Characterization of Plasmodium falciparum isolated from the Amazon region of Brazil: Evidence for quinine resistance

123Citations
Citations of this article
55Readers
Mendeley users who have this article in their library.

Abstract

The prevalence and severity of drag-resistant malaria is emerging rapidly in the Amazon basin of Brazil. In support of clinical trials using the new antimalarial drug combination of atovaquone and proguanil, we performed in vitro drug sensitivities, molecular characterization of parasite populations using the circumsporozoite protein, merozoite surface antigen-1 (MSA-1), and MSA-2 markers, and an analysis of the Plasmodium falciparum multidrug resistance (pfmdr1) gene sequence and copy number in 26 isolates of P. falciparum obtained in a gold-mining endemic area in Peixoto de Azevedo, Mato Grosso State. All 26 isolates were found to be resistant to chloroquine (50% inhibitory concentration [IC50] = 100-620 nM) and sensitive to mefloquine (IC50 < 23 nM) and halofantrine (IC50 < 6 nM). The isolates also show reduced susceptibility to quinine (IC50 = 48-280 nM). Sequence analysis of the pfmdr1 gene revealed Asn, Phe, Cys, Asp, and Tyr in positions 86, 184, 1034, 1042, and 1246, respectively. These point mutations were similar to that previously described in other Brazilian isolates. Southern blot analysis revealed no amplification of the pfmdr1 gene. These results suggest that three different mechanisms for drug resistance exist for chloroquine, mefloquine, and quinine.

Cite

CITATION STYLE

APA

Zalis, M. G., Pang, L., Silveira, M. S., Milhous, W. K., & Wirth, D. F. (1998). Characterization of Plasmodium falciparum isolated from the Amazon region of Brazil: Evidence for quinine resistance. American Journal of Tropical Medicine and Hygiene, 58(5), 630–637. https://doi.org/10.4269/ajtmh.1998.58.630

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free