title: RDTs as a source of DNA to study Plasmodium falciparum drug resistance in isolates from Senegal and the Comoros Islands.
abstract: BACKGROUND
  The World Health Organization has recommended rapid diagnostic tests (RDTs) for use in the diagnosis of suspected malaria cases. In addition to providing quick and accurate detection of Plasmodium parasite proteins in the blood, these tests can be used as sources of DNA for further genetic studies. As sulfadoxine-pyrimethamine is used currently for intermittent presumptive treatment of pregnant women in both Senegal and in the Comoros Islands, resistance mutations in the dhfr and dhps genes were investigated using DNA extracted from RDTs.
  
  
  METHODS
  The proximal portion of the nitrocellulose membrane of discarded RDTs was used for DNA extraction. This genomic DNA was amplified using HRM to genotype the molecular markers involved in resistance to sulfadoxine-pyrimethamine: dhfr (51, 59, 108, and 164) and dhps (436, 437, 540, 581, and 613). Additionally, the msp1 and msp2 genes were amplified to determine the average clonality between Grande-Comore (Comoros) and Thiès (Senegal).
  
  
  RESULTS
  A total of 201 samples were successfully genotyped at all codons by HRM; whereas, in 200 msp1 and msp2 genes were successfully amplified and genotyped by nested PCR. A high prevalence of resistance mutations were observed in the dhfr gene at codons 51, 59, and 108 as well as in the dhps gene at codons 437 and 436. A novel mutant in dhps at codon positions 436Y/437A was observed. The dhfr I164L codon and dhps K540 and dhps A581G codons had 100 % wild type alleles in all samples.
  
  
  CONCLUSIONS
  The utility of field-collected RDTs was validated as a source of DNA for genetic studies interrogating frequencies of drug resistance mutations, using two different molecular methods (PCR and High Resolution Melting). RDTs should not be discarded after use as they can be a valuable source of DNA for genetic and epidemiological studies in sites where filter paper or venous blood collected samples are nonexistent.
authors.affiliation: Laboratory of Bacteriology-Virology, Hospital Aristide Le Dantec, 7325, Dakar, Senegal. npapamze@gmail.com.
authors.forename: Nasserdine
authors.initials: N
authors.lastname: Papa Mze
authors.affiliation: Laboratoire of Parasitology and Mycology, Faculty of Medicine and Pharmacy, Cheikh Anta Diop University, 5005, Dakar, Senegal. ydndiaye@gmail.com.
authors.forename: Yaye Die
authors.initials: YD
authors.lastname: Ndiaye
authors.affiliation: Laboratory of Bacteriology-Virology, Hospital Aristide Le Dantec, 7325, Dakar, Senegal. cyrille.diedhiou@gmail.com.
authors.forename: Cyrille K
authors.initials: CK
authors.lastname: Diedhiou
authors.affiliation: Laboratory of National Malaria Control Programme, Moroni, Comoros. rsilai.pnlp@laposte.net.
authors.forename: Silai
authors.initials: S
authors.lastname: Rahamatou
authors.affiliation: Laboratoire of Parasitology and Mycology, Faculty of Medicine and Pharmacy, Cheikh Anta Diop University, 5005, Dakar, Senegal. dieyebaba2004@yahoo.fr.
authors.forename: Baba
authors.initials: B
authors.lastname: Dieye
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, MA, 02115, USA. rdaniels@broadinstitute.org.
authors.forename: Rachel F
authors.initials: RF
authors.lastname: Daniels
authors.affiliation: Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA. ejhamilto@gmail.com.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Hamilton
authors.affiliation: Laboratory of Bacteriology-Virology, Hospital Aristide Le Dantec, 7325, Dakar, Senegal. misbax@gmail.com.
authors.forename: Mouhamadou
authors.initials: M
authors.lastname: Diallo
authors.affiliation: Laboratory of Bacteriology-Virology, Hospital Aristide Le Dantec, 7325, Dakar, Senegal. abei@hsph.harvard.edu.|Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, MA, 02115, USA. abei@hsph.harvard.edu.
authors.forename: Amy K
authors.initials: AK
authors.lastname: Bei
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, MA, 02115, USA. dfwirth@hsph.harvard.edu.|Broad Institute: The Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA. dfwirth@hsph.harvard.edu.
authors.forename: Dyann F
authors.initials: DF
authors.lastname: Wirth
authors.affiliation: Laboratory of Bacteriology-Virology, Hospital Aristide Le Dantec, 7325, Dakar, Senegal. mboup@rarslbv.org.
authors.forename: Souleymane
authors.initials: S
authors.lastname: Mboup
authors.affiliation: Department of Immunology and Infectious Diseases, Harvard TH Chan School of Public Health, Boston, MA, 02115, USA. svolkman@hsph.harvard.edu.|Broad Institute: The Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA. svolkman@hsph.harvard.edu.|School of Nursing and Health Sciences, Simmons College, Boston, MA, 02115, USA. svolkman@hsph.harvard.edu.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Volkman
authors.affiliation: Laboratory of Bacteriology-Virology, Hospital Aristide Le Dantec, 7325, Dakar, Senegal. aahouidi@gmail.com.
authors.forename: Ambroise D
authors.initials: AD
authors.lastname: Ahouidi
authors.affiliation: Laboratoire of Parasitology and Mycology, Faculty of Medicine and Pharmacy, Cheikh Anta Diop University, 5005, Dakar, Senegal. dndiaye@hsph.harvard.edu.
authors.forename: Daouda
authors.initials: D
authors.lastname: Ndiaye
mesh_terms: D000962:Antimalarials / Q000494:pharmacology; D001483:Base Sequence; D017507:Comoros / Q000453:epidemiology; D016054:DNA, Protozoan / Q000235:genetics*; D004351:Drug Resistance / Q000235:genetics*; D006801:Humans; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000469:parasitology; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010274:Parasitology; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics*; D015995:Prevalence; D015800:Protozoan Proteins / Q000235:genetics; D011933:Reagent Kits, Diagnostic / Q000469:parasitology*; D012675:Senegal / Q000453:epidemiology
chemical_list: D000962:Antimalarials; D016054:DNA, Protozoan; D015800:Protozoan Proteins; D011933:Reagent Kits, Diagnostic