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Reduced accumulation of isometamidium by drug-resistant Trypanosoma congolense

Published online by Cambridge University Press:  06 April 2009

I. A. Sutherland ,
A. S. Peregrine ,
J. D. Lonsdale-Eccles  and
P. H. Holmes
I. A. Sutherland
Affiliation:
University of Glasgow Veterinary School, Bearsden Road, Glasgow G61 1QH, UK
A. S. Peregrine
Affiliation:
International Laboratory for Research on Animal Diseases(ILRAD), P. O. Box 30709, Nairobi, Kenya
J. D. Lonsdale-Eccles
Affiliation:
International Laboratory for Research on Animal Diseases(ILRAD), P. O. Box 30709, Nairobi, Kenya
P. H. Holmes
Affiliation:
University of Glasgow Veterinary School, Bearsden Road, Glasgow G61 1QH, UK
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Abstract

The accumulation of the trypanocide isometamidium chloride (Samorin®, RMB Animal Health Ltd, UK) by a range of clones of Trypanosoma congolense with varying sensitivity to the drug, was measured by methods based on the fluorescence of isometamidium. Fluorescence microscopy and flow cytometry showed a reduction in drug accumulation by resistant clones. Fluorescence spectrophotometry demonstrated an inverse correlation between the intensity of cell-associated fluorescence and the level of resistance of the clones expressed in vivo. The addition of the metabolic inhibitor SHAM/glycerol to the incubation medium resulted in a reduction of this apparent difference in drug accumulation between the clones; those clones which were sensitive to isometamidium showed a reduction in fluorescence while a percentage increase in fluorescence was observed as clones became more resistant to the trypanocide. These observations may be of value for the in vitro detection of resistant T. congolense populations and may also be used to estimate the mean level of resistance in a given sample. The results also imply that decreased accumulation of isometamidium by drug-resistant clones of the parasite may be responsible for the reduction in sensitivity.

Keywords

Trypanosoma congolenseisometamidium chloridechemo-resistancedrug accumulation
Type
Research Article
Information
Parasitology , Volume 103 , Issue 2 , October 1991 , pp. 245 - 251
Copyright
Copyright © Cambridge University Press 1991

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References

Beranek, A. P. (1974). Esterase variation and organophosphate resistance in populations of Aphis fabae and Myzus persicae. Entomologia Experimentalis et Applicata 17, 381–90.CrossRefGoogle Scholar
Bishop, A. (1959). Drug resistance in protozoa. Biological Reviews 34, 445–500.CrossRefGoogle Scholar
Boyt, W. P. (1985). A field guide for diagnosis, treatment and prevention in African animal trypanosomiasis. FAO Publication M/R 1662/E/5.85/1/1000.Google Scholar
Frommel, T. O. & Balber, A. E. (1987). Flow cytofluorimetric analysis of drug accumulation by multidrug-resistant Trypanosoma brucei brucei and T. b. rhodesiense. Molecular and Biochemical Parasitology 26, 183–92.CrossRefGoogle ScholarPubMed
Fairlamb, A. H., Opperdoes, F. R. & Borst, P. (1977). A new approach to screening drugs for activity against African trypanosomes. Nature, London 265, 270–1.CrossRefGoogle ScholarPubMed
Lanham, S. M. & Godfrey, D. G. (1970). Isolation of salivarian trypanosomes from man and older animals using DEAE-cellulose. Experimental Parasitology 28, 521–34.CrossRefGoogle Scholar
Opperdoes, F. R., Aarsen, P. N., Van Der Meer, C. & Borst, P. (1976). Trypanosome brucei: an evaluation of salicylhydroxamic acid as a trypanocidal drug. Experimental Parasitology 40, 198–205.CrossRefGoogle ScholarPubMed
Pinder, M. & Authie, E. (1984). The appearance of isometamidium resistant Trypanosoma congolense in West Africa. Acta Tropica 41, 247–52.Google ScholarPubMed
Rottcher, D. & Schillinger, D. (1985). Multiple drug resistance in Trypanosoma vivax in the Tana River District of Kenya. Veterinary Record 117, 557–8.CrossRefGoogle ScholarPubMed
Sones, K. R., Njogu, A. R. & Holmes, P. H. (1988). Assessment of sensitivity of Trypanosoma congolense to isometamidium chloride: a comparison of tests using cattle and mice. Acta Tropica 45, 153–64.Google ScholarPubMed
Sutherland, I. A., Lee, D. L. & Lewis, D. (1988). Detection of benzimidazole resistance in trichostrongylid nematodes. Parasitology Today 4, 22–4.CrossRefGoogle ScholarPubMed
Whitelaw, D. D., Bell, I. R., Holmes, P. H., Moloo, S. K., Hirumi, H., Urquhart, G. M. & Murray, M. (1986). Isometamidium chloride prophylaxis against Trypanosoma congolense challenge and the development of immune responses in Boran cattle. Veterinary Record 118, 722–6.CrossRefGoogle ScholarPubMed