title: Analysis of genetic polymorphism in select vaccine candidate antigens and microsatellite loci in Plasmodium falciparum from endemic areas at varying altitudes.
abstract: Plasmodium falciparum parasites obtained from symptomatic patients attending clinics in Bindura (altitude 1100 m), Chiredzi (600 m) and Kariba (<600 m), previously reported to differ in malaria endemicity were genotyped on the msp-1, msp-2 and glurp loci to examine the extent of parasite genetic diversity. While the parasites were monomorphic for msp-1 allele RO33 from the three locations, the K1 allele was over-represented in Kariba (p=0.02) and Mad20 alleles occurred at a higher frequency in Bindura. A similar PCR analysis for glurp and the two main allelic families of msp-2, i.e. IC/3D7 and FC-27 revealed minimal differences in the parasite population. A total of 8 msp-1 Block 2 and 11 msp-2 genotypes were identified from the three locations combined. On the glurp locus, 13 different genotypes ranging in size from 660 to 1160 bp were detected in parasites obtained from Bindura and Kariba. To gain further insight into P. falciparum genetic diversity in the three different geographical locations, parasites were examined for neutral microsatellite markers (C4M8, C13M30 and TA81). The number of microsatellite alleles ranged from 8 to 17 and the average expected heterozygosity (HE) for the three areas combined was 0.83 suggesting that the parasite population of Zimbabwe is genetically heterogeneous. These findings have implications in understanding the impact of genetic variation on immunity and possibly emergence of drug resistance.
authors.affiliation: Malaria Research Institute, Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, United States.
authors.forename: Godfree
authors.initials: G
authors.lastname: Mlambo
authors.forename: David
authors.initials: D
authors.lastname: Sullivan
authors.forename: Susan L
authors.initials: SL
authors.lastname: Mutambu
authors.forename: White
authors.initials: W
authors.lastname: Soko
authors.forename: Joel
authors.initials: J
authors.lastname: Mbedzi
authors.forename: James
authors.initials: J
authors.lastname: Chivenga
authors.forename: Thomas
authors.initials: T
authors.lastname: Jaenisch
authors.forename: Armin
authors.initials: A
authors.lastname: Gemperli
authors.forename: Nirbhay
authors.initials: N
authors.lastname: Kumar
mesh_terms: D000531:Altitude; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology; D019353:Endemic Diseases; D005838:Genotype; D017780:Malaria Vaccines / Q000235:genetics* / Q000276:immunology; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000469:parasitology*; D020066:Merozoite Surface Protein 1 / Q000235:genetics; D018895:Microsatellite Repeats; D010963:Plasmodium falciparum / Q000235:genetics* / Q000276:immunology; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics; D015030:Zimbabwe / Q000453:epidemiology
chemical_list: D000953:Antigens, Protozoan; D017780:Malaria Vaccines; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; C065974:merozoite surface protein 2, Plasmodium; C072492:glutamate-rich protein, Plasmodium