云南恶性疟原虫氯喹抗药性基因76位点突变研究

STUDY ON 76 POINT MUTATION OF CHLOROQUINE RESISTANCE TRANSMEMBRANE TRANSPORTER GENE IN PLASMODIUM FALCIPARUM IN YUNNAN PROVINCE

目的研究云南恶性疟原虫氯喹抗药性基因(pfcrt)76位点突变的情况,以及与抗药性表现型的关系。方法应用PCR和限制性酶切片段长度分析方法,检测现症病人干滤纸血样的恶性疟原虫pfcrt基因点突变。结果云南省恶性疟原虫pfcrt基因76位点的突变型很高,占85.0%(51/60);野生型和混合型较少,分别占8.3%(5/60)和6.7%(4/60)。体内法测定的氯喹抗性和敏感样本均有pfcrt76突变型;体外法测定的17份氯喹抗性样本中,有13份带有pf-crt76突变型。结论云南省恶性疟原虫pfcrt基因氨基酸编码76位点突变频度很高。体内和体外法测定的氯喹抗性表现与pfcrt76突变型有较高的一致性。

Objective To investigate prevalence of the 76 point mutation of chloroquine resistance transmembrane transporter gene in Plasmodium falciparum （pfcrt） in Yunnan Province, and explore the association between this point mutation and phenotype of chloroquine resistance. Methods The PCR and restriction enzyme fragment length polymorphism were used to detect the 76 point mutation of pfcrt from the blood dry filter samples which were suffered from falciparum malaria in the field in drug resistant P. falciparum endemic areas. Results 76 mutant type in pfcrt gene in Yunnan P. falciaprum was very high, account for 85.0% （51/ 60）; wild type and mixed were low, account for 8.3%（5/60） and 6.7%（4/60） respectively. Chloroquine resistant and sensitivity cases in vivo all carried mutant types, but in chloroquine resistance cases in vitro, 13 of 17 cases had mutant types. Conclusion Prevalence of 76 point mutation in the pfcrt gene was very high in Yunnan Province, and was better in accordance with chloroquine resistant phenotype in vivo and in vitro in epidemiology.