Molecular Surveillance of Artemisinin-Based Combination Therapies Resistance in Plasmodium falciparum Parasites from Bioko Island, Equatorial Guinea.

Artemisinin-based combination therapies (ACTs) resistance has emerged and could be diffusing in Africa. As an offshore island on the African continent, the island of Bioko in Equatorial Guinea is considered severely affected and resistant to drug-resistant Plasmodium falciparum malaria. However, the spatial and temporal distribution remain unclear.

Population genetic analysis of the Plasmodium falciparum erythrocyte binding antigen-175 (EBA-175) gene in Equatorial Guinea.

Background: Plasmodium falciparum erythrocyte binding antigen-175 (PfEBA-175) is a candidate antigen for a blood-stage malaria vaccine, while various polymorphisms and dimorphism have prevented to development of effective vaccines based on this gene. This study aimed to investigate the dimorphism of PfEBA-175 on both the Bioko Island and continent of Equatorial Guinea, as well as the genetic polymorphism and natural selection of global PfEBA-175.

Methods: The allelic dimorphism of PfEBA-175 region II of 297 bloods samples from Equatorial Guinea in 2018 and 2019 were investigated by nested polymerase chain reaction and sequencing.

Genetic diversity and natural selection on the thrombospondin-related adhesive protein (TRAP) gene of Plasmodium falciparum on Bioko Island, Equatorial Guinea and global comparative analysis.

Background: Thrombospondin-related adhesive protein (TRAP) is a transmembrane protein that plays a crucial role during the invasion of Plasmodium falciparum into liver cells. As a potential malaria vaccine candidate, the genetic diversity and natural selection of PfTRAP was assessed and the global PfTRAP polymorphism pattern was described.

Methods: 153 blood spot samples from Bioko malaria patients were collected during 2016-2018 and the target TRAP gene was amplified.

Genetic polymorphism of Plasmodium falciparum circumsporozoite protein on Bioko Island, Equatorial Guinea and global comparative analysis.

Background: Plasmodium falciparum circumsporozoite protein (PfCSP) is a potential malaria vaccine candidate, but various polymorphisms of the pfcsp gene among global P. falciparum population become the major barrier to the effectiveness of vaccines. This study aimed to investigate the genetic polymorphisms and natural selection of pfcsp in Bioko and the comparison among global P.

Trends in Molecular Markers Associated with Resistance to Sulfadoxine-Pyrimethamine (SP) Among Isolates on Bioko Island, Equatorial Guinea: 2011-2017.

Purpose: Antimalarial drug resistance is one of the major challenges in global efforts to control and eliminate malaria. In 2006, sulfadoxine-pyrimethamine (SP) replaced with artemisinin-based combination therapy (ACT) on Bioko Island, Equatorial Guinea, in response to increasing SP resistance, which is associated with mutations in the dihydrofolate reductase () and dihydropteroate synthase () genes.

Patients And Methods: To evaluate the trend of molecular markers associated with SP resistance on Bioko Island from 2011 to 2017, 179 samples collected during active case detection were analysed by PCR and DNA sequencing.

Evidence of positively selected G6PD A- allele reduces risk of Plasmodium falciparum infection in African population on Bioko Island.

Background: Glucose-6-phosphate dehydrogenase (G6PD) is an essential enzyme that protects red blood cells from oxidative damage. Although G6PD-deficient alleles appear to confer a protective effect of malaria, the link with clinical protection against Plasmodium infection is conflicting.

Methods: A case-control study was conducted on Bioko Island, Equatorial Guinea and further genotyping analysis used to detect natural selection of the G6PD A- allele.

Natural selection and genetic diversity of domain I of Plasmodium falciparum apical membrane antigen-1 on Bioko Island.

Background: Plasmodium falciparum apical membrane antigen-1 (PfAMA-1) is a promising candidate antigen for a blood-stage malaria vaccine. However, antigenic variation and diversity of PfAMA-1 are still major problems to design a universal malaria vaccine based on this antigen, especially against domain I (DI). Detail understanding of the PfAMA-1 gene polymorphism can provide useful information on this potential vaccine component.