Related Experiment Videos
Gene amplification in amphotericin B-resistant Leishmania tarentolae
A K Singh1, B Papadopoulou, M Ouellette
1Département de Microbiologie, Centre de Recherche en Infectiologie du Centre de Recherche du CHUL, Faculté de Medicine, Université Laval, Ste-Foy, Québec, G1V 4G2, Canada.
Experimental Parasitology
|February 16, 2002
Summary
Researchers developed drug resistance in Leishmania tarentolae cells against amphotericin B. DNA amplification in extrachromosomal circles correlated with resistance, suggesting complex genetic mechanisms.
Area of Science:
- Parasitology
- Molecular Biology
- Drug Resistance Studies
Background:
- Leishmania tarentolae is a model organism for studying the parasite Leishmania.
- Amphotericin B is a crucial second-line treatment for leishmaniasis.
- Understanding drug resistance mechanisms is vital for effective disease treatment.
Purpose of the Study:
- To investigate the genetic basis of amphotericin B resistance in Leishmania tarentolae.
- To characterize DNA amplification events associated with drug resistance.
- To explore the relationship between amplicon copy number and resistance levels.
Main Methods:
- Stepwise selection of Leishmania tarentolae for resistance to amphotericin B.
- Analysis of DNA amplification and characterization of amplicons (extrachromosomal circles).
- Gene transfection experiments to assess the role of amplified loci in resistance.
Main Results:
- Developed amphotericin B-resistant Leishmania tarentolae mutants, with one also showing ketoconazole cross-resistance.
- Observed DNA amplification resulting in stable, extrachromosomal circles derived from different chromosomes.
- Established a correlation between amplicon copy number and resistance levels.
- Transfection studies suggested a complex interplay of mutations, not a simple amplification-resistance link.
Conclusions:
- DNA amplification, particularly extrachromosomal circles, is a mechanism for developing amphotericin B resistance in Leishmania.
- The development of resistance is likely multifactorial, involving multiple mutations.
- Further research is needed to fully elucidate the complex genetic pathways conferring drug resistance in Leishmania.