No polymorphisms in K13-propeller gene associated with artemisinin resistance in Plasmodium falciparum isolated from Brazzaville, Republic of Congo

Abstract

BackgroundIn the Republic of Congo, artemisinin-based combinations have been recommended for the treatment of uncomplicated malaria since 2006. However, the emergence of resistant parasites again these combinations in Southeast Asia is a threat for the control of this disease, especially in sub-Saharan Africa where the weight of the disease is important. Indeed, polymorphisms in Plasmodium falciparum K13-propeller gene have been involved in variations of drug sensitivity of Plasmodium falciparum to artemisinin-based combinations. The aim of the current study is to determine the prevalence of mutations of this gene in isolates collected in three health centers in Brazzaville.MethodsFrom May 2015 to May 2016, a total of 131, 259 and 416 samples from patients with suspected malaria were collected at the Laboratoire National de Santé Publique, Hôpital de Mfilou, and the CSI «Maman Mboualé» respectively. After DNA isolation, genotyping and sequencing of Plasmodium falciparum K13-propeller were performed in positive Plasmodium falciparum isolates identified after msp-2 gene genotyping.ResultsAll 806 samples collected were msp-2 genotyped and Plasmodium falciparum infections were confirmed in 287 samples with 43, 85, 159 samples from Laboratoire National de Santé Publique, Hôpital de Mfilou, and the CSI «Maman Mboualé» respectively. Of these 287 msp-2 positives samples, K13-propeller nested PCR products were successfully obtained from 145 (50.52%) isolates and sequences were generated from 127(87.58%) nested products. None of mutations that were associated with ACTs resistance in Southeast Asia were detected on the samples from three different study sites from Brazzaville. However, one mutation type was observed at position 578, where alanine was substituted by serine (A578S) in two isolates (1.57%, 2/127), those from the Hôpital de Mfilou. No mutation was found in isolates from the two other sites.ConclusionThe current study shows a very limited polymorphism in the K13-propeller gene in isolates from the Republic of Congo and K13 polymorphisms associate with ACT resistance are not present in this country. However, permanent and large surveillance of resistant parasite population using K13-propeller gene is recommended.

Molecular assessment of kelch13 non-synonymous mutations in Plasmodium falciparum isolates from Central African Republic (2017–2019)

“…Our study on samples collected in Bangui between 2017 and 2019 demonstrate the presence of one non-synonymous mutation (Y653N) and three synonymous mutations (frequency of 2.1%). This frequency of PfKelch13 mutants is similar to those observed in neighboring countries (Brazzaville Congo, certain regions of Cameroon), which showed frequencies of 1.57% and 2.9%, respectively [26,27], confirming the absence of artemisinin resistance in Central Africa [20]. The only previous data on PfKelch13 polymorphism performed in 2014 in the CAR (K13 artemisinin resistance multicenter resistance, KARMA study), revealed a 4.5%…”

Efficacy and safety of artesunate-amodiaquine and artemether-lumefantrine and prevalence of molecular markers associated with resistance, Guinea, 2016

“…This finding is similar to those from studies in Africa [9,29,[40][41][42][43][44] reporting a lack of the pfk13 mutations associated with artemisinin combination therapeutic resistance that have been identified in Southeast Asia [40,[45][46][47][48].…”

Efficacy and safety of artesunate-amodiaquine and artemether-lumefantrine and prevalence of molecular markers associated with resistance, Guinea: an open-label two-arm randomised controlled trial

“…Absence of pfk13 mutations associated with artemisinin resistance is further evidence that parasites remain susceptible to artemisinin derivatives in Guinea. This nding is similar to those studies in Africa [11,30,[39][40][41][42] reporting a lack of the pfk13 mutations associated with artemisinin combination therapeutic resistance that have been identi ed in Southeast Asia [40,[43][44][45].…”