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Romig T, Wassermann M. Echinococcus species in wildlife. Int J Parasitol Parasites Wildl 2024; 23:100913. [PMID: 38405672 PMCID: PMC10884515 DOI: 10.1016/j.ijppaw.2024.100913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/31/2024] [Accepted: 02/01/2024] [Indexed: 02/27/2024]
Abstract
Transmission of Echinococcus spp. in life cycles that involve mainly wildlife is well recognized for those species with small mammals as intermediate hosts (e. g. E. multilocularis), as well as for E. felidis and the 'northern' genotypes of E. canadensis (G8 and G10). In contrast, the remaining taxa of E. granulosus sensu lato are best known for their domestic life cycles, and the numerous wild mammal species (mainly ungulates) that have been recorded with cystic echinococcosis in the past were mainly considered a result of spill-over from the dog-livestock transmission system. This view was challenged with the advent of molecular characterization, allowing discrimination of the metacestodes, although the contribution of wild mammals to various Echinococcus life cycles has remained uncertain for scarcity of wildlife studies. Numerous records of cysts in wild ungulates date back to the 20th century, but cannot with certainty be allocated to the Echinococcus species and genotypes that are recognized today. This means that our current knowledge is largely restricted to studies of the past two decades that kept adding gradually to our concepts of transmission in various geographic regions. In particular, new insights were gathered in the past years on E. granulosus s.l. in wildlife of sub-Saharan Africa, but also on transmission patterns of E. multilocularis in previously neglected regions, e. g. North America. Here, an update is provided on the current state of knowledge on wild mammals as hosts for all Echinococcus species, listing >150 species of wild hosts with references, as well as estimates on their epidemiological impact and our current gaps of knowledge.
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Affiliation(s)
- Thomas Romig
- University of Hohenheim, Parasitology Unit, 70599, Stuttgart, Germany
- University of Hohenheim, Center for Biodiversity and Integrative Taxonomy, 70599, Stuttgart, Germany
| | - Marion Wassermann
- University of Hohenheim, Parasitology Unit, 70599, Stuttgart, Germany
- University of Hohenheim, Center for Biodiversity and Integrative Taxonomy, 70599, Stuttgart, Germany
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Echinococcus multilocularis and Other Taeniid Metacestodes of Muskrats in Luxembourg: Prevalence, Risk Factors, Parasite Reproduction, and Genetic Diversity. Pathogens 2022; 11:pathogens11121414. [PMID: 36558748 PMCID: PMC9781964 DOI: 10.3390/pathogens11121414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/19/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
Muskrats (Ondatra zibethicus) are competent intermediate hosts for Echinococcus multilocularis, are frequently infected with this zoonotic cestode, and have even been proposed as a target species to monitor endemicity levels of this parasite. However, their contribution to maintaining the parasitic lifecycle is still unclear. To obtain data on infection frequency and reproductive potential, 280 muskrats from the Grand Duchy of Luxembourg were examined for cestode larvae in the years 2013−2017. Based on morphological and molecular identification, Echinococcus multilocularis was found at a prevalence of 14.6%. Other metacestodes were Hydatigera kamiyai, with a prevalence of 45.7%, Taenia martis with 8.9%, Taenia polyacantha with 5.0%, and Versteria mustelae, which was found in 0.7% of all muskrats. More than 80% of E. multilocularis-infected muskrats contained fertile metacestodes with a mean number of >300,000 (and up to 1,609,816) protoscoleces, which is by far the highest reproductive potential known from any intermediate host species in Europe. Temporal analysis of E. multilocularis prevalence within the study period (and in comparison with earlier data) strongly indicates a robust increase in the studied area. Host age seemed to be an important risk factor for infection, as well as co-infections with Hydatigera kamiyai. A preference for the right medial lobe of the liver as the location of E. multilocularis metacestode was observed. Intraspecific genetic variation among 89 discrete E. multilocularis metacestodes was non-existent based on 300−1590 bp sections of cox1. This is a stark contrast to H. kamiyai, of which nine haplotypes were found on a short 318 bp section of cox1, resulting in genetic diversity in the small country of Luxembourg at a similar level than previously reported from large stretches of Europe and northern Asia.
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Primary Infection by E. multilocularis Induces Distinct Patterns of Cross Talk between Hepatic Natural Killer T Cells and Regulatory T Cells in Mice. Infect Immun 2022; 90:e0017422. [PMID: 35862712 PMCID: PMC9387288 DOI: 10.1128/iai.00174-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The larval stage of the helminthic cestode Echinococcus multilocularis can inflict tumor-like hepatic lesions that cause the parasitic disease alveolar echinococcosis in humans, with high mortality in untreated patients. Opportunistic properties of the disease have been established based on the increased incidence in immunocompromised patients and mouse models, indicating that an appropriate adaptive immune response is required for the control of the disease. However, cellular interactions and the kinetics of the local hepatic immune responses during the different stages of infection with E. multilocularis remain unknown. In a mouse model of oral infection that mimics the normal infection route in human patients, the networks of the hepatic immune response were assessed using single-cell RNA sequencing (scRNA-seq) of isolated hepatic CD3+ T cells at different infection stages. We observed an early and sustained significant increase in natural killer T (NKT) cells and regulatory T cells (Tregs). Early tumor necrosis factor (TNF)- and integrin-dependent interactions between these two cell types promote the formation of hepatic lesions. At late time points, downregulation of programmed cell death protein 1 (PD-1) and ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1)-dependent signaling suppress the resolution of parasite-induced pathology. The obtained data provide fresh insight into the adaptive immune responses and local regulatory pathways at different infection stages of E. multilocularis in mice.
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Dillon D, Fernández Ajó A, Hunt KE, Buck CL. Investigation of keratinase digestion to improve steroid hormone extraction from diverse keratinous tissues. Gen Comp Endocrinol 2021; 309:113795. [PMID: 33891932 DOI: 10.1016/j.ygcen.2021.113795] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/16/2021] [Accepted: 04/17/2021] [Indexed: 12/29/2022]
Abstract
Monitoring the physiology of wild populations presents many technical challenges. Blood samples, long the gold standard of wildlife endocrinology studies, cannot always be obtained. The validation and use of non-plasma samples to obtain hormone data have greatly improved access to more integrated information about an organism's physiological state. Keratinous tissues like skin, hair, nails, feathers, or baleen store steroid hormones in physiologically relevant concentrations, are stable across decades, and can be used to retrospectively infer physiological state at prior points in time. Most protocols for steroid extraction employ physical pulverization or cutting of the sample, followed by mixing with a solvent. Such methods do produce repeatable and useful data, but low hormone yield and detectability issues can complicate research on small or rare samples. We investigated the use of keratinase, an enzyme that breaks down keratin, to improve the extraction and yield of corticosterone from vertebrate keratin tissues. Corticosterone content of keratinase-digested extracts were compared to non-keratinase extracts for baleen from three species of whale (blue, Balaenoptera musculus; bowhead, Balaena mysticetus; southern right, SRW; Eubalaena australis), shed skin from two reptiles (tegu lizard, Salvator merianae; narrow-headed garter snake, Thamnophis rufipunctatus), hair from arctic ground squirrel (AGS; Urocitellus parryii), feathers from Purple Martins (PUMA; Progne subis), and spines from the short-beaked echidna (Tachyglossus aculeatus). We tested four starting masses (10, 25, 50, 100 mg) for each sample; digestion was most complete in the 10 and 25 mg samples. A corticosterone enzyme immunoassay (EIA) was validated for all keratinase-digested extracts. In all sample types except shed skin from reptiles, keratinase digestion improved hormone yield, with PUMA feathers and blue whale baleen having the greatest increase in apparent corticosterone content (100% and 66% more hormone, respectively). The reptilian shed skin samples did not benefit from keratinase digestion, actually yielding less hormone than controls. With further optimization and refinement, keratinase digestion could greatly improve yield of steroid hormones from various wildlife epidermal tissue types, allowing more efficient use of samples and ultimately improving understanding of the endocrine physiology of wild populations.
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Affiliation(s)
- Danielle Dillon
- Department of Biological Sciences, Northern Arizona University, 617 S. Beaver St., Flagstaff, AZ 86011, USA.
| | - Alejandro Fernández Ajó
- Department of Biological Sciences, Northern Arizona University, 617 S. Beaver St., Flagstaff, AZ 86011, USA; Instituto de Conservación de Ballenas, Capital Federal, O'Higgins 4380, Ciudad Autónoma de Buenos Aires 1429, Argentina
| | - Kathleen E Hunt
- Smithsonian-Mason School of Conservation & Department of Biology, George Mason University, 1500 Remount Rd, Front Royal, VA 22630, USA
| | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, 617 S. Beaver St., Flagstaff, AZ 86011, USA
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Joekel DE, Nur S, Monné Rodriguez J, Kronenberg PA, Kipar A, LeibundGut-Landmann S, Deplazes P. Agranulocytosis leads to intestinal Echinococcus multilocularis oncosphere invasion and hepatic metacestode development in naturally resistant Wistar rats. Parasitology 2021; 148:53-62. [PMID: 33087186 PMCID: PMC11010136 DOI: 10.1017/s0031182020002012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/28/2020] [Accepted: 08/30/2020] [Indexed: 12/12/2022]
Abstract
Susceptibility to Echinococcus multilocularis infection considerably varies among intermediate (mostly rodents) and dead-end host species (e.g. humans and pig), in particular regarding intestinal oncosphere invasion and subsequent hepatic metacestode development. Wistar rats are highly resistant to infection and subsequent diseases upon oral inoculation with E. multilocularis eggs, however, after immunosuppressive treatment with dexamethasone, rats become susceptible. To address the role of the cellular innate immunity, Wistar rats were individually or combined depleted of natural killer (NK) cells, macrophages (MΦ) and granulocytes (polymorphonuclear cells, PMN) prior to E. multilocularis egg inoculation. Although NK cell and MΦ depletion did not alter the resistance status of rats, the majority of PMN-depleted animals developed liver metacestodes within 10 weeks, indicating that PMN are key players in preventing oncosphere migration and/or development in Wistar rats. In vitro studies indicated that resistance is not caused by neutrophil reactive oxygen species or NETosis. Also, light microscopical examinations of the small intestine showed that oral inoculation of E. multilocularis eggs does not elicit a mucosal neutrophil response, suggesting that the interaction of oncospheres and neutrophils may occur after the former have entered the peripheral blood. We suggest to consider granulocytes as mediators of resistance in more resistant species, such as humans.
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Affiliation(s)
- Deborah E. Joekel
- Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland
| | - Selim Nur
- Section of Immunology, Institute of Virology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, 8057Zurich, Switzerland
| | - Josep Monné Rodriguez
- Laboratory for Animal Model Pathology (LAMP), Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 268, 8057Zurich, Switzerland
| | - Philipp A. Kronenberg
- Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Mittelstrasse 43, 3012Bern, Switzerland
| | - Anja Kipar
- Laboratory for Animal Model Pathology (LAMP), Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 268, 8057Zurich, Switzerland
| | - Salomé LeibundGut-Landmann
- Section of Immunology, Institute of Virology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, 8057Zurich, Switzerland
| | - Peter Deplazes
- Institute of Parasitology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland
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Echinococcus granulosus sensu lato and Echinococcus multilocularis: A review. Res Vet Sci 2020; 135:517-522. [PMID: 33246571 DOI: 10.1016/j.rvsc.2020.11.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 11/12/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
Echinococcus spp. have a global distribution and are found on every continent except Antarctica. Infections with these parasites are considered extremely serious, contributing to significant morbidity and mortality in addition to substantial economic losses to the livestock industry. Echinococcus granulosus sensu lato (s.l.) and Echinococcus multilocularis, causing cystic echinococcosis (CE) and alveolar echinococcosis (AE) respectively, are the two main species of interest from a human and veterinary perspective. This review collates the current state-of-the-art understanding of these two parasites within four key areas of relevance to human and veterinary professionals: transmission and epidemiology, clinical signs and pathogenesis, diagnosis, and treatment and prevention. This review should serve as a broad introduction to the most important Echinococcus spp. The reader is advised to seek out specific literature on individual diseases and their causative parasites for a deeper understanding.
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Maksimov P, Isaksson M, Schares G, Romig T, Conraths FJ. Validation of PCR-based protocols for the detection of Echinococcus multilocularis DNA in the final host using the Intestinal Scraping Technique as a reference. Food Waterborne Parasitol 2019; 15:e00044. [PMID: 32095616 PMCID: PMC7034050 DOI: 10.1016/j.fawpar.2019.e00044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 02/24/2019] [Accepted: 02/26/2019] [Indexed: 12/28/2022] Open
Abstract
Oral uptake of infectious Echinococcus multilocularis eggs shed by canids with their faeces may lead to development of alveolar echinococcosis in humans, which is clinically similar to a malignant infiltrative tumor and may be fatal if left untreated. E. multilocularis is therefore regarded as one of the most important and neglected metazoan parasites in the Northern hemisphere. The diagnosis of this tapeworm in the final host plays a key role in the epidemiology of E. multilocularis. The diagnostic performance of a magnetic-capture (MC) DNA extraction protocol in combination with a minor groove-binder real time PCR (MC-MGBqPCR) for the detection of E. multilocularis eggs was determined relative to a highly sensitive variant of the Intestinal Scraping Technique (IST) using faecal samples of foxes. In addition, we compared results obtained by MC-MGBqPCR with those of a previously validated protocol (QIAamp Fast DNA Stool Mini Kit (QT) combined with a TaqMan qPCR). Furthermore, a workflow using the NucleoMagVet DNA extraction kit (NM) in combination with MGBqPCR and TaqMan-qPCR was also included in the comparisons. To estimate the analytical sensitivity, phosphate-buffered saline and fox faecal samples were spiked with different numbers of eggs and tested in defined combinations of DNA extraction and PCR protocols. To assess the diagnostic sensitivity of the different workflows, samples were used that had been collected from the ampulla recti or the rectum of 120 foxes hunted in Brandenburg, Germany. The samples represented five IST categories formed according to the E. multilocularis worm burden of the foxes. For DNA extraction by MC or using two other commercial extraction kits, the supernatants obtained from 3 g of bead-beaten faecal samples were used. The extracted DNAs were then processed in the respective PCR protocols. The MC-MGBqPCR showed the highest diagnostic sensitivity (93%; 95% Confidence Interval (CI): 86–97%) relative to IST. The QT extraction protocol in combination with TaqMan-qPCR had the second highest sensitivity (89%; 95% CI: 80–94%), followed by NM with MGBqPCR (86%; 95% CI: 77–93%) in comparison to IST. The lowest diagnostic sensitivity was found for the NM combined with the TaqMan-qPCR protocol (72%; 95% CI: 62–82%). In conclusion, the MC-MGBqPCR seems to represent a suitable alternative to IST. However, applied to 3 g faecal samples, the less costly QT-TaqMan-qPCR workflow yielded a similar diagnostic sensitivity relative to IST. However, differences between these two workflows were not statistically significant. PCR based protocols can be used for the detection of E. multilocularis in faeces of final hosts after careful validation A DNA capture method seems to represent a suitable alternative to the Intestinal Scraping Technique The QT-TaqMan-qPCR workflow yielded also a similar diagnostic sensitivity relative to the Intestinal Scraping Technique None of the DNA extraction kits was able to remove faecal PCR inhibitors completely
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Affiliation(s)
- P Maksimov
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald-Insel Riems, Germany
| | - M Isaksson
- Department of Virology Immunobiology and Parasitology, National Veterinary Institute, Uppsala, Sweden
| | - G Schares
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald-Insel Riems, Germany
| | - T Romig
- FG Parasitologie 220B, Universität Hohenheim, 70593 Stuttgart, Germany
| | - F J Conraths
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493 Greifswald-Insel Riems, Germany
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Foxp3 + T Regulatory Cells as a Potential Target for Immunotherapy against Primary Infection with Echinococcus multilocularis Eggs. Infect Immun 2018; 86:IAI.00542-18. [PMID: 30037796 PMCID: PMC6204723 DOI: 10.1128/iai.00542-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 07/13/2018] [Indexed: 02/08/2023] Open
Abstract
Alveolar echinococcosis (AE) is a lethal disease caused by infection with the metacestode stage of the helminth Echinococcus multilocularis, which develops into a tumorlike mass in susceptible intermediate hosts. The growth potential of this parasite stage is directly linked to the nature of the surrounding periparasitic immune-mediated processes. In a first step (experiment 1), mice were orally infected with E. multilocularis eggs, to be used for assessing the hepatic expression profiles of 15 selected cytokine and chemokine genes related to acquired immunity from 21 to 120 days postinfection. The early stage of infection in immunocompetent animals was marked by a mixed Th1/Th2 immune response, as characterized by the concomitant presence of gamma interferon (IFN-γ) and interleukin-4 (IL-4) and their related chemokines. At the late stage of AE, the profile extended to a combined tolerogenic mode including Foxp3, IL-10, and transforming growth factor beta (TGF-β) as key components. In a second step (experiment 2), the effect of T regulatory cell (Treg) deficiency on metacestode growth was assessed in E. multilocularis-infected DEREG (depletion of regulatory T cells) mice upon induction of Treg deficiency with diphtheria toxin (DT). The parasite lesions were significantly smaller in the livers of treated mice than in corresponding control groups. Foxp3+ Tregs appear to be one of the key players in immune-regulatory processes favoring metacestode survival by affecting antigen presentation and suppressing Th1-type immune responses. For these reasons, we suggest that affecting Foxp3+ Tregs could offer an attractive target in the development of an immunotherapy against AE.
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Beerli O, Guerra D, Baltrunaite L, Deplazes P, Hegglin D. Microtus arvalis and Arvicola scherman: Key Players in the Echinococcus multilocularis Life Cycle. Front Vet Sci 2017; 4:216. [PMID: 29326950 PMCID: PMC5733337 DOI: 10.3389/fvets.2017.00216] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 11/29/2017] [Indexed: 11/30/2022] Open
Abstract
A broad range of rodent species are described as potential intermediate hosts for Echinococcus multilocularis, a wide-spread zoonotic cestode causing alveolar echinococcosis. However, little is known about the relative contribution of these species for parasite reproduction and the maintenance of its life cycle. In a comparative study in a high endemic region in Zurich, Switzerland, we investigated prevalence rates and fertility of E. multilocularis in the most abundant vole species as well as the predation rate of foxes on these species. To ensure that the fox families had access to different vole species and that these voles were exposed to the same environmental contamination with parasite eggs, we selected eight study plots where at least two rodent species co-occurred. The parasite prevalence in Microtus arvalis [11.0%, confidence intervals (CI) 8.9–13.4] was significantly higher than in Arvicola scherman (5.3%, 3.9–7.1) and Myodes glareolus (3.9%, 2.0–6.7). None of the, only 29 individuals of, Microtus agrestis was infected (0%, 0.0–9.8) and the species was excluded for further analyses. Logistic regression models for the prevalences revealed significant differences between nearby study plots and higher infection rates for females, heavier individuals, and individuals trapped during spring, when the prevalence in M. arvalis peaked up to 65% (CI 50–79) in one plot. Furthermore, we detected significantly higher percentages of fertile infections in M. arvalis and M. glareolus than in A. scherman (OR 11.2 and 6.4, respectively) and a significantly higher protoscolex number in M. glareolus (median 100,000) than in M. arvalis (13,500) and A. scherman (4,290). The most abundant fox prey remains were of the genera Microtus (12.3%, CI 8.4–17.2) and Arvicola (11.5%, 7.7–16.3), whereas Myodes was never recorded as prey (0.0–1.3%). We conclude that M. arvalis and to a lesser extent A. scherman can be regarded as key intermediate hosts in Western and Central European high-endemic regions whereas M. glareolus and M. agrestis play a marginal role. We, therefore, postulate that distribution models of these species could contribute to predict parasite occurrence on a more detailed spatial scale than models of the distribution of foxes which have a very broad and uniform distribution.
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Affiliation(s)
- Olivia Beerli
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
| | - Diogo Guerra
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
| | - Laima Baltrunaite
- Laboratory of Mammalian Ecology, Nature Research Centre, Vilnius, Lithuania
| | - Peter Deplazes
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
| | - Daniel Hegglin
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
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Erickson RL, Browne CA, Lucki I. Hair corticosterone measurement in mouse models of type 1 and type 2 diabetes mellitus. Physiol Behav 2017; 178:166-171. [PMID: 28089708 PMCID: PMC5507747 DOI: 10.1016/j.physbeh.2017.01.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 12/24/2022]
Abstract
In diabetes, glucocorticoid secretion increases secondary to hyperglycemia and is associated with an extensive list of disease complications. Levels of cortisol in humans, or corticosterone in rodents, are usually measured as transitory biomarkers of stress in blood or saliva. Glucocorticoid concentrations accumulate in human or animal hair over weeks and could more accurately measure the cumulative stress burden of diseases like chronic diabetes. In this study, corticosterone levels were measured in hair in verified rodent models of diabetes mellitus. To induce type 1 diabetes, C57BL/6J mice were injected with streptozotocin and blood and hair samples were collected 28days following induction. Leptin receptor deficient (db/db) mice were used as a spontaneous model of type 2 diabetes and blood and hair samples were collected at 8weeks of age, after the development of hyperglycemia and obesity. Corticosterone levels from serum, new growth hair and total growth hair were analyzed using an enzyme immunoassay. Corticosterone levels in new growth hair and serum were significantly elevated in both models of diabetes compared to controls. In contrast, corticosterone levels in old hair growth did not differ significantly between diabetic and non-diabetic animals. Thus, hair removal and sampling of new hair growth was a more sensitive procedure for detecting changes in hair corticosterone levels induced by periods of hyperglycemia lasting for 4weeks in mice. These results validate the use of hair to measure long-term changes in corticosterone induced by diabetes in rodent models. Further studies are now needed to validate the utility of hair cortisol as a tool for measuring the stress burden of individuals with diabetes and for following the effects of long-term medical treatments.
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Affiliation(s)
- Rebecca L Erickson
- University Laboratory Animal Resources, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States; Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Caroline A Browne
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, United States
| | - Irwin Lucki
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, United States.
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Transmission ecology of taeniid larval cestodes in rodents in Sweden, a low endemic area for Echinococcus multilocularis. Parasitology 2017; 144:1041-1051. [PMID: 28274289 DOI: 10.1017/s0031182017000257] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Although local prevalence of Echinococcus multilocularis may be high, this zoonotic parasite has an overall low prevalence in foxes and rodents in Sweden. To better understand opportunities for E. multilocularis transmission in the Swedish environment, the aim of this study was to investigate other taeniid cestodes and to relate observed patterns to E. multilocularis. Cestode parasites were examined in fox feces and rodents caught in different habitats from four regions of Sweden. Arvicola amphibius and Microtus agrestis were parasitized with Versteria mustelae, Hydatigera taeniaeformis s. l., and E. multilocularis, whereas Myodes glareolus and Apodemus spp. were parasitized with V. mustelae, Taenia polyacantha, H. taeniaeformis s.l., and Mesocestoides spp. Rodents caught in field habitat (Ar. amphibius, Mi. agrestis) were more likely (OR 10, 95% CI 5-19) to be parasitized than rodents caught in forest habitat (My. glareolus, Apodemus spp.). The parasite preference for each rodent species was present regardless of the type of background contamination from fox feces. These results further support the importance of both ecological barriers and individual species susceptibility in parasite transmission, and indicate that future monitoring for E. multilocularis in the Swedish environment should focus in field habitats where Mi. agrestis and Ar. amphibius are abundant.
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Joekel DE, Deplazes P. Optimized dexamethasone immunosuppression enables Echinococcus multilocularis liver establishment after oral egg inoculation in a rat model. Exp Parasitol 2017; 180:27-32. [PMID: 28167206 DOI: 10.1016/j.exppara.2017.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 12/15/2016] [Accepted: 02/01/2017] [Indexed: 01/03/2023]
Abstract
Comparable with immunocompetent humans, rats are considered highly resistant to Echinococcus multilocularis oncosphere invasion, both in nature and after experimental oral inoculation with eggs. Pharmacological immunosuppression with dexamethasone (DMX) was shown to abrogate the resistance of RccHan™:WIST rats, but due to weight losses >20%, many animals had to be excluded from previous experiments. The optimized DXM (Dexafort, MSD Animal Health, Germany) dosage regime presented in this study (each animal: 750 μg DXM at day -13 and 600 μg DXM at day -9 before inoculation) applied subcutaneously to RccHan™:WIST rats, resulted in weight losses ≤20%, but led to liver alveolar echinococcosis (AE) in all eight inoculated animals. Untreated control groups (each n = 8) including RccHan™:WIST (Wistar) and F344/DuCrl (Fischer-344) rats showed no parasite establishment. Antibodies against E. multilocularis metacestode vesicle fluid were present in 7/8 of the infected RccHan™:WIST rats 70 days after inoculation but in none of the control animals. Serology can therefore be used to diagnose AE. This optimized animal model enables a high infection rate in rats and may be applied in future immunological and experimental studies.
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Affiliation(s)
- Deborah Elisabeth Joekel
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland
| | - Peter Deplazes
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057 Zurich, Switzerland.
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Romig T, Deplazes P, Jenkins D, Giraudoux P, Massolo A, Craig PS, Wassermann M, Takahashi K, de la Rue M. Ecology and Life Cycle Patterns of Echinococcus Species. ADVANCES IN PARASITOLOGY 2017; 95:213-314. [PMID: 28131364 DOI: 10.1016/bs.apar.2016.11.002] [Citation(s) in RCA: 252] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The genus Echinococcus is composed of eight generally recognized species and one genotypic cluster (Echinococcus canadensis cluster) that may in future be resolved into one to three species. For each species, we review existing information on transmission routes and life cycles in different geographical contexts and - where available - include basic biological information of parasites and hosts (e.g., susceptibility of host species). While some Echinococcus spp. are transmitted in life cycles that involve predominantly domestic animals (e.g., dog - livestock cycles), others are wildlife parasites that do or do not interact with domestic transmission. In many cases, life cycle patterns of the same parasite species differ according to geography. Simple life cycles contrast with transmission patterns that are highly complex, involving multihost systems that may include both domestic and wild mammals. Wildlife transmission may be primary or secondary, i.e., resulting from spillovers from domestic animals. For most of the species and regions, existing information does not yet permit a conclusive description of transmission systems. Such data, however, would be highly relevant, e.g., for anticipation of geographical changes of the presence and frequency of these parasites in a warming world, or for initiating evidence-based control strategies.
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Affiliation(s)
- T Romig
- University of Hohenheim, Stuttgart, Germany
| | - P Deplazes
- University of Zürich, Zurich, Switzerland
| | - D Jenkins
- Charles Sturt University, Wagga Wagga, NSW, Australia
| | - P Giraudoux
- University of Franche-Comté and Institut Universitaire de France, Besancon, France
| | - A Massolo
- University of Calgary, Calgary, Alberta, Canada
| | - P S Craig
- University of Salford, Greater Manchester, United Kingdom
| | | | | | - M de la Rue
- University of Santa Maria, Santa Maria RS, Brazil
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Abstract
The biology of Echinococcus, the causative agent of echinococcosis (hydatid disease) is reviewed with emphasis on the developmental biology of the adult and metacestode stages of the parasite. Major advances include determining the origin, structure and functional activities of the laminated layer and its relationship with the germinal layer; and the isolation, in vitro establishment and characterization of the multipotential germinal cells. Future challenges are to identify the mechanisms that provide Echinococcus with its unique developmental plasticity and the nature of activities at the parasite-host interface, particularly in the definitive host. The revised taxonomy of Echinococcus is presented and the solid nomenclature it provides will be essential in understanding the epidemiology of echinococcosis.
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Woolsey ID, Jensen PM, Deplazes P, Kapel CMO. Peroral Echinococcus multilocularis egg inoculation in Myodes glareolus, Mesocricetus auratus and Mus musculus (CD-1 IGS and C57BL/6j). INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2016; 5:158-63. [PMID: 27330986 PMCID: PMC4906142 DOI: 10.1016/j.ijppaw.2016.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/23/2016] [Accepted: 05/26/2016] [Indexed: 11/15/2022]
Abstract
Echinococcus multilocularis transmission predominantly occurs in Europe between the red fox (Vulpes vulpes) and various species of rodent intermediate hosts. We infected 3 species of rodent, Myodes glareolus (n = 47), Mesocricetus auratus (n = 11) and outbred Mus musculus (CD-1 IGS) (n = 9) with an E. multilocularis egg suspension that contained 100 eggs with viable oncospheres and performed post mortem examination 6, 8 (M. glareolus) and 10 weeks post inoculation (wpi). C57BL/6j mice (n = 4) were used as positive controls as they have been shown to exhibit macroscopic liver lesions 4 wpi. To the best of our knowledge, this is the first study to experimentally assess susceptibility in the ostensibly competent host M. glareolus. Lesions were only detected in 2 of 47 M. glareolus (4.3%) at 8 and 10 wpi and although both contained protoscolices (1675 at 8 wpi and 88 at 12 wpi) the low percentage of infected animals brings into question their role as transmitters of the parasite. Significant differences were observed between inbred and outbred mice with E. multilocularis infection in the former demonstrating increased establishment (p ≤ 0.0001) and growth (p ≤ 0.0001). No lesions were found in all 11 M. auratus.
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Affiliation(s)
- Ian David Woolsey
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Per Moestrup Jensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Peter Deplazes
- Institute of Parasitology, University of Zurich, Winterthurerstr. 266a, CH-8057 Zurich, Switzerland
| | - Christian Moliin Outzen Kapel
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
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Successful intestinal Echinococcus multilocularis oncosphere invasion and subsequent hepatic metacestode establishment in resistant RccHan™:WIST rats after pharmacological immunosuppression. Parasitology 2016; 143:1252-60. [DOI: 10.1017/s0031182016000809] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARYSusceptibility/resistance to larval Echinococcus multilocularis infection varies greatly depending on host species and strains. Whereas several mice strains and non-human primates are highly susceptible to alveolar echinococcosis, rats and most of humans are considered as more resistant. In this study, we aimed to elucidate factors responsible for host resistance in rats (Experiments A–D). (A) The parasite establishment was not observed in immunocompetent Wistar rats orally inoculated with sodium hypochlorite resistant eggs with/without pig bile, or activated/non-activated oncospheres (NAO). Peritoneal inoculation with NAO or metacestode tissue allowed the parasite establishment in rats. (B) T-cell-deficient athymic nude rats showed complete resistance against the metacestode establishment after oral inoculation with parasite eggs. This finding suggests that T-cell-independent parasite clearance occurred in the animals during early phase of the parasite invasion. Finally, Wistar rats that received pharmacological immunosuppression using either dexamethasone (DMS) alone or methotrexate (MTX) i.p. alone or a combination of these compounds were orally inoculated with the parasite's eggs. As a result (D), successful establishment of metacestode with protoscoleces was observed in all 3 rats treated with DMS (s.c.) alone or in all 6 rats treated with DMS (s.c.) plus MTX but not in 8 rats with MTX alone, suggesting that factors affected by DMS treatment are responsible to regulate the parasite invasion and establishment.
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Robertson LJ, Troell K, Woolsey ID, Kapel CMO. Fresh fruit, vegetables, and mushrooms as transmission vehicles for Echinococcus multilocularis in Europe: inferences and concerns from sample analysis data from Poland. Parasitol Res 2016; 115:2485-8. [PMID: 26987642 PMCID: PMC4863902 DOI: 10.1007/s00436-016-5015-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 03/10/2016] [Indexed: 11/30/2022]
Abstract
Fresh fruit, vegetables, mushrooms, and other fresh produce are recognised as important vehicles of infection for several foodborne parasites, particularly those with a faecal-oral transmission route and robust environmental transmission stages. Nevertheless, analysis of such foods for parasite transmission stages, even during outbreaks, tends to show only low contamination. Echinococcus multilocularis is considered one of the most important foodborne parasites, but there are few studies in which fresh produce or like foods collected in their natural habitat is analysed for contamination with E. multilocularis eggs. In this article, we question a recent study from Poland reporting over 23 % of fresh berries, vegetables, and mushroom being highly contaminated with E. multilocularis eggs. In particular, it appears unlikely that 20 % of raspberries, which are elevated from ground level, should be exposed to faecal contamination. Additionally, the similar egg contamination of vegetation in forest and plantation environments is surprising considering the preference of the parasite's most competent intermediate hosts for the latter environment. Furthermore, a lack of specific temporal information is concerning due to the varying infection pressure (and therefore environmental contamination) occurring in definitive hosts over the course of the year. Several important aspects of the study seem to us to have been neglected, and we are concerned that the published data might, if not questioned, lead to incorrect interpretation, and unnecessary losses in the agricultural sector.
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Affiliation(s)
- Lucy J Robertson
- Parasitology, Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, PO Box 8146 Dep., 0033, Oslo, Norway.
| | - Karin Troell
- Section of Bioinformatics and Molecular Biology, Department of Microbiology, National Veterinary Institute, SE-751 89, Uppsala, Sweden
| | - Ian David Woolsey
- Section of Organismal Biology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK1870, Frederiksberg C, Denmark
| | - Christian M O Kapel
- Section of Organismal Biology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, DK1870, Frederiksberg C, Denmark
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Miller AL, Olsson GE, Walburg MR, Sollenberg S, Skarin M, Ley C, Wahlström H, Höglund J. First identification of Echinococcus multilocularis in rodent intermediate hosts in Sweden. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2016; 5:56-63. [PMID: 27054089 PMCID: PMC4804384 DOI: 10.1016/j.ijppaw.2016.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/04/2016] [Accepted: 03/05/2016] [Indexed: 11/06/2022]
Abstract
Echinococcus multilocularis is a zoonotic tapeworm with a sylvatic lifecycle and an expanding range in Europe. Monitoring efforts following its first identification in 2011 in Sweden have focused on the parasite's definitive host, the red fox (Vulpes vulpes). However, identifying rodent intermediate hosts is important to recognize opportunities for parasite transmission. During 2013–2015, livers from a total of 1566 rodents from four regions in Sweden were examined for E. multilocularis metacestode lesions. Species identity of suspect parasite lesions was confirmed by PCR and sequencing. E. multilocularis positive lesions >6 mm in diameter were also examined histologically. One Microtus agrestis out of 187 (0.5%, 95%CI: 0–2.9%), 8/439 (1.8%, 95%CI: 0.8–3.6%) Arvicola amphibius, 0/655 (0%, 95%CI: 0–0.6%) Myodes glareolus, and 0/285 (0%, 95%CI: 0–1.3%) Apodemus spp. contained E. multilocularis metacestode lesions. Presence of protoscoleces was confirmed in the infected M. agrestis and in three of eight infected A. amphibius. Six of the nine positive rodents were captured from the same field. This is the first report of E. multilocularis in intermediate hosts in Sweden. The cluster of positive rodents in one field shows that local parasite prevalence can be high in Sweden despite overall low national prevalence in foxes (<0.1%). The presence of protoscoleces in infected M. agrestis and A. amphibius indicate these species can serve as competent intermediate hosts in Sweden. However, their relative importance for E. multilocularis transmission in the Swedish environment is not yet possible to assess. In contrast, the negative findings in all M. glareolus and Apodemus spp. suggest that these species are of no importance. Overall prevalence of Echinococcus multilocularis in rodents is low in Sweden. The distribution of infected rodents was focalized. Absence of competent intermediate hosts may limit parasite occurrence. Arvicola amphibius and Microtus agrestis are confirmed intermediate hosts in Sweden.
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Affiliation(s)
- Andrea L Miller
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Box 7036, Uppsala, 750 07, Sweden
| | - Gert E Olsson
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, 901 83, Sweden
| | - Marion R Walburg
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Box 7036, Uppsala, 750 07, Sweden
| | - Sofia Sollenberg
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Box 7036, Uppsala, 750 07, Sweden
| | - Moa Skarin
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Box 7036, Uppsala, 750 07, Sweden
| | - Cecilia Ley
- Department of Biomedical Sciences and Veterinary Public Health, Section for Pathology, Swedish University of Agricultural Sciences, Box 7028, Uppsala, 750 07, Sweden
| | - Helene Wahlström
- Department of Disease Control and Epidemiology, Zoonosiscenter, National Veterinary Institute, Uppsala, 751 89, Sweden
| | - Johan Höglund
- Department of Biomedical Sciences and Veterinary Public Health, Section for Parasitology, Swedish University of Agricultural Sciences, Box 7036, Uppsala, 750 07, Sweden
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