Detection And Analysis Of MDR1and MSP1Genes Polymorphism Of Plasmodium Falciparum From The China-myanmar Border

Objective： To understand the pfmdr1、 pfMSP1gene diversity and distributioncharacteristics of P. falciparum from the China-Myanmar border； To discuss theassociativity pfMSP1gene with pfmdr1gene and malaria clinical symptoms. To explorewhether pfmdr1is applied to the genotype study. To analysis the influence factors ofpfMSP1gene polymorphism.Methods：DNA of P. falciparum was extracted by chelex-100method, then nest-PCR isapplied to amplify fragments of pfmdr1gene including N86Y mutation and the Blocks2and3of pfMSP1. The structure and homology of the gene fragments is analyzed. Todetect whether the polymorphisms of pfMSP1relations with people age、sex、nationality、malaria history、parasite density and clinical symptoms by statistical analysis.Results：(1) The pfmdr1gene N86Y mutation is not detected in49PCR products. All ofthe PCR products have mutated at position25、27、28、29、30，The geographical indicationof pfmdr1gene is low from the phylogeny tree.(2) From49blood samples from P.falciparum patients,72gene fragments of the pfMSP1were amplified, of which theMAD20-type allele was dominant (63.89%)，followed by KI-type and R033-type alleles.Also, it exist the mixed infection phenomena of the different allelic type．(3) Comparisonswith the MAD20genetype of Thailand isolates （AB276006.1） the different pointmutations in position105、109、116、122、128、132、133、134、135in within MAD20genetype,especially T-109was very high,and its frequency was95.7%.Comparisonswith the K1genetype of Thailand isolates （AB276006.1） conclude the different pointmutations in position55、56、67、68、69、70、71、72、79、80、81、82、83、84、87、88、89、90、93、95、96、105、138、140、141in within K1genetype,especiallyT-87、-88、-89、-90、T-93、G-95and T-96,was very high,and its frequency was53.33%、53.33%、53.33%、53.33%、60%、53.33%and53.33%.Respectively.Comparisons with theRO33genetype of Ghana isolates （AB276005.1） the different point mutations in position55、56、57、67、119in within RO33genetype,especially D-55,was very high,andits frequency was63.6%.In short, pfMSP1gene polymorphism of Plasmodium falciparumfrom the China-Myanmar border is high.(4) The pfMSP1gene polymorphism isuncorrelated with age、sex、nationality、malaria history、parasite density and is presumedthat it is associated with wild pfmdr1gene、 mixed infection、 geographicalpostion.(5Symptoms is no difference between single infection and mixed infection ofpfMSP1.Two cases of with severe malaria isolats MAD20subtype in pfmsp1gene.Conclusion:(1) The pfmdr1gene present the polymorphism.（2）The study confrimpreliminary the geographical indication of pfmdr1gene is low，therefore，pfmdr1gene is not suitable as genotyping.（3）Three principal allelic types of pfMSP1gene(MAD20, K1and RO33type) exist in the China-Myanmar border, and theMAD20-type is the dominant； symptomatic malaria is Over-presented MAD20genetype，The MOI of pfMSP1gene is1.47.（4）There are higher polymorphism inPlasmodium falciparum from the China-Myanmar border.