应用基因分型技术研究幽门螺杆菌感染的家庭聚集现象

Application of genotyping in the study of intrafamilial clustering of Helicobacter pylori infection in children

目的探讨本地区Hp感染的可能途径。方法采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法分析60个家庭133名伴有上消化道症状的儿童及其一级亲属唾液和胃粘膜中的Hp尿素酶C(UreC)基因,通过比较两种限制性核酸内切酶HhaⅠ与AluⅠ酶切复合类型(RFLP-C)评价儿童获得Hp的可能途径。结果 78个Hp阳性的家庭成员共确定22个Hp酶切类型。25.0％(7/28)Hp阳性儿童从唾液中扩增出Hp,33.3％(10/30)Hp阳性的亲属从唾液中扩增出Hp,唾液与相应胃实Hp的RFLP-C类型一致。83.9％(26/31)先证者感染的Hp与其亲属感染的Hp类型相同。结论 PCR-RFLP分析Hp Ure C基因的酶切类型分辨率较高,直接扩增样本Hp方法简便,可应用于Hp的流行病学研究。Hp感染患者唾液与胃粘膜中扩增出的Hp Ure C基因RFLP-C酶切类型完全一致,同一家庭内感染的Hp Ure C基因RFLP类型高度相符,提示家庭内成员的口—口传播可能是儿童期获得Hp的重要模式。

Objectives To explore the possible source and transmission route of Hp within family members. Methods We applied PCR-RFLP method to clinical specimens including gastric mucosa and coupling samples of their saliva in 133 subjects belonging to 60 families. Results Thirty-one of 60(51.7%,31/60)family members were in concordance with Hp infection, and eighteen of 60(30.0%,18/60)families were in concordance without Hp infection. On the contrast, only seven of 60 families(11.7%,7/60) and four of 60(6.7%,4/60)families were disagreement with or without Hp infection. Analysis of the PCR-RFLP patterns revealed 22 distinct RFLP types from 78 Hp -positive family members,seven of 28 infected children(25.0%,7/28)and ten of 30 infected relatives(33.3%,10/30)were detected Hp in their saliva by PCR, all of the RFLP digest patterns in coupling saliva and gastric mucosa were identical. Sixty-seven of 73 specimens(91.8%,67/73),with 6 exception,yielded identical digest patterns from the specimens both at antrum and corpus, indicating that multiple strains of Hp infection exist uncommonly in this series. Twenty-six of 31(83.9%,26/31)infected children with fheir relatives shared the identical digest patterns of Hp, wheras the remaining 5(16.1%,5/31)had different digest patterns. Conclusions This study demonstrated that PCR-RFLP provides a useful and reliable reproducible and highly discriminatory typing scheme for the epidemiological study of Hp infection;The highly concordance of the Hp genotypes among the intrafamilial members indicates that oral-oral transmission within family members may be the most common way for children infected with Hp in Southern China.