Usefulness of non-invasive tests for diagnosing Helicobacter pylori infection in patients undergoing dialysis for chronic renal failure

BACKGROUND: Helicobacter pylori infection in chronic renal failure patients has been linked to peptic ulcer and gastric neoplasia after kidney transplantation. It may also contribute to the accelerated arteriosclerosis that is usual in this population. Few data are available on the usefulness of noninvasive diagnostic tests for H. pylori infection in dialyzed patients, especially regarding the new fecal antigen detection tests. The objective of this study was to determine the efficacy of a noninvasive test for H. pylori infection in patients with chronic renal failure. METHODS: Eighty-six patients were included in a cross-sectional study. Urea breath test, serology and three fecal tests--FemtoLab H. pylori (Connex, Germany), Premier Platinum HpSA (Meridian, USA) and Simple H. pylori (Operon SA, Spain) were performed. Helicobacter pylori status was determined by concordance of the tests. Sensitivity, specificity and positive and negative predictive values were calculated for each test. RESULTS: Sensitivity, specificity, positive and negative predictive values were 94%, 96%, 94% and 96% for the urea breath test; 97%, 64%, 66% and 97% for serology; 86%, 100%, 100% and 91%, for FemtoLab H. pylori; 58%, 96%, 91% and 76% for Premier Platinum HpSA and 61%, 78%, 74% and 67% for Simple H. pylori. CONCLUSIONS: The urea breath test seems to be the most reliable diagnostic method for H. pylori infection in patients with chronic renal failure. Serology has a low specificity, and the results of the fecal tests vary widely.     

Molecular diagnosis of Helicobacter pylori antibiotic resistance in the Taif region,Saudi Arabia

Success in eradication of Helicobacter pylori is declining globally because H. pylori has developed resistance against most of the antibiotics proposed for eradication regimens, mainly through point mutations. The present study included 200 patients with dyspepsia attending Taif Hospital. Gastric biopsies were obtained during gastroscopy and subjected to rapid urease testing. Molecular methods were used to confirm diagnoses of H. pylori infection and to identify resistance gene variants of four antibiotics; namely, clarithromycin, metronidazole, fluoroquinolones and tetracycline (23S rRNA, gyrA, rdxA and 16S rRNA respectively). Of all investigated patients, Molecular diagnoses were made in 143 of all investigated patients; thus, the prevalence was .5%. The overall rate of resistance to clarithromycin among the H. pylori‐positive patients was high (39.9%) and the rate of resistance significantly greater (48.2%) among the secondary resistance group, secondary resistance being defined as resistance as a result of previous exposure to the relevant antibiotic. The rate of resistance to fluoroquinolones was considered moderate; the difference in rate of resistance between the primary and secondary resistance groups (8.4% and 9.5%, respectively) was not significant Also, there was a low prevalence of both primary and the secondary tetracycline resistance in the study cohort. In contrast, the prevalence of metronidazole resistance was considered high with no significant difference between the two resistance groups. H. pylori showed an increased prevalence of resistance to all four of the commonly used therapeutic agents. Thus, eradication therapy should be based on the regional results of susceptibility testing. Moreover, treatment tailored according to individually determined H. pylori susceptibility may be a reasonable future goal.     

Antibacterial effects of the urushiol component in the sap of the lacquer tree (Rhus verniciflua Stokes) on Helicobacter pylori

Background: Urushiol is a major component of the lacquer tree which has been used as a folk remedy for the relief of abdominal discomfort in Korea. The aim of this study was to evaluate the antibacterial effects of the urushiol on Helicobacter pylori. Materials and Methods: Monomer and 2–4 polymer urushiol were used. In the in vitro study, pH‐ and concentration‐dependent antibacterial activity of the urushiol against H. pylori were investigated. In addition, the serial morphological effects of urushiol on H. pylori were examined by electron microscopy. In vivo animal study was performed for the safety, eradication rate, and the effect on gastritis of urushiol. The expression of pro‐inflammatory cytokines was checked. Results: All strains survived within a pH 6.0–9.0. The minimal inhibitory concentrations of the extract against strains ranged 0.064–0.256 mg/mL. Urushiol caused separation of the membrane and lysis of H. pylori within 10 minutes. Urushiol (0.128 mg/mL × 7 days) did not cause complications on mice. The eradication rates were 33% in the urushiol monotherapy, 75% in the triple therapy (omeprazole + clarithromycin + metronidazole), and 100% in the urushiol + triple therapy, respectively. H. pylori‐induced gastritis was not changed by urushiol but reduced by eradication. Only the expression of interleukin‐1β in the gastric tissue was significantly increased by H. pylori infection and reduced by the urushiol and H. pylori eradication (p = .014). Conclusions: The urushiol has an antibacterial effect against H. pylori infection and can be used safely for H. pylori eradication in a mouse model.     

Detection of Helicobacter pylori DNA by a simple stool PCR method in adult dyspeptic patients

INTRODUCTION: Helicobacter pylori is the major agent causing peptic ulcer, gastric cancer and mucosa-associated lymphoid tissue (MALT) gastric lymphoma. A simple stool polymerase chain reaction (PCR) method was performed and compared with the gold standards for the diagnosis of H. pylori infection. MATERIAL AND METHODS: A total of 54 adult patients (mean age, 46.41 +/- 13.12 years) with dyspeptic symptoms from Gastroenterology at Dokuz Eylül University Hospital between May and November 2003 were included. Two antrum and corpus biopsies were taken from each patient. Infection by H. pylori was defined as positivity and negativity of the gold standards. DNA extraction of stool specimens was done using QIAamp DNA Stool Mini Kit (QIAGEN) and PCR conditions included amplification and reamplification steps using the H. pylori ureA gene specific primers (HPU1, HPU2) and were visualized on 1% agarose gel stained with ethidium bromide. RESULTS: Forty-six of 54 patients (85.2%) were diagnosed positive and eight (14.8%) were negative for H. pylori infection by the gold standard methods. Thirty-two patients were positive (59.3%) and 22 of them (40.7%) were detected negative by stool PCR method. The stool PCR method and gold standard methods showed a statistical difference for the detection of H. pylori infection (p < .0001). Sensitivity, specificity, likelihood ratio, and positive and negative predictive values were 65.22%, 75%, 2.61%, 93.75%, and 27.7%, respectively. DISCUSSION: The PCR on the stool specimens resulted as being a very specific test. We suggest that a simple stool PCR method that we developed can be used to detect H. pylori, virulence genes, and in drug resistance studies either first line diagnostic methods in the laboratory or in the clinical management of dyspeptic patients.     

Previous Helicobacter pylori infection–induced atrophic gastritis: A distinct disease entity in an understudied population without a history of eradication

Individuals with chronic atrophic gastritis who are negative for active H. pylori infection with no history of eradication therapy have been identified in clinical practice. By excluding false‐negative and autoimmune gastritis cases, it can be surmised that most of these patients have experienced unintentional eradication of H. pylori after antibiotic treatment for other infectious disease, unreported successful eradication, or H. pylori that spontaneously disappeared. These patients are considered to have previous H. pylori infection–induced atrophic gastritis. In this work, we define these cases based on the following criteria: absence of previous H. pylori eradication; atrophic changes on endoscopy or histologic confirmation of glandular atrophy; negative for a current H. pylori infection diagnosed in the absence of proton‐pump inhibitors or antibiotics; and absence of localized corpus atrophy, positivity for autoantibodies, or characteristic histologic findings suggestive of autoimmune gastritis. The risk of developing gastric cancer depends on the atrophic grade. The reported rate of developing gastric cancer is 0.31%‐0.62% per year for successfully eradicated severely atrophic cases (pathophysiologically equal to unintentionally eradicated cases and unreported eradicated cases), and 0.53%‐0.87% per year for spontaneously resolved cases due to severe atrophy. Therefore, for previous H. pylori infection–induced atrophic gastritis cases, we recommend endoscopic surveillance every 3 years for high‐risk patients, including those with endoscopically severe atrophy or intestinal metaplasia. Because of the difficulty involved in the endoscopic diagnosis of gastric cancer in cases of previous infection, appropriate monitoring of the high‐risk subgroup of this understudied population is especially important.     

The prevalence and incidence of Helicobacter pylori infections among young recruits during service in the Hungarian Army

BACKGROUND: A vast number of data indicate that the prevalence of Helicobacter pylori infections is positively correlated with age and is different in various countries. Although our knowledge of transmission of H. pylori is very limited, it is reasonable to assume that it could be much more contagious in closed communities, for example in garrisons, than in normal populations. METHODS: Young male recruits (aged 19-23 years) in the Hungarian Army were tested for seropositivity at the beginning and at the end of their military service. RESULTS: The prevalence of H. pylori seropositivity was found to be 23% (*CI95%: 21-24%) among the young male recruits. Seroconversion among the formerly seronegative persons after completing either their 9-month or 6-month military service was 30% (CI95%: 25-35%) and 23% (CI95%: 8-45%), respectively. In those groups, where either the H. pylori infection was eradicated by antibiotics or hygienic countermeasures were introduced, the infection rate was reduced from 23% to 11% (CI95%: 3-25%) and to 0% (CI95%: 0-6%); p > .2 and p < .002, respectively. CONCLUSION: Our data suggest that, although H. pylori has a very high contagiosity in closed communities, its spread can be reduced or even prevented by medication of the infected persons and/or by improving the hygienic conditions and introducing anti-infective sanitary regulations.     

Practical rapid, minimally invasive, reliable nonendoscopic method to obtain Helicobacter pylori for culture

BACKGROUND: Helicobacter pylori culture typically requires endoscopy. AIM: To develop a minimally invasive rapid and reliable method to obtain H. pylori cultures. METHODS: An extendable oro-gastric brush, contained within a plastic over-tube, was constructed (Baylor Brush, US Endoscopy). After topical oral anesthesia, the 5-mm diameter brush assembly was swallowed. The brush was extended in the stomach and the mucosa was brushed three or four times. The brush was then retracted into the protective sleeve and withdrawn from the patient. The brush was either cultured directly or placed in cysteine transport medium with 20% glycerol which was then sampled immediately or after freezing at -70 degrees C. RESULTS: Twenty-five adult H. pylori-infected subjects (13 male, 12 female) were studied. Helicobacter pylori recovery rate was 100% (11 of 11) when cultured immediately or after storage in transport medium at -70 degrees C for 1 or 2 weeks or after storage at 4 degrees C for 24 hours (four of four) or 72 hours (four of four) before being cultured. Freezing on dry ice and air shipment did not reduce recovery. CONCLUSION: Rapid, reliable, nonendoscopic culture of gastric mucus is a practical method to obtain culture of H. pylori for clinical or research purposes. The method is amenable to being performed in a doctor's office or in the field.     

Methodology and transport medium for collection of Helicobacter pylori on a string test in remote locations

BACKGROUND: Helicobacter pylori can be isolated from patients using the string test but contaminating oral and nasopharyngeal microflora need to be suppressed by rapid plating out onto selective culture media. Recently, use of this diagnostic method was enhanced by using a novel transport medium to collect specimens from subjects in a remote Australian clinic over 1300 km from the laboratory. METHODS: Retrieved string tests were transported to the laboratory in chilled polystyrene boxes in 5 ml screw-cap bottles with 3 ml of a brain heart infusion broth plus antibiotics. These were 20 g/ml vancomycin, 10 g/ml trimethoprim, 10 g/ml cefsulodin, and 10 g/ml amphotericin B. A comparison was made between subjects who gargled with a chlorhexidine mouthwash before swallowing the string test and those who did not. RESULTS: Forty-five urea breath test-positive subjects were tested and H. pylori was isolated from 34 of them. Successful culture was achieved from string tests that were in transit for up to 29 hours and where the maximum temperature in the transport box was 14 degrees C. The additional use of a mouthwash had a marked effect on the isolation rate. H. pylori was cultured from 75% of subjects who gargled but only from 39% who did not. CONCLUSIONS: This methodology and transport medium can broaden the use of the string test to more remote geographic areas where endoscopy is not feasible so that H. pylori isolates may still be obtained for diagnostic and epidemiologic studies. The value of this promising methodology of collection and transport should be assessed in a controlled study.     

Optimized conditions for the fermentation of Helicobacter pylori and production of vacuolating cytotoxin

Abstract We report here improvements to the growth media and fermentation conditions which result in a substantial increase of Helicobacter pylori growth and in the enhanced production of vacuolating cytotoxin. Addition of glucose to the medium resulted in the increase of cell yield, cell viability and a significant improvement in the production of vacuolating cytotoxin.     

Importance of the host genetic background on immune responses to Helicobacter pylori infection and therapeutic vaccine efficacy

In order to investigate the role of host factors in Helicobacter pylori infection and immunity, two different strains of inbred mice, C57BL/6 and BALB/c, were infected with a standard H. pylori strain, SS1. A month later, infected mice were immunized orally with whole-cell lysates of H. pylori SS1 and cholera toxin on days 1, 3, 6, 30, and 54. Ten days after the last immunization, mice were sacrificed and the stomach was collected to assess H. pylori colonization density by quantitative culture. H. pylori SS1 colonization was significantly greater in C57BL/6 than in BALB/c (P<0.02 and P<0.003 at 2 and 13 weeks post-inoculation, respectively). Colonization in C57BL/6 persisted at equivalent levels for 13 weeks but the colonization density in BALB/c decreased significantly during this period. In contrast to the pattern of bacterial colonization, antibody responses following H. pylori SS1 infection were greater in BALB/c than in C57BL/6, suggesting that host factors may modulate the immune responses to H. pylori infection. Following therapeutic immunization, H. pylori colonization in BALB/c mice was also significantly reduced (P<0.03), while no significant differences in bacterial density were observed in C57BL/6. These observations collectively demonstrate the great importance of host factors in H. pylori infection and the development of effective immune responses.     

A Population-Based Epidemiologic Study of Helicobacter Pylori Infection and its Association with Systemic Inflammation

Background:  Infection with Helicobacter pylori is associated with a variety of non-gastrointestinal sequelae. These may be mediated by an increase in systemic inflammation. We assessed if serologic evidence of infection with H. pylori is associated with increased serum C-reactive protein (CRP) levels.
Methods:  The study design consisted of a randomly selected, cross-sectional population-based study of 2633 individuals phenotyped in 1991, of whom 2361 participants provided serum samples to permit measurement of H. pylori 's serologic status and CRP levels.
Results:  Male gender (odds ratio (OR): 1.65; 95% confidence interval (CI): 1.23–2.21), age (OR per year: 1.05; 95% CI: 1.04–1.06), height (OR per meter: 0.05; 95% CI: 0.01–0.24), current smoking habit (compared with never smokers, OR: 1.46; 95% CI: 1.13–1.88), and less affluent socioeconomic status were associated with increased odds of being seropositive for H. pylori . Helicobacter pylori infection was associated with increased risk of having an elevated serum CRP (above 3 mg/L) after adjustment for gender, age, height, smoking status, and socioeconomic status (OR: 1.32; 95% CI: 1.05–1.67). Similar associations were seen using a threshold for elevated serum CRP of greater than 1 mg/L.
Conclusions:  Our data suggest that infection with H. pylori is associated with increased systemic inflammation. This suggests one potential mechanism to explain the extra-gastrointestinal conditions associated with H. pylori infection.     

幽门螺杆菌L型的体外诱导

应用胃内可能影响ＮＰ变成Ｌ型的一些因素,如抗生素、胃液、胆汁等为诱导剂,进行ＨＰ一Ｌ型的体外诱导。梭芋青霉素纸片法和含药平板法可诱导出ＨＰ一Ｌ型的园球体和丝状体,在Ｌ型平板上形成典型的“油煎蛋”佯或丝状菌落。梭千青霉素诱导ＨＰ一Ｌ型纸片法浓度为１０一２００ｕｇ／片,含药平板法浓度为０．１５６一０．０１ｕｇ／ｍｌ。融羧苄青霉素诱导的“油煎蛋”样菌落不稳定易回复,丝状菌落则较稳定,在Ｓｋｉｒｒｏｗ平板上也能生长。胃液可诱导ＨＰ形成稳定的Ｌ型,这种Ｌ型为丝状菌落,涂片油镜下呈长丝体。胆汁对４株不同的ＨＰ经多次诱导均未成功,形成的ＨＰ一Ｌ型作了免疫酶（ＰＡＰ法）染色和染色体ＤＮＡ酶切图谱分析。     

Comparison of two management strategies for Helicobacter pylori treatment: clinical study and cost-effectiveness analysis

BACKGROUND: First-line proton pump inhibitor-based triple and quadruple therapies for Helicobacter pylori eradication present similar levels of efficacy. Cross-over treatment (quadruple following triple failure, and triple following quadruple failure) seems the most sensible approach to treatment failures, but the two strategies -'quadruple first' versus 'triple first'- have not been previously compared. The aims of our study were to assess the usefulness and the cost-effectiveness of the two treatment strategies. MATERIAL AND METHODS: Forty-nine out of 344 patients included in a previous study comparing triple therapy - 7 days of omeprazole, amoxicillin and clarithromycin twice a day - with quadruple therapy - 7 days of omeprazole twice a day, plus tetracycline, metronidazole and bismuth subcitrate three times a day - failed initial treatment and were assigned to cross-over therapy. Cure was determined by urea breath test. A decision analysis was performed to compare the two eradication strategies. RESULTS: Intention to treat cure rates were 46% (10/22 patients; 95% CI 24-68%) for second-line triple therapy and 63% (17/27 patients; 95% CI 42-81%) for second-line quadruple therapy. Per protocol cure rates were 71% and 85%, respectively. Intention to treat cure rates were 87% (95% CI 81-92%) for the 'triple first' versus 86% (95% CI 80-91%) for the 'quadruple first' strategy (p = .87). The 'quadruple first' strategy was more cost-effective. The incremental cost of 'triple first' strategy per person was 19 in the low-cost area and 65 US dollars in the high-cost area. CONCLUSIONS: The effectiveness of 'triple first' and 'quadruple first' strategies is similar, although the latter seems slightly more cost-effective.     

Prevalence of Helicobacter pylori vacA, cagA, cagE, iceA, babA2 genotypes and correlation with clinical outcome in Turkish patients with dyspepsia

BACKGROUND: Distinct virulence factors of Helicobacter pylori have been associated with clinical outcome of the infection; however, considerable variations have been reported from different geographic regions and data on genotypes of Turkish H. pylori isolates are sparse. AIM: To determine the prevalence of specific genotypes of H. pylori in Turkish patients with dyspepsia. MATERIALS AND METHODS: Ninety-three H. pylori-positive patients [30 with non-ulcer dyspepsia (NUD), 30 with duodenal ulcer (DU), and 33 with gastric cancer (GC)] who were admitted to our endoscopy unit due to dyspepsia were enrolled in the study. H. pylori infection was confirmed in all patients by histology and rapid urease test (RUT). The presence of vacA alleles, cagA, cagE, iceA, and babA2 genotypes were determined by polymerase chain reaction (PCR). Chi-squared test and Fisher's exact test were used for statistical comparisons and multivariate regression analysis was performed to find out independent predictors of different clinical outcomes. RESULTS: Turkish strains examined predominantly possessed the vacA s1,m2 (48.4%) and s1,m1 (40.7%) genotypes. The vacA s1a genotype was detected in 66.7, 96.4, and 87.9% of isolates from patients with NUD, DU, and GC, respectively, and its presence was significantly associated with that of DU (p = .004), GC (p = .043), and cagA gene (p = .021). None of the cases was found to harbor the s1c genotype. The frequencies of the cagA and cagE genes among studied isolates were 73.6 and 59.3%, respectively. The cagA gene was significantly associated with the presence of DU (p = .004) and GC (p = .003), and the cagE gene, too, was significantly associated with the presence of DU (p = .002) and GC (p = .000). All H. pylori isolates possessed the iceA gene. In all, 68 isolates (74.7%) were positive for iceA1 and 23 (25.3%) for iceA2. The frequency of icea1 gene was significantly higher in cases with GC (85%) than in cases with NUD (60%) (p = .026). The frequency of babA2 gene was 23.3, 46.4, and 87.9% in isolates of patients with NUD, DU, and GC, respectively. When compared to cases with NUD (p = .000) and DU (p = .000), the presence of babA2 gene was significantly higher in cases with GC. Multivariate regression analysis disclosed cagE (p = .006) and vacA s1a (p = .027) genotypes to be independent predictors of DU and babA2 (p = .000) and cagE (p = .013) genotypes to be independent predictors of GC. CONCLUSIONS: H. pylori vacA s1a, cagA, cagE genotypes have significant relations with the presence of DU and GC, and iceA1, babA2 with GC in Turkish patients with dyspepsia, whereas cagE and vacA s1a genotypes are independent predictors of DU, and babA2 and cagE genotypes are independent predictors of GC.     

幽门螺杆菌感染与慢性口臭关系的初步研究

目的 调查主诉口臭患者的幽门螺杆菌（H．pylori）感染率和主诉消化不良的口臭发生率。方法 研究对象为125例主诉慢性口臭患者和212例主诉慢性消化不良患者。口臭以口气挥发性硫化物（VSC）检测与闻诊联合诊断,H．pylori感染以^14C-尿素呼气试验诊断。结果 125例主诉慢性口臭的患者有87例是真性口臭,其余38例为假性口臭,真性口臭患者的H．pylori感染率显著高于假性口臭（40．2％和13．2％,P〈0．01）。212例主诉慢性消化不良的患者发生口臭105例（49．5％）、感染H．pylori 94例（44．3％）,H．pylori阳性患者的口臭发生率显著高于H．pylori阴性患者（57．5％和43．2％,P〈0．05）。无论何种主诉,大部分口臭患者属于VSC阳性（88．5％）,但H．pylori阳性患者和H．pylor阴性患者口气VSC水平差异无显著性,VSC阳性口臭和VSC阴性口臭的H．pylori感染率差异也无显著性。结论 H．pylori感染可能与口臭的发生有一定关系,但口气VSC并非由H．pylori直接产生。