We have analyzed the in vitro activities of pyronaridine and methylene blue against 59 Plasmodium falciparum isolates from Kenya in association with polymorphisms in Pfcrt (codon 76), Pfmdr1 (codon 86), and Pfnhe (full sequence). The median inhibitory concentrations that kill 50% of parasites were 13.5 and 3.3 nM for pyronaridine and methylene blue, respectively. Their activities were not assoc...

Malaria is a major public health problem in the Democratic Republic of Congo. Despite progress achieved over the past decade in the fight against malaria, further efforts have to be done such as in the surveillance and the containment of Plasmodium falciparum resistant strains. We investigated resistance to artemisinin-based combination therapies currently in use in Democratic Republic of Congo...

The determinants of transcriptional regulation in malaria parasites remain elusive. The presence of a well-characterized gene expression cascade shared by different Plasmodium falciparum strains could imply that transcriptional regulation and its natural variation do not contribute significantly to the evolution of parasite drug resistance. To clarify the role of transcriptional variation as a ...

Cambodia is located in an area of resistance to multiple antimalarials and has been the first country to implement the systematic use of an artesunate-mefloquine combination as first-line treatment for Plasmodium falciparum malaria. Little is known, however, about the prevalence of resistance mutations within the natural parasite populations, impeding rational drug policy in this context. Using...

Background. In Cameroon, both Artesunate-amodiaquine (AS/AQ) and artemether-lumefantrine (AL) are used as first-line treatment against uncomplicated malaria in line with the WHO recommendations. We compared the efficacy and safety of both therapeutic combinations and determined the prevalence of drug resistance conferring mutations in three parasite genes. Methods. One hundred and fifty acute m...

BACKGROUND The use of amodiaquine in prophylaxis is associated with serious toxicity, resulting from its metabolic conversion into a reactive quinone-imine metabolite by the hepatic cytochrome P450. To circumvent this toxicity, several amodiaquine analogues that lack the potential to form a quinone-imine derivative, while retaining antimalarial activity, have been designed. Isoquine is one of t...

BACKGROUND Drug resistance is one of the greatest challenges of malaria control programmes, with the monitoring of parasite resistance to artemisinins or to Artemisinin Combination Therapy (ACT) partner drugs critical to elimination efforts. Markers of resistance to a wide panel of antimalarials were assessed in natural parasite populations from southwestern Cameroon. METHODS Individuals with...

The association between the clinical outcome of chloroquine treatment and mutations in the putative Plasmodium falciparum chloroquine resistance transporter (Pfcrt) gene at codon 76 and multidrug resistance gene 1 (Pf mdr1) at codon 86 were investigated among 406 children with uncomplicated malaria presenting at five sentinel health centres in Ghana. Presence of mutations in isolates taken at p...

The recent reports of resistance in Plasmodium falciparum to artemisinin derivatives and their partner drugs demand intensive studies toward understanding the molecular mechanisms of resistance. In this study, we examined the in vitro susceptibility of 63 P. falciparum field isolates collected from the China-Myanmar border area to chloroquine (CQ) and piperaquine (PPQ). Parasite isolates remain...