儿童幽门螺杆菌感染途径的研究

为探讨儿童幽门螺杆菌感染的可能途径，对198例儿童及69例一级亲属，采用PCR方法扩增唾液和胃粘膜H.pylori尿素酶C（UreC)基因（820bp)，扩增产物分别用限制性核酸内切酶Hha I与Alu I酶切消化，得出H.pylori的酶切类型（RFLPc)。结果显示，Ｈ.pylori UreC基因扩增片断经限制性核酸内切酶ＨhaI与Ａlu I酶切后，分别得到９种和７种不同的酶切图谱，结合两种酶切类型共确定22个独立的酶切类型；在31个儿童与亲属同时感染的家庭中，25．0％（7／28例）的儿童唾液中可扩增出H.phylori，且唾液与相应胃粘膜中的幽门螺杆菌RFLPc酶切类型一致；83．9％（26／31例）儿童感染的H.pylori与其亲属感染的H.pylori类型相同，16．1％（5／31例）不相同（P＜0．05）。表明PCR－RFLP分析H.pylori UreC基因的酶切类型分辨率较高，直接扩增样本H.pylori方法简便，可用于H.pylori的流行病学研究；唾液可作为家庭内成员H.pylori感染的传播因素。

Exploration for possible source of Helicobacter pylori infection in children

To explore the possible source of Helicobacter pylori (H.pylori) infection in children,UreC gene in both of saliva and gastric mucosa collected by gastroscopy were amplified by PCR_RFLP method in 196 children with upper digestive tract symptoms and 69 first_degree relatives among these children.Amplified produces were further digested by restrietion endonucleases Hha I and Alu I for obtaining RFLPc patterns of H.pylori.The results showed that nine digest patterns by Hha I and seven digest patterns by Alu I were obtained in amplified produces of UreC gene.A total of 22 RFLRc patterns of H.pylori were confirmed based on the digest patterns with combination of restriction endonucleases Hha I and Alu I.It was found that H.pylori in saliva could be amplified in 25%(7/28)of children among 31 infectious families,and RFLPc patterns were identical in both of saliva and gastric mucosa.Identical digest patterns were also confirmed in 83.9%(26/31)of infectious families(P<0.05).It is concluded that PCR_RFLP method is a sensitive and reliable way for the investigation of epidemiology of H.pylori infection.Accordant RFLPc patterns were confirmed in both of saliva and gastric mucosa and infectious children and their first_degree relatives,that suggest oral_oral transmission be a main media type to infect H.pylori in children probably.