Journal ArticleDOI
Pyrimethamine and Proguanil Resistance-Conferring Mutations in Plasmodium falciparum Dihydrofolate Reductase: Polymerase Chain Reaction Methods for Surveillance in Africa
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TLDR
Methods for collecting fingerstick blood onto filter paper strips that are air-dried, then stored and transported at room temperature and a nested PCR technique that has improved sensitivity and specificity are reported.Abstract:
As chloroquine resistance spreads across Africa, the dihydrofolate reductase (DHFR) inhibitors pyrimethamine and proguanil are being used as alternative first-line drugs for the treatment and prevention of Plasmodium falciparum malaria. Resistance to these drugs is conferred by point mutations in parasite DHFR. These point mutations can be detected by polymerase chain reaction (PCR) assays, but better methods for sample collection, DNA extraction, and a diagnostic PCR are needed to make these assays useful in malaria-endemic areas. Here we report methods for collecting fingerstick blood onto filter paper strips that are air-dried, then stored and transported at room temperature. Cell lysis and DNA extraction are accomplished by boiling in Chelex-100. We also report a nested PCR technique that has improved sensitivity and specificity. These procedures readily detect mixed infections of parasites with both sensitive and resistant genotypes (confirmed by direct sequencing) and are reliable at parasite densities less than 250/mm3 in field surveys.read more
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Journal ArticleDOI
Antimicrobial resistance in developing countries.
TL;DR: Better access to diagnostic laboratories is needed, as well as improved surveillance of the emergence of resistance, better regulation of antibiotics' use, and better education of the public, physicians, and veterinarians in the appropriate use of drugs.
Journal ArticleDOI
Molecular Markers for Failure of Sulfadoxine-Pyrimethamine and Chlorproguanil-Dapsone Treatment of Plasmodium falciparum Malaria
James G. Kublin,Fraction K. Dzinjalamala,Deborah D. Kamwendo,Elissa M. Malkin,Joseph F. Cortese,Lisa M. Martino,Rabia A G Mukadam,Stephen J. Rogerson,Andres G. Lescano,Malcolm E. Molyneux,Malcolm E. Molyneux,Peter Winstanley,Phillips Chimpeni,Terrie E. Taylor,Christopher V. Plowe +14 more
TL;DR: Infections caused by parasites with 3 DHFR mutations and 2 DHPS mutations (the "quintuple mutant") were associated with sulfadoxine-pyrimethamine treatment failure but not with chlorproguanil-dapsone treatment failure.
Journal ArticleDOI
Mechanisms of Resistance of Malaria Parasites to Antifolates
TL;DR: Molecular epidemiological techniques for monitoring parasite drug resistance may contribute to development of strategies for prolonging the useful therapeutic life of this important class of drugs.
Journal ArticleDOI
Mutations in Plasmodium falciparum Dihydrofolate Reductase and Dihydropteroate Synthase and Epidemiologic Patterns of Pyrimethamine-Sulfadoxine Use and Resistance
Christopher V. Plowe,Joseph F. Cortese,Abdoulaye A. Djimde,Okey C. Nwanyanwu,William M. Watkins,Peter A. Winstanley,Jose G. Estrada Franco,René Mollinedo,Juan Carlos Avila,Jose Luis Cespedes,Darrick Carter,Ogobara K. Doumbo +11 more
TL;DR: Identification of specific sets of mutations causing in vivo drug failure may lead to the development of molecular surveillance methods for pyrimethamine-sulfadoxine resistance.
Journal ArticleDOI
Return of Chloroquine Antimalarial Efficacy in Malawi
Miriam K. Laufer,Phillip C. Thesing,Nicole D. Eddington,Rhoda Masonga,Fraction K. Dzinjalamala,Shannon L. Takala,Terrie E. Taylor,Christopher V. Plowe +7 more
TL;DR: Chloroquine is again an efficacious treatment for malaria, 12 years after it was withdrawn from use in Malawi.