Barati Sahar, Haghi Afsaneh Motevalli, Nateghpour Mehdi, Zamani Zahra, Khodaveisi Sadegh, Etemadi Soudabeh
Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Biochemistry Department, Pasteur Institute of Iran, Pasteur Avenue, Tehran, Iran.
Iran J Parasitol. 2023 Oct-Dec;18(4):445-455. doi: 10.18502/ijpa.v18i4.14244.
Resistance to artemisinin has threatened major achievements in malaria control, more investigations is needed about resistant strains and related genes. We aimed to induce resistance to artesunate in the 3D7 strain using intermittent exposure method and comparing gene sequence between susceptible and resistance strains.
3D7 strain was cultured according to Trager & Jensen method with some modifications. Serial concentrations between 10 mol/l, to 10mol/l were prepared, then 3D7 was exposed to each of the dilution to determine IC50 and lethal dose. Sensitivity reduction process was started from the concentration of 10mol/l and ended at 10mol/l. Exposed parasites were collected after at least 27 days after cultivation in each drug concentration. DNA extraction, PCR and sequencing process were performed to investigate any possible mutations in the gene sequence.
Effectiveness of 10-2mol/l concentration of artemisinin was found as a lethal dose. IC50 value was equal to 5×10 mol/l. The resistant strain was provided in the lab, sequenced and registered in the gene bank as , (accession number MH796123. 1). Alignment of this registered sample showed no mutation in gene in comparison with standard strain submitted in the GenBank.
Resistance to artesunate in malaria parasite may occur but with no mutation in the gene. Therefore, whole genome sequencing should be applied to determine mutations in resistant strains.
对青蒿素的耐药性已威胁到疟疾控制方面的重大成果,需要对耐药菌株及相关基因进行更多研究。我们旨在采用间歇暴露法诱导3D7株对青蒿琥酯产生耐药性,并比较敏感株和耐药株之间的基因序列。
对Trager&Jensen方法进行一些修改后培养3D7株。制备10⁻⁷mol/l至10⁻¹mol/l的系列浓度,然后将3D7暴露于每种稀释液中以确定半数抑制浓度(IC50)和致死剂量。敏感性降低过程从10⁻⁷mol/l的浓度开始,在10⁻¹mol/l结束。在每种药物浓度下培养至少27天后收集暴露的寄生虫。进行DNA提取、聚合酶链反应(PCR)和测序过程,以研究基因序列中是否存在任何可能的突变。
发现10⁻²mol/l浓度的青蒿素具有致死作用。IC50值等于5×10⁻⁷mol/l。在实验室中获得了耐药株,对其进行测序并在基因库中注册为,(登录号MH796123.1)。与GenBank中提交的标准菌株相比,该注册样本的基因比对未显示基因突变。
疟原虫对青蒿琥酯可能产生耐药性,但基因未发生突变。因此,应采用全基因组测序来确定耐药株中的突变。