Plasmodium falciparum: high frequency of pfcrt point mutations and emergence of new mutant haplotypes in Colombia.
BACKGROUND
Studies on the molecular epidemiology of antimalarial resistance constitute a useful tool to understand the events underlying treatment failure and resistance in falciparum malaria in Colombia. Several authors have reported on the efficacy of some molecular markers to predict drug resistance in Plasmodium falciparum. The P. falciparum pfcrt gene has been widely characterized in this context.


OBJECTIVE
The frequency of pfcrt gene mutations in P. falciparum were associated with treatment failure to the antimalarials chloroquine, mefloquine, amodiaquine and sulfadoxine/pyrimethamine.


METHODS
A representative sample of 172 patients with non-complicated falciparum malaria was selected from two highly malaria-endemic areas of northeastern Colombia, the Turbo and Bajo Cauca regions. These patients were assessed for treatment response together with the status of codons 72, 74, 75 and 76 in the pfcrt gene using a PCR-RFLP approach.


RESULTS
A high frequency of treatment failure to chloroquine (82%) and to amodiaquine (29%) was confirmed, whereas mefloquine and combined therapy remained effective. The presence of the T76 mutation in pfcrt was confirmed in all samples. The most common haplotype was CMNT (67%).


CONCLUSIONS
No significant association was confirmed between specific haplotypes and the treatment response in any of the treatment groups. Two haplotypes, SMET and SMNT, were reported for the first time in Colombia. Twelve percent of the samples carried both mixed mutant and wild-type alleles.
Restrepo
Eliana
E
Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
Carmona-Fonseca
Jaime
J
Maestre
Amanda
A
D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D003105:Colombia; D004351:Drug Resistance; D005260:Female; D006239:Haplotypes; D006801:Humans; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics*; D010963:Plasmodium falciparum / Q000235:genetics*; D017354:Point Mutation; D015800:Protozoan Proteins / Q000235:genetics*
D000962:Antimalarials; D015415:Biomarkers; D026901:Membrane Transport Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins