Kumar Amit, Moirangthem Romilla, Gahlawat Suresh Kumar, Chandra Jagdish, Gupta Purva, Valecha Neena, Anvikar Anup, Singh Vineeta
National Institute of Malaria Research, Sector-8 Dwarka, New Delhi 110077, India.
Department of Biotechnology, Chaudhary Devi Lal University, Haryana 125055, India.
Infect Genet Evol. 2015 Dec;36:190-198. doi: 10.1016/j.meegid.2015.08.027. Epub 2015 Aug 28.
Genotyping the sulfadoxine-pyrimethamine (SP) genes will help in identifying the genes under drug selection and the emergence of resistance in dhfr and dhps genes. India is an important hotspot for studying malaria due to the immense climatic diversity prevalent in the country. The central and eastern parts of the country are most vulnerable sites where malaria cases are reported throughout the year. From different regions of the country 173 field isolates were genotyped at various loci in dhfr and dhps genes collected between 1994 and 2013. This encompasses the period before antimalarial resistance emerged and the period after the use of combination therapy was made mandatory in the country. We observed the rise of resistant SP alleles from very low frequencies (in the year 1994) to steadily rising (in the year 2000) and maintaining this increasing trend subsequently (in the year 2013) as shown by the sequence analysis of dhfr and dhps genes. This study assessed the prevalence of mutations in dhfr and dhps genes associated with SP resistance in samples indicative of increase in resistance levels of Plasmodium falciparum to SP even after the change in malaria treatment policy in the country.
对磺胺多辛-乙胺嘧啶（SP）基因进行基因分型，将有助于识别处于药物选择压力下的基因以及二氢叶酸还原酶（dhfr）和二氢蝶酸合成酶（dhps）基因中耐药性的出现情况。由于印度国内气候差异巨大，它是研究疟疾的一个重要热点地区。该国中部和东部地区是最脆弱的地点，全年都有疟疾病例报告。从该国不同地区收集了1994年至2013年间的173株野外分离株，并对其dhfr和dhps基因的各个位点进行了基因分型。这涵盖了该国出现抗疟药耐药性之前的时期以及强制使用联合疗法之后的时期。通过对dhfr和dhps基因的序列分析表明，我们观察到耐药性SP等位基因的频率从非常低（1994年）稳步上升（2000年），并在随后（2013年）保持这种上升趋势。本研究评估了与SP耐药性相关的dhfr和dhps基因中的突变流行情况，这些样本表明即使在该国疟疾治疗政策改变后，恶性疟原虫对SP的耐药水平仍在增加。
