title: Restricted genetic diversity of Plasmodium falciparum major merozoite surface protein 1 in isolates from Colombia.
abstract: The merozoite surface protein 1 (MSP-1) gene of Plasmodium falciparum encodes a major immune target under development as a malaria vaccine. In this study, we typed MSP-1 variable regions of parasites obtained from Buenaventura, Colombia. Four MSP-1 gene types were detected corresponding to prototype and recombinant K1 and MAD20 block 4 sequences. In contrast to variability within block 4, blocks 2, 6, and 16-17 corresponded exclusively to the MAD20 allelic type. Most (80%) blood samples contained multiple MSP-1 gene types. The presence of four MSP-1 variants within block 4 against a MAD20 background indicates that current P. falciparum populations in Buenaventura are derived from parasites expressing K1 and MAD20 alleles, some of which underwent two recombination events within or flanking block 4. Restricted MSP-1 diversity appears to be relatively stable in Buenaventura and suggests that selection has resulted in the dominance of the MAD20 type in most of the polymorphic blocks with the exception of block 4.
authors.affiliation: Department of Microbiology, Faculty of Medicine, University of Panama, Panama City, Panama. zilkat@cwpanama.net
authors.forename: Zilka I
authors.initials: ZI
authors.lastname: Terrientes
authors.forename: Juana
authors.initials: J
authors.lastname: Vergara
authors.forename: Kenton
authors.initials: K
authors.lastname: Kramer
authors.forename: Sócrates
authors.initials: S
authors.lastname: Herrera
authors.forename: Sandra P
authors.initials: SP
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D003105:Colombia / Q000453:epidemiology; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D016778:Malaria, Falciparum / Q000453:epidemiology* / Q000469:parasitology*; D008297:Male; D020066:Merozoite Surface Protein 1 / Q000235:genetics*; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D020066:Merozoite Surface Protein 1