[The point mutations in Pfcrt and Pfmdr1 genes in Plasmodium falciparum isolated from Hainan Province].
OBJECTIVE
To evaluate the point mutations in Pfcrt and Pfmdr1 genes in Plasmodium falciparum isolated from Hainan Province.


METHODS
Nested polymerase chain reaction and restriction fragment length polymorphism were used to detect the point mutations at codon 76 of Pfcrt and at codon 86, 1246 of Pfmdr1 in P. falciparum isolates. Chloroquine resistance was measured by the in vitro microtest recommended by WHO.


RESULTS
In 36 samples tested, 28 were successfully amplified for Pfcrt, 64.3% of them carried mutant allele at codon 76, 21.4% with wild allele K76 and 14.3% with mixed allele mutation. While for Pfmdr1, 3.4% isolates displayed the 86Y mutation, 89.7% with wild allele N86 and 6.9% with the mixed alleles in 29 isolates which were amplified successfully for N86Y. No point mutation in Pfmdr1 at codon 1246 was found in 13 isolates from the total 36 samples. By the in vitro test, 72.2% (26/36) showed resistance to chloroquine. The 76T and 86Y mutant alleles were present in both in vitro susceptible and resistant isolates. There was a significant difference between susceptible and resistant isolates carrying 76T mutant codon (P < 0.05), but no significant difference was found in Pfmdr1 (P < 0.05).


CONCLUSIONS
There is a significant difference of the 76T prevalence in Pfcrt gene between the susceptible isolate and resistant one of P. falciparum to chloroquine in vitro. The Pfcrt 76T may be used as a predictive marker for chloroquine resistance surveillance.
Guan
Ya-Yi
YY
National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention, Shanghai 200025, China.
Tang
Lin-Hua
LH
Hu
Ling
L
Feng
Xiao-Ping
XP
Liu
De-Quan
DQ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002648:Child; D002738:Chloroquine / Q000494:pharmacology*; D003062:Codon / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology*; D008565:Membrane Proteins / Q000235:genetics*; D026901:Membrane Transport Proteins; D008875:Middle Aged; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D010963:Plasmodium falciparum / Q000187:drug effects / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D015800:Protozoan Proteins / Q000235:genetics*
D000962:Antimalarials; D002738:Chloroquine; D003062:Codon; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D015800:Protozoan Proteins; C513498:Mdr1 protein, Plasmodium falciparum; C416369:PfCRT protein, Plasmodium falciparum