Sarıbaş Zeynep, Demir Hülya, Saltık Temizel Inci Nur, Simşek Halis, Ozen Hasan, Akyön Yakut
Hacettepe Üniversitesi Tıp Fakültesi, Tıbbi Mikrobiyoloji Anabilim Dalı, Ankara, Türkiye.
Mikrobiyol Bul. 2010 Jul;44(3):461-5.
Helicobacter pylori is a gram-negative, microaerophilic bacterium that colonizes human gastric mucosa and affects approximately 50% of the whole world population. It has put the blame on gastric ulcer, duodenal ulcer, chronic atrophic gastritis, mucosa-associated lymphoid tissue lymphoma and stomach adenocarcinoma, as the etiological agent. The cagA (cytotoxin-associated gene A) gene which is one of the most important virulence factors of H.pylori, encodes a 120-145 kDa protein called CagA antigen that may cause cell transformation. The prevalence of cagA positive H.pylori infections varies according to geographical area and age of the patients. Recent studies have suggested that cagA positive H.pylori strains play a role in the development of gastric carcinoma. The aim of this study was to evaluate the prevalence of cagA positive H.pylori isolates in adult and pediatric patient groups in Hacettepe University, Faculty of Medicine. The study was performed on 198 H.pylori stocked strains which have been isolated between 1997-2003 period from biopsy specimens of 107 adult and 91 pediatric patients with gastrointestinal pathology. Chromosomal DNA was extracted by the cetyltrimethyl-ammonium bromide (CTAB) method, and a 348 bp region of the cagA gene was amplified by an "in-house" polymerase chain reaction (PCR) using F1 and B1 primers (Gene Bank number: L11714 position 1231 and 1578R). The evaluation of PCR products revealed that 58.6% (116/198) of the isolates were cagA positive. The rates of cagA positive H.pylori among the adult and pediatric isolates were 62% and 55%, respectively. The present study demonstrates the prevalence of cagA in clinical isolates of H.pylori in our university hospital, and our data was found concordant with the results of studies reported from developed countries.
幽门螺杆菌是一种革兰氏阴性、微需氧菌，可定殖于人类胃黏膜，全世界约50%的人口受其影响。它被认为是胃溃疡、十二指肠溃疡、慢性萎缩性胃炎、黏膜相关淋巴组织淋巴瘤和胃腺癌的病原体。cagA（细胞毒素相关基因A）基因是幽门螺杆菌最重要的毒力因子之一，编码一种名为CagA抗原的120 - 145 kDa蛋白质，可能导致细胞转化。cagA阳性幽门螺杆菌感染的患病率因地理区域和患者年龄而异。最近的研究表明，cagA阳性幽门螺杆菌菌株在胃癌的发生发展中起作用。本研究的目的是评估在哈杰泰佩大学医学院的成人和儿童患者组中cagA阳性幽门螺杆菌分离株的患病率。该研究对198株储存的幽门螺杆菌菌株进行，这些菌株于1997 - 2003年期间从107名患有胃肠道疾病的成人和91名儿童患者的活检标本中分离得到。采用十六烷基三甲基溴化铵（CTAB）法提取染色体DNA，并使用F1和B1引物（基因库编号：L11714位置1231和1578R）通过“内部”聚合酶链反应（PCR）扩增cagA基因的一个348 bp区域。对PCR产物的评估显示，58.6%（116/198）的分离株为cagA阳性。成人和儿童分离株中cagA阳性幽门螺杆菌的比例分别为62%和55%。本研究证明了我校医院临床分离的幽门螺杆菌中cagA的患病率，我们的数据与发达国家报道的研究结果一致。
