Genome-wide mutagenesis and multi-drug resistance in American trypanosomes induced by the front-line drug benznidazole.
Genome-wide mutagenesis and multi-drug resistance in American trypanosomes induced by the front-line drug benznidazole.
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DOI：
10.1038/s41598-017-14986-6
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发表时间：
2017-10-31
影响因子：
4.6
通讯作者：
Kelly JM
中科院分区：
文献类型：
--
作者：
Campos MC;Phelan J;Francisco AF;Taylor MC;Lewis MD;Pain A;Clark TG;Kelly JM
恰加斯病是由原生动物寄生虫克氏锥虫引起的，在拉丁美洲影响着500-800万人。尽管硝基杂环化合物苯硝唑几十年来一直是一线药物，但治疗失败的情况很常见。苯硝唑是一种前体药物，在寄生虫体内被线粒体硝基还原酶TcNTR-1生物激活，导致产生具有杀锥虫活性的反应性代谢物。为了更好地评估药物作用和耐药性，我们对克鲁兹毛滴虫Y株(35.5Mb)和来自单个药物选择群体的三个苯硝唑抗性克隆的基因组进行了测序。这揭示了除了DNA拷贝数的变化外，耐药寄生虫的突变在全基因组范围内积累。我们观察到DNA修复基因的突变，这与DNA烷基化和链间交联剂的易感性增加有关。TcNTR-1的终止密码子产生突变与对其他硝基杂环类药物的交叉耐药性有关。出乎意料的是，这些克隆人还对麦角固醇生物合成抑制剂泊沙康唑和苯硝唑具有高度抗药性。泊沙康唑是一种建议用于对抗克氏毛滴虫感染的药物。因此，我们的发现确定了苯硝唑代谢产物在克氏锥虫中的高度诱变活性，证明了这可能导致多重耐药，并表明如果苯硝唑用于联合治疗将需要警惕。
Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and affects 5–8 million people in Latin America. Although the nitroheterocyclic compound benznidazole has been the front-line drug for several decades, treatment failures are common. Benznidazole is a pro-drug and is bio-activated within the parasite by the mitochondrial nitroreductase TcNTR-1, leading to the generation of reactive metabolites that have trypanocidal activity. To better assess drug action and resistance, we sequenced the genomes of T. cruzi Y strain (35.5 Mb) and three benznidazole-resistant clones derived from a single drug-selected population. This revealed the genome-wide accumulation of mutations in the resistant parasites, in addition to variations in DNA copy-number. We observed mutations in DNA repair genes, linked with increased susceptibility to DNA alkylating and inter-strand cross-linking agents. Stop-codon-generating mutations in TcNTR-1 were associated with cross-resistance to other nitroheterocyclic drugs. Unexpectedly, the clones were also highly resistant to the ergosterol biosynthesis inhibitor posaconazole, a drug proposed for use against T. cruzi infections, in combination with benznidazole. Our findings therefore identify the highly mutagenic activity of benznidazole metabolites in T. cruzi, demonstrate that this can result in multi-drug resistance, and indicate that vigilance will be required if benznidazole is used in combination therapy.