Molecular surveillance of Plasmodium vivax dhfr and dhps mutations in isolates from Afghanistan

• Published in: Malaria Journal
• Main Authors: Butt Waqar, Safi Najibullah, Raeisi Ahmad, Ghasemi Faezeh, Afsharpad Mandana, Zakeri Sedigheh, Atta Hoda, Djadid Navid D
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2010
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1186/1475-2875-9-75; https://doaj.org/article/4c61f27de6f14ac78bcc8b430f4aca4d

Abstract Background Analysis of dihydrofolate reductase ( dhfr ) and dihydropteroate synthase ( dhps ) mutations in Plasmodium vivax wild isolates has been considered to be a valuable molecular approach for mapping resistance to sulphadoxine-pyrimethamine (SP). The present study investigates the frequency of SNPs-haplotypes in the dhfr and dhps genes in P. vivax clinical isolates circulating in two malaria endemic areas in Afghanistan. Methods P. vivax clinical isolates (n = 171) were collected in two different malaria endemic regions in north-west (Herat) and east (Nangarhar) Afghanistan in 2008. All collected isolates were analysed for SNP-haplotypes at positions 13, 33, 57, 58, 61, 117 and 173 of the pvdhfr and 383 and 553 of the pvdhps genes using PCR-RFLP methods. Results All 171 examined isolates were found to carry wild-type amino acids at positions 13, 33, 57, 61 and 173, while 58R and 117N mutations were detected among 4.1% and 12.3% of Afghan isolates, respectively. Based on the size polymorphism of pvdhfr genes at repeat region, type B was the most prevalent variant among Herat (86%) and Nangarhar (88.4%) isolates. Mixed genotype infections (type A/B and A/B/C) were detected in only 2.3% (2/86) of Herat and 1.2% (1/86) of Nangarhar isolates, respectively. The combination of pvdhfr and pvdhps haplotypes among all 171 samples demonstrated six distinct haplotypes. The two most prevalent haplotypes among all examined samples were wild-type (86%) and single mutant haplotype I 13 P 33 F 57 S 58 T 61 N 117 I 173/ A 383 A 553 (6.4%). Double (I 13 P 33 S 57 R 58 T 61 N 117 I 173 /A 383 A 553 ) and triple mutant haplotypes (I 13 P 33 S 57 R 58 T 61 N 117 I 173 / G 383 A 553 ) were found in 1.7% and 1.2% of Afghan isolates, respectively. This triple mutant haplotype was only detected in isolates from Herat, but in none of the Nangarhar isolates. Conclusion The present study shows a limited polymorphism in pvdhfr from Afghan isolates and provides important basic information to establish an epidemiological map of ...