Penuliar Gil M, Nakada-Tsukui Kumiko, Nozaki Tomoyoshi
Department of Parasitology, National Institute of Infectious Diseases Tokyo, Japan ; Department of Parasitology, Gunma University Graduate School of Medicine Maebashi, Japan.
Department of Parasitology, National Institute of Infectious Diseases Tokyo, Japan.
Front Microbiol. 2015 May 5;6:354. doi: 10.3389/fmicb.2015.00354. eCollection 2015.
Antimicrobial chemotherapy is critical in the fight against infectious diseases caused by Entamoeba histolytica. Among the drugs available for the treatment of amebiasis, metronidazole (MTZ) is considered the drug of choice. Recently, in vitro studies have described MTZ resistance and the potential mechanisms involved. Costs to fitness and adaptive responses associated with resistance, however, have not been investigated. In this study we generated an HM-1 derived strain resistant to 12 μM MTZ (MTZR). We examined its phenotypic and transcriptional profile to determine the consequences and mRNA level changes associated with MTZ resistance. Our results indicated increased cell size and granularity, and decreased rates in cell division, adhesion, phagocytosis, cytopathogenicity, and glucose consumption. Transcriptome analysis revealed 142 differentially expressed genes in MTZR. In contrast to other MTZ resistant parasites, MTZR did not down-regulate pyruvate:ferredoxin oxidoreductase, but showed increased expression of genes for a hypothetical protein (HP1) and several iron-sulfur flavoproteins, and downregulation of genes for leucine-rich proteins. Fisher's exact test showed 24 significantly enriched GO terms in MTZR, and a 3-way comparison of modulated genes in MTZR against those of MTZR cultured without MTZ and HM-1 cultured with MTZ, showed that 88 genes were specific to MTZR. Overall, our findings suggested that MTZ resistance is associated with specific transcriptional changes and decreased parasite virulence.
抗微生物化疗在对抗由溶组织内阿米巴引起的传染病中至关重要。在可用于治疗阿米巴病的药物中，甲硝唑（MTZ）被认为是首选药物。最近，体外研究描述了MTZ耐药性及其潜在机制。然而，与耐药性相关的适应性代价和适应性反应尚未得到研究。在本研究中，我们构建了一株对12 μM MTZ耐药的HM-1衍生菌株（MTZR）。我们检查了其表型和转录谱，以确定与MTZ耐药性相关的后果和mRNA水平变化。我们的结果表明，细胞大小和颗粒度增加，细胞分裂、黏附、吞噬作用、细胞致病性和葡萄糖消耗率降低。转录组分析显示MTZR中有142个差异表达基因。与其他MTZ耐药寄生虫不同，MTZR没有下调丙酮酸：铁氧化还原蛋白氧化还原酶，但显示一种假定蛋白（HP1）和几种铁硫黄素蛋白的基因表达增加，富含亮氨酸蛋白的基因下调。Fisher精确检验显示MTZR中有24个显著富集的GO术语，将MTZR中调控基因与无MTZ培养的MTZR和有MTZ培养的HM-1的调控基因进行三向比较，结果显示有88个基因是MTZR特有的。总体而言，我们的研究结果表明MTZ耐药性与特定的转录变化和寄生虫毒力降低有关。
