Tetracycline resistance in Chilean clinical isolates of Helicobacter pylori.
Tetracycline resistance in Chilean clinical isolates of Helicobacter pylori.
复制标题
智利幽门螺杆菌临床分离株的四环素耐药性。
DOI：
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发表时间：
2010
影响因子：
5.2
通讯作者：
R. López
中科院分区：
文献类型：
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作者：
H. Toledo;R. López
目标
由于幽门螺杆菌对四环素的高度耐药与16S rRNA基因中的AGA926-928-->；TTC突变有关，本研究的目的是通过最近报道的分子检测方法来筛查从智利圣地亚哥获得的幽门螺杆菌临床分离株对四环素的耐药性。
方法
对幽门螺杆菌16S rRNA基因rRNA/B(710~1245位核苷酸之间)的保守区进行聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)分析，并对从四环素耐药临床分离株中获得的相同片段进行DNA测序。
结果
聚合酶链式反应-限制性片段长度多态性分析显示，四环素耐药菌株缺乏AGA926-928-->；TTC替换。相比之下，对11株四环素耐药幽门螺杆菌智利临床分离株的DNA测序显示，低水平的四环素耐药性与两个16S rRNA基因的1个碱基(A928C)或2个碱基(AG926-927-->；GT和/或A926G/A928C)替换有关。
结论
仅用聚合酶链式反应-限制性片段长度多态性(HInfI)方法检测幽门螺杆菌临床分离株对四环素的耐药性是不可靠的。为此，必须通过对BP-PCR片段进行测序来补充。
OBJECTIVES
Since high-level tetracycline resistance in Helicobacter pylori has been associated with a AGA926-928-->TTC substitution in the 16S rRNA genes rrnA/B, the aim of the study was to screen for tetracycline resistance in H. pylori clinical isolates obtained from Santiago, Chile by using a recently reported molecular assay.
METHODS
A PCR-restriction fragment length polymorphism (PCR-RFLP) assay of the conserved 535 bp region of the H. pylori 16S rRNA genes rrnA/B (between nucleotides 710 and 1245) using HinfI was followed by DNA sequencing of the same fragment obtained from tetracycline-resistant H. pylori clinical isolates.
RESULTS
The PCR-RFLP assay revealed that the tetracycline-resistant H. pylori isolates lacked the AGA926-928-->TTC substitution. In contrast, DNA sequencing of the 535 bp PCR fragment from 11 tetracycline-resistant H. pylori Chilean clinical isolates showed an association of low-level tetracycline resistance with 1 bp (A928C) or 2 bp (AG926-927-->GT and/or A926G/A928C) substitutions in both 16S rRNA genes.
CONCLUSIONS
The PCR-RFLP (HinfI) assay alone is unreliable for the detection of tetracycline resistance in Chilean clinical isolates of H. pylori. To that end, it must be complemented by sequencing of the 535 bp PCR fragment.