{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,27]],"date-time":"2026-09-27T11:30:56Z","timestamp":1790508656297,"version":"4.1.0"},"reference-count":55,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2020,7,31]],"date-time":"2020-07-31T00:00:00Z","timestamp":1596153600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006454","name":"Bundesamt f\u00fcr Lebensmittelsicherheit und Veterin\u00e4rwesen","doi-asserted-by":"publisher","award":["4.19.01"],"award-info":[{"award-number":["4.19.01"]}],"id":[{"id":"10.13039\/501100006454","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Different helminths and protozoa are transmitted to humans by oral uptake of environmentally resistant parasite stages after hand-to-mouth contact or by contaminated food and water. The aim of this study was to develop and validate a method for the simultaneous detection of parasite stages from fresh produce (lettuce) by a one-way isolation test kit followed by genetic identification (PCR, sequencing). Three sentinel zoonotic agents (eggs of Toxocara canis, Echinococcus multilocularis and oocysts of Toxoplasma gondii) were used to investigate the practicability and sensitivity of the method. The detection limits (100% positive results) in the recovery experiments were four Toxocara eggs, two E. multilocularis eggs and 18 T. gondii oocysts (in 4\/5 replicates). In a field study, helminth DNA was detected in 14 of 157 lettuce samples including Hydatigera taeniaeformis (Syn. Taenia taeniaeformis) (four samples), T. polyacantha (three), T. martis (one), E. multilocularis (two) and Toxocara cati (four). Toxoplasma gondii was detected in six of 100 samples. In vivo testing in mice resulted in metacestode growth in all animals injected with 40\u201360 E. multilocularis eggs, while infection rates were 20\u201340% with 2\u201320 eggs. The developed diagnostic strategy is highly sensitive for the isolation and genetic characterisation of a broad range of parasite stages from lettuce, whereas the sensitivity of the viability tests needs further improvement.<\/jats:p>","DOI":"10.3390\/pathogens9080624","type":"journal-article","created":{"date-parts":[[2020,7,31]],"date-time":"2020-07-31T04:15:31Z","timestamp":1596168931000},"page":"624","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["A Sensitive, One-Way Sequential Sieving Method to Isolate Helminths\u2019 Eggs and Protozoal Oocysts from Lettuce for Genetic Identification"],"prefix":"10.3390","volume":"9","author":[{"given":"Annina R.","family":"Guggisberg","sequence":"first","affiliation":[{"name":"Institute of Parasitology, Vetsuisse and Medical Faculty, University of Z\u00fcrich, 8057 Z\u00fcrich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8069-7607","authenticated-orcid":false,"given":"Cristian A.","family":"Alvarez Rojas","sequence":"additional","affiliation":[{"name":"Institute of Parasitology, Vetsuisse and Medical Faculty, University of Z\u00fcrich, 8057 Z\u00fcrich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Philipp A.","family":"Kronenberg","sequence":"additional","affiliation":[{"name":"Institute of Parasitology, Vetsuisse and Medical Faculty, University of Z\u00fcrich, 8057 Z\u00fcrich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nadia","family":"Miranda","sequence":"additional","affiliation":[{"name":"Institute of Parasitology, Vetsuisse and Medical Faculty, University of Z\u00fcrich, 8057 Z\u00fcrich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter","family":"Deplazes","sequence":"additional","affiliation":[{"name":"Institute of Parasitology, Vetsuisse and Medical Faculty, University of Z\u00fcrich, 8057 Z\u00fcrich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,7,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"547","DOI":"10.1016\/j.pt.2003.10.002","article-title":"Soil-transmitted helminth infections: Updating the global picture","volume":"19","author":"Brooker","year":"2003","journal-title":"Trends Parasitol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1521","DOI":"10.1016\/S0140-6736(06)68653-4","article-title":"Soil-transmitted helminth infections: Ascariasis, trichuriasis, and hookworm","volume":"367","author":"Bethony","year":"2006","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1016\/j.gtc.2006.03.006","article-title":"An updated review on cryptosporidium and giardia","volume":"35","author":"Huang","year":"2006","journal-title":"Gastroenterol. Clin. N. Am."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1128\/CMR.05038-11","article-title":"Enteric protozoa in the developed world: A public health perspective","volume":"25","author":"Fletcher","year":"2012","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_5","unstructured":"Pr\u00fcss-\u00dcst\u00fcn, A., Bos, R., Gore, F., and Bartram, J. (2008). Safer Water, Better Health: Costs, Benefits and Sustainability of Interventions to Protect and Promote Health, World Health Organization."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.vetpar.2015.04.020","article-title":"The role of wild canids and felids in spreading parasites to dogs and cats in Europe. Part II: Helminths and arthropods","volume":"213","author":"Otranto","year":"2015","journal-title":"Vet. Parasitol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.vetpar.2011.07.014","article-title":"Role of pet dogs and cats in the transmission of helminthic zoonoses in Europe, with a focus on echinococcosis and toxocarosis","volume":"182","author":"Deplazes","year":"2011","journal-title":"Vet. Parasitol."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Bastien, M., Vaniscotte, A., Combes, B., Umhang, G., Germain, E., Gouley, V., Pierlet, A., Quintaine, T., Forin-Wiart, M.A., and Villena, I. (2018). High density of fox and cat faeces in kitchen gardens and resulting rodent exposure to Echinococcus multilocularis and Toxoplasma gondii. Folia Parasitol., 65.","DOI":"10.14411\/fp.2018.002"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"e00034","DOI":"10.1016\/j.fawpar.2018.e00034","article-title":"Identifying drivers of fox and cat faecal deposits in kitchen gardens in order to evaluate measures for reducing contamination of fresh fruit and vegetables","volume":"14","author":"Bastien","year":"2019","journal-title":"Food Waterborne Parasitol."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Macpherson, C.N.L., Meslin, F.X., and Wandeler, A.I. (2000). Dogs, Zoonoses, and Public Health, CABI.","DOI":"10.1079\/9780851994369.0000"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/j.pt.2003.11.011","article-title":"Wilderness in the city: The urbanization of Echinococcus multilocularis","volume":"20","author":"Deplazes","year":"2004","journal-title":"Trends Parasitol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1016\/j.pt.2015.04.007","article-title":"Wilderness in the \u2018city\u2019 revisited: Different urbes shape transmission of Echinococcus multilocularis by altering predator and prey communities","volume":"31","author":"Liccioli","year":"2015","journal-title":"Trends Parasitol."},{"key":"ref_13","unstructured":"WHO (2004). Waterborne Zoonoses: Identification, Causes and Control, IWA Publishing."},{"key":"ref_14","first-page":"2088","article-title":"Risk factors for alveolar echinococcosis in humans","volume":"10","author":"Kern","year":"2004","journal-title":"Emerg. Infect. Dis."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1093\/oxfordjournals.aje.a008942","article-title":"Risk factors for Toxoplasma gondii infection in pregnancy. Results of a prospective case-control study in Norway","volume":"144","author":"Kapperud","year":"1996","journal-title":"Am. J. Epidemiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1136\/bmj.321.7254.142","article-title":"Sources of toxoplasma infection in pregnant women: European multicentre case-control study. European Research Network on Congenital Toxoplasmosis","volume":"321","author":"Cook","year":"2000","journal-title":"BMJ"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"878","DOI":"10.1086\/605433","article-title":"Risk factors for Toxoplasma gondii infection in the United States","volume":"49","author":"Jones","year":"2009","journal-title":"Clin. Infect. Dis."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Maurelli, M.P., Santaniello, A., Fioretti, A., Cringoli, G., Rinaldi, L., and Menna, L.F. (2019). The presence of Toxocara eggs on dog\u2019s fur as potential zoonotic risk in animal-assisted interventions: A systematic review. Animals, 9.","DOI":"10.3390\/ani9100827"},{"key":"ref_19","unstructured":"FAO\/WHO (2014). Multicriteria-Based Ranking for Risk Management of Food-Borne Parasites, Food and Agriculture Organization of the United Nations (FAO)\/World Health Organization (WHO)."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Koutsoumanis, K., Allende, A., Alvarez-Ord\u00f3\u00f1ez, A., Bolton, D., Bover-Cid, S., Chemaly, M., Davies, R., Cesare, A., Herman, L., and Hilbert, F. (2018). Public health risks associated with food-borne parasites. EFSA J., 16.","DOI":"10.2903\/j.efsa.2018.5495"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1007\/s40588-018-0091-0","article-title":"Assessing the contamination of food and the environment with Taenia and Echinococcus eggs and their zoonotic transmission","volume":"5","author":"Mathis","year":"2018","journal-title":"Curr. Clin. Microbiol. Rep."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Tamarozzi, F., Deplazes, P., and Casulli, A. (2020). Reinventing the wheel of Echinococcus granulosus sensu lato transmission to humans. Trends Parasitol.","DOI":"10.1016\/j.pt.2020.02.004"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2485","DOI":"10.1007\/s00436-016-5015-4","article-title":"Fresh fruit, vegetables, and mushrooms as transmission vehicles for Echinococcus multilocularis in Europe: Inferences and concerns from sample analysis data from Poland","volume":"115","author":"Robertson","year":"2016","journal-title":"Parasitol. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1051\/parasite\/2018009","article-title":"Assessing viability and infectivity of foodborne and waterborne stages (cysts\/oocysts) of Giardia duodenalis, Cryptosporidium spp., and Toxoplasma gondii: A review of methods","volume":"25","author":"Rousseau","year":"2018","journal-title":"Parasite"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.exppara.2015.03.016","article-title":"In vivo viability of Echinococcus multilocularis eggs in a rodent model after different thermo-treatments","volume":"154","author":"Federer","year":"2015","journal-title":"Exp. Parasitol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"911","DOI":"10.1017\/S0031182007002235","article-title":"Identification of taeniid eggs in the faeces from carnivores based on multiplex PCR using targets in mitochondrial DNA","volume":"134","author":"Trachsel","year":"2007","journal-title":"Parasitology"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1787","DOI":"10.1128\/jcm.27.8.1787-1792.1989","article-title":"Direct and sensitive detection of a pathogenic protozoan, Toxoplasma gondii, by polymerase chain reaction","volume":"27","author":"Burg","year":"1989","journal-title":"J. Clin. Microbiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1017\/S0022149X00015443","article-title":"An improved test system for PCR-based specific detection of Echinococcus multilocularis eggs","volume":"70","author":"Mathis","year":"1996","journal-title":"J. Helminthol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"249","DOI":"10.1016\/j.ijppaw.2016.07.002","article-title":"Detection of taeniid (Taenia spp., Echinococcus spp.) eggs contaminating vegetables and fruits sold in European markets and the risk for metacestode infections in captive primates","volume":"5","author":"Federer","year":"2016","journal-title":"Int. J. Parasitol. Parasites Wildl."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Adler, F.R., Green, A.M., and \u015eekercio\u011flu, \u00c7.H. (2020). Citizen science in ecology: A place for humans in nature. Ann. N. Y. Acad. Sci., 26.","DOI":"10.1111\/nyas.14340"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"588","DOI":"10.1089\/heq.2019.0042","article-title":"Translational health disparities research in a data-rich world","volume":"3","author":"Breen","year":"2019","journal-title":"Health Equity"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"590","DOI":"10.1186\/s13071-019-3834-8","article-title":"A novel protocol to isolate, detect and differentiate taeniid eggs in leafy greens and berries using real-time PCR with melting curve analysis","volume":"12","author":"Frey","year":"2019","journal-title":"Parasites Vectors"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"e00068","DOI":"10.1016\/j.fawpar.2019.e00068","article-title":"A new SYBR green real-time PCR assay for semi-quantitative detection of Echinococcus multilocularis and Echinococcus canadensis DNA on bilberries (Vaccinium myrtillus)","volume":"17","author":"Lavikainen","year":"2019","journal-title":"Food Waterborne Parasitol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"108636","DOI":"10.1016\/j.foodres.2019.108636","article-title":"A novel multiplex real-time PCR for the detection of Echinococcus multilocularis, Toxoplasma gondii, and Cyclospora cayetanensis on berries","volume":"125","author":"Temesgen","year":"2019","journal-title":"Food Res. Int."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"4023","DOI":"10.1007\/s00436-015-4630-9","article-title":"The first detection of Echinococcus multilocularis DNA in environmental fruit, vegetable, and mushroom samples using nested PCR","volume":"114","author":"Lass","year":"2015","journal-title":"Parasitol. Res."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"624","DOI":"10.1089\/vbz.2015.1937","article-title":"First detection of Toxoplasma gondii DNA in the fresh leafs of vegetables in South America","volume":"16","author":"Marchioro","year":"2016","journal-title":"Vector Borne Zoonotic Dis."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.fm.2016.01.002","article-title":"Simultaneous detection of the protozoan parasites Toxoplasma, Cryptosporidium and Giardia in food matrices and their persistence on basil leaves","volume":"57","author":"Hohweyer","year":"2016","journal-title":"Food Microbiol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1101","DOI":"10.1007\/s10096-011-1414-8","article-title":"The first detection of Toxoplasma gondii DNA in environmental fruits and vegetables samples","volume":"31","author":"Lass","year":"2012","journal-title":"Eur. J. Clin. Microbiol. Infect. Dis."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Reischl, U., Bretagne, S., Kr\u00fcger, D., Ernault, P., and Costa, J.M. (2003). Comparison of two DNA targets for the diagnosis of Toxoplasmosis by real-time PCR using fluorescence resonance energy transfer hybridization probes. BMC Infect. Dis., 3.","DOI":"10.1186\/1471-2334-3-7"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"342","DOI":"10.1016\/j.ijppaw.2019.03.013","article-title":"Wildlife-transmitted Taenia and Versteria cysticercosis and coenurosis in humans and other primates","volume":"9","author":"Deplazes","year":"2019","journal-title":"Int. J. Parasitol. Parasites Wildl."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1017\/S0031182099005351","article-title":"High prevalence of Echinococcus multilocularis in urban red foxes (Vulpes vulpes) and voles (Arvicola terrestris) in the city of Z\u00fcrich, Switzerland","volume":"120","author":"Hofer","year":"2000","journal-title":"Parasitology"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1017\/S0022149X07868775","article-title":"Infection of red foxes with Echinococcus multilocularis in western Switzerland","volume":"81","author":"Brossard","year":"2007","journal-title":"J. Helminthol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.fawpar.2016.01.001","article-title":"Detection of Cyclospora cayetanensis, Cryptosporidium spp., and Toxoplasma gondii on imported leafy green vegetables in Canadian survey","volume":"2","author":"Lalonde","year":"2016","journal-title":"Food Waterborne Parasitol."},{"key":"ref_44","unstructured":"Bethea, D.A. (2014). Detection of Toxoplasma Gondii in Fresh Produce, University of Georgia."},{"key":"ref_45","first-page":"27","article-title":"Incidence of zoonotic parasites in Egyptian raw vegetable salads","volume":"13","author":"Ahmad","year":"2016","journal-title":"Life Sci. J."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"20","DOI":"10.3923\/ijtmed.2010.20.23","article-title":"Prevalence of intestinal parasites in leafy vegetables in Riyadh, Saudi Arabia","volume":"5","year":"2010","journal-title":"Int. J. Trop. Med."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"597","DOI":"10.1007\/s10344-010-0470-1","article-title":"Hunters and non-hunters: Skewed predation rate by domestic cats in a rural village","volume":"57","author":"Tschanz","year":"2011","journal-title":"Eur. J. Wildl. Res."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1024\/0036-7281\/a000341","article-title":"Incidence and genotypes of Toxoplasma gondii in the muscle of sheep, cattle, pigs as well as in cat feces in Switzerland","volume":"154","author":"Frey","year":"2012","journal-title":"Schweiz. Arch. Tierheilkd."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.parint.2018.12.005","article-title":"Intestinal parasites and lungworms in stray, shelter and privately owned cats of Switzerland","volume":"69","author":"Zottler","year":"2019","journal-title":"Parasitol. Int."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"925","DOI":"10.1007\/s00436-011-2578-y","article-title":"In vitro viability test for the eggs of Echinococcus granulosus: A rapid method","volume":"110","author":"Moazeni","year":"2012","journal-title":"Parasitol. Res."},{"key":"ref_51","unstructured":"Eckert, J., Gemmell, M.A., Meslin, F.X., and Paw\u0142owski, Z.S. (2001). Echinococcosis in animals: Clinical aspects, diagnosis and treatment. WHO\/OIE Manual on Echinococcosis in Humans and Animals: A Public Health Problem of Global Concern, World Organisation for Animal Health."},{"key":"ref_52","first-page":"307","article-title":"Mass collection and storage of Taenia hydatigena eggs and isolation of viable oncospheres","volume":"130","author":"Deplazes","year":"1988","journal-title":"Schweiz. Arch. Tierheilkd."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1016\/j.vetpar.2007.11.022","article-title":"Patent Toxocara canis infections in previously exposed and in helminth-free dogs after infection with low numbers of embryonated eggs","volume":"152","author":"Fahrion","year":"2008","journal-title":"Vet. Parasitol."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1007\/s00436-003-1043-y","article-title":"Polymerase chain reaction for detection of patent infections of Echinococcus granulosus (\u201csheep strain\u201d) in naturally infected dogs","volume":"92","author":"Shaikenov","year":"2004","journal-title":"Parasitol. Res."},{"key":"ref_55","doi-asserted-by":"crossref","unstructured":"Ye, J., Coulouris, G., Zaretskaya, I., Cutcutache, I., Rozen, S., and Madden, T.L. (2012). Primer-BLAST: A tool to design target-specific primers for polymerase chain reaction. BMC Bioinform., 13.","DOI":"10.1186\/1471-2105-13-134"}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/9\/8\/624\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:53:12Z","timestamp":1760176392000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/9\/8\/624"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,7,31]]},"references-count":55,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2020,8]]}},"alternative-id":["pathogens9080624"],"URL":"https:\/\/doi.org\/10.3390\/pathogens9080624","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,7,31]]}}}