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An improved test system for PCR-based specific detection of Echinococcus multilocularis eggs

Published online by Cambridge University Press:  05 June 2009

A. Mathis
Affiliation:
Institute of Parasitology, University of Zurich, Winterthurerstr 266a, CH-8057 Zurich, Switzerland
P. Deplazes
Affiliation:
Institute of Parasitology, University of Zurich, Winterthurerstr 266a, CH-8057 Zurich, Switzerland
J. Eckert
Affiliation:
Institute of Parasitology, University of Zurich, Winterthurerstr 266a, CH-8057 Zurich, Switzerland

Abstract

For the sensitive detection of eggs of Echinococcus multilocularis in fox faeces by PCR we have evaluated a method based on the previous concentration of helminth eggs by a combination of sequential sieving of faecal samples and flotation of the eggs in zinc chloride solution. The eggs were microscopically detected in the fractions retained in 40 and 20µm mesh sieves. DNA of the taeniid eggs retained in the 20 µm sieve was obtained after alkaline lysis and PCR was performed using E. multilocularis species-specific primers. Compared to the parasitological findings after examination of the small intestines of the foxes, the specificity of the PCR was 100% (no false-positive result with 20 foxes free of E. multilocularis) and the sensitivity was 94% (33 positive results from total 35 foxes proven to be infected with E. multilocularis). Both false-negative results were obtained with faeces from foxes harbouring immature worms. Using faecal volumes between 2 and 20 ml, no inhibition of PCR was observed as was demonstrated by the amplification of size-modified target in parallel reactions. The tests were undertaken with fresh faeces stored in 70% ethanol, but egg detection by PCR was also possible after inactivation of eggs by freezing the faeces at −80°C for one week or by incubation at +70°C for 2 h.

Type
Research Papers
Copyright
Copyright © Cambridge University Press 1996

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References

Bretagne, S., Guillou, J.P., Morand, M. & Houin, R. (1993) Detection of Echinococcus Multilocularis DNA in fox faeces using DNA amplification. Parasitology 106, 193199.CrossRefGoogle ScholarPubMed
Chapman, A., Vallejo, V., Mossie, K.G., Ortiz, D., Agabian, N. & Flisser, A. (1995) Isolation and characterization of species-specific DNA probes from Taenia solium and Taenia saginata and their use in an egg detection assay. Journal of Clinical Microbiology 33, 12831288.CrossRefGoogle Scholar
Craig, P.S. (1993) Immunodiagnosis of Echinococcus granulosus. pp. 85118in Anderson, F.L., Chai, J. & Liu, F. (Eds) Compendium on cystic echinococcosis. Provo (UT), Brigham Young University Print Service.Google Scholar
Deplazes, P. & Eckert, J. (1996) Diagnosis of the Echinococcus Multilocularis infection in final hosts. Applied Parasitology (in press).Google ScholarPubMed
Deplazes, P., Gottstein, B., Eckert, J., Jenkins, D.J., Ewald, D. & Jimenez-Palacios, S. (1992) Detection of Echinococcus coproantigens by enzyme-linked immunosorbent assay in dogs, dingoes and foxes. Parasitology Research 78, 303308.CrossRefGoogle ScholarPubMed
Eckert, J., Deplazes, P., Ewald, D. & Gottstein, B. (1991) Parasitologische und immunologische Methoden zum Nachweis von Echinococcus Multilocularis bei Füchsen. Mitteilungen der Österreichischen Gesellschaft für Tropenmedizin und Parasitologie 13, 2530.Google Scholar
Gottstein, B. & Mowatt, M.R. (1991) Sequencing and characterization of an Echinococcus Multilocularis DNA probe and its use in the polymerase chain reaction. Molecular and Biochemical Parasitology 44, 83194.CrossRefGoogle ScholarPubMed
Gottstein, B., Deplazes, P., Tanner, I. & Skaggs, J.S. (1991) Diagnostic identification of Taenia saginata with the polymerase chain reaction. Transactions of the Royal Society of Tropical Medicine and Hygiene 85, 248249.CrossRefGoogle ScholarPubMed
Mathis, A. & Deplazes, P. (1995) PCR and in vitro cultivation for detection of Leishmania spp. in diagnostic samples from humans and dogs. Journal of Clinical Microbiology 33, 11451149.CrossRefGoogle ScholarPubMed
Veit, P., Bilger, B., Schad, V., Schäfer, J., Frank, W. & Lucius, R. (1995) Influence of environmental factors on the infectivity of Echinococcus Multilocularis eggs. Parasitology 110, 7986.CrossRefGoogle ScholarPubMed