Co-existence of Dihydrofolate Reductase (dhfr108) Gene with Plasmodium falciparum Chloroquine Resistance Transporter Gene (Pfcrt T76) in P. falciparum Isolates from Gezira State, Central Sudan

Malaria parasite multi-drug resistance poses serious health problems in tropical countries. The aim of this study was to assess the Sulfadoxine-pyrimethamine (S/P) resistance of Plasmodium falciparum parasite in central Sudan, using the molecular markers. The genotying of P. falciparum parasite from forty-four patients using RFLP and PCR showed that the polymorphism of dhfr gene was in codons 51, 59 and 108. In codon 51; two strains (4.5%) were mutant type; 3 (6.8%) were found as mixed infection (both mutant and wild types) and 28 (63.6%) were found as wild type. One sample (2.2 %) was dhfr 59 mutant and 31 (70.4. %) were wild type, while 14 (31.8%) were dhfr 108 mutant; three (6.8%) were found as mixed infection and 24 (54.5%) were wild types. The Screening of dhps 540 polymorphisms of the gene revealed that 2 (4.5%) were found as mixed infection, and 42 (95.5%) as wild type. Fifteen samples were analyzed for Pfcrt T76, and Pfmdr-1 Y 86 for CQ resistant polymorphisms from the current study, the result showed that 33.3% were found to be mutant at dhfr 108 and PfcrtT76 genes reflecting the link between dhfr108 and Pfcrt76 genes. In conclusion, the polymorphism in the dhfr and dhps genes in central Sudan are increasing, but less abundant compared to the neighboring countries. However, the current studies indicate the link between dhfr108 and Pfcrt76 genes. Therefore, further study is need for using the S/P in areas that confirmed with chloroquine resistant strains.