Polymorphisms of the artemisinin resistant marker (K13) in Plasmodium falciparum parasite populations of Grande Comore Island 10 years after artemisinin combination therapy

Abstract

BackgroundPlasmodium falciparum malaria is a significant public health problem in Comoros, and artemisinin combination therapy (ACT) remains the first choice for treating acute uncomplicated P. falciparum. The emergence and spread of artemisinin-resistant P. falciparum in Southeast Asia, associated with mutations in K13-propeller gene, poses a potential threat to ACT efficacy. Detection of mutations in the P. falciparum K13-propeller gene may provide the first-hand information on changes in parasite susceptibility to artemisinin. The objective of this study is to determinate the prevalence of mutant K13-propeller gene among the P. falciparum isolates collected from Grande Comore Island, Union of Comoros, where ACT has been in use since 2004.MethodsA total of 207 P. falciparum clinical isolates were collected from the island during March 2006 and October 2007 (n = 118) and March 2013 and December 2014 (n = 89). All isolates were analysed for single nucleotide polymorphisms (SNPs) and haplotypes in the K13-propeller gene using nested PCR and DNA sequencing.ResultsOnly three 2006–2007 samples carried SNPs in the K13-propeller gene, one having a synonymous (G538G) and the other having two non-synonymous (S477Y and D584E) substitutions leading to two mutated haplotypes (2.2 %, 2/95). Three synonymous mutations (R471R, Y500Y, and G538G) (5.9 %, 5/85) and 7 non-synonymous substitutions (21.2 %, 18/85) with nine mutated haplotypes (18.8 %, 16/85) were found in isolates from 2013 to 2014. However, none of the polymorphisms associated with artemisinin-resistance in Southeast Asia was detected from any of the parasites examined.ConclusionThis study showed increased K13-propeller gene diversity among P. falciparum populations on the Island over the course of 8 years (2006–2014). Nevertheless, none of the polymorphisms known to be associated with artemisinin resistance in Asia was detected in the parasite populations examined. Our data suggest that P. falciparum populations in Grande Comore are still effectively susceptible to artemisinin. Our results provide insights into P. falciparum populations regarding mutations in the gene associated with artemisinin resistance and will be useful for developing and updating anti-malarial guidance in Comoros.

The Diversity of the Plasmodium falciparum K13 Propeller Domain Did Not Increase after Implementation of Artemisinin-Based Combination Therapy in Uganda

“…Additional studies comparing the genetic diversity in K13PD before and after the introduction of ACTs in Africa have generally been consistent with our findings from Uganda, with no significant difference in the proportion of parasites with a NS-SNP before and after the introduction of ACTs (35)(36)(37)(38). However, a report from Kenya described a significant decrease, and one from Comoros described an increase in K13PD polymorphisms following the introduction ACTs (39,40). The nucleotide diversity we report for the K13PD is in scale with that reported from other regions of Africa, as is the presence of an excess of rare alleles (41).…”

K13 propeller domain mutations and pfmdr1 amplification in isolates of Plasmodium falciparum collected from Thai-Myanmar border area in 2006-2010

“…Seven mutations were previously detected in isolates from African countries, i.e. D464E (Huang et al 2015a, Madamet et al 2017 (Cooper et al 2015). Three mutations which were previously detected in both Asian and African countries were also detected in this study, i.e.…”

“…The identified K13 mutations C580Y, Y493H and R539T were shown to be associated with the delay in parasite clearance both in vitro and in vivo (Ariey et al 2014). However, these mutations were not detected in P. falciparum isolates in African countries (Conrad et al 2014, Cooper et al 2015, Huang et al 2015a, Menard et al 2016b.…”

Artemisinin-Resistant Plasmodium falciparum Malaria

“…Several studies have confirmed that some K13-propeller mutations are also markers of slow parasite clearance outside Cambodia, in Thailand, Vietnam, Myanmar, and China (10,26,40,41 Togo, Uganda, and Zambia (55)(56)(57)(58)(59)(60)(61)(62)(63)(64)(65)(66). The most frequent mutation in SSA is A578S; however, haplotype analysis does not show evidence of selection of this mutation in the African P. falciparum population and this mutation is present naturally in P. vivax and P. knowlesi [67].…”