Related Experiment Videos
Quinacrine-resistant Giardia duodenalis
J A Upcroft1, R W Campbell, P Upcroft
1Queensland Institute of Medical Research, Brisbane, Australia.
Parasitology
|March 1, 1996
Summary
Quinacrine resistance was induced in Giardia duodenalis, with resistant strains actively excluding the drug. Pre-existing resistance to other drugs influenced quinacrine adaptation.
Area of Science:
- Parasitology
- Molecular Biology
- Drug Resistance Studies
Background:
- Giardia duodenalis is a significant enteric protozoan parasite.
- Drug resistance is a growing concern for treating giardiasis.
- Quinacrine is an antimalarial drug with antiprotozoal activity.
Purpose of the Study:
- To investigate the mechanisms of quinacrine resistance in Giardia duodenalis.
- To determine if pre-existing drug resistance affects quinacrine susceptibility.
Main Methods:
- Induction of quinacrine resistance in Giardia duodenalis laboratory stocks.
- Maintenance of resistant lines at lethal quinacrine concentrations (5-20 microM).
- Fluorescence microscopy to study drug uptake and localization in sensitive and resistant trophozoites.
Main Results:
- Quinacrine resistance was successfully induced in Giardia duodenalis.
- Resistant trophozoites actively excluded quinacrine, unlike sensitive cells.
- No specific intracellular accumulation sites for quinacrine were identified.
- Parasite lines with prior furazolidone resistance adapted more readily to quinacrine.
Conclusions:
- Giardia duodenalis can develop resistance to quinacrine through active drug exclusion.
- Cross-resistance patterns suggest varying degrees of cross-resistance with other antiprotozoal drugs.
- Understanding these resistance mechanisms is crucial for developing effective giardiasis treatments.