Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-26T00:30:27.836Z Has data issue: false hasContentIssue false
  • English
  • Français

The dynamics of the host-parasite relationship

I. Nematodirus spathiger infection in sheep

Published online by Cambridge University Press:  06 April 2009

A. D. Donald ,
J. K. Dineen ,
J. H. Turner  and
B. M. Wagland
A. D. Donald
Affiliation:
Division of Animal Health, C.S.I.R.O., McMaster Laboratory, Glebe, N.S.W., Australia
J. K. Dineen
Affiliation:
Division of Animal Health, C.S.I.R.O., McMaster Laboratory, Glebe, N.S.W., Australia
J. H. Turner
Affiliation:
Division of Animal Health, C.S.I.R.O., McMaster Laboratory, Glebe, N.S.W., Australia
B. M. Wagland
Affiliation:
Division of Animal Health, C.S.I.R.O., McMaster Laboratory, Glebe, N.S.W., Australia
Get access Rights & Permissions [Opens in a new window]

Extract

The studies presented in this paper describe the effects of control exerted by the immunological response of the host (sheep) on the developmental stages and fecundity of the parasite Nematodirus spathiger. Thirty Merino lambs, maintained worm-free, were randomly divided among three treatment groups each containing ten animals. The group 1 lambs were each given a single dose of 50,000 infective larvae, the group 2 animals were given a single dose of 130,000 infective larvae, and the group 3 animals were given twenty-five consecutive daily doses of 2000 infective larvae. Group fecundity was estimated by performing worm egg counts on daily faecal samples and development of the parasite burden was followed by carrying out differential worm counts on animals slaughtered at crucial stages during the infections. Total fecundity was greatest in group 1 and least in group 3 with group 2 intermediate. An inverse relationship between total fecundity and percentage retardation of development (percentage of 4th-stage larvae in the total worm burden) was demonstrated between the three treatment groups.

The results of the studies also show that control of the parasitic infection is mediated about threshold levels of immunological responsiveness and is expressed by (1) elimination at the infective (L3) stage, (2) retardation of development at the L4 stage, (3) reduction in egg production of the adult female, (4) elimination of adult worms, and (5) discrimination against the female in both the degree of retardation in the L4 stage and the extent of elimination in the adult stage.

Great variation in response was observed between individuals within treatment groups. The source of variation is attributed to differences in degree of antigenic disparity of the parasite with individual members of the heterozygous host population in which antigenic characters are not uniformly segregated.

The concept of ‘fitness’ of the parasitic species was introduced into the discussion to provide a rational interpretation of the results.

We are indebted to Dr S. S. Y. Young, Division of Animal Genetics, C.S.I.R.O., for advice and assistance with the statistical analyses, which were performed by Mrs M. Tonkin, and to Dr D. F. Stewart for his constructive criticism of the manuscript. Careful technical assistance was given by Mr E. Teleki and Misses Helen Giller and Berenice Merchant.

Type
Research Article
Information
Parasitology , Volume 54 , Issue 3 , August 1964 , pp. 527 - 544
Copyright
Copyright © Cambridge University Press 1964

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

Brunsdon, R. V. (1962). Age resistance of sheep to infestation with the nematodes, Nemato-dirusfilicollisand Nematodirus spathiger. N.Z. vet. J. 10, 1–16.CrossRefGoogle Scholar
Dineen, J. K. (1963a). Immunological aspects of parasitism. Nature, Lond., 197, 268–9.CrossRefGoogle ScholarPubMed
Dineen, J. K. (1963 6). Antigenic relationship between host and parasite. Nature, Lond., 197, 471–2.CrossRefGoogle Scholar
Dunsmore, J. D. (1961). Effect of whole-body irradiation and cortisone on the development of Ostertagiaspp. in sheep. Nature, Lond., 192, 139–40.CrossRefGoogle ScholarPubMed
Gibson, T. E. (1953). The effect of repeated anthelmintic treatment with phenothiazine on the faecal egg counts of housed horses, with some observations on the life cycle of Tricho-nemaspp. in the horse. J. Helminth. 27, 29–40.CrossRefGoogle Scholar
Gordon, H. McL. & Whitlock, H. V. (1939). A new technique for counting nematode eggs in sheep faeces. J. Coun. sci. industr. Res. Aust. 12, 50–2.Google Scholar
Kates, K. C. (1950). Survival on pasture of free-living stages of some common gastrointestinal nematodes of sheep. Proc. helm. Soc. Wash. 17, 39–59.Google Scholar
Kates, K. C. & Turner, J. H. (1953). Observations on the life cycle of Nematodirus spathiger,a nematode parasitic in the intestine of sheep and other ruminants. Amer. J. vet. Res. 16, 105–15.Google Scholar
Kauzal, G. (1933). Seasonal incidence of gastro-intestinal parasites of fat sheep in New South Wales. Aust. vet. J. 9, 179–86.CrossRefGoogle Scholar
Michel, J. F. (1962). Studies on resistance to Dictyocaulusinfection. IV. The rate of acquisition of protective immunity in infection of D. viviparus. J. comp. Path. 72, 281–5.CrossRefGoogle ScholarPubMed
Roberts, F. H. S. & Keith, R. K. (1959). Observations on the effect of treatment with phenothiazine on the development of resistance by calves to infestation with the stomach worm, Haemonchus placei(Place 1893) Ransom 1911. Aust. vet. J. 35, 409–14.CrossRefGoogle Scholar
Seghetti, L. (1955). A method for mass recovery and hatching of Nematodirus eggs. Proc. helm. Soc. Wash. 22, 53–5.Google Scholar
Taylor, E. L. & Michel, J. F. (1953). The parasitological and pathological significance of arrested development in nematodes. J. Helminth. 27, 199–205.CrossRefGoogle Scholar
Whitlock, H. V. (1948). Some modifications of the McMaster helminth egg-counting technique and apparatus. J. Coun. sci. industr. Res. Aust. 21, 177–80.Google Scholar