Presence of pyrimethamine and cycloguanil resistance genotype in West Africa? Evidence of a single mutation 59Arg in the dhfr gene of Plasmodium falciparum.

In 3 different geographical areas of West Africa (Guinea-Bissau, S. Tomé e Princípe and Angola) where chloroquine activity against P. falciparum seems to have decreased, the choice for prevention and/or treatment of malaria is often based on second line drugs such as Fansidar® (pyrimethamine/sulphadoxine). Little is known about the genetic basis of dhfr-ts gene mutations from parasites from these areas. In this study a PCR/RFLP methodology was used to screen 33 field isolates, without intervening steps of in vitro culture, for the pyrimethamine and cycloguanil sensitive/resistant genotype of P. falciparum. Analysis of the digested fragments revealed a prevalence of a Ser108 to Asn108 change in 63.63% of the samples tested.In 3 different geographical areas of West Africa (Guinea-Bissau, S. Tomé e Princípe and Angola) where chloroquine activity against P. falciparum seems to have decreased, the choice for prevention and/or treatment of malaria is often based on second line drugs such as Fansidar® (pyrimethamine/sulphadoxine). Little is known about the genetic basis of dhfr-ts gene mutations from parasites from these areas. In this study a PCR/RFLP methodology was used to screen 33 field isolates, without intervening steps of in vitro culture, for the pyrimethamine and cycloguanil sensitive/resistant genotype of P. falciparum. Analysis of the digested fragments revealed a prevalence of a Ser108 to Asn108 change in 63.63% of the samples tested