胃十二指肠疾病儿童幽门螺杆菌cagA、vacA 和iceA 基因型分布

Prevalence of Helicobacter pylori cagA, vacA, and iceA genotypes in children with gastroduodenal diseases

摘要:

目的 了解来自于江西地区胃十二指肠疾病儿童感染的幽门螺杆菌 （H.pylori）临床分离菌株cagA、vacA和iceA基因亚型分布情况，并探讨H.pyloricagA、vacA和iceA基因亚型与儿童胃十二指肠疾病类型之间的关系。方法 从来自江西地区的316例患有胃十二指肠疾病儿童的胃窦黏膜中，培养出107株H.pylori菌株，提取菌株基因组DNA，采用PCR法检测H.pyloriureA、cagA、vacA及iceA基因亚型。结果 在107株H.pylori临床分离菌株中，H.pyloriureA基因和cagA基因检出率分别为100% （107/107）和94.4% （101/107）。vacA基因总检出率为100% （107/107），vacAs1a、vacAs1c、vacAm1和vacAm2基因检出率分别为74.8% （80/107）、25.2% （27/107）、29.9% （32/107）和69.2% （74/107），其中0.9% （1/107）H.pylori菌株同时检测出vacAm1和vacAm2基因型；在vacA基因的嵌合体中，vacAs1a/m1、vacAs1a/m2、vacAs1c/m1和vacAs1c/m2基因检出率分别为26.2% （28/107）、51.4% （55/107）、3.7% （4/107）和17.8% （19/107） （P<0.001）。iceA1和iceA2基因阳性检出率分别为79.4% （85/107）和9.3% （10/107） （P<0.001）；iceA1和iceA2基因亚型均阳性的检出率为7.5% （8/107）。H.pylori各基因亚型在消化性溃疡、慢性胃炎和十二指肠球炎3组间的检出率比较差异无统计学意义 （P>0.05）。结论 来自于江西地区胃十二指肠疾病儿童感染的H.pylori优势基因亚型是cagA、vacAs1a/m2和iceA1；H.pylori感染存在不同基因型菌株混合感染；H.pylori基因亚型与胃十二指肠疾病类型无相关性。

Abstract:

Objective To investigate the prevalence of cagA, vacA, and iceA genotypes in the isolated strains of Helicobacter pylori (H.pylori) from children with gastroduodenal diseases in Jiangxi, China, as well as the association between cagA, vacA, and iceA genotypes and the type of gastroduodenal diseases. Methods The samples of gastric antral mucosa were collected from 316 children with gastroduodenal diseases in Jiangxi, and a total of 107 strains of H.pylori were isolated. The genomic DNA of these strains was extracted, and PCR was used to determine the ureA, cagA, vacA, and iceA genotypes. Results Of all the 107 isolated strains of H.pylori, the detection rates of ureA and cagA genes were 100% (107/107) and 94.4% (101/107) respectively. The overall detection rate of vacA gene was 100% (107/107), and the detection rates of vacAs1a, vacAs1c, vacAm1, and vacAm2 genes were 74.8% (80/107), 25.2% (27/107), 29.9% (32/107), and 69.2% (74/107) respectively, with both vacAm1 and vacAm2 genes detected in 0.9% (1/107) of all H.pylori strains. In the chimera of vacA gene, the detection rates of vacAs1a/m1, vacAs1a/m2, vacAs1c/ m1, and vacAs1c/m2 genes were 26.2% (28/107), 51.4% (55/107), 3.7% (4/107), and 17.8% (19/107) respectively (P<0.001). The detection rates of iceA1 and iceA2 genes were 79.4% (85/107) and 9.3% (10/107), respectively (P<0.001), and both iceA1 and iceA2 genes were detected in 7.5% (8/107) of all strains. The detection rates of the genotypes of H.pylori showed no significant differences between the peptic ulcer, chronic gastritis, and duodenal bulbar inflammation groups (P>0.05). Conclusions The dominant genotypes of H.pylori are cagA, vacAs1a/m2, and iceA1, and there are mixed infections with H.pylori strains of different genotypes in children with gastroduodenal disease from Jiangxi, China. The genotypes of H.pylori are not associated with the type of gastroduodenal disease.