Kuo Chao-Hung, Hu Huang-Ming, Tsai Pei-Yun, Yang Sheau-Fang, Chang Lin-Li, Wang Jaw-Yuan, Chen Angela, Jan Chang-Ming, Wang Wen-Ming, Wu Deng-Chyang
Division of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung, Taiwan.
J Gastroenterol. 2008;43(1):32-7. doi: 10.1007/s00535-007-2121-1. Epub 2008 Feb 24.
Our aim was to evaluate the accuracy of the stool antigen test and the optimal time point for detecting Helicobacter pylori infection in a Mongolian gerbil model.
We inoculated 8-week-old Mongolian gerbils with H. pylori (Vac A (+)/CagA(+)). The gerbil-infected model was developed as follows: H. pylori was put into broth (about 10(9) CFU/ml), and 50 gerbils were then fed with 1 ml intragastrically twice within a 3-day interval. Another ten gerbils were fed broth only. Twenty-six weeks after the inoculation, the gerbils were killed. The gastric mucosa was sampled for a series of examinations including culture, histology, rapid urease test, and polymerase chain reaction. Stool samples for a stool antigen test, H. pylori-specific stool antigen assay (HpSA), were collected during weeks 4, 6, 8, 12, and 26 after inoculation. Of the 50 gerbils inoculated with H. pylori, the inoculation was successful in 88%. Severe active gastritis, ulceration, and intestinal metaplasia were obvious.
The HpSA test results were sensitivity, 88.6%; specificity, 100%; positive predictive value (PPV), 100%; negative predictive value (NPV), 54.5%, and accuracy, 90%. The HpSA test began to be more sensitive and accurate (P < 0.05) beginning during week 6 after inoculation. We also found that H. pylori could be detected earlier and more easily in the group with high H. pylori density.
HpSA seems to be suitable for confirming colonization of gerbils with H. pylori. The optimal testing time point is around 6 weeks after inoculation. This test is a good choice for long-term observation of H. pylori infection in Mongolian gerbils.
我们的目的是评估粪便抗原检测在蒙古沙鼠模型中检测幽门螺杆菌感染的准确性及最佳时间点。
我们用幽门螺杆菌（Vac A(+) / CagA(+)）接种8周龄的蒙古沙鼠。蒙古沙鼠感染模型建立如下：将幽门螺杆菌置于肉汤中（约10⁹CFU/ml），然后在3天间隔内分两次给50只沙鼠每只灌胃1ml。另外10只沙鼠仅喂肉汤。接种26周后，处死沙鼠。采集胃黏膜进行一系列检查，包括培养、组织学、快速尿素酶试验和聚合酶链反应。在接种后第4、6、8、12和26周采集粪便样本进行粪便抗原检测，即幽门螺杆菌特异性粪便抗原检测（HpSA）。在接种幽门螺杆菌的50只沙鼠中，接种成功率为88%。严重的活动性胃炎、溃疡和肠化生明显。
HpSA检测结果的敏感性为88.6%；特异性为100%；阳性预测值（PPV）为100%；阴性预测值（NPV）为54.5%，准确性为90%。接种后第6周开始，HpSA检测变得更加敏感和准确（P < 0.05）。我们还发现，在幽门螺杆菌密度高的组中，幽门螺杆菌能更早、更易被检测到。
HpSA似乎适用于确认蒙古沙鼠是否被幽门螺杆菌定植。最佳检测时间点是接种后约6周。该检测是长期观察蒙古沙鼠幽门螺杆菌感染的一个好选择。
