A better method for confirming <Emphasis Type="Italic">Helicobacter pylori</Emphasis> infection in Mongolian gerbils

Background. 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. Methods. 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 10⁹ 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. Results. 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. Conclusions. 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.     

3种粪便隐血试剂的实验评估及影响因素探讨

目的 比较3种不同品牌的免疫胶体金粪便隐血试纸条敏感性、特异性、干扰试验检测结果,了解和探讨免疫胶体金潜血试剂的优缺点及影响因素.方法 使用不同浓度的血红蛋标准液对3种隐血试纸条的灵敏度进行比对测定;选取中山市古镇医院本院消化科确诊上消化道出血患者粪便标本25例;下消化道出血患者粪便标本50例,体检中心健康体检者粪便标本60例,对3种隐血试纸条进行临床标本验证试验;采用8种动物抗凝血、4种不同浓度维生素C、5种不同浓度过氧化物酶、铁剂对这3种隐血试纸条进行干扰试验.结果 3种试剂条的最低敏感度血红蛋白均达到0.18 μg/mL,干扰试验结果显示均为阴性;在临床标本验证实验结果中,健康体检者的粪便标本检测结果均为阴性.结论 对高度怀疑上、下消化道出血的患者,胶体金试纸条检测结果为阴性的临床标本,建议稀释该标本或使用其他方法进行复测.     

Evaluation of Helicobacter pylori stool antigen test before and after eradication therapy

BACKGROUND AND AIM: The Helicobacter pylori stool antigen (HpSA) test is useful for initial diagnosis of H. pylori infection, but there is disagreement regarding its diagnostic accuracy after eradication therapy. The aim of the present study was to evaluate the diagnostic accuracy of the HpSA test before and after eradication therapy. METHODS: One hundred and thirty-six patients underwent upper gastrointestinal endoscopy with biopsies for the diagnosis of H. pylori infection using culture, histology and the rapid urease test. Fifty-four H. pylori-positive patients were treated with 1-week triple therapy. Six to 10 weeks after the end of therapy, the patients underwent re-endoscopy and received the same biopsy-based methods. In addition, the 13C-urea breath test was performed. The HpSA test was performed before and 6-10 weeks after the end of therapy. In 23 patients, the HpSA test was also performed at the end of therapy. RESULTS: Before therapy, the sensitivity and specificity of the HpSA test was 98.3% (95% confidence interval (CI): 95.9-100%) and 95.0% (95% CI: 75.1-99.9%), respectively. At the end of therapy, the HpSA tests were all negative both for eradication and non-eradication patients. The sensitivity and specificity of the HpSA test after eradication therapy were 90% (95% CI: 55.5-99.7%) and 97.7% (95% CI: 93.3-100%), respectively. CONCLUSIONS: The HpSA test is a useful method for the diagnosis of H. pylori infection before and after eradication therapy.     

1760例婴幼儿腹泻中轮状病毒检出率及临床意义

目的了解沙井地区婴幼儿腹泻中轮状病毒(RV)感染现状,为临床诊断和治疗提供可靠依据。方法采用胶体金法对1760例来我院就诊的腹泻患儿的粪便标本进行RV抗原检测,并比较检测结果。结果1760例腹泻标本中有852例RV结果阳性,阳性率为48.41%;其中0.5-1岁组腹泻患儿阳性率可达69.96%;以每年11、12月份为发病高峰。结论轮状病毒是本地区婴幼儿腹泻的主要病原,且有明显的季节性。     

山西省从粪便中分离到产霍乱毒素的拟态弧菌

目的从山西省霍乱样粪便中分离到拟态弧菌,并检测其是否携带霍乱毒素基因。方法采集患者粪便、患者家用自来水、金鱼和鱼缸水标本,按照WS289-2008和《霍乱防治手册》(第5版)方法 ,对标本进行增菌和选择性培养基的分离培养,疑似菌落以霍乱弧菌血清凝集试验检测,并用API20E系统鉴定菌种。同时,疑似菌落用PCR检测O1、O139群特异性和是否携带霍乱毒素基因。结果粪便标本经增菌后接种选择性培养基,在庆大琼脂和碱性琼脂上均有霍乱弧菌疑似菌落,但在TCBS琼脂上为绿色、透明、中等大小、光滑、湿润的菌落;血平板上可见灰白色、湿润菌落,有透明溶血环;染色镜检湿片暗视野下未见流星状运动细菌。氧化酶和粘丝实验阳性,霍乱弧菌O1、O139群血清凝集试验阴性。菌株经API20E鉴定为拟态弧菌(93.5%可能性)。环境标本中未分离和检测到拟态弧菌。PCR检测该拟态弧菌中携带霍乱毒素基因,而O1、O139群特异性为阴性。结论从急性霍乱样腹泻粪便中分离到1株拟态弧菌,对于临床类似霍乱样症状的病例标本,当病原的霍乱弧菌血清凝集为阴性时,应进一步做霍乱毒素的检测。     

Comparison between the <Superscript>13</Superscript>C-urea breath test and stool antigen test for the diagnosis of childhood <Emphasis Type="Italic">Helicobacter pylori</Emphasis> infection

Background As noninvasive tests for Helicobacter pylori infection, the ¹³C-urea breath test (UBT) and stool antigen test have been widely used. In children, however, there are few studies reporting which test shows superior performance. The purpose of this study was to compare the ¹³C-UBT and stool antigen test for their accuracy in diagnosing H. pylori infection in children.Methods A total of 123 Japanese children, ages 2 to 17 years (mean, 12 years) who underwent gastric biopsies for H. pylori infection were studied. The diagnoses included gastritis (n = 55), gastric ulcer (n = 5), duodenal ulcer (n = 20), iron-deficiency anemia (n = 7), and other conditions (n = 36). The cutoff value of the ¹³C-UBT was defined to be 3.5. The stool antigen test was performed using the HpSA enzyme-linked immunosorbent assay (ELISA) (Premier Platinum HpSA). In 16 patients who received eradication therapy, the ¹³C-UBT and HpSA were repeated 2 months after treatment.Results Based on biopsy tests, 60 children were infected with H. pylori and 63 children were not. For the ¹³C-UBT, the sensitivity, specificity, and accuracy were 95.0% (95% confidence interval [CI], 86.1%–99.0%), 98.4% (95% CI, 91.5%–100%), and 96.4% (95% CI, 93.6%–99.9%), respectively. For the HpSA, the sensitivity, specificity, and accuracy were 98.3% (95% CI, 90.8%–100%), 98.4% (95% CI, 91.2%–100%), and 98.3% (95% CI, 96.0%–100%), respectively. There were no significant differences between the performance of these two tests. In the assessment of H. pylori eradication, the results of ¹³C-UBT and HpSA agreed with those of biopsy tests.Conclusions The ¹³C-UBT and the HpSA are equally accurate for the diagnosis of active H. pylori infection in Japanese children.Kazuie Iinuma, for the Japanese Pediatric Helicobacter study Group     

不同化学染色法对日本血吸虫虫卵染色的效果分析

目的探索不同化学染色法对日本血吸虫虫卵染色的效果,以期获得在镜检下可分辨虫卵和粪渣的染色方法,为粪检血吸虫虫卵的计算机自动化识别奠定基础。方法用AO-EB、罗丹明、中性红、酸性品红、甲苯胺兰、台盼蓝、考马斯亮蓝和孔雀绿等化学染料,选择3个不同浓度和2个不同温度条件,分别对含日本血吸虫虫卵粪液进行染色、涂片镜检,用虫卵和粪渣反差程度作为主要评价指标,比较各种方法的染色效果。结果在8种化学染色方法中,以AO-EB染色和中性红染色的虫卵与粪渣其反差最大,镜下粪涂片中虫卵易于辨认,AO-EB法和中性红法的检出率分别为67.5%和65.0%,明显高于改良加藤法的检出率(40.0%)。结论AO-EB法和中性红染色法有助于提高粪检血吸虫虫卵检出率。     

血吸虫病流行区居民血便症状与感染关系的研究

本文对血吸虫病不同程度流行区进行了血便症状出现率与血吸虫感染率关系的调查和分析。结果初步表明居民血便出现率与感染率呈正相关关系．近两周内有血便症状出现的比例在１６％以上可作为重疫区的划分标准。     

日本血吸虫卵在粪便中分布特点的研究

本文采用Kato－Katz法，首次对日本血吸虫病患者粪便的内、外层及混匀样本各作50张涂片定量检查。结果各感染度患者粪便虫卵平均数均以外层显著高于内层，混匀后虫卵数居两者之间；每视野虫卵平均数亦均以外层高于内层，混匀后居中。各感染度粪便的内、外层均以前段粪便虫卵平均数多，中段次之，尾段明显减少。虫卵在低感染度粪便内、外层的分布一般为poisson分布。这一特点为Kato－Katz法的取样和准确定量感染度提供了参考依据。