Prevalence of mutations in the Plasmodium falciparum chloroquine resistance transporter, PfCRT, and association with ex vivo susceptibility to common anti-malarial drugs against African Plasmodium falciparum isolates

Abstract

Background: The Plasmodium falciparum chloroquine transporter gene (pfcrt) is known to be involved in chloroquine and amodiaquine resistance, and more particularly the mutations on the loci 72 to 76 localized within the second exon. Additionally, new mutations (T93S, H97Y, C101F, F145I, M343L, C350R and G353V) were recently shown to be associated with in vitro reduced susceptibility to piperaquine in Asian or South American P. falciparum strains. However, very few data are available on the prevalence of these mutations and their effect on parasite susceptibility to anti-malarial drugs, and more particularly piperaquine in Africa. Methods: A molecular investigation of these mutations was performed in 602 African P. falciparum parasites collected between 2017 and 2018 on malaria patients hospitalized in France after a travel in African countries. Associations between genotypes and in vitro susceptibilities to piperaquine and standard antimalarial drugs were assessed. Results: None of the mutations, previously described as associated with piperaquine resistance, was found in the 602 P. falciparum African isolates. The K76T mutation is associated with resistance to chloroquine (p < 0.0002) and desethylamodiaquine (p < 0.002) in Africa. The K76T mutation is not associated with in vitro reduced susceptibility to piperaquine. The mutation I356T, identified in 54.7% (n = 326) of the African isolates, was significantly associated with reduced susceptibility to quinine (p < 0.02) and increased susceptibility to mefloquine (p < 0.04). The K76T and I356T mutations were significantly associated in West African isolates (p = 0.008). Conclusion: None of the mutations in pfcrt found to be associated with piperaquine reduced susceptibility in Asia or South America (T93S, H97Y, C101F, F145I, M343L C350R and G353V) were found in the 602 African isolates including the three isolates with reduced susceptibility to piperaquine. The K76T mutation, involved in resistance to chloroquine and amodiaquine, and the I356T mutation were not associated with in vitro reduced susceptibility to piperaquine.

Molecular surveillance of anti-malarial resistance pfcrt, pfmdr1, and pfk13 polymorphisms in African Plasmodium falciparum imported parasites to Wuhan, China

“…In this study, no mutations were detected at loci 93, 97, 101, 145, 343, 350, and 353. In an investigation of African isolates, consistent with the results of this study, no mutations at these sites were reported [ 13 ]. In this study, 5 isolates carried the mutant allele, and 3 isolates were mixed type at loci 356.…”

“…However, long-term use of anti-malarial drugs particularly PPQ induced ADR [ 14 ]. Previous studies indicated that several mutations of pfcrt (93 S , 97 Y , 101 F , 145 I , 343 L , 353 V , and 356 T ) were related to reducing parasite sensitivity to PPQ [ 13 , 14 , 36 – 39 ]. In this study, no mutations were detected at loci 93, 97, 101, 145, 343, 350, and 353.…”

“…The 356 T mutation was found in 54.7% of P. falciparum detected in Africa in 2017–2018. However, they also reported that the 356 T mutation was not associated with in vitro reduced susceptibility to PPQ [ 13 ]. Therefore, continuous observations of pfcrt mutations and susceptibility tests in vitro related to PPQ are necessary.…”

“…The target fragments of the pfcrt , pfmdr1 , and pfk13 genes were amplified from the gDNA sample via nested PCR and traditional PCR. Following previously published primer information and a previous procedure [ 13 , 16 , 22 , 23 ], the pfcrt , pfmdr1 , and pfk13 genes were successfully amplified. The reaction system and procedure for PCR are listed in Additional file 2 : Table S1.…”

“…Several mutations in pfmdr1 are related to the resistance of P. falciparum to CQ, amodiaquine (AQ) and mefloquine (MQ) [ 20 , 21 ]. At present, several newly detected mutations in pfcrt, including 93 S , 97 Y , 101 F , 145 I , 343 L , 353 V and 356 T , have been identified to be associated to with PPQ with a decreasing trend for the susceptibility of P. falciparum strains in South America [ 13 ]. However, there was limited information on the effects of these alleles on PPQ in Africa, where malaria is endemic.…”