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

Abstract

Background: Over the last decade, artemisinin-based combination therapy (ACT) has contributed substantially to the decrease in malaria-related morbidity and mortality. The emergence of Plasmodium falciparum parasites resistant to artemisinin derivatives in Southeast Asia and the risk of their spread or of local emergence in sub-Saharan Africa are a major threat to public health. This study thus set out to estimate the proportion of P. falciparum isolates, with Pfkelch13 gene mutations associated with artemisinin resistance previously detected in Southeast Asia. Methods: Blood samples were collected in two sites of Bangui, the capital of the Central African Republic (CAR) from 2017 to 2019. DNA was extracted and nested PCR were carried out to detect Plasmodium species and mutations in the propeller domain of the Pfkelch13 gene for P. falciparum samples. Results: A total of 255 P. falciparum samples were analysed. Plasmodium ovale DNA was found in four samples (1.57%, 4/255). Among the 187 samples with interpretable Pfkelch13 sequences, four samples presented a mutation (2.1%, 4/187), including one non-synonymous mutation (Y653N) (0.5%, 1/187). This mutation has never been described as associated with artemisinin resistance in Southeast Asia and its in vitro phenotype is unknown. Conclusion: This preliminary study indicates the absence of Pfkelch13 mutant associated with artemisinin resistance in Bangui. However, this limited study needs to be extended by collecting samples across the whole country along with the evaluation of in vitro and in vivo phenotype profiles of Pfkelch13 mutant parasites to estimate the risk of artemisinin resistance in the CAR.

Limited Polymorphism in Plasmodium falciparum Artemisinin Resistance Kelch13-Propeller Gene Among Clinical Isolates from Bushenyi District, Uganda

“…Our study is in agreement with previous studies conducted in Uganda, 32 , 33 which also recorded new mutations not previously reported in Southeast Asia. A more recent study 34 conducted in Central Africa Republic, a country having close proximity to Uganda, has also reported a non‑synonymous mutation at locus Y653N with a prevalence of 0.5%, a mutation that has not been associated before with artemisinin resistance in Southeast Asia. In addition, other new non-synonymous mutations (M472I; Y558C; K563R; P570L; P615S) have been reported in other places but have not shown any role in conferring resistance.…”

“…Furthermore, previously reported artemisinin resistance in Southeast Asian countries and poor responses of the malaria parasites in some parts of Africa and South America remain major threats in efforts to combat malaria in the world. 20 With the possibility of malaria resistance spreading worldwide by following the previously recorded patterns of chroloquine and sulphodoxine-pyrimethamine resistance, 21 we should develop standard surveillance methods to identify the possible emergence of resistance to artemisinin combined therapies. Thus, this study was aimed at identifying the presence of K13 P. falciparum resistance markers.…”

Prevalence of potential mediators of artemisinin resistance in African isolates of Plasmodium falciparum

“…Plasmodium falciparum polymerase chain reaction positive (PCR +) samples were 18,292 out of 32,406 total samples collected [39][40][41][42][43][44][45], yielding PCR positivity rate of 56.4% malaria in both clinical and community…”

Ex vivo RSA and pfkelch13 targeted-amplicon deep sequencing reveal parasites susceptibility to artemisinin in Senegal, 2017

“…Prompt management of malaria cases remains a vital component of malaria control and elimination strategies [ 1 ]. Over the two last decades, artemisinin (ART)-based combination therapy (ACT) has contributed significantly to the reduction of malaria-related morbidity and mortality in sub-Saharan Africa [ 2 ]. Since 2006, the Senegalese National Malaria Control Programme (NMCP) has recommended artemether–lumefantrine (AL) as the first-line treatment for uncomplicated malaria [ 3 ].…”