Acosta Claudia Patricia, Quiroga Andrés Javier, Sierra Carlos H, Trespalacios Alba Alicia
Grupo de Investigación en Genética Humana Aplicada, Facultad de Ciencias de la Salud, Universidad del Cauca, Popayán, Colombia Fundación InnovaGen, Popayán, Colombia.
Biomedica. 2017 Jun 1;37(2):191-199. doi: 10.7705/biomedica.v37i2.3007.
Resistance to metronidazole is a key factor associated with Helicobacter pylori treatment failure. Even though resistance is mostly associated with RdxA nitroreductase mutations, studies of this H. pylori protein in Popayán (Colombia) are still incipient.
To evaluate the frequency of mutations in the RdxA nitroreductase in a population of patients with H. pylori-positive gastrointestinal disease.
We amplified the DNA of 170 gastric biopsies by PCR to detect mutations in the RdxA nitroreductase. An analysis of DNA sequences translated into amino acid sequences was done and then compared to the reference strain 26695.
The frequency of RdxA nitroreductase mutations in this study population was 78%. Its most frequent distribution was found in positions D59N (153 samples), R131K (101 samples), R90K (97 samples), A118T (42 samples), I160F (32 samples) and H97T (26 samples), and meaningful stop codons Q50*, D59*; E75*, C159* and I160* in five, one, three, ten and six samples, respectively. The most common virulence genotype was vacAs1/m1 cagA negative (48.6 %).
The high frequency of RdxA nitroreductase mutations in H. pylori isolates in Popayán (Colombia) indicates that empirical therapy with metronidazole may not be a valid option for the eradication of H. pylori in patients of the studied population.
对甲硝唑耐药是与幽门螺杆菌治疗失败相关的关键因素。尽管耐药主要与RdxA硝基还原酶突变有关，但在波帕扬（哥伦比亚）对这种幽门螺杆菌蛋白的研究仍处于起步阶段。
评估幽门螺杆菌阳性胃肠道疾病患者群体中RdxA硝基还原酶的突变频率。
我们通过聚合酶链反应（PCR）扩增了170份胃活检组织的DNA，以检测RdxA硝基还原酶中的突变。对翻译成氨基酸序列的DNA序列进行了分析，然后与参考菌株26695进行比较。
本研究群体中RdxA硝基还原酶突变的频率为78%。其最常见的分布位于D59N（153个样本）、R131K（101个样本）、R90K（97个样本）、A118T（42个样本）、I160F（32个样本）和H97T（26个样本）位点，以及有意义的终止密码子Q50*、D59*；E75*、C159和I160，分别在5个、1个、3个、10个和6个样本中出现。最常见的毒力基因型是vacAs1/m1 cagA阴性（48.6%）。
在波帕扬（哥伦比亚）的幽门螺杆菌分离株中，RdxA硝基还原酶突变的高频率表明，对于该研究群体中的患者，甲硝唑经验性治疗可能不是根除幽门螺杆菌的有效选择。
