Veterinary parasitology最新文献

{"title":"Failure of doramectin and ivermectin in preventing Cochliomyia hominivorax myiasis in a subtropical region: A pharmacokinetic-pharmacodynamic study.","authors":"Sebastián Muchiut, María Victoria Miró, Oscar Anziani, Santiago Nava, Adrián Lifschitz","doi":"10.1016/j.vetpar.2024.110384","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110384","url":null,"abstract":"<p><p>The aim of this work is to present a case study where the failure of IVM 3.15 % and DRM 1 % to prevent natural infestations of C. hominivorax larvae in Argentina is investigated based on field efficacy tests and a pharmacokinetic and pharmacodynamic analysis. Thirty male crossbred Braford calves were randomly assigned to three experimental groups (n = 10), the IVM 3.15 % group (subcutaneously at 630 µg/kg), the DRM 1 % group (subcutaneously at 200 µg/kg) and the control group (saline solution subcutaneously). All treatments were performed at the time of castration surgery through a scrotal incision, and the wounds were exposed to natural infestations of C. hominivorax. Wound inspections were carried out on days 3, 6, and 13 post-treatments. Jugular blood samples were taken from experimental animals at 3- and 6-days post-treatment. In presence of C. hominivorax larvae, samples of both the larvae and wound secretions were collected in plastic vials on days 3 and 6 to measure concentrations of both drugs by high-performance liquid chromatography. On day 3 post-treatment, active myiasis was observed in 9 animals from the control group, 5 from the IVM 3.15 % group, and 6 from the DRM 1 % group. On day 6 post-treatment, 5 and 3 new myiasis were detected in the IVM 3.15 % and DRM 1 % group, respectively. No larvae were observed in the wounds on day 13 post-treatment. Interestingly, DRM concentrations tended to be higher in larvae compared to IVM on day 3 post-treatment (p = 0.051), and IVM plasma concentrations tended to be higher than those measured for DRM on day 6 (p = 0.087). There was a very strong correlation between DRM and IVM concentrations in plasma and wound secretions and larvae. The uptake of DRM from wound secretions to larvae was 83 % greater than that of IVM (p = 0.03). The results of this trial suggest the presence of C. hominivorax resistance to DRM and highlight concern about the lack of effectiveness of IVM 3.15 % in preventing C. hominivorax infestations.</p>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110384"},"PeriodicalIF":2.0,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142903564","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 national survey of the gastrointestinal nematode control practices used by goat producers in the United States.","authors":"Ryan H Avery, Natalie J Urie, Matthew A Branan, Alyson M Wiedenheft, Elliott Dennis, Katherine L Marshall, Joan M Burke, James E Miller","doi":"10.1016/j.vetpar.2024.110375","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110375","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Gastrointestinal nematode (GIN) parasites are a major constraint to goat production. GIN parasite control has relied primarily on the use of anthelmintic drugs. A major issue in goat operations globally, including in the United States (U.S.), is that GIN populations have developed widespread resistance to current anthelmintic drugs. Widespread anthelmintic resistance is a major concern to U.S. goat producers, but there currently remains limited information on what goat production practices are used nationally to combat GIN infections and prevent anthelmintic resistance. The current practices used by goat producers to control GIN parasites and reduce anthelmintic resistance on their operations were evaluated as part of the 2019 National Animal Health Monitoring System (NAHMS) study, which was conducted by the U.S. Department of Agriculture (USDA). The study aims were to determine GIN parasite burden at both the individual animal- and operation-level, investigate geographic patterns of GIN parasitism, and identify risk factors associated with infection prevalence and intensity. The study covered 24 U.S. states, representing 80.4 % of U.S. goats on operations with ≥ 5 goats and 75.8 % of operations with ≥ 5 goats. Data from fecal samples submitted for fecal egg count (FEC) analysis and individual goat- and operation-level questionnaires were collected from 9879 goats across 623 operations. The estimated, weighted mean operation- and animal-level FEC for goats was 658 and 651 eggs per gram, respectively. Across all goats tested, parasite burden was found to be over-dispersed, with the top 24.1 % of animals contributing to 80 % of the total FEC. Geographically, lungworm prevalence was significantly lower in the Southwest region compared with the Northeast, Northwest, and Southeast regions. For GIN FEC values, the highest operation-level counts were found in the Northeast and Southeast region, and the highest animal-level counts were found in the Southeast region by univariate analysis and the Northeast and Southeast regions by multiple regression analysis. Univariate analysis revealed that primary operation production type, primary land/facility management type, primary grazing/browsing management, FAMACHA© card usage, body condition categorization, and month of sample collection were significant factors impacting mean FEC at both the operation- and animal-level. U.S. regionality, goat type, breed, FAMACHA© score, and browsing schedule were found to be significant at the animal-level. Multiple regression analysis at the operation-level revealed that deworming frequency in the previous 12 months, pasture housing practices, and the interaction between region and sample collection date were significant factors that impacted the mean FEC. Multiple regression analysis at the animal-level revealed that goat type, FAMACHA© score, body condition categorization, primary grazing/browsing management, primary operation production type, the interaction betwe","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110375"},"PeriodicalIF":2.0,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142932737","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":"Occurrence and risk factors of equine piroplasmosis in Portugal: A five-year retrospective study.","authors":"Ana Cabete, Ângela Xufre, Ludovina Padre, Elisa Bettencourt, Telmo Nunes, Jacinto Gomes","doi":"10.1016/j.vetpar.2024.110378","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110378","url":null,"abstract":"<p><p>Equine piroplasmosis (EP) is a tick-borne disease of equids caused by Theileria equi, Theileria haneyi, and Babesia caballi. EP is endemic in most tropical and subtropical regions worldwide, and there is a likelihood that it is also endemic in Portugal. This retrospective study aimed to determine the seroprevalence, prevalence, and potential risk factors of EP in our country over the past five years. A total of 3063 diagnostic test records were analysed. Results from the competitive enzyme-linked immunosorbent assay (cELISA) revealed a seroprevalence of 32.7 % and 15.7 % for T. equi and B. caballi, respectively, with a coinfection rate of 7.4 %. For the indirect fluorescent antibody test (IFAT), 38.8 % of the samples were positive for T. equi, 45.7 % for B. caballi, and 23.1 % for both parasites. Prevalence determined using quantitative polymerase chain reaction (qPCR) showed 40.5 % T. equi-positive cases, 8.3 % B. caballi-positive cases, and 3.2 % mixed infections in the studied population. Considering risk factors, age and season appear to be associated with higher seropositivity, and location was also found to play a significant role. This study represents the first retrospective analysis carried out in Portugal, confirming the endemicity of EP in the country. Further studies are needed to corroborate our findings, to determine actual prevalence and seroprevalence in the Portuguese general equine population, and to identify risk factors better, helping breeders and owners to minimise the health and economic impact of EP.</p>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110378"},"PeriodicalIF":2.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142898383","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":"Effects of a laminarin-rich algal extract on caecal microbiota composition, leukocyte counts, parasite specific immune responses and growth rate during Eimeria tenella infection of broiler chickens.","authors":"Malin Boyner, Emma Ivarsson, Alma Hansen, Anna Lundén, Osama Ibrahim, Robert Söderlund, Gunnar Cervin, Henrik Pavia, Eva Wattrang","doi":"10.1016/j.vetpar.2024.110377","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110377","url":null,"abstract":"<p><p>Coccidiosis, infection with protozoan parasites of genus Eimeria, is a major problem in poultry husbandry world-wide. The disease is currently managed by coccidiostats and live vaccines, but these approaches are not sustainable. Hence, it is important to identify new means to control the infection and/or ameliorate its detrimental effects on gut health. Laminarin, a β-glucan found in marine brown algae, has prebiotic and bioactive properties that could be beneficial in coccidiosis control. The present study aimed to examine the potential of laminarin as an immunostimulatory and microbiota-regulatory compound in broiler chickens infected with E. tenella. Chickens were continuously fed a diet supplemented with a laminarin-rich algal extract (AE) from first feed and subsequently infected with E. tenella at 19 days old. The outcome of infection including caecal microbiota and some immune parameters were monitored during the experiment. Results showed that AE supplementation affected some lymphocyte subpopulations, with increased numbers of TCRγ/δ+CD8-, B-cells and CD4-CD8αβ+ cells and lower numbers of CD4+CD8αα+ cells in blood and increased proportions of CD4-CD8αβ+ spleen cells compared to those in control chickens. The AE diet did not affect parasite excretion, lesion scores or E. tenella specific T-cell responses. However, reductions of E. tenella induced contraction of Bifidobacteriaceae and expansion of Clostridiaceae in caecal microbiota were observed for AE fed chickens compared to chickens fed the control diet. Thus, AE feed supplementation induced some immunostimulatory activity in chickens and affected some of the alterations in caecal microbiota evoked by E. tenella infection.</p>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110377"},"PeriodicalIF":2.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142878204","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":"Profiling host- and parasite-derived miRNAs associated with Strongylus vulgaris infection in horses.","authors":"Katrine Toft, Marie Louise Honoré, Nichol Ripley, Martin K Nielsen, Maibritt Mardahl, Bastian Fromm, Ylva Hedberg-Alm, Eva Tydén, Lise N Nielsen, Peter Nejsum, Stig Milan Thamsborg, Susanna Cirera, Tina Holberg Pihl","doi":"10.1016/j.vetpar.2024.110379","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110379","url":null,"abstract":"<p><p>The equine bloodworm, Strongylus vulgaris, is a common and highly pathogenic parasite in horses due to its migratory life cycle involving the intestinal arteries. Current diagnostic techniques cannot detect the prepatent migrating stages of S. vulgaris, highlighting the need for new biomarkers. Parasites release microRNAs (miRNAs) into their environment, which could potentially be detectable in host blood samples. Additionally, host miRNA expression patterns may change in response to infection. This study aimed to identify miRNAs associated with S. vulgaris infection by profiling the horse's miRNA response in the larval predilection site, the Cranial Mesenteric Artery (CMA) and examining the circulating parasite and horse-derived miRNAs in plasma of S. vulgaris-infected horses. Plasma samples were collected from 27 horses naturally infected with S. vulgaris and 28 uninfected horses. Arterial tissue samples from the CMA and Aorta were collected from a subset (n = 12) of the infected horses. Small RNA sequencing (small RNAseq) of a subset of the plasma samples (n = 12) identified miRNAs of interest, followed by quantitative real-time PCR (qPCR) evaluation of selected miRNAs in plasma from a larger cohort of horses. Small RNAseq detected 138 parasite-derived and 533 horse-derived miRNAs in the plasma samples. No difference in parasite-derived miRNA abundance was found between the infected and uninfected horses, but 140 horse-derived miRNAs were significantly differentially abundant between the two groups. When evaluated by qPCR, none of the selected parasite-derived miRNAs were detectable in plasma, but seven horse-derived miRNAs were confirmed differentially abundant in plasma between the two groups. Seven horse-derived miRNAs were differentially expressed in CMA tissue affected by migrating S. vulgaris compared with unaffected aortic tissue, with Eca-Mir-223-3p (Log2FC: 4.74) and Eca-Mir-140-3p (Log2FC: -3.64) being most differentially expressed. A receiver operating characteristic curve analysis suggested that Eca-Mir-486-5p and Eca-Mir-140-3p had the best diagnostic performance for distinguishing between infected and uninfected horses, with areas under the curve (AUC) of 0.78 and 0.77, respectively. Notably, Eca-Mir-140-3p was associated with age, and correcting for interaction with age increased the AUC to 0.96. In conclusion, several horse-derived miRNAs were associated with S. vulgaris infection and could differentiate between infected and uninfected horses based on their plasma abundance. However, the levels of these miRNAs were influenced by other factors (i.e age, breed), complicating their use as biomarkers. Parasite-derived miRNA abundance did not differ between S. vulgaris infected horses and those infected with other parasites using small RNAseq and were below detection limits of qPCR.</p>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110379"},"PeriodicalIF":2.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142898394","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 the transmission of Anaplasma marginale by Amblyomma tonelliae.","authors":"Matilde Nahime Mazzucco Panizza, Evelina Luisa Tarragona, Patrick Stephan Sebastian, Fernando Sebastian Flores, Atilio José Mangold, Santiago Nava","doi":"10.1016/j.vetpar.2024.110380","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110380","url":null,"abstract":"<p><p>This study aimed to evaluate A. marginale transstadial (TST) and transovarial transmission (TOT) by Amblyomma tonelliae through vector competence assays and analysis of natural infection in free-living ticks. This three-host tick species was chosen as model because it is a usual parasite of cattle in all their parasitic stages, making them potential vectors through TST or TOT. Experiment 1 was performed to evaluate TST of A. marginale field strains and M1 strain, and the experiment 2 to evaluate TST and TOT of A. marginale S1P strain from an experimentally acutely infected calf. Free-living larvae, nymphs and adults of A. tonelliae were analyzed to evaluate natural infection with A. marginale. One nymph pool of the experiment 2 resulted positive (minimum infection rate of 1.25 %). However, the negative results of both vector competence assays and the molecular analysis of free-living ticks indicate that the transmission of A. marginale by A. tonelliae would not occur. This finding aligns with three of the four existing studies on the TST and TOT of A. marginale by ticks of the Amblyomma genus.</p>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110380"},"PeriodicalIF":2.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142872858","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 deep learning-based mobile application for the identification of Coccidia species in pigs using microscopic images.","authors":"Naseeb Singh, Vijay Mahore, Meena Das, Simardeep Kaur, Surabhi Basumatary, Naphi Roi Shadap","doi":"10.1016/j.vetpar.2024.110376","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110376","url":null,"abstract":"<p><p>Coccidiosis is a gastrointestinal parasitic disease caused by different species of Eimeria and Isospora, poses a significant threat to pig farming, leading to substantial economic losses attributed to reduced growth rates, poor feed conversion, increased mortality rates, and the expense of treatment. Traditional methods for identifying Coccidia species in pigs rely on fecal examination and microscopic analysis, necessitating expert personnel for accurate species identification. To address this need, a deep learning-based mobile application capable of automatically identifying different species of Eimeria and Isospora was developed. The present study focused on six species, namely, E. debliecki, E. perminuta, E. porci, E. spinosa, E. suis, and Isospora suis, commonly found in pigs of the North Eastern Hill (NEH) region of India. Utilizing a two-stage approach, segmentation of coccidia oocysts in microscopic images using convolutional neural networks (CNNs), followed by species identification by same network was carried out in this work. Resource-efficient models, including EfficientNetB0, EfficientNetB1, MobileNet, and MobileNetV2, within an encoder-decoder architecture were utilized to extract features. Transfer learning was applied to enhance model accuracy during training. Additionally, a marker-controlled watershed algorithm was implemented to separate touching cells, thus reducing misclassification. The results demonstrate that all the developed models effectively segmented/classified Coccidia species, achieving mean Intersection-over-Union (m-IoU) values exceeding 0.92, with individual class IoU scores above 0.90. MobileNetV2 exhibited the highest m-IoU of 0.95, followed by EfficientNetB1 with an m-IoU of 0.94. For classification, MobileNetV2 demonstrated the highest performance, with accuracy, precision, and recall values of 0.93, 0.96, and 0.96, respectively. EfficientNetB1 yielded an accuracy of 0.91. The developed mobile application, tested on new data, achieved an identification accuracy of 91.0 %. These findings highlight the potential of deep learning-based mobile applications in effectively identifying Coccidia species in pigs, thus, providing a promising solution to mitigate reliance on expert personnel and laborious time-consuming experiments in this domain.</p>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110376"},"PeriodicalIF":2.0,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142830083","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":"Antagonistic activity of Pochonia chlamydosporia against three helminth eggs and characterization of its serine protease.","authors":"Luyao Hao, Fengmiao Zhao, Yuan Guo, Yuan Ma, Zhengyi Li, Wen Wang, Hongliang Luo, Rui Wang","doi":"10.1016/j.vetpar.2024.110374","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110374","url":null,"abstract":"<p><p>To address the economic burden caused by livestock parasitic diseases, particularly gastrointestinal nematodes (GIN) and liver flukes, which are exacerbated by growing anthelmintic resistance, researchers are increasingly focusing on biological control strategies as a promising solution. Among these, the fungus Pochonia chlamydosporia has demonstrated promising helminth control properties. This study explored the potential of P. chlamydosporia in controlling helminth infections by examining its effects on helminth eggs. P. chlamydosporia was cultured on 2 % water agar (WA) plates, and the eggs of three parasite species (Fasciola hepatica, Parascaris spp., and Nematodirus oiratianus) were placed on these plates. The impact of the fungus on the eggs was assessed using light microscopy and scanning electron microscopy (SEM). Eggs were introduced into a liquid medium to stimulate P. chlamydosporia' s predatory activity. The culture filtrate was tested for protease activity and its efficacy against nematode eggs was evaluated. The extracellular alkaline serine protease was purified and characterized through ammonium sulfate precipitation and Sephadex G - 100 chromatography. P. chlamydosporia showed type 1, type 2, and type 3 effects on eggs. (Type 1 effect: physiological and biochemical impact without morphological damage to the eggshell, with visible hyphae adhering to the eggshell; Type 2 effect: lytic effect causing morphological changes in both the embryo and eggshell, without hyphal penetration; Type 3 effect: lytic effect with morphological changes in the embryo and eggshell, along with hyphal penetration and internal egg colonization). Light microscope and SEM observations revealed that P. chlamydosporia destroyed the eggs through mycelial growth, appressoria formation, penetration, and degradation stages. Moreover, the addition of nematode eggs stimulated the secretion of extracellular proteins, including proteases, with induction filtrate showing high ovicidal activity. The molecular mass of the protease was approximately 40 kDa estimated by SDS-PAGE. The optimum activity of the protease was at pH 10 and 60 ℃. The purified protease was highly sensitive to phenylmethyl sulfonyl fluoride (PMSF), indicating it belonged to the serine protease family. The findings suggest that P. chlamydosporia could be an effective biological control agent for helminth diseases in livestock.</p>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110374"},"PeriodicalIF":2.0,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142819466","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":"First report of acute, visceral, fatal toxoplasmosis in a naturally infected calf (Bos taurus).","authors":"Jitender P Dubey, Alan F Julian","doi":"10.1016/j.vetpar.2024.110373","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110373","url":null,"abstract":"<p><p>Cattle are considered resistant to clinical toxoplasmosis and viable Toxoplasma gondii is rarely isolated from bovine tissues. Currently, there is no histologically confirmed case of clinical toxoplasmosis in cattle. Here, the first confirmed case of acute toxoplasmosis in cattle is reported. A calf from New Zealand died of acute toxoplasmosis in 2012. Severe lesions were found in the intestinal mesentery and mesenteric lymph nodes. The mesenteric lymph nodes were edematous, and necrosis affected the entire parenchyma including blood vessels, associated with enormous numbers of tachyzoites. Lesions in liver were inflammatory, affecting periportal areas and central veins. Some hepatocytes were engorged with tachyzoites, and tissue cysts were present in the parenchyma. Focal pneumonitis and nephritis were associated with tachyzoites. Tachyzoites were seen in bronchioles, in renal glomeruli and in renal tubules. Diagnosis was confirmed immunohistochemically using T. gondii specific antibodies, but not Neospora caninum -specific antibodies. The presence of numerous tissue cysts was confirmed by immunohistochemical staining with bradyzoite-specific T. gondii antibodies (BAG1).</p>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110373"},"PeriodicalIF":2.0,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142814469","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":"Inhibition of Neospora caninum activity by niclosamide: Evidence from in vitro and in vivo studies.","authors":"Feixue Liu, Xin Li, Liuzhenxiu Yan, Xu Zhang, Jin Sun, Haitao Su, Lu Li, Sining Chen, Lanbi Gao, Pengtao Gong, Nan Zhang, Xichen Zhang, Jianhua Li, Xiaocen Wang","doi":"10.1016/j.vetpar.2024.110362","DOIUrl":"https://doi.org/10.1016/j.vetpar.2024.110362","url":null,"abstract":"<p><p>Neosporosis caused by Neospora caninum (N. caninum) is one of the main causes of bovine miscarriage, but there are currently no effective drugs or vaccines for treatment and prevention. Our previous works have found that NLRP3 inflammasome activation participated in controlling N. caninum proliferation and niclosamide has been regarded as an NLRP3 inflammasome inducer. This study aimed to evaluate the resistance of niclosamide to N. caninum infection. Niclosamide-mediated NLRP3 inflammasome activation was determined by LDH and ELISA measurement of IL-1β release as a marker for inflammasome activation in a model of N. caninum-infected macrophages. The in vitro antiparasitic effect of niclosamide was further explored in Vero cells by plaque assays, qPCR, and Giemsa staining. The in vivo effects were investigated in N. caninum-infected mice by measuring parasite burden, histopathology, and survival. Results showed that niclosamide partially enhanced macrophage-mediated clearance of N. caninum via the NLRP3 inflammasome activation and displayed direct antiparasitic activity. Plaque assays confirmed significant inhibition of N. caninum growth, and niclosamide effectively reduced cell invasion and intracellular proliferation compared to toltrazuril. In vivo, after niclosamide treatment, the body weight was regained, survival rate was increased, tissue damage was reduced, and parasite burden in tissues was significantly decreased. The numerous vacuole formations were observed in niclosamide-treated N. caninum tachyzoites by electron microscopy. Mitochondrial membrane potential and ATP production of N. caninum tachyzoites were reduced considerably by niclosamide treatment. In conclusion, niclosamide showed strong potential as a therapeutic agent for N. caninum infection, offering a promising treatment option for neosporosis.</p>","PeriodicalId":23716,"journal":{"name":"Veterinary parasitology","volume":"334 ","pages":"110362"},"PeriodicalIF":2.0,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142787228","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}