Characterization of putative drug resistant markers in Plasmodium falciparum isolated in Ghanaian blood donors

Abstract

Background: Plasmodium falciparum parasites are commonly detected in blood donors in malaria-endemic areas. Even though few cases of transfusion-transmitted malaria have been reported, this study sought to establish the relative proportions of putative anti-malaria drug biomarkers in Ghanaian blood donors. Methods & Materials: Blood donors were randomly selected from five districts in Greater Accra region, Ghana. Each donor sample was screened with SD Bioline rapid diagnostic test kit (RDT). Dry blood spots were prepared from positive samples and shipped to Malaria Genome Laboratory, Wellcome Sanger Institute, Hinxton-UK for sequencing by genotyping of Pfcrt, Pfmdr1, Pfdhfr, Pfdhps and Kelch 13 genes. Results: A total of 771 blood donors were sampled out of which 91 (11.8%) were confirmed infected by RDT. Analysis of sequence reads indicated successful genotyping of Pfcrt, Pfmdr1, Pfdhfr, Pfdhps and Kelch 13 genes in 67 (73.6%), 64 (70.3%), 69 (75.8%), 69 (75.8%) and 84 (92.3%) of the genotyped isolates respectively. Of the total isolates, 191 different mutant haplotypes and single nucleotide polymorphisms were identified. In Pfcrt, CVIET haplotype was observed in 9 (13.4%) samples. In Pfmdr1, NFD, NYY, YFN and NFY haplotypes were identified in 4 (6.3%), 4 (6.3%), 6 (9.4%) and 8 (12.5%) samples respectively. In Pfdhfr gene single [NRSI, n = 17 (24.6%); NCNI, n = 20 (28.9%)], double [IRNI, n = 13 (18.8%); NRNI, n = 6 (8.6%)] and triple [IRNI, n = 6 (8.6%)] mutations were observed while in Pfdhps gene, the following haplotypes were seen: SGKAA (n = 19, 27.5%), AGKAA (n = 17, 24.6%), AGKAS (n = 13, 18.8%), AGKSA (n = 9, 13.0%), FGKAS (n = 5, 7.2%), AGKSS (n = 5, 7.2%) and AGESS (n = 1, 1.4%). Finally, in Kelch 13 gene, four non-synonymous mutations were identified in 11 isolates; P615L (n = 4, 4.8%), A578S (n = 4, 4.8%), I543 V (n = 2, 2.4%) and A676S (n = 1, 1.2%). Conclusion: The results obtained in this study indicated up to 28.9% risk of being transmitted with anti-malaria drug resistant gene during transfusion of P. falciparum infected blood. However, not higher than 12.5% putative drug resistant biomarkers could reduce efficacy of artemisinin combination therapy.