Alfaresi Mubarak S, Abdulsalam Adeel Islam, Elkoush Abida A
Department of Pathology and Laboratory Medicine, Microbiology Division, Zayed Military Hospital, Abu Dhabi, United Arab Emirates.
Indian J Gastroenterol. 2007 Sep-Oct;26(5):221-4.
To determine the virulence attributes (presence of cagA and vacA genes) of Helicobacter pylori , and presence of clarithromycin resistance genes in gastric mucosal biopsy samples obtained in the United Arab Emirates.
DNA was extracted from antral gastric biopsy samples from 91 dyspeptic patients. Real-time PCR and melting curve analysis were used to identify patients infected with H. pylori and to further identify strains containing the A(2142/43)G or the A(2142)C mutations that are associated with clarithromycin resistance. PCR was also used to identify cagA - and vacA -positive strains.
Real-time PCR analysis detected the presence of H. pylori in 55 (60%) samples. Thirty-six pathogen-positive samples contained at least one of three point mutations associated with clarithromycin resistance. The vacA gene was present in 40 (72.7%) and cagA was present in 41 (74.5%) of the positive samples. Both genes were present in 36 (65%) of the positive samples. The presence of each clarithromycin-inducing mutation was largely independent of the others. Mutation at one position, A(2142/43)G, was strongly associated with the presence of both the vacA gene and the cagA gene.
A high proportion of gastric mucosal biopsies obtained in the UAE is positive for genes associated with clarithromycin resistance. This may have implications for treatment of the infection.
确定阿联酋胃黏膜活检样本中幽门螺杆菌的毒力属性（cagA和vacA基因的存在情况）以及克拉霉素耐药基因的存在情况。
从91例消化不良患者的胃窦活检样本中提取DNA。采用实时荧光定量PCR和熔解曲线分析来鉴定感染幽门螺杆菌的患者，并进一步鉴定含有与克拉霉素耐药相关的A(2142/43)G或A(2142)C突变的菌株。PCR还用于鉴定cagA和vacA阳性菌株。
实时荧光定量PCR分析在55份（60%）样本中检测到幽门螺杆菌的存在。36份病原体阳性样本含有与克拉霉素耐药相关的三种点突变中的至少一种。vacA基因在40份（72.7%）阳性样本中存在，cagA基因在41份（74.5%）阳性样本中存在。两个基因都存在于36份（65%）阳性样本中。每种克拉霉素诱导突变的存在在很大程度上相互独立。一个位置的突变，即A(2142/43)G，与vacA基因和cagA基因的存在密切相关。
在阿联酋获得的胃黏膜活检样本中，很大一部分与克拉霉素耐药相关的基因呈阳性。这可能对该感染的治疗有影响。
