浙江人群幽门螺杆菌cagA/vacA优势基因型和不同基因型混合感染的调查

目的　了解消化性溃疡和慢性胃炎患者感染的幽门螺杆菌 (Hp)cagA vacA优势基因型及不同基因型Hp感染、混合感染与疾病的关系。 方法　选择胃窦、胃体双份活检标本均培养出Hp的 42例慢性胃炎 (CG)和 3 6例消化性溃疡 (PU )患者作为研究对象 ,采用聚合酶链反应 (PCR)检测156份Hp分离株的cagA基因、vacA基因的信号区 (s)和中间区 (m )亚型 ,分析Hp基因型及多株Hp混合感染在CG和PU中的分布。结果　胃窦标本cagA基因的检测中 78例患者中有 75例 (96.2 % )为cagA阳性 ,相应的胃体标本中 ,76例患者 (97.4% )为cagA阳性 ,有 1例 (1.3 % )患者胃窦、胃体检出cagA状态不一的Hp混合菌株。在胃窦标本的vacA基因分型中 ,s1a m1、s1a m2、s1a m1b、s1a m1b m2 4种vacA基因型在 78例患者中所占比例分别为 6.4% (5 78)、55.1% (43 78)、2 6.9% (2 1 78)和 1.3 % (1 78) ,多株混合感染为 3 .8% (3 78) ;而相应的胃体标本中 ,前述四种vacA基因型所占比例依次为 6.4% (5 78)、53 .8% (42 78)、2 5.6% (2 0 78)和 3 .8% (3 78) ,多株混合感染为 5.1% (4 78)。cagA+ s1a m2和cagA+ s1a m1b在胃窦标本中占 51.3 % (40 78)和 2 6.9% (2 1 78) ,而在相应的胃体标本中占 52 .6% (41 78)和 2 5.6% (2 0 78)。少量胃窦、胃体

Investigation on cagA/vacA dominant genotypes and the coinfection of Helicobacter pylori isolates from patients in Zhejiang

ObjectiveTo determine cagA/vacA dominant g enotypes of Helicobacter pylori in patients suffing from chronic gastritis (CG) or peptic ulcer (PU), and to understand the correlation of different genoty pe H.pylori infection, coinfection and the gastroduodenal diseases. MethodsH. pylori strains were isolated from antrum and corpus samples on 42 patients with CG and 36 patients with PU. Polymerase c hain reaction was used to detect cagA and the s and m regions of vacA in 156 H. pylori isolates fr om both antrum and corpus. The distribution of H. pylori genotypes and coinf ection in CG and PU was analyzed. Results Almost all of the isolated H.pylori strai ns were cagA positive. In region of vacA, only one genotype of signal region (s1 a) and four genotypes of the middle region (m1, m2, m1b and m1b-m2) were found. T he proportions of s1a/m1, s1a/m2, s1a/m1b, s1a/m1b-m2 and coinfection of multi ple H.pylori strains in 78 isolates from antrum samples were 6.4 %, 55.1 %, 26.9 %, 1.3 % and 3.8 %;and the related proportions of those from c orpus samples were 6.4 %, 53.8 %, 25.6 %, 3.8 % and 5.1 %, respecti vely. Sixteen ( 20.5 %) patients had multiple H.pylori strains with differ ent cagA and vacA genotypes, and multiple samples were better than single sampl e taken from one stomach to increase the positive proportion of coinfection. ConclusioncagA + s1a/m2 was the dominant genotype of H.pylori in the CG or PU patients followed by cagA + s1a/m1b in the Zhejiang area of China. Some of the patients were coinfected with multiple H.pylori strains of different cagA and vacA genotypes. However, there was no significi ent correlation between the genotypes or mixed infection with multiple strains, CG or PU.