Genetic polymorphism of merozoite surface protein-1 and merozoite surface protein-2 in Plasmodium falciparum field isolates from Myanmar.
BACKGROUND
Merozoite surface protein-1 (MSP-1) and MSP-2 of Plasmodium falciparum are potential vaccine candidate antigens for malaria vaccine development. However, extensive genetic polymorphism of the antigens in field isolates of P. falciparum represents a major obstacle for the development of an effective vaccine. In this study, genetic polymorphism of MSP-1 and MSP-2 among P. falciparum field isolates from Myanmar was analysed.


METHODS
A total of 63 P. falciparum infected blood samples, which were collected from patients attending a regional hospital in Mandalay Division, Myanmar, were used in this study. The regions flanking the highly polymorphic characters, block 2 for MSP-1 and block 3 for MSP-2, were genotyped by allele-specific nested-PCR to analyse the population diversity of the parasite. Sequence analysis of the polymorphic regions of MSP-1 and MSP-2 was also conducted to identify allelic diversity in the parasite population.


RESULTS
Diverse allelic polymorphism of MSP-1 and MSP-2 was identified in P. falciparum isolates from Myanmar and most of the infections were determined to be mixed infections. Sequence analysis of MSP-1 block 2 revealed that 14 different alleles for MSP-1 (5 for K1 type and 9 for MAD20 type) were identified. For MSP-2 block 3, a total of 22 alleles (7 for FC27 type and 15 for 3D7 type) were identified.


CONCLUSIONS
Extensive genetic polymorphism with diverse allele types was identified in MSP-1 and MSP-2 in P. falciparum field isolates from Myanmar. A high level of mixed infections was also observed, as was a high degree of multiplicity of infection.
Kang
Jung-Mi
JM
Department of Parasitology, Brain Korea 21 Biomedical Center, and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 660-751, South Korea.
Moon
Sung-Ung
SU
Kim
Jung-Yeon
JY
Cho
Shin-Hyeong
SH
Lin
Khin
K
Sohn
Woon-Mok
WM
Kim
Tong-Soo
TS
Na
Byoung-Kuk
BK
D000483:Alleles; D000953:Antigens, Protozoan / Q000235:genetics* / Q000378:metabolism; D005838:Genotype; D006801:Humans; D016778:Malaria, Falciparum / Q000175:diagnosis / Q000469:parasitology; D020066:Merozoite Surface Protein 1 / Q000235:genetics* / Q000378:metabolism; D002052:Myanmar; D010963:Plasmodium falciparum / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA
D000953:Antigens, Protozoan; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; C065974:merozoite surface protein 2, Plasmodium