Ex vivo susceptibility of Plasmodium falciparum to Chloroquine and prevalence of pfcrt-76T and pfmdr1-86Y mutations in Bobo-Dioulasso.

Abstract

Malaria remains a major cause of morbidity and mortality in Burkina Faso. Current treatment of uncomplicated malaria is based essentially on artemether/lumefantrine, dihydro-artemisinin and artesunate-pyronaridine. Monitoring the effectiveness of available antimalarial drugs remains a high priority. In this study, we assessed ex vivo susceptibility of Plasmodium falciparum to Chloroquine and the prevalence of pfcr-76T and pfmdr1-86Y mutations in Bobo Dioulasso. We sampled venous blood from 92 malaria patients attending the Sakaby and Hamdallaye health centers between July and December 2022. IC50 values were calculated using a standard 72-hour growth inhibition test. Parasite DNA extracted by the Chelex100 method and amplified using nested PCR followed by enzymatic digestion to determine the prevalence of pfcrtK76T and pfmdr1N86Y mutations. Overall, 71/92 (77%) samples were successfully grown. The median IC50 was 21nM (9 -29) with 5 samples (7.04%) having IC50 values greater than or equal to 100nM, the value considered as threshold for P. falciparum resistance to chloroquine. The majority of samples showed wild-type genotypes, with 87% for pfcrt-K76 and 96% for pfmdr1-N86. Unlike pfmdr1-86Y, the presence of pfcrt-76T mutation was highly associated with reduced sensitivity to chloroquine ( p= 0.001 and OR = 0.03). Our findings suggest excellent susceptibility of Plasmodium falciparum isolates from Bobo-Dioulasso to CQ, with low prevalence of pfcrt-76T and pfmdr1-86Y mutations associated with chloroquine resistance.