Genetic polymorphism of merozoite surface protein-1 and merozoite surface protein-2 in Plasmodium falciparum isolates from children in South of Benin

• Published in: Parasite (Paris) 2013, Vol.20, p.37-37
• Main Authors: Ogouyèmi-Hounto, Aurore, Gazard, Dorothée Kinde, Ndam, Nicaise, Topanou, Elsa, Garba, Olivia, Elegbe, Pancras, Hountohotegbe, Tatiana, Massougbodji, Achille
• Format: Article
• Language: English
• Subjects: Adolescent; Alleles; Antigens, Protozoan - genetics; Benin; Benin - epidemiology; Child; Child, Preschool; Children; Density; Deoxyribonucleic acid; DNA; DNA, Protozoan - genetics; DNA, Protozoan - isolation & purification; Erythrocytes; Female; Fever; Filter paper; Fragmentation; Fragments; Gene polymorphism; Gene sequencing; Genetic diversity; Genotype; Genotypes; Genotyping; Humans; Infant; Infections; Malaria; Malaria, Falciparum - epidemiology; Malaria, Falciparum - parasitology; Male; Merozoite surface protein; Merozoite Surface Protein 1 - genetics; MSP-1 gene; MSP-2 gene; Multiplicity of infection; Parasites; Plasmodium falciparum; Plasmodium falciparum - classification; Plasmodium falciparum - genetics; Plasmodium falciparum - isolation & purification; Polymerase chain reaction; Polymorphism; Polymorphism, Genetic; Population studies; Proteins; Protozoan Proteins - genetics; Smear; Vector-borne diseases
• ISSN: 1776-1042; 1252-607X; 1776-1042
• DOI: 10.1051/parasite/2013039

The aim of this study was to determine the genetic diversity of Plasmodium falciparum by analyzing the polymorphism of the msp-1 and msp-2 genes and the multiplicity of infection in children with uncomplicated malaria in southern Benin. Blood samples of children with fever or history of fever with thick smear positive P. falciparum were collected on filter paper. After extraction of DNA by Chelex®, the samples underwent nested PCR. 93 isolates from children were genotyped. For the msp-1 gene, the K1 and R033 sequences were the most represented in the study population with 85.2% and 83% prevalence, respectively. Regarding the msp-2 gene, the FC27 family was more highly represented with 99% prevalence against 81.5% for 3D7. Mixed infections accounted for 80.4% of the samples. Twenty-five alleles were identified for msp-1 and 28 for msp-2. Fourteen and ten alleles belonged to the K1 (100–500 bp) and MAD20 (100–500 bp) families, respectively. The RO33 sequence did not show any polymorphism, with only one variant (160 bp) detected. The msp-2 gene was present as 16 FC27 family fragments (250–800 bp) and 12 of the 3D7 family (350–700 bp). The multiplicity of infection was estimated at 3.8 for msp-1 and 3.9 for msp-2 with 77 (87.5%) and 84 (91.3%) samples harboring more than one parasite genotype for msp-1 and msp-2, respectively. The multiplicity of infection (MOI) was influenced neither by age nor by parasite density. This study shows a significant diversity of P. falciparum in southern Benin with an MOI unaffected by age or by parasite density. Le but de cette étude était de déterminer la diversité génétique de Plasmodium falciparum en analysant le polymorphisme des gènes msp-1 et msp-2 et la multiplicité de l’infection chez les enfants souffrant de paludisme simple au sud du Bénin. Les enfants présentant une fièvre ou antécédents de fièvre avec une goutte épaisse positive à P. falciparum ont subi un prélèvement de sang sur papier buvard. Après extraction de l’ADN au Chelex®, les échantillons ont fait l’objet d’une PCR nichée. Les isolats de 93 enfants ont été génotypés. Pour le gène msp-1, les familles K1 et R033 étaient les plus représentées dans la population d’étude avec respectivement 85,2 % et 82,9 %. Pour msp-2, la famille FC27 était la plus représentée avec 98,9 % contre 81,6 % pour 3D7. Les infections mixtes représentaient 80,4 % des échantillons. Vingt-cinq allèles ont été identifiés pour msp-1 et 28 pour msp-2. Quatorze et dix allèles appartenaient r