Hostname: page-component-7c8c6479df-27gpq Total loading time: 0 Render date: 2024-03-28T16:56:03.441Z Has data issue: false hasContentIssue false

The inheritance of thiabendazole resistance in Haemonchus contortus

Published online by Cambridge University Press:  06 April 2009

L. F. Le Jambre
Affiliation:
CSIRO Division of Animal Health, Pastoral Research Laboratory, Armidale, N.S.W. 2350
W. M. Royal
Affiliation:
CSIRO Division of Animal Health, Pastoral Research Laboratory, Armidale, N.S.W. 2350
P. J. Martin
Affiliation:
CSIRO Division of Animal Health, Pastoral Research Laboratory, Armidale, N.S.W. 2350

Summary

Haemonchus contortus worm populations isolated from naturally infected sheep at the Pastoral Research Laboratory, Armidale, N.S.W., were found to contain approximately 20% of worms resistant to a 50 mg/kg dose of thiabendazole. Following 3 generations of selection with 50 mg/kg thiabendazole the number of worms removed by the anthelmintic was too small to detect differences between treated and control groups. After more than 15 generations of selection, matings between males from the selected strain and non-resistant females produced resistant males and females in equal numbers. Thus, thiabendazole resistance does not appear to be sex-linked. A dose–response assay on the F2 adults indicated that worms from female resistant × male non-resistant crosses were more resistant than F2 adults of the reciprocal cross. An in vitro technique that identified thiabendazole-resistant eggs by their ability to hatch in a solution containing thiabendazole and 0·1% NaCl solution was also used to study the inheritance of resistance. F1 eggs had similar LC50's to the resistant parents. F2 and back-cross eggs from an original mating of thiabendazole-resistant females × non-resistant males had a higher LC50 than F2 and back-cross eggs from the reciprocal mating, indicating a degree of matroclinous inheritance of resistance. However, the resistant parents had tolerances to thiabendazole exceeding those of F2. F3 eggs had a resistance distribution that ranged from that of the resistant to the non-resistant parent. No significant deviation from linearity was observed in any of the dose–response lines. These results indicate that thiabendazole resistance in H. contortus worms is inherited as an autosomal and semi-dominant trait.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1979

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

Bliss, C. I. (1967). Statistics in Biology, vol. 1. New York: McGraw-Hill.Google Scholar
Brown, H. D., Matzuk, A. R., Ilves, I. R., Peterson, L. H., Harris, S. A., Sarett, L. H., Egerton, J. R., Yakstis, J. J., Campbell, W. A. & Cuckler, A. C. (1961). Antiparasitic drugs. IV. 2-(4'-Thaizolyl)-benzimidazole, a new anthelmintic. Journal of the American Chemical Society 83, 1764–5.CrossRefGoogle Scholar
Drudge, J. H., Szanto, J., Wyant, Z. N. & Elam, G. (1964). Field studies on parasite control in sheep: comparison of thiabendazole, ruelene and phenothiazine. American Journal of Veterinary Research 25, 1512–18.Google ScholarPubMed
Georghiou, G. P. (1965). Genetic studies on insecticide resistance. Advances in Pest Control Research 6, 171230.Google ScholarPubMed
Hoskins, W. M. (1960). Use of the dosage–mortality curve in quantitative estimation of insecticide resistance. Miscellaneous Publication Entomological Society of America 2, 8591.Google Scholar
Hoskins, W. M. & Gordon, H. T. (1956). Arthropod resistance to chemicals. Annual Review of Entomology 1, 89122.CrossRefGoogle Scholar
Le Jambre, L. F. (1976). Egg hatch as an in vitro assay of thiabendazole resistance in nematodes. Veterinary Parasitology 2, 285391.CrossRefGoogle Scholar
Le Jambre, L. F., Crofton, H. D. & Whitlock, J. H. (1970). An assay technique for nematode egg hatchability. Transactions of the American Microscopic Society 89, 397406.CrossRefGoogle Scholar
Le Jambre, L. F., Southcott, W. H. & Dash, K. M. (1976). Resistance of selected lines of Haemonchus contortus to thiabendazole, morantel tartrate and levamisole. International Journal for Parasitology 6, 217–22.CrossRefGoogle ScholarPubMed
Le Jambre, L. F. & Royal, W. M. (1977). Genetics of vulvar morph types in Haemonchus contortus: Haemonchus contortus from the Northern Tablelands of New South Wales. International Journal for Parasitology 7, 481–7.CrossRefGoogle Scholar
May, P. F. & Ellem, B. M. (1976). On parallel regression. CSIRO Division of Mathematics and Statistics Newsletter 21, 8.Google Scholar
McFarland, J. W. (1972). The chemotherapy of intestinal nematodes. Progress in Drug Research 16, 157–93.Google ScholarPubMed