Treatment of Helicobacter pylori infection

Effects of cinnamon extract on complications of treatment and eradication of Helicobacter pylori in infected people

Introduction: Treatment of Helicobacter pylori has various side effects like antibiotic resistance. The purpose of this study was to evaluate the effects of cinnamon extract on complications of treatment and eradication of H. pylori in infected people. Methods: In this randomized clinical trial, a total of 98 eligible healthy and H. pylori-infected patients approved by esophageal endoscopy were selected. The cinnamon group received multi-drug treatment including clarithromycin, amoxicillin and pantoprazole as well as a cinnamon extract capsule. The control group received multi-drug treatment and a 40 mg starch capsule. In order to analyze the cinnamon extract efficacy, the urea breath test (UBT) was performed 3 months after the start of treatment. Clinical symptoms were evaluated by a questionnaire at the beginning (day of 0), 7 days and 14 days after starting treatment. Results: The clinical symptoms such as nausea, vomiting, diarrhea, constipation, blurred vision, headache, metallic flavor, epigastric pain, burp, and appetite were significantly reduced in the cinnamon group (P < 0.05). The odds ratio exhibited a higher eradication rate of H. pylori in the cinnamon group (73.47% in the cinnamon group compared to 53.06% in the control group) (P = 0.036). Conclusion: Cinnamon as assisted therapy is able to alleviate the disease and reduce the complications of H. pylori treatment.

Eradication of Helicobacter pylori in Children by Triple Therapy Regimens of Amoxicillin, Omeprazole, and Clarithromycin or Azithromycin

Background and Objectives:

The present study aimed to evaluate the effect of classical and azithromycin-containing triple therapy eradication regimen against H. Pylori in children, and to determine the level of patients’ tolerance.

Patients and Methods:

This single clinical trial was performed in 2014 on 2 to 15 years old children. All children, in whom H. Pylori infection was confirmed through multiple biopsies of the stomach and required treatment, were enrolled in the study. H. Pylori-positive patients were treated alternately with two different drug regimens; Group OCA received clarithromycin 7.5 mg/kg/day every 12 hours for 10 days, amoxicillin 50 mg/kg/day every 12 hours for 10 days, and omeprazole 1 mg/kg/day every 12 hours for two weeks, and Group OAA received azithromycin 10 mg/kg/day once a day (before meal) for 6 days along with amoxicillin and omeprazole. Four to six weeks after completion of treatment, patients’ stool was tested for H. Pylori through the monoclonal method using the Helicobacter antigen quick kit.

Results:

There were no significant differences between the two groups regarding gender and age of patients. Based on ITT analysis, the therapeutic response in the OAA and OCA groups were 56.2% and 62.5%, respectively (P = 0.40). Drug adverse effects were 15.6% in the OCA and 3.1% in the OAA group (P = 0.19).

Conclusions:

The therapeutic response was seen in more than half of the patients treated with triple therapy of H. Pylori eradication regimen including azithromycin or clarithromycin, and there was no significant difference between the two treatment groups.

The efficacy of moxifloxacin-based triple therapy in treatment of Helicobacter pylori infection: a systematic review and meta-analysis of randomized clinical trials

Recent evidence shows that moxifloxacin could exert an antimicrobial effect against Helicobacter pylori in both in vitro and in vivo models. To systematically evaluate whether moxifloxacin-containing triple therapy could improve eradication rates and reduce side effects in first-line or second-line anti-H. pylori treatment, eligible articles were identified by searches of electronic databases. We included all randomized trials comparing moxifloxacin-based triple therapy with standard triple or quadruple therapy during H. pylori eradication treatment. Statistical analysis was performed with Review Manager 5.0.10. Subanalysis/sensitivity analysis was also performed. We identified seven randomized trials (n=1263). Pooled H. pylori eradication rates were 79.03% (95%CI: 75.73-82.07) and 68.33% (95%CI: 64.44-72.04) for patients with moxifloxacin-based triple therapy or with standard triple or quadruple therapy, respectively (intention-to-treat analysis). The odds ratio (OR) was 1.82 (95%CI: 1.17-2.81), the occurrence of total side effects was 15.23% (95%CI: 12.58-18.20) and 27.17% (95%CI: 23.64-30.92) for groups with or without moxifloxacin, and the summary OR was 0.45 (95%CI: 0.26-0.77). In subgroup analyses, we noted that the second-line eradication rate in the moxifloxacin group was significantly higher than that in the quadruple therapy group (73.33 vs 60.17%, OR: 1.78, 95%CI: 1.16-2.73, P<0.001). However, there was no difference in first-line eradication treatment. Findings from this meta-analysis suggest that moxifloxacin-based triple therapy is more effective and better tolerated than standard triple or quadruple therapy. Therefore, a moxifloxacin-based triple regimen should be used in the second-line treatment of H. pylori infection.

The rOmp22-HpaA fusion protein confers protective immunity against helicobacter pylori in mice

Helicobacter pylori (H. pylori) plays an essential role in the development of various gastroduodenal diseases; however, no vaccines preventing H. pylori infection have been available now. This study was to evaluate the protective effect of rOmp22-HpaA fusion protein against H. pylori infection in mouse model and to screen the candidate to be used in the development of an oral vaccine against H. pylori. rOmp22, rHpaA, rOmp22+rHpaA, and rOmp22-HpaA groups were used to immunize mice with mLT63 as adjuvant by intragastric route, respectively, four times at 1-week intervals. Two weeks after last immunization, all of the animals were orally challenged with H. pylori NCTC11637 and then were killed after another 2 weeks. The mice gastric tissue of all groups was separated to detect the presence of infection by urease tests, to culture H. pylori, and to observe the histological characteristics. The protective effect against H. pylori challenge in mice immunized with rOmp22-HpaA fusion protein and mLT63 adjuvant was significantly higher than PBS and mLT63 control groups (P < 0.05), but no significant difference was detected among rOmp22, rHpaA, rOmp22+rHpaA, and rOmp22-HpaA groups (P > 0.05). rOmp22-HpaA fusion protein retained immunogenicity and could be used as an antigen candidate in the development of an oral vaccine against H. pylori infection.

[The trend of eradication rate of Helicobacter pylori infection and clinical factors that affect the eradication of first-line therapy]

BACKGROUND/AIMS

Although triple combination therapy containing a proton pump inhibitor (PPI) and two antibiotics is considered as a standard regimen for the first-line anti-Helicobacter pylori treatment, the recent trend of eradication rates following this therapy has been declined in the last few years. The purpose of this study was to investigate the trend of H. pylori eradication rates over the last 9 years and to evaluate are clinical factors affecting eradication rates.

METHODS

From January 2001 to June 2009, H. pylori eradication rates in 709 patients with documented H. pylori infection who received triple combination therapy for 7 days were retrospectively evaluated according to years and various clinical factors. H. pylori status was evaluated by 13C urea breath test 4-6 weeks after completion of treatment. results: The overall H. pylori eradication rate was 77.0%. The annual eradication rates from year 2001 to 2009 were 78.9%, 72.5%, 81.0%, 75.0%, 79.1%, 77.1%, 77.8%, 77.8%, and 75.0% by per-protocol analysis. There was no decreasing tendency of the eradiation rate over 9 years (p=0.974). There was no statistical difference in the eradication rates according to age, sex, smoking, alcohol, NSAIDs, underlying diseases, endoscopic diagnosis, and PPI. However, the eradication rate was lower in patients who took aspirin (OR=0.509, 95% CI=0.292-0.887, p=0.001) and antibiotics within 6 months (OR=0.347, 95% CI=0.183-0.658, p=0.001).

CONCLUSIONS

The H. pylori eradication rate has not changed at Gwangju-Chonnam province in Korea for recent 9 years. Lower eradication rate in aspirin and antibiotics users warrants further attention.

Guidance for substantiating the evidence for beneficial effects of probiotics: prevention and management of infections by probiotics

The rationale for the use of probiotics in the management of infectious diseases is supported by their potential to influence and stabilize the composition of gut microbiota, enhance colonization resistance, and modulate immune function parameters. A literature review was conducted to determine the efficacy of using probiotics in selected infections: 1) infectious diarrhea in infants and children, 2) traveler's diarrhea, 3) necrotizing enterocolitis in infants, 4) Helicobacter pylori infection, 5) respiratory tract infections in adults and children, 6) ear, nose, and throat infections, and 7) infectious complications in surgical and critically ill patients. The different types of infections that have been subject to clinical studies with different probiotics obviously prevent any generic conclusions. Furthermore, the lack of consistency among studies focusing on 1 specific infection, in study design, applied probiotic strains, outcome parameters, and study population, along with the still limited number of studies, preclude clear and definite conclusions on the efficacy of probiotics and illustrate the need for better-aligned study designs and methodology. Exceptions were the management of infectious diarrhea in infants and traveler's diarrhea, antibiotic-associated diarrhea, and necrotizing enterocolitis. Sufficient consistent data exist for these applications to conclude that certain probiotics, under certain conditions, and in certain target populations, are beneficial in reducing the risk of infection. In addition, some evidence exists, although conclusions are premature, for the management of Helicobacter pylori infection and possible reduction of treatment side effects. Certain probiotics may also reduce the risk of various symptoms of respiratory tract infections in adults and children, including ear, nose, and throat infections, although data are currently far too limited to distill any clinical recommendations in this area. Positive but also negative results have been obtained in prevention of infectious complications in surgical and critically ill patients. For future studies it is recommended that researchers provide adequate power, identify pathogens, and report both clinical outcomes and immune biomarkers relating to putative underlying mechanisms.

Azithromycin-containing versus standard triple therapy for Helicobacter pylori eradication: A meta-analysis

AIM: To evaluate whether adding azithromycin to first-line Helicobacter pylori (H pylori) eradication improved eradication and reduced side effects.

METHODS: Eligible articles were identified by searches of electronic databases. We included all randomized trials that compared azithromycin-containing with standard triple-therapy regimens for first-line treatment of H pylori infection. Statistical analysis was performed with Review Manager 5.0.10. Sub-analyses were also performed.

RESULTS: We identified 14 randomized trials (1431 patients). Pooled H pylori eradication rates were 72.01% (95% CI: 58.09%-85.93%) and 69.78% (95% CI: 66.47%-73.09%) for patients with or without azithromycin by intention-to-treat analysis, and the odds ratio (OR) was 1.17 (95% CI: 0.64-2.14). The occurrence of side effects differed significantly and was 15.81% (95% CI: 12.50%-19.12%) and 25.20% (95% CI: 21.44%-28.96%) for treatment with or without azithromycin, respectively, and the summary OR was 0.58 (95% CI: 0.41-0.82). Furthermore, the azithromycin-containing group had a lower occurrence of diarrhea, nausea and taste disturbance.

CONCLUSION: Our review suggests that azithromycin-containing triple-therapy regimens could be equally effective in eradication of H pylori compared with standard first-line triple-therapy regimens.

Meta-analysis: Lactobacillus containing quadruple therapy versus standard triple first-line therapy for Helicobacter pylori eradication

BACKGROUND

Recent evidence showed that Lactobacilli could exert an inhibitory effect on Helicobacter pylori both in vitro and in vivo models. To systematically evaluate whether adding Lactobacilli to H. pylori eradication regimens could improve eradication rates and reduce side effects during anti-H. pylori treatment.

MATERIALS AND METHODS

Eligible articles were identified by searches of electronic databases. We included all randomized trials comparing Lactobacilli supplementation to placebo or no treatment during anti-H. pylori regimens. Statistical analysis was performed with Review Manager 5.0.10. Subanalysis analysis was also performed.

RESULTS

We identified eight randomized trials (n = 1372). Pooled H. pylori eradication rates were 82.26% (95% CI = 78.01-86.51%) and 76.97% (95% CI = 73.11-80.83%) for patients with or without Lactobacilli by intention-to-treat analysis, respectively, the odds ratio (OR) was 1.78 (95% CI = 1.21-2.62). The occurrence of total side effects had no significant difference and were 30.84% (95% CI = 24.82-36.86%) and 42.24% (95% CI = 35.89%-48.59%) for two groups, the summary OR was 0.49 (95% CI = 0.24-1.02); However, Lactobacilli supplementation group had lower occurrence of diarrhoea, bloating and taste disturbance.

CONCLUSIONS

Our review suggests that supplementation with Lactobacilli could be effective in increasing eradication rates of anti-H. pylori therapy for first-treated patients. Furthermore, Lactobacilli showed a positive impact on some H. pylori therapy-related side effects.

Meta-analysis of the efficacy of levofloxacin-based triple regimen and quadruple rescue regimen therapy for eradication of Helicobacter pylori

AIM: To systematically evaluate the efficacy and tolerability of levofloxacin-based triple regimen and quadruple rescue regimen therapy during anti-H. pylori treatment for people who failed eradication previously.

METHODS: Eligible articles were identified by searching electronic databases. We included all randomized trials comparing levofloxacin-based triple regimen and quadruple rescue regimen during anti-H. pylori treatment. Statistical analysis was performed with Review Manager 5.0.10. Sensitivity analysis was also performed.

RESULTS: We identified 13 randomized trials (n = 1181). Pooled H. pylori eradication rates were 77.5% (95%CI 74.1%-80.9%) and 70.5% (95%CI 66.8%-74.2%) for patients with levofloxacin-based triple regimen and quadruple rescue regimen by intention-to-treat analysis, respectively. The odds ratio (OR) was 1.51 (95%CI 0.91-2.53); the occurrences of total side effects were 21.3% (95%CI 17.7%-24.9%) and 36.0% (95%CI 31.8%-40.2%) for groups with levofloxacin-based triple regimen and quadruple rescue regimen, and the summary OR was 0.45 (95%CI 0.29-0.71).

CONCLUSION: Our review suggests that levofloxacin-based triple regimen has equal efficacy compared with quadruple rescue regimen in patients with eradication failure. Furthermore, levofloxacin-based triple therapy shows fewer side effects during anti-H. pylori treatment.

Meta-analysis: the effect of supplementation with lactoferrin on eradication rates and adverse events during Helicobacter pylori eradication therapy

BACKGROUND

Recent evidence shown that lactoferrin could exert an antimicrobial effect against Helicobacter pylori both in vitro and in vivo models. To systematically evaluate whether adding lactoferrin to H. pylori eradication regimens could improve eradication rates and reduce side-effects during anti-H. pylori treatment.

MATERIALS AND METHODS

Eligible articles were identified by searches of electronic databases. We included all randomized trials comparing lactoferrin supplementation to placebo or no treatment during anti-H. pylori regimens. Statistical analysis was performed with Review Manager 5.0.10. Subanalysis/Sensitivity analysis was also performed.

RESULTS

We identified nine randomized trials (n = 1343). Pooled H. pylori eradication rates were 86.57% (95% confidence interval (CI) = 83.99-89.15%) and 74.44% (95% CI = 71.14-77.74%) for patients with or without lactoferrin by intention-to-treat analysis, respectively, the odds ratio (OR) was 2.26 (95% CI = 1.70-3.00); the occurrence of total side-effects was 9.05% (95% CI = 6.83-11.27%) and 16.28% (95% CI = 13.43%-19.13%) for groups with or without lactoferrin, especially for nausea, the summary OR was 0.15 (95% CI = 0.04-0.54).

CONCLUSIONS

Our review suggests that supplementation with lactoferrin could be effective in increasing eradication rates of anti-H. pylori therapy, and could be considered helpful for patients with eradication failure. Furthermore, lactoferrin shows a positive impact on H. pylori therapy-related side-effects.

Meta-analysis on the efficacy of lactoferrin supplementation combined with standard treatment during Helicobacter pylori eradication therapy

AIM: To systematically evaluate whether adding lactoferrin to H pylori eradication regimens could improve eradication rates and reduce side effects during anti-H pylori treatment.

METHODS: Eligible articles were identified by searching electronic databases. We included all randomized trials comparing lactoferrin supplementation to placebo or no treatment during anti-H pylori regimens. Statistical analysis was performed with Review Manager 5.0.10. Subanalysis/Sensitivity analysis was also performed.

RESULTS: We identified 9 randomized trials (n = 1343). Pooled H pylori eradication rates for patients with and without lactoferrin were 86.57% (95% CI: 83.99%-89.15%) and 74.44% (95% CI: 71.14%-77.74%) by intention-to-treat analysis, respectively, and the odds ratio (OR) was 2.26 (95% CI: 1.70-3.00); the occurrence of total side effects, especially nausea, for groups with or without lactoferrin were 9.05% (95% CI: 6.83%-11.27%) and 16.28% (95% CI: 13.43%-19.13%), respectively; the summary OR was 0.15 (95% CI: 0.04-0.54).

CONCLUSION: Our review suggests that supplementation with lactoferrin could be effective in increasing eradication rates of anti-H pylori therapy, and could be considered helpful for patients with eradication failure.

Efficacy of a new therapeutic regimen versus two routinely prescribed treatments for eradication of Helicobacter pylori: a randomized, double-blind study of doxycycline, co-amoxiclav, and omeprazole in Iranian patients

This study compared a new regimen (group A: doxycycline, co-amoxiclav, omeprazole) and two routinely prescribed regimens (group B: amoxicillin, omeprazole, furazolidone, bismuth; group C: amoxicillin, clarithromycin, omeprazole) to find an acceptable first-line treatment option for Helicobacter pylori. The study population consisted of 189 patients who referred to our clinic to undergo endoscopy due to ulcer-like dyspepsia. The H. pylori eradication rate was 68% in group A, 56% in group B, and 70% in group C according to per-control analysis. There was no statistically significant difference in H. pylori eradication between groups A and B (P = 0.187), groups A and C (P = 0.857), and groups B and C (P = 0.15). In conclusion, although none of the three eradication regimens can be recommended as a first-line eradication treatment, the new regimen is at least as effective and probably better tolerated than the two routinely applied regimens.

Growth inhibitory action of cranberry on Helicobacter pylori

BACKGROUND AND AIM

Cranberry is a fruit that originated in North America, and it has been used by Native Americans for bacterial infections. Recent studies have revealed it to be effective for preventing refractory urinary infections, while also suggesting that it plays a possible role in the eradication of Helicobacter pylori (H. pylori).

METHODS

The H. pylori strains used in the present study were NCTC11637 and 11638. Sugar and organic acid-rich, and polyphenol-rich fractions were obtained from cranberry juice concentrate by Amberlite XAD7HP-column chromatography. The H. pylori growth inhibition was estimated by OD(660) and titration in liquid culture, and by an agar dilution plate method. The shapes of the bacteria were analyzed by scanning electron microscopy.

RESULTS

Cranberry extract suppressed bacterial proliferation in a dose-dependent manner. In the comparison with other juices, polyphenol-rich fruits (cranberries, blueberries, and red grapes) showed similar growth inhibitory activity, whereas polyphenol-poor fruits (oranges, pineapples, apples, and white grapes) did not show any activity. The polyphenol-rich fraction of cranberry maintained the H. pylori-growth inhibitory activity. More bacteria in a coccoid form were observed after culture with cranberry.

CONCLUSION

Cranberry extract inhibited H. pylori proliferation and it is suggested that polyphenols are responsible for this action. The morphological analysis suggested that cranberry induces H. pylori to develop a coccoid form, thereby inhibiting its growth bacteriostatically. Further basic studies to clarify these mechanisms in combination with in vivo studies are needed.

Determination of mutations of the 23S rRNA gene of Helicobacter pylori by allele specific primer-polymerase chain reaction method

BACKGROUND AND AIMS

Susceptibility to clarithromycin of Helicobacter pylori (H. pylori) is caused by single nucleotide polymorphisms (SNPs) of the 23SrRNA gene. Allele specific primer-polymerase chain reaction (ASP-PCR) is one of the methods for determining SNPs, which can measure SNPs easily within a short period by PCR amplification alone without digestion with restriction enzymes. The aim of the present study was to develop the ASP-PCR assay for determining SNPs at positions 2,142 and 2,143 of the 23S rRNA gene of H. pylori.

METHODS

In total, 112 patients with H. pylori infection based on positive results of a rapid urease test (RUT) were enrolled in the study. Thirty-five had failed to eradicate H. pylori by a clarithromycin-based regimen. DNA was extracted from the RUT-positive gastric tissue samples. SNPs from adenine to guanine at positions 2,142 and 2,143 of the 23S rRNA of H. pylori (A2,142G and A2,143G) were determined by the ASP-PCR method. Minimum inhibitory concentrations (MICs) of clarithromycin for H. pylori were also measured.

RESULTS

Forty-nine of 112 patients were infected with wild-type strains of H. pylori. Thirty-nine patients were infected with strains with A2,143G mutations. Twenty-three patients were infected with both wild-type strains and those with A2,143G mutations. Only one patient was infected with the strain with A2,142G mutation. H. pylori strains with A2,143G or A2,142G mutation had significantly higher MICs for clarithromycin.

CONCLUSION

The ASP-PCR assay for 23S rRNA mutation of H. pylori is a useful method to detect clarithromycin-resistant strains of H. pylori easily.

Optimal length of triple therapy for H pylori eradication in a population with high prevalence of infection in Chile

AIM: To compare the efficacy of 7-d versus 14-d triple therapy for the treatment of H pylori infection in Chile, with a prevalence of 73% in general population.

METHODS: H pylori-infected patients diagnosed by rapid urease test, with non-ulcer dyspepsia or peptic ulcer disease were randomized to receive omeprazole 20 mg bid, amoxicillin 1 g bid, and clarithromycin 500 mg bid for 7 (OAC7) or 14 (OAC14) d. Primary outcome was eradication rate 6 wk after the treatment. Subgroup analysis was carried out considering the eradication rate among patients with or without peptic ulcer disease and eradication rate among smokers or non-smokers.

RESULTS: One hundred and thirty-one patients were randomized to OAC7 (n = 69) or OAC14 (n = 62). The overall eradication rate (intention-to-treat) was 78.3% in OAC7 and 85.5% in OAC14 groups, without a significant difference (P =0.37). No significant difference in the eradication rate was found among the patients with peptic ulcer disease (n = 31) between the OAC7 group (85.7%) and OAC14 group (87.5%). However, smokers had an obviously lower eradication rate compared to non-smokers, particularly in the OAC7 group (57.1% in smokers vs 83.6% in non-smokers; P = 0.06). Adverse effects rate were similar between both groups.

CONCLUSION: Short-term efficacy of triple therapy with OAC for 7 d is comparable to 14 d in this high-prevalence population. Longer follow-up, and studies focused to some subgroups of patients (smokers and non-ulcer patients) are necessary to support widespread use of 7-d instead of 10-14-d triple therapy in a developing country like Chile.

HorB (HP0127) is a gastric epithelial cell adhesin

BACKGROUND

The Helicobacter pylori protein HorB (encoded by HP0127) is a member of a paralogous family that includes the adhesins BabA, AlpA, AlpB, and HopZ, which contribute to adhesion to gastric epithelial cells. Of the verified H. pylori porins, the HorB sequence is most similar to that of HopE, but the function of HorB is unknown. The aim of our study was to investigate the role of HorB in H. pylori gastric epithelial cell adhesion.

MATERIALS AND METHODS

We disrupted the horB gene in H. pylori and measured the adhesion to gastric epithelial cells (AGS cells). We then assessed the effect that HorB disruption had on lipopolysaccharide (LPS) O-chain production and Lewis x and Lewis y antigen expression. A HorB mutant in the mouse-adapted strain H. pylori SS1 was created by marker exchange and mouse stomach colonization was quantified. Using reverse transcription polymerase chain reaction, human gastric biopsy material from H. pylori-infected patients was then examined for expression of the horB gene.

RESULTS

Disruption of the horB gene reduced H. pylori adhesion by more than twofold. Adhesion in the horB knockout strain was restored to wild-type levels by re-introduction of HorB into the chromosome. Disruption of HorB reduced production of LPS O-chains and lowered the level of expression of Lewis x and Lewis y antigens. Insertional mutagenesis of the horB gene in H. pylori SS1 reduced mouse stomach colonization threefold. Finally, expression of the horB gene was detected in human gastric biopsy material from H. pylori-infected patients.

CONCLUSIONS

From these data we conclude that HorB has a role in H. pylori adhesion during infection.

[Comparison of three diagnostic methods to confirm Helicobacter pylori infection]

INTRODUCTION

Helicobacterpylori induces gastric inflammation in host and such gastritis increases the risk of gastric and duodenal ulceration as well as adenocarcinoma. Because peptic ulcer disease is the major cause of morbidity, accurate diagnosis of H. pylori infection is very important. Unfortunately, there is no gold standard among diagnostic tests for Helicobacter infections. If gastroscopy is performed, histopathology and urease test are the most often used. Still, culturing of this bacterium is essential for drug susceptibility testing and analysis of virulence factors.

OBJECTIVE

The aim of this study was to compare three diagnostic procedures--histopathology, urease test and culture, which are used to verify H. pylori infection.

METHOD

Three pairs of gastric mucosal biopsy specimens were collected from each of 28 dyspeptic patients undergoing endoscopy. Nineteen patients were not pretreated with antibiotics, while nine had received eradication therapy earlier. One pair of biopsy specimens was used for histopathologic examination, the second for urease test and the third was simultaneously cultured on nonselective and selective solid media. Isolate was identified as H. pylori on the basis of colony morphology, morphological properties and biochemical tests.

RESULTS

In 14 out of 28 patients, H. pylori infection was confirmed on the basis of results of all diagnostic procedures. The concordance of these three methods was very good, because the results of histopathology, urease test and culture corresponded in 26 from 28 patients.

CONCLUSION

The conclusion of our study is that culture, as the method with high degree of concordance with other two procedures and the only that can give information on drug susceptibility of Helicobacter, is recommended for diagnosis of Helicobacter pylori infection along with histopathology and urease test.

Helicobacter pylori and probiotics

Helicobacter pylori infection, a highly prevalent pathogen, is a major cause of chronic gastritis and peptic ulcer and a risk factor for gastric malignancies. Antibiotics-based H. pylori eradication treatment is 90% effective. However, it is expensive and causes side effects and antibiotic resistance. Probiotics could present a low-cost, large-scale alternative solution to prevent or decrease H. pylori colonization. A literature search of the MEDLINE database (1966-2006) has been performed selecting all in vitro, animal, and human fully published English-language studies dealing with H. pylori and probiotics. Probiotics had an in vitro inhibitory effect on H. pylori. Animal studies demonstrated that probiotic treatment is effective in reducing H. pylori-associated gastric inflammation. Seven of 9 human studies showed an improvement of H. pylori gastritis and decrease in H. pylori density after administration of probiotics. The addition of probiotics to standard antibiotic treatment improved H. pylori eradication rates (81% vs. 71%, with combination treatment vs. H. pylori-eradication treatment alone; chi(2)test: P=0.03). Probiotic treatment reduced H. pylori therapy-associated side effects (incidence of side effects: 23% vs. 46%, with combination therapy vs. H. pylori-eradication treatment alone; chi(2)test: P=0.04). No study could demonstrate the eradication of H. pylori infection by probiotic treatment. So long-term intake of products containing probiotic strains of probiotics may have a favorable effect on H. pylori infection in humans, particularly by reducing the risk of developing disorders associated with high degrees of gastric inflammation.

Construction of recombinant attenuated Salmonella typhimurium DNA vaccine expressing H pylori ureB and IL-2

AIM: To construct a recombinant live attenuated Salm-onella typhimurium DNA vaccine encoding H pylori ureB gene and mouse IL-2 gene and to detect its immunogenicity in vitro and in vivo.

METHODS: H pylori ureB and mouse IL-2 gene fragments were amplified by polymerase chain reaction (PCR) and cloned into pUCmT vector. DNA sequence of the amplified ureB and IL-2 genes was assayed, then cloned into the eukaryotic expression vector pIRES through enzyme digestion and ligation reactions resulting in pIRES-ureB and pIRES-ureB-IL-2. The recombinant plasmids were used to transform competent E. coli DH5α, and the positive clones were screened by PCR and restriction enzyme digestion. Then, the recombinant pIRES-ureB and pIRES-ureB-IL-2 were used to transform LB5000 and the recombinant plasmids extracted from LB5000 were finally introduced into the final host SL7207. After that, recombinant strains were grown in vitro repeatedly. In order to detect the immunogenicity of the vaccine in vitro, pIRES-ureB and pIRES-ureB-IL-2 were transfected to COS-7 cells using Lipofectamine^TM2000, the immunogenicity of expressed UreB and IL-2 proteins was assayed with SDS-PAGE and Western blot. C57BL/6 mice were orally immunized with 1 × 10⁸ recombinant attenuated Salmonella typhimurium DNA vaccine. Four weeks after vaccination, mice were challenged with 1 × 10⁷ CFU of live H pylori SS1. Mice were sacrificed and the stomach was isolated for examination of H pylori 4 wk post-challenge.

RESULTS: The 1700 base pair ureB gene fragment amplified from the genomic DNA was consistent with the sequence of H pylori ureB by sequence analysis. The amplified 510 base pair fragment was consistent with the sequence of mouse IL-2 in gene bank. It was confirmed by PCR and restriction enzyme digestion that H pylori ureB and mouse IL-2 genes were inserted into the eukaryotic expression vector pIRES. The experiments in vitro showed that stable recombinant live attenuated Salmonella typhimurium DNA vaccine carrying ureB and IL-2 genes was successfully constructed and the specific strips of UreB and IL-2 expressed by recombinant plasmids were detected through Western blot. Study in vivo showed that the positive rate of rapid urease test of the immunized group including ureB and ureB-IL-2 was 37.5% and 12.5% respectively, and was significantly lower than that (100%) in the control group (P < 0.01).

CONCLUSION: Recombinant attenuated Salmonella typhimurium DNA vaccine expressing UreB protein and IL-2 protein with immunogenicity can be constructed. It can protect mice against H pylori infection, which may help the development of a human-use H pylori DNA vaccine.

Third-line rescue therapy for Helicobacter pylori infection

H pylori gastric infection is one of the most prevalent infectious diseases worldwide. The discovery that most upper gastrointestinal diseases are related to H pylori infection and therefore can be treated with antibiotics is an important medical advance. Currently, a first-line triple therapy based on proton pump inhibitor (PPI) or ranitidine bismuth citrate (RBC) plus two antibiotics (clarithromycin and amo-xicillin or nitroimidazole) is recommended by all consensus conferences and guidelines. Even with the correct use of this drug combination, infection can not be eradicated in up to 23% of patients. Therefore, several second line therapies have been recommended. A 7 d quadruple therapy based on PPI, bismuth, tetracycline and metronidazole is the more frequently accepted. However, with second-line therapy, bacterial eradication may fail in up to 40% of cases. When H pylori eradication is strictly indicated the choice of further treatment is controversial. Currently, a standard third-line therapy is lacking and various protocols have been proposed. Even after two consecutive failures, the most recent literature data have demonstrated that H pylori eradication can be achieved in almost all patients, even when antibiotic susceptibility is not tested. Different possibilities of empirical treatment exist and the available third-line strategies are herein reviewed.

Bovine lactoferrin for Helicobacter pylori eradication: an open, randomized, multicentre study

BACKGROUND

Cure rates for eradication of Helicobacter pylori appear to be decreasing, thus more effective therapies must be identified.

AIM

To evaluate the efficacy of bovine lactoferrin in the treatment of H. pylori infection.

METHODS

In a multicentered prospective study, 402 (mean age 52.4, range 19-84 years) H. pylori-positive patients were assigned to one of three regimens: group A - esomeprazole 20 mg b.d., clarithromycin 500 mg b.d. and tinidazole 500 mg b.d. for 7 days; group B - lactoferrin 200 mg b.d. for 7 days followed by the same schedule of group A; group C - esomeprazole 20 mg b.d., clarithromycin 500 mg b.d. and tinidazole 500 mg b.d. plus lactoferrin 200 mg b.d. for 7 days.

RESULTS

Of the 402 patients, 389 completed the study. Six patients were discontinued due to side effects, one patient in group B died and six patients were lost to follow up. The eradication rate (intention-to-treat analysis) was 77% in group A (105/136), 73% in group B (97/132) and 90% in group C (120/134) (chi(2)-test P < 0.01). The incidence of side effects was 9.5% in group A, 9% in group B and 8.2% in group C (chi(2)-test P = 0.1).

CONCLUSION

This study demonstrates that bovine lactoferrin is an effective adjuvant to 7-day triple therapy for eradication of H. pylori infection.

Helicobacter pylori antibiotic resistance in Iran

AIM: To examine the frequency of antibiotic resistance in Iranian Helicobacter pylori (H pylori) strains isolated from two major hospitals in Tehran.

METHODS: Examination of antibiotic resistance was performed on 120 strains by modified disc diffusion test and PCR-RFLP methods. In addition, in order to identify the possible causes of the therapeutic failure in Iran, we also determined the resistance of these strains to the most commonly used antibiotics (metronidazole, amoxicillin, and tetracycline) by modified disc diffusion test.

RESULTS: According to modified disc diffusion test, 1.6% of the studied strains were resistant to amoxicillin, 16.7% to clarithromycin, 57.5% to metronidazole, and there was no resistance to tetracycline. Of the clarithromycin resistant strains, 73.68% had the A2143G mutation in the 23S rRNA gene, 21.05% A2142C, and 5.26% A2142G. None of the sensitive strains were positive for any of the three point mutations. Of the metronidazole resistant strains, deletion in rdxA gene was studied and detected in only 6 (5%) of the antibiogram-based resistant strains. None of the metronidazole sensitive strains possessed rdxAgene deletion.

CONCLUSION: These data show that despite the fact that clarithromycin has not yet been introduced to the Iranian drug market as a generic drug, nearly 20% rate of resistance alerts toward the frequency of macrolide resistance strains, which may be due to the widespread prescription of erythromycin in Iran. rdxA gene inactivation, if present in Iranian H pylori strains, may be due to other genetic defects rather than gene deletion.

Alginate-based in situ gelling suspensions and emulsions comprising N4-alkyloxycarbonyl derivatives of cytosine: zero-order release and effect of physicochemical properties

As an alternative to incorporation of various excipients, N(4)-alkyloxycarbonyl-cytosine derivatives possessing various physicochemical properties and cytosine regeneration rates have been examined to modify release rate and kinetics from in situ gelling alginate formulations, e.g., liquid formulations that gel in acidic gastric juice and release the entrapped derivative or parent cytosine. Linear relationships were obtained between the release rate constants and the square root of the solubility for suspension formulations. Calculated diffusion coefficients were observed to be similar for suspension and solution formulations; however, for in situ gelling emulsion formulations, diffusivity correlated linearly to log P. Zero-order release of parent cytosine was observed from in situ gelling suspensions of the poorly soluble acid-labile N(4)-adamantyloxycarbonyl-cytosine prodrug.

Detection of Helicobacter pylori-specific genes in the oral yeast

BACKGROUND

Until today, human stomach is the only recognized habitat of Helicobacter pylori. However, recruitment of DNA-based methods has made possible the detection of H. pylori in water and oral cavity, thus suggesting fecal-oral and oral-oral routes for transmission of H. pylori, respectively. In this study, yeast has been proposed as a common vector for transmission of H. pylori. Thus designed primers were recruited to target 16S rDNA and cagA genes in the oral yeasts by PCR.

MATERIALS AND METHODS

Eighteen yeasts were examined microscopically for the presence of bacterial-like bodies. DNAs were extracted from oral yeasts using phenol-chloroform method. Amplification conditions were optimized as 33 cycles and annealing temperatures of 63 degrees C for 16S rDNA and 51 degrees C and 52 degrees C for cagA gene which was targeted in two steps. DNAs of H. pylori and Saccharomyces cerevisiae were used as controls. Polymerase chain reaction (PCR) products of two genes from one yeast and from H. pylori were cloned in pCAP and subsequently subcloned in pSK+ and were sequenced.

RESULTS

Bacterial-like bodies were observed in all oral yeasts. The amplified products of 16S rDNA from all oral yeasts were homologous in size with those of H. pylori. Fifteen out of eighteen (83%) yeasts contained cagA gene, homologous to H. pylori. CagA was not amplified from three yeasts and S. cerevisiae. Analysis of the sequenced products of 16S rDNA and cagA from one oral yeast showed 98% homology with those of H. pylori.

CONCLUSIONS

The presence of H. pylori inside the yeast was indicated by light microscopy and PCR. It appears that yeasts, which are abundant in nature and thrive the mucosal surfaces of human, might serve as reservoirs and vehicles of H. pylori.

Molecular biology methods for the characterization of Helicobacter pylori infections and their diagnosis

Helicobacter pylori infects approximately half of the human population; however, the outcome of infection is affected by many factors, including strain and host genotype characteristics and bacterial density within the stomach. Many molecular methods have been developed to provide information with respect to these characteristics. Methods that provide results within 24 h of endoscopy may be used to develop individualized treatment that is more effective, results in fewer side effects, cuts costs,decreases the number of treatment failures and results in the development of fewer antibiotic-resistant H. pylori strains.

Helicobacter pylori infection in hemodialysis patients: Susceptibility to amoxicillin and clarithromycin

AIM: To evaluate susceptibility of Helicobacter pylori to amoxicillin and clarithromycin in end-stage renal disease (ESRD) patients and non-uremic controls.

METHODS: The subjects with dyspeptic complaints were 33 ESRD patients and 46 age- and sex-matched non-uremic controls who exhibited H pylori on antral biopsy specimens. The two groups were age and sex matched. The H pylori strains’ pattern of susceptibility to amoxicillin and clarithromycin was investigated with the agar dilution technique.

RESULTS: None of the H pylori strains from either group showed resistance to amoxicillin with the agar dilution method. Twelve (36.4%) of the ESRD group strains and 7 (15.2%) of the control group strains showed resistance to clarithromycin, and this difference was statistically significant (P<0.05).

CONCLUSION: Resistance to amoxicillin does not appear to be an important problem in H pylori-infected ESRD and non-uremic patients in our region. In contrast, the rates of resistance to clarithromycin are high, particularly in the ESRD population.

Construction of a recombinant attenuated Salmonella typhimurium DNA vaccine carrying Helicobacter pylori hpaA

AIM: To construct a recombinant attenuated Salmonella typhimurium DNA vaccine carrying Helicobacter pylori hpaA gene and to detect its immunogenicity.

METHODS: Genomic DNA of the standard H pylori strain 17 874 was isolated as the template, hpaA gene fragment was amplified by polymerase chain reaction (PCR) and cloned into pUCmT vector. DNA sequence of the amplified hpaA gene was assayed, then cloned into the eukaryotic expression vector pIRES through enzyme digestion and ligation reactions. The recombinant plasmid was used to transform competent Escherichia coli DH5α, and the positive clones were screened by PCR and restriction enzyme digestion. Then, the recombinant pIRES-hpaA was used to transform LB5000 and the recombinant plasmid isolated from LB5000 was finally used to transform SL7207. After that, the recombinant strain was grown in vitro repeatedly. In order to identify the immunogenicity of the vaccine in vitro, the recombinant pIRES-hpaA was transfected to COS-7 cells using LipofectamineTM2000, the immunogenicity of expressed HpaA protein was detected with SDS-PAGE and Western blot.

RESULTS: The 750-base pair hpaA gene fragment was amplified from the genomic DNA and was consistent with the sequence of H pylori hpaA by sequence analysis. It was confirmed by PCR and restriction enzyme digestion that H pylori hpaA gene was inserted into the eukaryotic expression vector pIRES and a stable recombinant live attenuated Salmonella typhimurium DNA vaccine carrying H pylori hpaA gene was successfully constructed and the specific strip of HpaA expressed by pIRES-hpaA was detected through Western blot.

CONCLUSION: The recombinant attenuated Salmonella typhimurium DNA vaccine strain expressing HpaA protein with immunogenicity can be constructed and it may be helpful for further investigating the immune action of DNA vaccine in vivo.

N4-alkyloxycarbonyl derivatives of cytosine: physicochemical characterisation, and cytosine regeneration rates and release from alginic acid gels

Nucleobase containing compounds might constitute a potential alternative to conventional antibiotics in the treatment of Helicobacter pylori infections. N4-alkyloxycarbonyl-cytosine derivatives were synthesized and subjected to basic physicochemical characterisation including assessment of hydrolytic stability in various matrices. pH-rate profiles of selected compounds (range 0-12) were constructed. Hydrolysis of the derivatives in slightly alkaline solution (60 degrees C) resulted in quantitative conversion to parent cytosine whereas at acidic pH (60 degrees C) liberation of cytosine was in most cases accompanied by the parallel formation of uracil. Interestingly the lipophilic N4-adamantyloxycarbonyl-cytosine prodrug exhibited a half-life of 41 min (pH 1.1 at 37 degrees C) with quantitative conversion to parent cytosine, the degradation rate being approximately 200 times faster than that of the non-cyclic aliphatic derivatives investigated. The presence of pig stomach homogenates, pepsin A and H. pylori did not have a noteworthy catalytic effect on the hydrolysis of the derivatives. The release of parent cytosine was markedly delayed from alginic acid gels loaded with the acid-labile and poorly soluble ADC prodrug as compared to gels loaded with parent cytosine.

Open, randomized multicenter comparative trial of rabeprazole, ofloxacin and amoxicillin therapy for Helicobacter pylori eradication: 7 vs. 14 day treatment

BACKGROUND

Because of the increasing resistance to clarithromycin and metronidazole, two of the antibiotics used for the eradication of Helicobacter pylori, new therapeutic alternatives are needed. The aim of this study was to determine the efficacy of a randomized, comparative trial of 7 vs. 14-day triple treatment with rabeprazole, ofloxacin and amoxicillin for H. pylori eradication.

MATERIAL AND METHODS

The present authors studied 76 dyspeptic patients infected with H. pylori diagnosed by both histology and a rapid urease test. Patients were randomized to receive rabeprazole (20 mg b.i.d.), plus ofloxacin (400 mg b.i.d.) and amoxicillin (1000 mg b.i.d.) for 7 days (group 1) vs. 14 days (group 2) and were followed by 6 weeks. Eradication was assessed 4 weeks after completing the course of study treatment by the (14)C-urea breath test. Per protocol and intention-to-treat eradication rates were determined.

RESULTS

For the intention to treat analysis, the eradication rate was 62.2% for group 1 and 92.3% for group 2 (p =.004). For the per protocol analysis, eradication rate for group 1 was 63.9% and for group 2 was 97.3% (p =.001).

CONCLUSIONS

Triple therapy with rabeprazole, amoxicillin and ofloxacin by 14 days was efficient for H. pylori eradication and therefore deserves further study. The same regimen prescribed for 7 days had a significantly lower and unacceptable cure rate and should not be used.

Establishment of mouse models with long-term infection of H. pylori

AIM: To develop a mouse model with long-term infection of H. pylori.

METHODS: Each mouse was inoculated with H. pylori Sydney strain 1 (SS1). Noninfected control mice and infected mice were killed at 4, 12 and 24 wk after H. pylori infection. A piece of gastric mucosa obtained from the posterior wall of the antrum of each mouse was used for culture of H. pylori, rapid urease testing and histopathological detection. Serum was obtained to measure the IgG antibody level to H. pylori.

RESULTS: After 4 wk of infection, the H. pylori was cultured from 6 of 7 infected Babl/c mice and 5 of 7 the H. pylori-infected C57BL/6 mice. After 12 and 24 wk of infection, all of 7 infected Babl/c and 6 of 7 the H. pylori-infected C57BL/6 mice showed the positive results. At the different wk, the rapid urease test results were consistent with the H. pylori culture test. At 12 wk after inoculation, chronic inflammation was observed in the pyloric mucosa by histopathological examination. At 24 wk after inoculation, lymphoid follicles were especially conspicuous in the submucosa, and they were also found in the deep portion of the mucosa.

CONCLUSION: H. pylori SS1 can colonize easily in the glandular stomach mucosa of mouse, and the histopathological changes are similar to those of humans with H. pylori infection.