Determinación de la mutación asn-108 del gen dhfr de Plasmodium Falciparum asociada con resistencia «in vitro» a pirimetamina en aislados del departamento de Sucre, Colombia

Abstract

The malaria is an infectious disease caused by  Plasmodium parasites.  Plasmodium falciparum is the responsible of the most severe form of the disease. The report of cases of malaria in Sucre (Colombia) increased of 371 in 2000 to 611 in 2004, according to data of the epidemiology department of DASSALUD; in spite of this, studies published about of causes of this increase do not exist. One of the factors related to the increase of the morbidity and mortality by malaria at world is the resistance that  P. falciparum has developed towards antimalarials drugs . The resistance to pirimetamina has been related to point mutations in the gene that codifies for the Dihydrofolate reductase (DHFR), component of the biosynthetic route of folate of the parasite. The objective of the present study was to detect the presence in Sucre, of  P.falciparum strain with the Asn 108 DHFR mutation, associated with  in vitro pyrimethamine resistance. The investigation was carried out between October of 2002 and March of 2004. The detection of the wild genotype Ser- 108 and the mutant genotype Asn -108 was made by allele specific PCR. During the study 122 cases of  falciparum  malaria were reported, of which 6.6 % were native infections and 93.4% were acquired in endemic departments. Of 36 analyzed samples by PCR, 27.7 % displayed the genotype Asn -108, the rest of the samples displayed the genotype Ser -108. These results indicate that one of the main causes of the increase of registered malaria cases in Sucre, are the migrations and frequent flow of infected people, originating of endemic region. This is an important factor by the appearance of native infection and favors the introduction of  P. falciparum strain with resistance to pirimetamina.