Infection and Drug Resistance (Jan 2024)
Unraveling Key Chloroquine Resistance-Associated Alleles Among Plasmodium falciparum Isolates in South Darfur State, Sudan Twelve Years After Drug Withdrawal
Abstract
Abdalmoneim M Magboul,1 Bakri YM Nour,2 Abdelhakam G Tamomh,1 Rashad Abdul-Ghani,3,4 Sayed Mustafa Albushra,5 Hanan Babiker Eltahir6 1Department of Parasitology & Medical Entomology, Faculty of Medical Laboratory Sciences, University of El Imam El Mahdi, Kosti, Sudan; 2Department of Parasitology, Faculty of Medical Laboratory Sciences, University of Gezira, Wad Madani, Sudan; 3Department of Medical Parasitology, Faculty of Medicine and Health Sciences, Sana’a University, Sana’a, Yemen; 4Tropical Disease Research Center, Faculty of Medicine and Health Sciences, University of Science and Technology, Sana’a, Yemen; 5Department of Internal Medicine, Faculty of Medicine, University of Gezira, Wad Madani, Sudan; 6Department of Biochemistry, Faculty of Medicine, University of El Imam El Mahdi, Kosti, SudanCorrespondence: Abdelhakam G Tamomh, Email [email protected]; [email protected]: Due to the increasing resistance of Plasmodium falciparum to chloroquine (CQ) in Sudan, a shift from CQ to artesunate combined with sulfadoxine/pyrimethamine as a first-line treatment for uncomplicated falciparum malaria was adopted in 2004. This study aimed to determine the frequency distribution of K76T and N86Y mutations in P. falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes as key markers of resistance to CQ among P. falciparum isolates from patients in Nyala district of South Darfur state, west of Sudan.Methods: A descriptive, cross-sectional study was conducted among 75 P. falciparum isolates from Sudanese patients diagnosed with falciparum malaria mono-infection. Parasite DNA was extracted from dried blood spots and amplified using a nested polymerase chain reaction (PCR). Then, restriction fragment length polymorphism (RFLP) was used to detect the genetic polymorphisms in codons 76 of pfcrt and 86 of pfmdr1. PCR-RFLP products were analyzed using 1.5% gel electrophoresis to identify the genetic polymorphisms in the studied codons. The wild-type (pfcrt K76 and pfmdr1 N86), mutant (pfcrt 76T and pfmdr1 86Y) and mixed-type (pfcrt K76T and pfmdr1 N86Y) alleles were expressed as frequencies and proportions.Results: The wild-type pfcrt K76 allele was observed among 34.7% of isolates and the mutant 76T allele among 20% of isolates, while the mixed-type K76T allele was observed among 45.3% of isolates. On the other hand, 54.7% of isolates harbored the wild-type pfmdr1 N86 allele and 5.3% of isolates had the mutant 86Y allele, while the mixed-type N86Y allele was observed among 40% of isolates.Conclusion: The key molecular markers associated with CQ resistance (pfcrt 76T and pfmdr1 86Y) are still circulating in high frequency among P. falciparum isolates in South Darfur state, about twelve years after the official withdrawal of the drug as a treatment for uncomplicated falciparum malaria.Keywords: chloroquine, drug resistance, molecular markers, pfcrt, pfmdr1, Sudan
