Hao Qing, Li Yan, Zhang Zhi-Jie, Liu Yong, Gao Hong
Department of Gastroenterology, the 2nd Affiliated Hospital, China Medical University, Shenyang 110004, Liaoning Province, China.
World J Gastroenterol. 2004 Apr 1;10(7):1075-7. doi: 10.3748/wjg.v10.i7.1075.
To investigate the resistance rate of Helicobacter pylori (H pylori ) to clarithromycin, metronidazole, amoxicillin and tetracycline to guide clinical practice, and to study the mechanism of H pylori resistant to clarithromycin.
Thirty H pylori strains were isolated from the mucosa of peptic ulcer, gastric tumor and chronic gastritis patients, then the minimal inhibitory concentration (MIC) to clarithromycin, metronidazole, amoxicillin and tetracycline was evaluated by E-test method. The sequence analysis of PCR fragments was conducted in 23S rRNA gene of H pylori resistant to clarithromycin to get the resistance mechanism of the bacteria.
Among 30 H pylori strains, 7 cases were resistant to clarithromycin, 12 to metronidazole, 2 to tetracycline and no strain was found to be resistant to amoxicillin. The resistance rates were 23.3%, 40%, 6.7% and 0%, respectively. Three new mutation points were found to be related to the clarithromycin resistance in H pylori isolates, which were G2224A, C2245T and T2289C.
In northeast China, H pylori shows high resistance to metronidazole, while sensitive to amoxicillin. The mechanism of resistance to clarithromycin may be related to the mutation of G2224A, C2245T and T2289C in the 23S rRNA gene.
研究幽门螺杆菌（H pylori）对克拉霉素、甲硝唑、阿莫西林和四环素的耐药率以指导临床实践，并探讨H pylori对克拉霉素耐药的机制。
从消化性溃疡、胃肿瘤及慢性胃炎患者的黏膜中分离出30株H pylori菌株，然后采用E-test法评估其对克拉霉素、甲硝唑、阿莫西林和四环素的最低抑菌浓度（MIC）。对克拉霉素耐药的H pylori的23S rRNA基因进行PCR片段序列分析，以了解细菌的耐药机制。
30株H pylori菌株中，7株对克拉霉素耐药，12株对甲硝唑耐药，2株对四环素耐药，未发现对阿莫西林耐药的菌株。耐药率分别为23.3%、40%、6.7%和0%。发现3个新的突变位点与H pylori分离株对克拉霉素的耐药性有关，分别为G2224A、C2245T和T2289C。
在中国东北地区，H pylori对甲硝唑耐药率高，而对阿莫西林敏感。对克拉霉素耐药的机制可能与23S rRNA基因中的G2224A、C2245T和T2289C突变有关。
