Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-23T23:49:11.206Z Has data issue: false hasContentIssue false
  • English
  • Français

The course of infection in rats given small primary doses of Strongyloides ratti and S. venezuelensis

Published online by Cambridge University Press:  05 June 2009

K. Christine Carter  and
P. A. G. Wilson
K. Christine Carter
Affiliation:
Department of Zoology, Edinburgh University, West Mains Road, Edinburgh EH9 3JT, UK
P. A. G. Wilson*
Affiliation:
Department of Zoology, Edinburgh University, West Mains Road, Edinburgh EH9 3JT, UK
*
*Author for correspondence.
Get access Rights & Permissions [Opens in a new window]

Abstract

Development of exact doses (<100) of Strongyloides venezuelensis third-stage larvae in adult Wistar rats was insignificant (mean proportion of 0·076 of the dose at day 8, n = 16) compared with a homogonic strain of S. ratti (0·538, n = 6; 0·726, n = 6) and heterogonic S. ratti (0·681, n = 6). Newly-weaned Wistars allowed development of a mean proportion of S. venezuelensis of 0·298 (n = 4) compared with 0·013 (n = 4) of the same sample of larvae in adult hosts. Experiments with 75Se-labelled larvae established that S. venezuelensis effectively failed to migrate from skin to intestine in adult animals, while mean proportions of 0·141 (n = 5) and 0·138 (n = 4) of the label was found in the intestines of newly-weaned rats 72 h after skin application. Labelled larvae of homogonic S. ratti migrated equally well in both age groups of host (0·350 and 0·358 in 12- and 3-week-olds respectively). Adult S. venezuelensis transferred surgically to the intestines of previously uninfected full-grown Wistars survived over a 21-day period to the same extent as either strain of S. ratti. Resistance of Wistar rats to S. venezuelensis therefore appears to affect the migratory stage preferentially. S. venezuelensis developed better in mature PVG inbred rats (mean = 0·301, n = 20). Studies of S. ratti showed that infections of both strains initiated by exact (<100) doses in Wistar rats had decayed to insignificance between days 26 and 32. The rate of loss of adults of the heterogonic strain was significantly greater than that for the homogonic. The egg content of worms declined as infection progressed and rats were idiosyncratic in their influence on parasite reproduction from the earliest time of sampling (8 d). It was established that ‘autoinfection’ was an unlikely feature of the biology of homogonic S. ratti following the surgical transfer of 450 first-stage larvae to the intestines of 8 adult Wistar rats. No evidence of infection appeared in the guts of these animals 8 days post-transfer. The significance of these results in terms of the biology of Strongyloides spp. naturally occurring in the rat is discussed.

Keywords

Strongyloides rattiStrongyloides venezuelensisratsmall doseprimary infectionsurgical transferautoinfectionradioactive labelling
Type
Research Article
Information
Journal of Helminthology , Volume 63 , Issue 2 , June 1989 , pp. 107 - 114
Copyright
Copyright © Cambridge University Press 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Araujo, P. (1967) Distribucao de helmintos no intestino delgado de Rattus norvegicus naturalmente infestados. II. Strongyloides ratti Sandground 1925 e S. venezuelensis Brumpt, 1934. Revista de la Faculdad de Farmacia e Bioquimica da Universidad de Sao Paulo, Brazil, 5, 179–190.Google Scholar
Bell, R. G., Adams, L. S. & Gerb, J. (1981) Strongyloides ratti: Dissociation of the rat's protective immunity into systemic and intestinal components. Experimental Parasitology, 52, 386–395.CrossRefGoogle ScholarPubMed
Brumpt, E. (1947) Precis de Parasitologie 6th ed. Masson et Cie., Paris.Google Scholar
Carter, K. C. (1986) The specificity of the host's immunological response to invasive nematode parasites of rats. Ph.D. Thesis, University of Edinburgh.Google Scholar
Genta, R. M. & Ward, P. A. (1980) The histopathology of experimental strongyloidiasis. American Journal of Pathology, 99, 207–219.Google ScholarPubMed
Harper, J. S. III, Genta, R. M., Gam, A., London, W. T. & Neva, F. A. (1984) Experimental disseminated strongyloidiasis in Erythrocebus patas I. Pathology. American Journal of Tropical Medicine & Hygiene, 33, 431–443.CrossRefGoogle ScholarPubMed
Little, M. D. (1961) Concurrent infections of Strongyloides venezuelensis and S. ratti in wild rats in New Orleans. Journal of Parasitology, 47 (Suppl.), 17.Google Scholar
Little, M. D. (1966) Comparative morphology of six species of Strongyloides (Nematoda) and redefintion of the genus. Journal of Parasitology, 52, 69–84.CrossRefGoogle ScholarPubMed
Moqbel, R. & Denham, D. A. (1977) Strongyloides ratti: 1. Parasitological observations on primary and secondary infections in the small intestine of rats. Journal of Helminthology, 51, 301–308.Google Scholar
Moqbel, R. & Denham, D. A. (1978) Strongyloides ratti: The effect of betamethasone on the course of infection in rats. Parasitology, 76, 289–298.CrossRefGoogle ScholarPubMed
Moqbel, R., Mclaren, D. J. & Wakelin, D. (1980) Strongyloides ratti: the reversibility of immune damage to adult worms. Experimental Parasitology, 49, 153–166.CrossRefGoogle ScholarPubMed
Moqbel, R. & Wakelin, D. (1981) Immunity to Strongyloides ratti in rats. 1. Adoptive transfer with mesenteric lymph node cells. Parasite Immunology, 3, 181–189.CrossRefGoogle ScholarPubMed
Murrell, K. D. (1980) Strongyloides ratti: Acquired resistance in the rat to preintestinal migrating larvae. Experimental Parasitology, 50, 417–425.CrossRefGoogle ScholarPubMed
Neva, F. A. (1986) Biology and immunology of human strongyloidiasis. Journal of Infectious Diseases, 153, 397–406.CrossRefGoogle ScholarPubMed
Nolan, T. J. & Katz, F. F. (1981) Transmammary transmission of Strongyloides venezuelensis (Nematoda) in rats. Proceedings of the Helminthological Society of Washington, 48, 8–12.Google Scholar
Olson, C. E. & Schiller, E. L. (1978) Strongyloides ratti infections in rats II. Effects of cortisone treatment. American Journal of Tropical Medicine & Hygiene, 27, 527–531.CrossRefGoogle ScholarPubMed
Schad, G. A., Hellman, M. E. & Muncey, D. W. (1984) Strongyloides stercoralis hyperinfection in immunosuppressed dogs. Experimental Parasitology, 57, 287–296.CrossRefGoogle ScholarPubMed
Sheldon, A. J. (1937) Studies on the active acquired resistance, natural and artificial, in the rat to infection with Strongyloides ratti. American Journal of Hygiene, 25, 53–65.Google Scholar
Wertheim, G. (1963) Helminth parasites of the rat, Rattus norvegicus, from Haifa and Tel-Aviv. Bulletin of the Research Council of Israel, 10E, 125–129.Google Scholar
Wertheim, G. (1970) Growth and development of Strongyloides venezuelensis Brumpt, 1934, in the albino rat. Parasitology, 61, 381–388.CrossRefGoogle ScholarPubMed
Wertheim, G. & Lengy, J. (1964) The seasonal occurrence of Strongyloides ratti Sandground, 1925, and S. venezuelensis Brumpt, 1934, in a population of Rattus norvegicus. Journal of Helminthology, 38, 393–398.CrossRefGoogle Scholar
Wilson, P. A. G. (1979) Tracking radioactive larvae of Strongyloides ratti in the host. Parasitology, 79, 29–38.CrossRefGoogle ScholarPubMed
Wilson, P. A. G., Cameron, M. & Scott, D. S. (1978a) Strongyloides ratti in virgin female rats: studies of oestruos cycle effects and general variability. Parasitology, 76, 221–227.CrossRefGoogle ScholarPubMed
Wilson, P. A. G., Cameron, M. & Scott, D. S. (1978b) Patterns of milk transmission of Strongyloides ratti. Parasitology, 77, 87–96.CrossRefGoogle ScholarPubMed
Wilson, P. A. G., Simpson, N. E. & Seaton, D. S. (1986) The effect of method of infection on the pathway of juvenile Strongyloides ratti in the host. Journal of Helminthology, 60, 79–91.CrossRefGoogle ScholarPubMed
Wilson, P. A. G. & Simpson, N. E. (1981) Dynamics of infection in rats given low doses of homogonic and heterogonic Strongyloides ratti. Parasitology, 83, 459–475.CrossRefGoogle Scholar
Wilson, P. A. G. & Simpson, N. E. (1982) Strongyloides ratti: studies of 75Se labelled larvae of the homogonic strain in female hosts. Parasitology, 84, 443–454.CrossRefGoogle ScholarPubMed