High prevalence of sulfadoxine/pyrimethamine-resistant alleles of Plasmodium falciparum isolates in pregnant women at the time of introduction of intermittent preventive treatment with sulfadoxine/pyrimethamine in Gabon.
OBJECTIVE
The frequency of dhfr and dhps point mutations was assessed in Plasmodium falciparum isolates from pregnant women in Libreville.


METHODS
PCR-restriction fragment length polymorphism of polymorphic codons of the dhfr gene (51, 59 and 108) and the dhps gene (436, 437 and 540) was performed in matched peripheral and placental blood samples.


RESULTS
The proportion of multiple mutations was high (98%), and was not different between women with and without a history of intermittent preventive treatment with sulfadoxine/pyrimethamine (IPTp/SP). The prevalence of triple dhfr mutation was 80%, and that of quadruple and quintuple mutations was 53% and 22%, respectively. The Glu540 mutation was present in two isolates. The concordance of resistant alleles in matched peripheral and placental isolates was >90% for both genes.


CONCLUSIONS
These findings underline the need for a regular assessment of the relationship between the presence of resistant isolates and in vitro/in vivo IPTp/SP efficacy, and evaluation of an alternative drug.
Bouyou-Akotet
Marielle Karine
MK
Department of Parasitology, Mycology and Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, Libreville, Gabon. mariellebouyou@gmail.com
Mawili-Mboumba
Denise Patricia
DP
Tchantchou
Tanguy de Dieu
Tde D
Kombila
Maryvonne
M
D000483:Alleles; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D001769:Blood / Q000469:parasitology; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004094:Dihydropteroate Synthase / Q000235:genetics; D004338:Drug Combinations; D004351:Drug Resistance; D005260:Female; D005681:Gabon; D005838:Genotype; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology*; D020125:Mutation, Missense; D010920:Placenta / Q000469:parasitology; D010963:Plasmodium falciparum / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000469:parasitology*; D015995:Prevalence; D015800:Protozoan Proteins / Q000235:genetics*; D011739:Pyrimethamine / Q000494:pharmacology*; D013413:Sulfadoxine / Q000494:pharmacology*; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics
D000962:Antimalarials; D004338:Drug Combinations; D015800:Protozoan Proteins; C001205:fanasil, pyrimethamine drug combination; D013413:Sulfadoxine; D013762:Tetrahydrofolate Dehydrogenase; D004094:Dihydropteroate Synthase; D004262:DNA Restriction Enzymes; D011739:Pyrimethamine