Ciftci Ihsan Hakkı, Uslan Ihsan, Dilek Fatma Hüsniye, Aşık Gülşah, Ozgür Mihrican Aydın, Dilek Osman Nuri
Afyon Kocatepe University Faculty of Medicine, Department of Medical Microbiology, Afyonkarahisar, Turkey.
Mikrobiyol Bul. 2011 Apr;45(2):228-33.
Several virulence factors of Helicobacter pylori play crucial role in the pathogenesis of the infections.H.pylori iceA gene which is induced by the contact with epithelium during the attachment of bacterium to the gastric mucosa, possess two variants (iceA1 and iceA2). Although there are some data indicating the relationship between H.pylori iceA1 and peptic ulcer, this concept is still controversial. The aims of this study were to investigate the presence and prevalence of H.pylori iceA1 and iceA2 gene regions in the tissue samples of patients diagnosed as chronic gastritis and gastric cancer, and to evaluate whether any correlation existed between these genotypes and clinical manifestations. A total of 109 tissue samples obtained from chronic gastritis (n= 55) and gastric cancer (n= 54) patients whose H.pylori infections have been confirmed by histopathologic examination of biopsy samples, were included in the study. The presence of H.pylori in the samples were also confirmed by amplification of the ureA gene region by inhouse polymerase chain reaction (PCR). H.pylori iceA1 and iceA2 genes were directly genotyped with the use of specific primers in the gastric biopsy specimens by PCR. The total positivity rates of iceA1 and ice- A2 genotypes in patients were found as 58% (63/109) and 24% (26/109), respectively. With the special attention to chronic gastritis and gastric cancer patients, the frequencies of iceA1 gene were 51% (28/55) and 65% (35/54), while the frequencies of iceA2 gene were 20% (11/55) and 28% (15/54), respectively. The difference of positivity rates of iceA1 and iceA2 genotypes between the patient groups were not statistically significant (p> 0.05). There was also no statistically significant correlation between the genotypes and clinical manifestation (r> 0.01). As a result, H.pylori iceA1 genotype was predominant (58%) in chronic gastritis and gastric cancer patients in our region, however the prevalence of iceA2 genotype was lower (24%) similar to those data reported in the literature. Our results supported the concept that iceA gene reflects geographical differences rather than determining the clinical picture and virulence. In conclusion, multicenter and large scaled studies are needed for better evaluation of H.pylori iceA gene and disease relationship.
幽门螺杆菌的几种毒力因子在感染的发病机制中起关键作用。幽门螺杆菌iceA基因在细菌附着于胃黏膜过程中与上皮细胞接触时被诱导产生，有两种变体（iceA1和iceA2）。尽管有一些数据表明幽门螺杆菌iceA1与消化性溃疡之间存在关联，但这一概念仍存在争议。本研究的目的是调查在被诊断为慢性胃炎和胃癌的患者组织样本中幽门螺杆菌iceA1和iceA2基因区域的存在情况和流行率，并评估这些基因型与临床表现之间是否存在任何相关性。本研究纳入了109份组织样本，这些样本来自经活检样本组织病理学检查确诊为幽门螺杆菌感染的慢性胃炎患者（n = 55）和胃癌患者（n = 54）。通过内部聚合酶链反应（PCR）扩增ureA基因区域，也证实了样本中存在幽门螺杆菌。通过PCR在胃活检标本中使用特异性引物直接对幽门螺杆菌iceA1和iceA2基因进行基因分型。患者中iceA1和iceA2基因型的总阳性率分别为58%（63/109）和24%（26/109）。特别关注慢性胃炎和胃癌患者时，iceA1基因的频率分别为51%（28/55）和65%（35/54），而iceA2基因的频率分别为20%（11/55）和28%（15/54）。患者组之间iceA1和iceA2基因型阳性率的差异无统计学意义（p>0.05）。基因型与临床表现之间也无统计学意义的相关性（r>0.01）。结果，在我们地区的慢性胃炎和胃癌患者中，幽门螺杆菌iceA1基因型占主导（58%），然而iceA2基因型的流行率较低（24%），与文献报道的数据相似。我们的结果支持iceA基因反映地理差异而非决定临床情况和毒力这一概念。总之，需要进行多中心、大规模研究以更好地评估幽门螺杆菌iceA基因与疾病的关系。
