and specific amino acid substitutions that confer instability—are complemented by a minimal set of TgACT1-binding proteins (e.g., formins, TgPRF, toxofilin, ADF) to maintain a readily available pool of polymerization-competent monomers. The force for motility is generated by the glideosome, a specialized motor complex where myosin A walks along short, dynamic filaments, translocating adhesins rearward to propel the parasite. Finally, the therapeutic potential of targeting this essential and divergent system is discussed, highlighting the druggability of TgACT1 and the immunogenic properties of key regulators. Understanding the molecular mechanisms of TgACT1 dynamics reveals vulnerabilities that could be exploited for novel anti-parasitic strategies.
{"title":"From nucleation to capping: The lifecycle of an actin filament in Toxoplasma gondii gliding","authors":"Muhammad Farhab , Yu-Guo Yuan","doi":"10.1016/j.vetpar.2025.110679","DOIUrl":"10.1016/j.vetpar.2025.110679","url":null,"abstract":"<div><div><em>Toxoplasma gondii</em> is an obligate intracellular apicomplexan parasite whose motility, host cell invasion, and egress are powered by a unique actomyosin system. Unlike canonical actins that form stable filaments, <em>T. gondii</em> actin (TgACT1) is highly dynamic, existing predominantly in a monomeric state. This review traces the lifecycle of TgACT1, from nucleation to capping, to elucidate how the parasite harnesses rapid cytoskeletal turnover for gliding motility. This review discusses how TgACT1’s intrinsic properties—including isodesmic polymerization, rapid subunit turnover, and specific amino acid substitutions that confer instability—are complemented by a minimal set of TgACT1-binding proteins (e.g., formins, TgPRF, toxofilin, ADF) to maintain a readily available pool of polymerization-competent monomers. The force for motility is generated by the glideosome, a specialized motor complex where myosin A walks along short, dynamic filaments, translocating adhesins rearward to propel the parasite. Finally, the therapeutic potential of targeting this essential and divergent system is discussed, highlighting the druggability of TgACT1 and the immunogenic properties of key regulators. Understanding the molecular mechanisms of TgACT1 dynamics reveals vulnerabilities that could be exploited for novel anti-parasitic strategies.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"342 ","pages":"Article 110679"},"PeriodicalIF":2.2,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840053","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}
The fox tapeworm, Echinococcus multilocularis, is the etiological agent of the severe zoonotic disease alveolar echinococcosis. The Sedimentation and Counting Technique (SCT) has long been considered the gold standard for detecting these worms in the intestines of dead foxes. Several alternative methods, including the Segmental Sedimentation and Counting Technique (SSCT), have been developed, aiming to reduce time of analysis while maintaining high sensitivity. In this study, the performance of the SSCT was first evaluated by comparison with the SCT in the context of E. multilocularis surveillance in three countries and, secondly, a proficiency test scheme was organized to assess the capability of national reference laboratories for parasites in 14 European countries to perform the SSCT. The analysis of 375 small intestines of positive red foxes (Vulpes vulpes) divided in four equal segments showed that combining the second (S2) and fourth (S4) segments achieved the highest sensitivity (99.2 %). Moreover, the same segment combination reached 100 % sensitivity among 11 infected raccoon dogs. The SSCT based on the analysis of the segments pair S4/S2 can therefore be recommended for the diagnosis of E. multilocularis infection in red foxes. For raccoon dogs (Nyctereutes procyonoides), the S4/S2 segments pair analysis also seems highly promising, though additional data are needed. Results from this proficiency test confirm the easy implementation of the method, even in laboratories without routine experience in scraping methods. Overall, this study demonstrates that the SSCT can be considered a simple, rapid, and highly sensitive reference method for post mortem diagnosis of E. multilocularis infection in red foxes, including for large-scale surveillance programs.
{"title":"International multicentre study to validate the Segmental Sedimentation and Counting Technique (SSCT) for the surveillance of Echinococcus multilocularis in red fox","authors":"Gérald Umhang , Fanny Bastien , Christophe Caillot , Gunita Deksne , Jacek Karamon , Rebecca Davidson , Maira Mateusa , Małgorzata Samorek-Pieróg , Azzurra Santoro , Federica Santolamazza , Relja Beck , James O’Shaughnessy , Rebecca P.K.D. Berg , Pikka Jokelainen , Anna Lunden , Pavlo Maksimov , Epp Moks , Marja Isomursu , Antti Oksanen , Ants Tull , Franck Boué","doi":"10.1016/j.vetpar.2025.110678","DOIUrl":"10.1016/j.vetpar.2025.110678","url":null,"abstract":"<div><div>The fox tapeworm, <em>Echinococcus multilocularis,</em> is the etiological agent of the severe zoonotic disease alveolar echinococcosis. The Sedimentation and Counting Technique (SCT) has long been considered the gold standard for detecting these worms in the intestines of dead foxes. Several alternative methods, including the Segmental Sedimentation and Counting Technique (SSCT), have been developed, aiming to reduce time of analysis while maintaining high sensitivity. In this study, the performance of the SSCT was first evaluated by comparison with the SCT in the context of <em>E. multilocularis</em> surveillance in three countries and, secondly, a proficiency test scheme was organized to assess the capability of national reference laboratories for parasites in 14 European countries to perform the SSCT. The analysis of 375 small intestines of positive red foxes (<em>Vulpes vulpes</em>) divided in four equal segments showed that combining the second (S2) and fourth (S4) segments achieved the highest sensitivity (99.2 %). Moreover, the same segment combination reached 100 % sensitivity among 11 infected raccoon dogs. The SSCT based on the analysis of the segments pair S4/S2 can therefore be recommended for the diagnosis of <em>E. multilocularis</em> infection in red foxes. For raccoon dogs (<em>Nyctereutes procyonoides</em>), the S4/S2 segments pair analysis also seems highly promising, though additional data are needed. Results from this proficiency test confirm the easy implementation of the method, even in laboratories without routine experience in scraping methods. Overall, this study demonstrates that the SSCT can be considered a simple, rapid, and highly sensitive reference method for post mortem diagnosis of <em>E. multilocularis</em> infection in red foxes, including for large-scale surveillance programs.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"342 ","pages":"Article 110678"},"PeriodicalIF":2.2,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145834770","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}
Pub Date : 2025-12-15DOI: 10.1016/j.vetpar.2025.110677
Afito Luciano , Yuxin Huo , Sha Tan , Mandie Liu , Yuting Ma , Binta J.J. Jallow , Seydou Fane , Bing Zhang , Fanming Meng
Ticks are responsible for transmitting infectious pathogens of public health and veterinary importance worldwide. Chemosensory perception in ticks constitutes a fundamental pathway in host location and disease transmission. This study aims to analyze the function of the Rhipicephalus microplus microplusin-like protein (MLP) in the perception of volatile organic compounds. To obtain the results, AlphaFold2, Swiss Model, and AlphaFold3 were utilized for protein prediction. UCSF Chimera, AutoDock Vina in Linux, and Discovery Studio Visualizer were employed for docking analyses and interaction visualizations. The GROMACS software in a virtual Linux environment was used for molecular dynamics simulations. Out of 46 volatile molecules selected based on literature and used for docking, the four top compounds were evaluated for their interaction, including squalene with a binding energy of −5.183 kcal/mol, uric acid with −5.169 kcal/mol, beta-ionone with −5.037 kcal/mol, and 2,4-Di-tert-butylphenol with −5.035 kcal/mol. The stability of MLP with the top two compounds, squalene and uric acid, was evaluated through molecular dynamics simulations. The uric acid complex was more stable. It showed lower and more stable root-mean-square deviation (∼2 nm), as well as hydrogen bonding (2–4 bonds), smoother solvent-accessible surface area, and gyration radius profiles. In contrast, the squalene complex showed greater conformational variability, lacking hydrogen bonding. The Gibbs free energy landscape and principal component analysis revealed that squalene had stabilization at the start of the simulation. In contrast, uric acid showed stronger long-term conformational convergence and stabilization by the end of the simulation. This study demonstrated the potential role of microplusin-like protein in recognizing volatile organic compounds. It provides insights into the potential to develop new tick-control strategies.
{"title":"Investigating the olfactory function of microplusin-like proteins in Rhipicephalus microplus through molecular docking and dynamics simulations","authors":"Afito Luciano , Yuxin Huo , Sha Tan , Mandie Liu , Yuting Ma , Binta J.J. Jallow , Seydou Fane , Bing Zhang , Fanming Meng","doi":"10.1016/j.vetpar.2025.110677","DOIUrl":"10.1016/j.vetpar.2025.110677","url":null,"abstract":"<div><div>Ticks are responsible for transmitting infectious pathogens of public health and veterinary importance worldwide. Chemosensory perception in ticks constitutes a fundamental pathway in host location and disease transmission. This study aims to analyze the function of the <em>Rhipicephalus microplus</em> microplusin-like protein (MLP) in the perception of volatile organic compounds. To obtain the results, AlphaFold2, Swiss Model, and AlphaFold3 were utilized for protein prediction. UCSF Chimera, AutoDock Vina in Linux, and Discovery Studio Visualizer were employed for docking analyses and interaction visualizations. The GROMACS software in a virtual Linux environment was used for molecular dynamics simulations. Out of 46 volatile molecules selected based on literature and used for docking, the four top compounds were evaluated for their interaction, including squalene with a binding energy of −5.183 kcal/mol, uric acid with −5.169 kcal/mol, beta-ionone with −5.037 kcal/mol, and 2,4-Di-tert-butylphenol with −5.035 kcal/mol. The stability of MLP with the top two compounds, squalene and uric acid, was evaluated through molecular dynamics simulations. The uric acid complex was more stable. It showed lower and more stable root-mean-square deviation (∼2 nm), as well as hydrogen bonding (2–4 bonds), smoother solvent-accessible surface area, and gyration radius profiles. In contrast, the squalene complex showed greater conformational variability, lacking hydrogen bonding. The Gibbs free energy landscape and principal component analysis revealed that squalene had stabilization at the start of the simulation. In contrast, uric acid showed stronger long-term conformational convergence and stabilization by the end of the simulation. This study demonstrated the potential role of microplusin-like protein in recognizing volatile organic compounds. It provides insights into the potential to develop new tick-control strategies.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"342 ","pages":"Article 110677"},"PeriodicalIF":2.2,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145775672","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}
The infestation of crustacean parasites affects the freshwater and marine fishes, causing retarded growth rate, reduced production, low reproduction, and mass mortality. Fish parasites from the isopod family Aegidae, in recent years, have received increased global attention due to their serious socio-economic, ecological, and welfare consequences in finfish aquaculture. This is particularly true for the buccal-inhabiting genus Alitropus typus, which has emerged as a major parasitic threat to freshwater and brackishwater fish populations across tropical and subtropical regions, adversely affecting the health of both farmed and wild-caught fish. As research on this group increases, so does our understanding of their prevalence, infestation, and morphological characterization. The present review focuses on the infestation, intensity, prevalence, and diversity of A. typus in different fish communities. The biochemical composition of crustaceans and various control strategies, including the use of chemicals, vaccination, and biological treatments, are briefly described and explained. The risk of parasite transmission from the aquaculture enterprises to wild fish populations underscores the urgent need for the initiation of control programmes to safeguard the original endemic fish stocks. The review aims to highlight the advantages of using bacteria as an alternative treatment to eradicate parasites in aquaculture and to show the possible negative environmental impacts of chemical treatments used in fish farming systems. Finally, we also highlight the potential of the bacterial consortium to control parasites in fish farming as it assures health health-promising effect to the fish community due to parasiticidal activity without any side effects.
{"title":"Prevalence, infestation, and morphological characterization of the fish parasitic isopod Alitropus typus","authors":"Kavanat Beerahassan Rajeena , Vadavanath Prabhakaran Vineetha","doi":"10.1016/j.vetpar.2025.110676","DOIUrl":"10.1016/j.vetpar.2025.110676","url":null,"abstract":"<div><div>The infestation of crustacean parasites affects the freshwater and marine fishes, causing retarded growth rate, reduced production, low reproduction, and mass mortality. Fish parasites from the isopod family Aegidae, in recent years, have received increased global attention due to their serious socio-economic, ecological, and welfare consequences in finfish aquaculture. This is particularly true for the buccal-inhabiting genus <em>Alitropus typus</em>, which has emerged as a major parasitic threat to freshwater and brackishwater fish populations across tropical and subtropical regions, adversely affecting the health of both farmed and wild-caught fish. As research on this group increases, so does our understanding of their prevalence, infestation, and morphological characterization. The present review focuses on the infestation, intensity, prevalence, and diversity of <em>A</em>. <em>typus</em> in different fish communities. The biochemical composition of crustaceans and various control strategies, including the use of chemicals, vaccination, and biological treatments, are briefly described and explained. The risk of parasite transmission from the aquaculture enterprises to wild fish populations underscores the urgent need for the initiation of control programmes to safeguard the original endemic fish stocks. The review aims to highlight the advantages of using bacteria as an alternative treatment to eradicate parasites in aquaculture and to show the possible negative environmental impacts of chemical treatments used in fish farming systems. Finally, we also highlight the potential of the bacterial consortium to control parasites in fish farming as it assures health health-promising effect to the fish community due to parasiticidal activity without any side effects.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"342 ","pages":"Article 110676"},"PeriodicalIF":2.2,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145828654","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}
Pub Date : 2025-12-11DOI: 10.1016/j.vetpar.2025.110675
C. Black , S. Pruitt , J. Weisent
Understanding the range and potential spread of tick-borne pathogens is vital for the protection of susceptible animals and humans. Free-roaming feline populations may serve as unique sentinel hosts for tick-borne illnesses because of their high association with human-populated areas and high interface with ticks. Our study analyzed indirect immunofluorescence assay (IFA) of feline serum collected from 2019 to 2020 and 2013–2014). Samples were screened for Ehrlichia spp., Rickettsia spp., and Borrelia spp. Due to the high seroprevalence of Borrelia spp., additional samples were tested over multiple time periods to characterize potential chance. Results demonstrated Borrelia spp. in 41.3 % of the 2019–2020 samples and 9.7 % of the 2013–2014 samples. Generalized linear models were constructed to determine the factors correlated with positive Borrelia spp. cases; however, none of the models were statistically significant for predicting Borrelia spp. infection in free-roaming cats. This novel detection method demonstrated high prevalence of Borrelia spp. likely B. burgdorferi in free-roaming cats in the Eastern Tennessee Valley region of the U.S., an area that has seen significant changes in tick population and human disease in the past 20 years. While the specific role of free-roaming cats as sentinel hosts in disease cycling is still unknown, free-roaming cats may serve as reliable predictors for human infections over time. This study underscores the importance of implementing parasite prevention measures for ectoparasites and vectors in trap-neuter-release facilities and highlights the impact that free-roaming cats may have on vector-borne diseases.
{"title":"Rising seroprevalence of Borrelia spp. in free roaming felines in the eastern Tennessee valley","authors":"C. Black , S. Pruitt , J. Weisent","doi":"10.1016/j.vetpar.2025.110675","DOIUrl":"10.1016/j.vetpar.2025.110675","url":null,"abstract":"<div><div>Understanding the range and potential spread of tick-borne pathogens is vital for the protection of susceptible animals and humans. Free-roaming feline populations may serve as unique sentinel hosts for tick-borne illnesses because of their high association with human-populated areas and high interface with ticks. Our study analyzed indirect immunofluorescence assay (IFA) of feline serum collected from 2019 to 2020 and 2013–2014). Samples were screened for <em>Ehrlichia spp.</em>, <em>Rickettsia</em> spp., and <em>Borrelia</em> spp. Due to the high seroprevalence of <em>Borrelia</em> spp., additional samples were tested over multiple time periods to characterize potential chance. Results demonstrated <em>Borrelia</em> spp. in 41.3 % of the 2019–2020 samples and 9.7 % of the 2013–2014 samples. Generalized linear models were constructed to determine the factors correlated with positive <em>Borrelia</em> spp. cases; however, none of the models were statistically significant for predicting <em>Borrelia</em> spp. infection in free-roaming cats. This novel detection method demonstrated high prevalence of <em>Borrelia</em> spp. likely <em>B. burgdorferi</em> in free-roaming cats in the Eastern Tennessee Valley region of the U.S., an area that has seen significant changes in tick population and human disease in the past 20 years. While the specific role of free-roaming cats as sentinel hosts in disease cycling is still unknown, free-roaming cats may serve as reliable predictors for human infections over time. This study underscores the importance of implementing parasite prevention measures for ectoparasites and vectors in trap-neuter-release facilities and highlights the impact that free-roaming cats may have on vector-borne diseases.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"342 ","pages":"Article 110675"},"PeriodicalIF":2.2,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145782883","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}
Pub Date : 2025-12-08DOI: 10.1016/j.vetpar.2025.110674
Marisa Beatriz da Silva Rocha , Barbara Rauta Avelar , Gabriela Carmelinda Martins dos Santos , Thais Paes Ferreira , Thiago de Sousa Vieira , Gabriela Ferreira de Oliveira , Bruno Toledo Gomes , Guilherme Marcondes Klafke , Thais Ribeiro Correia , Yara Peluso Cid , Fábio Barbour Scott
The objective of this study was to standardize a stall-trial methodology for horses in order to evaluate the pharmacokinetics and efficacy of a 1 % fipronil pour-on formulation against Dermacentor nitens. Brazilian pony breed horses were housed in individual stalls within a covered barn and artificially infested with D. nitens larvae on alternate days from day –31 to –1 before treatment. The animals were treated on day 0 with a fipronil 1 % pour-on at a dose of 1 mg/Kg body weight. To determine the therapeutic efficacy, the number of engorged females naturally detached from control and treated groups was recorded for 29 days after treatment. To evaluate the persistent efficacy, further larvae infestations were performed on days 7, 14 and 21 after treatment and tick counts were recorded until day 50. The determination of fipronil and its metabolite fipronil sulfone concentration in the plasma was performed at times of 0, 4 h and on days 1, 2, 7, 12, 14, 15, 16, 21, 28, and 48 after treatment. The overall acaricidal efficacy was 91.83 % from day 1–29. The persistent efficacy was 99.69; 99.19 and 99.32 % against tick infestation challenges performed on days 7, 14 and 21, respectively. In plasma, the Cmax of fipronil was 0.71 ± 0.30 µg/mL on day 7 and 0.27 ± 0.06 µg/mL for fipronil sulfone on day 21. The implementation of a stall trial with horses enables the evaluation of the effectiveness of acaricides against all life stages of ticks without interference from environmental factors. The observed reduction in the number of detached, engorged ticks indicates that Fipronil 1 % pour-on is effective against all parasitic stages present on the animal: larvae, nymphs, and adults. Therefore, fipronil 1 % pour-on is both therapeutically and preventively effective against D. nitens in horses.
{"title":"Pharmacokinetics of a fipronil pour-on formulation and its efficacy against Dermacentor nitens (Acari: Ixodidae) in horses","authors":"Marisa Beatriz da Silva Rocha , Barbara Rauta Avelar , Gabriela Carmelinda Martins dos Santos , Thais Paes Ferreira , Thiago de Sousa Vieira , Gabriela Ferreira de Oliveira , Bruno Toledo Gomes , Guilherme Marcondes Klafke , Thais Ribeiro Correia , Yara Peluso Cid , Fábio Barbour Scott","doi":"10.1016/j.vetpar.2025.110674","DOIUrl":"10.1016/j.vetpar.2025.110674","url":null,"abstract":"<div><div>The objective of this study was to standardize a stall-trial methodology for horses in order to evaluate the pharmacokinetics and efficacy of a 1 % fipronil pour-on formulation against <em>Dermacentor nitens</em>. Brazilian pony breed horses were housed in individual stalls within a covered barn and artificially infested with <em>D. nitens</em> larvae on alternate days from day –31 to –1 before treatment. The animals were treated on day 0 with a fipronil 1 % pour-on at a dose of 1 mg/Kg body weight. To determine the therapeutic efficacy, the number of engorged females naturally detached from control and treated groups was recorded for 29 days after treatment. To evaluate the persistent efficacy, further larvae infestations were performed on days 7, 14 and 21 after treatment and tick counts were recorded until day 50. The determination of fipronil and its metabolite fipronil sulfone concentration in the plasma was performed at times of 0, 4 h and on days 1, 2, 7, 12, 14, 15, 16, 21, 28, and 48 after treatment. The overall acaricidal efficacy was 91.83 % from day 1–29. The persistent efficacy was 99.69; 99.19 and 99.32 % against tick infestation challenges performed on days 7, 14 and 21, respectively. In plasma, the Cmax of fipronil was 0.71 ± 0.30 µg/mL on day 7 and 0.27 ± 0.06 µg/mL for fipronil sulfone on day 21. The implementation of a stall trial with horses enables the evaluation of the effectiveness of acaricides against all life stages of ticks without interference from environmental factors. The observed reduction in the number of detached, engorged ticks indicates that Fipronil 1 % pour-on is effective against all parasitic stages present on the animal: larvae, nymphs, and adults. Therefore, fipronil 1 % pour-on is both therapeutically and preventively effective against <em>D. nitens</em> in horses.</div></div>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"342 ","pages":"Article 110674"},"PeriodicalIF":2.2,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737273","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}
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