幽门螺杆菌在宿主间传播途径模型的初步研究

Preliminary study on transmission route model of Helicobacter pylori among hosts

目的建立幽门螺杆菌(Hp)在宿主间的直接传播模型,探索自然环境中Hp通过各种途径传染致下一宿主的可能性及其能力。方法采集Hp感染者和非感染者的胃黏膜、胃液、口腔含漱液、粪便标本行Hp PCR检测,以结果阳性的标本污染到新鲜牛乳,室内自然放置4h、24 h、72 h、1 W、2 W后分别灌喂SPF级小鼠2次,继续喂养4 W后处死取胃黏膜病理检测,统计Hp的感染概率。结果纳入研究志愿者中Hp阳性12例(A组),Hp阴性14例(B组),分别采集胃黏膜、胃液、含漱液、粪便标本,进行Hp PCR检测筛查,A组标本阳性率胃黏膜100%、粪便91.67%、胃液16.67%、口腔含漱液为0;B组标本Hp PCR检测均阴性;以A组Hp PCR阳性的胃黏膜、胃液、粪便标本污染食物,自然放置4 h灌喂导致实验鼠Hp传染率分别为21.43%、13.33%、15.38%;24 h传染率分别为14.29%、0%、7.69%;72 h传染率分别为26.67%、15.38%、24.29%;1 W传染率分别为21.43%、6.67%、15.38%;2 W传染率分别为38.46%、8.33%、18.18%;每种标本在各时间点感染率差异无统计学意义(P=0.682);各标本合计导致传染的比率由高到低分别为胃黏膜24.28%、粪便14.06%、胃液8.57%,差异有统计学意义(P=0.035);阴性对照组标本传染率为0。结论来自Hp感染者体内的Hp可耐受消化道环境以粪便为载体排出体外并传染给下一宿主,粪-口传播途径可能是Hp传染的主要途径;未发现口-口传播途径证据。

Objective To establish a direct transmission model of Helicobacter pylori(Hp) among hosts, and to explore the possibility and ability of Hp to infect the next host through various ways in the natural environment. Methods The gastric mucosa, gastric juice, oral gargle and feces samples from Hp-infected patients and non-infected patients were collected for Hp PCR detection, and samples with positive results were used to contaminate the fresh milk;at the point of 4 h, 24 h, 72 h, 1 W, and 2 W after being placed in indoor natural environment, the contaminated milk was used to feed SPF rats for two times respectively. The rats were executed 4 weeks after feeding, and the gastric mucosa was collected for pathological examination;the Hp infection rate was calculated. Results Gastric mucosa, gastric juice, gargle, and feces samples were collected from 12 Hp-positive volunteers(group A) and 14 Hp-negative volunteers(group B) for Hp PCR screening. The positive rates of gastric mucosa, feces, gastric juice and oral gargle in group A were 100%, 91.67%, 16.67% and 0%, respectively;all the results in group B were negative. The Hp infection rates of rats fed with food contaminated by Hp-positive samples of gastric mucosa, gastric juice and feces in group A were 21.43%, 13.33% and 15.38% respectively at the point of 4 h after feeding, 14.29%, 0% and 7.69% respectively at the point of 24 h after feeding, 26.67%, 15.38% and 24.29% respectively at the point of 72 h after feeding, 21.43%, 6.67% and 15.38% respectively at the point of 1 W after feeding, and 38.46%, 8.33% and 18.18% respectively at the point of 2 W after feeding. There was no statistically significant difference in the infection rate of each sample at each point of time(P=0.682). The infection rates of gastric mucosa, feces, and gastric juice were 24.28%, 14.06%, and 8.57% respectively, which was statistically significantly different(P=0.035). The infection rate of negative control group was 0%. Conclusion Hp from infected patients can withstand the gastrointestinal environment and excreted in feces as carrier to infect the next host, and fecal-oral transmission may be the main route of Hp infection. No evidence of oral-oral transmission was found.