Laboratorio de Fisiología Gastrointestinal, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas (IVIC), Miranda, Venezuela.
University of Bordeaux, INSERM, UMR1053 Bordeaux Research in Translational Oncology, BaRITOn, 33076 Bordeaux, France.
J Med Microbiol. 2019 Sep;68(9):1287-1291. doi: 10.1099/jmm.0.001051.
The molecular mechanism of resistance to tetracycline involves mutations in the primary binding site of the ribosome. A resistance or reduced susceptibility to tetracycline could be the result of single, double or triple mutations in the 16S gene of . We investigated if the genotype was correlated to tetracycline resistance as determined phenotypically for 96 . isolates in the gastroesophageal mucosa of Venezuelan individual hosts. E-test for antimicrobial susceptibility test and real-time PCR for the detection of 16S gene mutations were performed in 96 . isolates (48 obtained from antrum, and 48 from oesophagus) from eight dyspeptic patients. In the gastric mucosa, 38 isolates were identified sensitive and 10 resistant to tetracycline by E-test, whereas 44 sensitive and 4 resistant isolates were found in the oesophagus. Real-time PCR detection of the 16S gene exhibited mutants with a single base-pair substitution (AGAGGA) in six antrum isolates and seven oesophagus isolates, whereas only three harboured a low level of tetracycline resistance . Our results indicate that real-time PCR detection of 16S is a reliable method to classify among tetracycline-resistant genotypes and useful in patients who have experienced a first-line treatment failure with triple therapy.
耐药的分子机制涉及核糖体的主要结合部位的突变。对四环素的耐药性或敏感性降低可能是核糖体 16S 基因中单个、双个或三个突变的结果。我们研究了基因型是否与表型上确定的 96 名委内瑞拉个体宿主胃食管黏膜中的四环素耐药性相关。对 8 名消化不良患者的 96 株（48 株来自胃窦，48 株来自食管）进行了药敏试验和 16S 基因突变的实时 PCR。在胃黏膜中，E 试验鉴定 38 株对四环素敏感，10 株耐药，而在食管中，44 株敏感，4 株耐药。16S 基因实时 PCR 检测显示，6 株胃窦和 7 株食管分离株存在单个碱基替换（AGAGGA）的突变体，而只有 3 株携带低水平的四环素耐药性。我们的结果表明，16S 的实时 PCR 检测是一种可靠的方法，可以对四环素耐药基因型进行分类，对经历一线三联疗法治疗失败的患者有用。
