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Malaria Research and Treatment
Volume 2016, Article ID 9694372, 6 pages
http://dx.doi.org/10.1155/2016/9694372
Research Article

Increased Prevalence of Mutant Allele Pfdhps 437G and Pfdhfr Triple Mutation in Plasmodium falciparum Isolates from a Rural Area of Gabon, Three Years after the Change of Malaria Treatment Policy

Department of Parasitology-Mycology and Tropical Medicine, Faculty of Medicine, Université des Sciences de la Santé, BP 4009, Libreville, Gabon

Received 23 October 2015; Revised 22 January 2016; Accepted 16 February 2016

Academic Editor: Donatella Taramelli

Copyright © 2016 Jacques-Mari Ndong Ngomo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

In Gabon, sulfadoxine-pyrimethamine (SP) is recommended for intermittent preventive treatment during pregnancy (IPTp-SP) and for uncomplicated malaria treatment through ACTs drug. P. falciparum strains resistant to SP are frequent in areas where this drug is highly used and is associated with the occurrence of mutations on Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthetase (Pfdhps) genes. The aim of the study was to compare the proportion of mutations on Pfdhfr and Pfdhps genes in isolates collected at Oyem in northern Gabon, in 2005 at the time of IPTp-SP introduction and three years later. Point mutations were analyzed by nested PCR-RFLP method. Among 91 isolates, more than 90% carried Pfdhfr 108N and Pfdhfr 59R alleles. Frequencies of Pfdhfr 51I (98%) and Pfdhps 437G (67.7%) mutant alleles were higher in 2008. Mutations at codons 164, 540, and 581 were not detected. The proportion of the triple Pfdhfr mutation and quadruple mutation including A437G was high: 91.9% in 2008 and 64.8% in 2008, respectively. The present study highlights an elevated frequency of Pfdhfr and Pfdhps mutant alleles, although quintuple mutations were not found in north Gabon. These data suggest the need of a continuous monitoring of SP resistance in Gabon.