Diagnosis of helicobacter pylori infection by polymerase chain reaction: is it worth it?

The aim of this study was to determine to what degree polymerase chain reaction (PCR) was superior to histology and culture, and whether a noncommercial urease test was of value, in detecting Helicobacter pylori in gastric biopsy specimens. Gastric biopsy specimens from the antrum and corpus of 134 consenting patients were subjected to PCR, targeting the glmM (ureC) gene, histology, culture, and a rapid urease test. PCR detected H. pylori in the biopsy specimens from 59 patients. All methods showed a high degree of sensitivity and specificity, but histology gave 2 false-negatives, and culture and the urease test gave 1 false-negative compared with PCR. PCR of a glmM gene segment was superior to the other methods for the detection of H. pylori infection and was comparable to histology in terms of cost. Nevertheless, in this study, histology and culture were found to be relatively reliable methods for examining gastric biopsy specimens.     

Identification of Helicobacter Pylori in stomach contents

Development of noninvasive methods for the diagnosis of Helicobacter pylori infection is an important problem. We investigated the possibility of detecting the bacterium in gastric juice. Noninvasive methods (bacteriological and urease test) for detection of H. pylori in gastric aspiration biopsy specimens are proposed.     

Direct gram stain and urease test to detect Helicobacter pylori.

Antral biopsies were obtained by gastrointestinal endoscopy on 143 adult patients with dyspeptic symptoms of gastritis or peptic ulcer disease. A direct Gram stain and a direct urease test were performed on each biopsy in addition to culture. Forty-three biopsies (30%) were considered positive for Helicobacter pylori based on culture or histologic examination, or both. Thirty-one biopsies (72% sensitivity) were positive for both direct tests, whereas 95 of 100 negative cultures were negative for both tests. Thirty-eight of the 43 positive biopsies were Gram stain positive (sensitivity, 88%; specificity, 100%). The direct urease test alone was positive at 4 hr for 29 biopsies (sensitivity, 67%; specificity, 100%) and at 24 hr for 38 biopsies (sensitivity, 74%; specificity, 95%). Rapid presumptive diagnosis of H. pylori in antral biopsies was obtained when at least one direct test, Gram stain or urease, was positive.     

Laboratory tests for the evaluation of Helicobacter pylori infections.

Helicobacter pylori is a highly motile bacterium with multiple unipolar flagella, and it produces the urease enzyme. The flagella and urease are the virulence factors of H. pylori. H. pylori often establishes a chronic infection in the stomach that may lead to gastric and duodenal ulcers, gastric cancers, gastric lymphomas, and other gastrointestinal diseases. There are several different invasive and noninvasive clinical laboratory tests for H. pylori. Laboratory testing is not indicated in asymptomatic patients and should be considered only if treatment of H. pylori infection is planned. Invasive tests for H. pylori, such as tissue histology, culture, and rapid urease tests, are used if an endoscopy is performed on the patient. The noninvasive tests for H. pylori, such as enzyme antibody and urea breath tests, are recommended in patients whose symptoms do not warrant endoscopy. The urea breath test is very useful and is recommended to evaluate effectiveness in the eradication and treatment of H. pylori infections. Nucleic acid tests can complement other diagnostic procedures, and are useful in evaluating fixed biopsy tissue, environmental samples, gastric juices, oral secretions, and stool samples.     

PCR法扩增脲酶B基因在快速诊断幽门螺杆菌感染中的应用研究

应用基于幽门累杆菌脲酶Ｂ基因的引物建立了检测幽门螺杆菌的ＰＣＲ方法。５６例内窥镜胃组织标本中,细菌培养阳性３４份,ＰＣＲ阳性３６份;１７２份用自制采样器所取的胃粘液标本中,ＰＣＲ阳性１０６份,其中经组织培养ＨＰ阳性的３４例患者的胃粘标本ＰＣＲ阳性。研究结果提示,ＰＣＲ方法扩增酶基因检测幽螺杆菌具有快速、简便、准确的优点,在幽门螺杆菌感染的快速诊断、疗效观察、复发机理和流行病学调查研究中均有重要价值     

Detection and evaluation of salivary antibodies to Helicobacter pylori in dyspeptic patients

Helicobacter pylori infection is one of the most prevalent infections in humans. The high prevalence and the association with peptic ulceration and gastric cancer require simple and non-invasive methods for the diagnosis of the infection. Detection of salivary anti-H. pylori IgG antibodies has advantages compared with those on serum. In this study, salivary immunoglobulin G response to H. pylori was evaluated in 100 consecutive dyspeptic patients by enzyme-linked immunosorbent assay (ELISA), in comparison with culture and histopathologic examination of gastric biopsy specimens obtained at endoscopic procedures and assessed the accuracy of salivary diagnosis of the infection. The overall sensitivity and specificity of the test were 87 and 73%, respectively. These results suggest that saliva testing for H. pylori antibodies could be used reliably for screening dyspeptic patients in general practice, especially in children in whom venesection is more difficult.     

内镜下酚红喷洒染色诊断胃内幽门螺杆菌感染

目的：通过内镜喷洒酚红溶液,直接观察胃内颜色改变诊断胃内幽门螺杆菌感染。方法：14例慢性胃炎,11例消化性溃疡患者,于检查前1天的睡前服兰索拉唑30mg,内镜检查时从活检孔道将0．1％的酚红溶液与5％的尿素溶液喷洒于胃粘膜上,观察胃粘膜的颜色变化,分别取染色和非染色胃粘膜组织4块,2块做病检查,2块做细菌检查。结果：7例慢性胃炎胃粘膜染色,其中5例全胃染色,2例胃窦染色,9例消化性溃疡胃粘膜染色,其中2例全胃染色,5例胃窦染色,1例胃体染色,1例胃底染色。染色部位的病理检查、细菌培养（除1例因消化道出血连续3d静脉注射洛赛克40mg为阴性外）均阳性,未染色部位病理检查、细菌培养均阴性。结论：内镜下酚红喷洒染色可诊断胃内幽门螺杆菌感染。     

The evaluation of diagnostic methods for the detection of Helicobacter pylori in gastric biopsy specimens

PCR is a rapid, sensitive and accurate method for the specific detection of Helicobacter pylori from gastric biopsy specimens. In our study, 104 gastric tissue specimens from symptomatic adult patients were examined by staining, culture, PCR and nested PCR methods for detection of H. pylori. According to our results, positivity was achieved in 24% (25/104) with Giemsa staining, 34% (36/104) with histopathology, 36% (38/104) with PCR and 41% (43/104) with nested PCR respectively, whereas H. pylori was isolated in only 33% (35/104) of the cultures on the biopsy specimens. Both the sensitivity and the positive predictive value of the nested PCR method were 100%, and both the specificity and negative predictive value were 98%. As a conclusion, our results suggest the nested PCR as a highly valuable method in the detection of H. pylori with a reasonably high sensitivity and specificity.     

Urease test of the gastric content deposits for diagnosis of Helicobacter pylori infection in the gastric mucosa

A rapid urease test was applied to the examination of the deposit of gastric juice for diagnosing H. pylori in the gastric mucosa. Two hundred and twenty patients blindly randomized were examined in a case control study. The standard rapid urease test kit Jatrox-H.p.-Test (Rohm Pharma, Germany) was used to determine urease activity in the deposit of gastric juice and duodenal [n = 110 (Group 1)] and gastroduodenal [n = 110 (Group 2)] mucosae. Giemsa staining was employed as a comparison method to examine H. pylori infection in the gastric and duodenal mucosae. The availability of regions of duodenal metaplasia was confirmed by periodic acid-Schiff and alcian blue (Serva) staining tests (pH 1.0 and 2.5, respectively). The results of evaluation of the efficiency of the rapid urease test of gastric juice deposit and gastric and duodenal mucosae in Groups 1 and 2 were as follows: sensitivity (SE) (0.97, 0.99, 0,96), specificity (SP) (0.97, 0.97, 0.99), prevalence (0.64, 0.67, 0.24), test accuracy (TA) (0.96, 0.98, 0.98), negative (0.95, 0.97, 0.99) and positive (0.98, 0.99, 0.96) predictive values; positive (38.8, 33.0, 96.0) and negative (0.03, 0.01, 0.04) likelihood ratios. It is expedient to employ the rapid urease test for the diagnosis of H. pylori infection in the stomach (Se 96-99%, Sp 97%, TA 97-98%). When the test of gastric juice deposit and gastric biopsy is positive, the probability of gastric H. pylori availability is 98-99%. When the test is negative (the probability of H. pylori absence is 95-97%), duodenal biopsy is made. When the test of duodenal biopsy is positive, the probability of H. pylori availability is 96%. When it is negative, the probability of H. pylori absence is 99%. An algorithm of use of the rapid urease test to diagnose H. pylori in different intestinal parts (stomach, duodenum) has been developed.     

Helicobacter pylori Infection in Endoscopic Biopsy Specimens of Gastric Antrum: Laboratory Diagnosis and Comparative Efficacy of Three Diagnostic Tests

Aims and objectives The present study was undertaken to compare the diagnostic yield of three available test procedures for detecting Helicobacter pylori (H. pylori) infection in endoscopic biopsies.Methods H. pylori infection was sought in 150 patients referred for upper gastrointestinal (GI) endoscopy. Multiple (about six) biopsy specimens were taken from pyloric antrum in each patient. Two biopsy specimens were subjected to one minute endoscopy room test - OMERT (a modified form of urease test), two were sent for histopathological analysis, where multiple sections were subjected to Giemsa staining and two were sent for microbiological evaluation after Gram's staining of heat fixed biopsy material.Results H. pylori positivity using histology, microbiology and OMERT was observed to be 33%, 30% and 27% respectively. However, overall 40% patients were infected when the results from three test procedures were combined, as H. pylori positivity was repeated more than once by these procedures separately. Histology was found to be superior to other two tests in our study, especially when multiple sections were examined, for the distribution of the organism was patchy. Amongst the infected, H. pylori was seen in only 30% of all 3-8 sections cut from a biopsy, whereas in 70% it was noted in a single section only.Conclusion The study revealed that histology has the highest detection rate and can be chosen as the "gold standard" amongst the three low cost test procedures available at present in our setup.     

Helicobacter pylori Infection in Various ABO Blood Groups of Kashmiri Population

Aim: This study was carried out to assess the prevalence of Helicobacter pylori infection in various ABO blood groups of people of Kashmir.Method: The study comprised 80 individuals - 50 peptic ulcer patients (whose disease was diagnosed by endoscopy) and 30 asymptomatic volunteers. Every subject's blood group and Rhesus status was determined by standard serological tests. Helicobacter pylori infection was diagnosed by three different methods viz., one minute endoscopy room test (urease test), Gram staining and by histology. The detection of Helicobacter pylori by histological examination using Giemsa staining was taken as the 'gold standard' for the presence of Helicobacter pylori infection.Results: Out of 80 individuals, 67 were males and 13 females aged between 18-65 years. The majority of peptic ulcer patients had blood group 'O' (n = 28.56%). The prevalence of Helicobacter pylori infection amongst peptic ulcer patients was 76%. There was no difference in Helicobacter pylori positivity in various blood groups.Conclusion: Blood group 'O' though a risk factor for peptic ulcer (Duodenal ulcer) is not a risk factor for acquiring Helicobacter pylori infection.     

粪便抗原检测对幽门螺杆菌感染的诊断价值

目的：研究幽门螺杆菌粪便抗原（HpSA）检测诊断幽门螺杆菌（HP）感染的临床应用价值。方法：采用ELISA法检测98例因上消化道症状接受胃镜检查病人的HpSA,同时进行细菌培养,快速尿素酶试验和^14C－尿素呼气试验检查。将后三项检查中二项阳性或细菌培养一项阳性作为诊断HP感染的金标准。结果：金标准诊断HP感染,阳性54例,阴性44例。金标准阳性的54例中,HpSA检测阳性为51例,阴性为3例;金标准阴性的44例中,HpSA检测阴性为42例,阳性为2例。HpSA检测诊断HP感染的敏感度94．4％（51／54）,特异度95．5％（42／44）,准确度94．9％（93／98）,阳性预测值96．2％（51／53）,阴性预测值93．3％（42／45）。结论：HpSA检测有较高的敏感性和特异性,是一种简便可靠,非侵入性的诊断HP感染的方法,易于临床推广。     

儿童牙垢幽门螺杆菌抗原检测的临床研究

目的探讨牙垢幽门螺杆菌抗原检测在诊断儿童幽门螺杆菌感染及治疗后复查的价值。方法采用天津瑞爱金生物科技有限公司幽门螺杆菌快速检定卡对56例有消化道症状的患儿牙垢幽门螺杆菌抗原检测,并同时进行胃黏膜抗原检测,以胃黏膜幽门螺杆菌抗原为标准,对牙垢幽门螺杆菌抗原检测方法进行评价。结果胃黏膜幽门螺杆菌抗原检测阳性47例、阴性9例,牙垢幽门螺杆菌抗原检测阳性50例。阴性6例。胃黏膜幽门螺杆菌抗原阳性中有1例牙垢幽门螺杆菌抗原阴性,胃黏膜幽门螺杆菌抗原阴性中有4例牙垢幽门螺杆菌抗原阳性。牙垢幽门螺杆菌抗原检测HP感染的敏感度97．9％（46／47）,阳性预测值为92％（46／50）,阴性预测值为83．3％（5／6）,检测的准确性为91．1％（51／56）。结论牙垢幽门螺旋杆菌抗原检测法可提供一种非侵人性的Hp检测法,具有取材方便、操作简单、快捷,多次重复获取牙垢标本,患儿无痛苦,又经济,是儿童HP感染的诊断及治疗后复查最好的方法。     

Comparison of PCR and common clinical tests for the diagnosis of H. pylori in dyspeptic patients

Helicobacter pylori has been recognized as a major gastric pathogen. The objective of this study was to assess the diagnostic value of common clinical tests to detect H. pylori infection, by comparison with PCR. Serum and gastric biopsy specimens from 106 dyspeptic patients were examined. Serology was performed with Pyloriset Dry test, and biopsies were examined histologically, for rapid urease activity and PCR amplification of an ureA gene segment of H. pylori. PCR primers were specific for H. pylori and required at least 1.47 pg of H. pylori DNA, corresponding to about 800 bacterial cells. According to serology, histology, rapid urease, and PCR, positive results were respectively found in 56%, 86%, 64%, and 85% of dyspeptic patients, primarily with gastritis. Relative to PCR, the sensitivity (and specificity) was 55% (38%) for serology, 86% (13%) for histology, 70% (69%) for urease. When combining histology and urease, Bayesian analysis of data indicated no advantage of using combined methods over rapid urease test alone. Histology should not any longer be considered a gold standard test for Helicobacter pylori. Urea breath test still seems the first option for non invasive diagnostic. If an invasive diagnostic is justified, highly specific and sensitive molecular methods should be used to examine specimens.     

Antibiotic therapy for Helicobacter pylori

Helicobacter pylori is one of the most common bacterial infections in the world. H pylori infection of the gastric mucosa is the most common cause of peptic ulcers and is believed to be responsible for 50% to 60% of all gastric carcinomas. This infection is difficult to treat because the bacterium is located within the gastric lumen in the mucus and not within the gastric tissue. Antimicrobial therapy for H pylori includes two or three antibiotics plus either a proton pump inhibitor or a histamine receptor antagonist. H pylori readily develops resistance to antibiotics; therefore, if the initial treatment is unsuccessful, repeat treatment should include different antibiotics.     

PC R 检测技术在幽门螺杆菌诊断检测中的应用探讨

目的探寻聚合酶联反应(PCR)检测技术在幽门螺杆菌(H .pylori ,Hp)检测中的应用.方法通过对该院消化内科疑是患胃或十二指肠溃疡、胃或胃窦炎、胃癌患者于胃镜下取其病变部位组织标本,进行 Hp分离培养、PCR体外扩增,患者同时做尿素酶试验、血清学抗体检查,将结果进行比较分析.结果170份病例标本中,分离培养67例、尿素酶试验82例、Hp抗体检查152例、PCR扩增144例阳性.阳性率分别为39.4%、48.2%、89.5%、84.7%.以细菌培养为金标准,则尿素酶试验、抗体检查、PCR灵敏度分别为88.1%、89.5%、98.5%,特异性分别为94.6%、77.4%、81.7%.这4种检测方法中,灵敏度最高的为PCR基因扩增法,其次为抗体检查和尿素酶试验;特异性最高的为尿素酶试验,其次为PCR扩增和抗体检查.结论 PCR试验特异性和灵敏度均较高,可以用作Hp感染的确诊、基因分型、流行病学调查、微量取材等的检查.     

PCR and RFLP analysis for identification and typing of Helicobacter pylori strains isolated from gastric biopsy specimens

Helicobacter pylori (H. pylori) infection is the most common gastrointestinal tract infection which plays an important role in the ethiopathogenesis of peptic ulcer and gastritis. In recent years, molecular biological methods have been presented for detection of H. pylori in addition to histopathological and microbiological methods. Among these methods, polymerase chain reaction (PCR) and following restriction fragment length polymorphism analyses (RFLP) are highly sensitive methods for diagnosis and follow up of patients. In this present study our aim was to amplify H. pylori urease A and B genes by PCR and perform RFLP analysis. Gastric biopsy specimens from 17 female and 18 male patients were included in the study. Amplified PCR products were subjected to RFLP analysis and typing of the bacteria in pre and posttreatment specimens were performed. H. pylori urease A and B gene amplification was observed in 32 pretreatment samples and in 8 of 21 posttreatment specimens. As a result, PCR is a sensitive method to determine the H. pylori infection. RFLP, which is another effective method in order to demonstrate the reinfection of H. pylori.     

Quantitative correlation of Helicobacter pylori stool antigen (HpSA) test with the severity of H. pylori-related gastritis

The Helicobacter pylori (H. pylori) load in both stomach and stool and the resulting severity of gastritis are important criteria in validating the status of H. pylori infection. We aimed to assess the reliability of the H. pylori stool antigen (HpSA) test for the primary diagnosis of H. pylori infection by calculating the best cut-off value to obtain the highest sensitivity and specificity in dyspeptic patients. We also investigated the correlation of HpSA test with the severity of gastritis and H. pylori load. The H. pylori statuses of 95 patients were evaluated by the positivity of both rapid urease test and microscopic detection of H. pylori in biopsy specimens, 88 subjects of whom were H. pylori positive. The sensitivity and specificity of the HpSA test were 51.1% (45/88) and 100% (7/7), respectively, according to the manufacturer's recommended cut-off value of 0.16. However, with the best cut-off value of 0.048, calculated by receiver operator characteristics analysis, the sensitivity of the test increased to 92.0% (81/88) with the same specificity. High values of the HpSA test were correlated with high scores of corpus H. pylori load and the severity of antrum and corpus inflammation (p < 0.05). With the best cut-off value of the HpSA test, the primary diagnosis of H. pylori infection can be made with higher sensitivity and specificity. The HpSA test is a helpful tool that evaluates the severity of H. pylori infection and the degree of gastric inflammatory activity and gastric H. pylori load.     

慢性胃炎与消化性溃疡患者幽门螺杆菌的感染状况及诊断方法

本文通过200例患者活检标本的对比研究证明,幽门螺杆菌在消化性溃疡与活动期慢性胃炎中有较高的感染率,分别为68%～92%和62.9%～92.6%;而非活动期慢性胃炎仅为36.6%～39.8%.同时证明,用pH试纸检测尿素酶的存在是一个经济、简易、快速、有较高特异性和敏感性的诊断幽门螺杆菌感染的方法.     

Helicobacter pylori associated antral gastritis in peptic ulcer disease patients and normal healthy population of kashmir, India

Aim: To study the association of Helicobacter pylori infection with chronic antral gastritis in peptic ulcer disease patients and healthy population of Kashmir.Methods: 50 peptic ulcer patients (duodenal ulcer = 46, gastric ulcer = 2 and combined duodenal and gastric ulcer = 2) and 30 asymptomatic healthy volunteers were included in this study. Peptic ulcer was diagnosed on endoscopic examination. 4-6 punch biopsies were taken from gastric antrum in all the individuals and in case of gastric ulcer an additional biopsy was taken from the edge of the ulcer to exclude its malignant nature. Helicobacter pylori (H. pylori) organism was diagnosed using three different test methods, viz. Histology (using Giemsa Stain), Microbiology (Gram Stain) and Biochemistry (using one minute Endoscopy Room Test). Histological diagnosis of H. pylori was taken as the "gold standard" for the presence of H. pylori organism. Histological diagnosis of gastritis was made using Hematoxylin and Eosin Stain and the gastritis was classified as active chronic gastritis and superficial chronic gastritis.Results: Out of 30 peptic ulcer disease patients with associated antral gastritis, 27 (90%) were positive for H. pylori on histological examination (13 superficial chronic gastritis and 14 active chronic gastritis) whereas out of 8 healthy volunteers with histological evidence of chronic antral gastritis, H. pylori was observed in 7 individuals (87.50%) (4 active chronic gastritis and 3 superficial chronic gastritis).Conclusion: A highly significant association between H. pylori infection with chronic antral gastritis both in peptic ulcer disease patients and healthy volunteers of Kashmir was found in this study. Association between H. pylori infection and chronic gastritis was 90% in peptic ulcer group and 87.50% in healthy population (P<0.005).