Helicobacter pylori treatment: a practical approach

The biophysics of bacterial infections: Adhesion events in the light of force spectroscopy

Bacterial infections are the most eminent public health challenge of the 21st century. The primary step leading to infection is bacterial adhesion to the surface of host cells or medical devices, which is mediated by a multitude of molecular interactions. At the interface of life sciences and physics, last years advances in atomic force microscopy (AFM)-based force spectroscopy techniques have made possible to measure the forces driving bacteria-cell and bacteria-materials interactions on a single molecule/cell basis (single molecule/cell force spectroscopy). Among the bacteria-(bio)materials surface interactions, the life-threatening infections associated to medical devices involving Staphylococcus aureus and Escherichia coli are the most eminent. On the other hand, Pseudomonas aeruginosa binding to the pulmonary and urinary tract or the Helicobacter pylori binding to the gastric mucosa, are classical examples of bacteria-host cell interactions that end in serious infections. As we approach the end of the antibiotic era, acquisition of a deeper knowledge of the fundamental forces involved in bacteria - host cells/(bio)materials surface adhesion is crucial for the identification of new ligand-binding events and its assessment as novel targets for alternative anti-infective therapies. This article aims to highlight the potential of AFM-based force spectroscopy for new targeted therapies development against bacterial infections in which adhesion plays a pivotal role and does not aim to be an extensive overview on the AFM technical capabilities and theory of single molecule force spectroscopy.

Co-delivery of hesperidin and clarithromycin in a nanostructured lipid carrier for the eradication of Helicobacter pylori in vitro

Effective and precise eradication of Helicobacter pylori (H. pylori) is the most promising approach to avoid H. pylori-related gastrointestinal disorders. The present study was conducted to demonstrate the efficacy of the co-delivery of hesperidin (Hesp) and clarithromycin (CLR) in nanostructured lipid carriers (NLCs) against H. pylori. We have produced a new delivery system by combining bioflavonoid Hesp and CLR NLCs to address the failure in single antibiotic therapies. Briefly, a blend of solid lipid, liquid lipid, and surfactant was used. Homogeneous NLCs with all the formulations showed a nano size and surface-negative charge and presented high in vitro stability and slow release of the drug even after 24 h. Bioimaging studies by scanning electron microscopy, transmission electron microscopy, and imaging flow cytometry indicated that NLCs interacted with the membrane by adhering to the outer cell membrane and disrupted the membrane that resulted in the leakage of cytoplasmic contents. The prepared NLCs provide sustained and controlled drug release that can be used to increase the rate of H. pylori eradication.

Sequential Helicobacter pylori eradication therapy in Myanmar; a randomized clinical trial of efficacy and tolerability

BACKGROUND AND AIM

There is little published research to examine the best approach to the management of Helicobacter pylori in Myanmar. This study aimed to determine the relative efficacy and tolerability of sequential eradication therapy compared to Myanmar's current recommendation of a concomitant four drug regimen.

METHODS

Patients were screened for H. pylori using monoclonal Stool Antigen Testing (SAT). Those testing positive were randomized 1:1 to receive receive Myanmar's first-line regimen of 14 days of concomitant rabeprazole, clarithromycin, amoxycillin and tinidazole (140 pills, cost US$23) or 10 days of sequential rabeprazole, clarithromycin, amoxycillin and tinidazole (60 pills, cost US$10). Adherence and adverse effects were recorded, and the efficacy of the regimens assessed with repeat SAT.

RESULTS

Of the 1011 patients screened for H. pylori infection, 313 (31%) tested positive. There was no statistical difference in the cure rates of the two regimens in either intention-to-treat: 128/157 (82%; 95% confidence interval (CI): 75-87%) receiving sequential therapy versus 123/156 (79%; 95% CI: 72-85%) receiving concomitant therapy (P = 0.55) or per-protocol analysis: 125/131 (95%; 95% CI: 90-98) receiving sequential therapy versus 121/130 (93%; 95% CI: 87-96) receiving concomitant therapy (P = 0.42). Side effects of therapy were reported in 54/157 (47%) patients taking sequential therapy compared with 62/156 (53%) taking concomitant therapy, but this difference did not reach statistical significance (P = 0.33).

CONCLUSIONS

In this high-burden, resource-poor setting, less expensive sequential therapy was as effective and as well tolerated as the currently recommended concomitant four drug regimen for eradication of H. pylori.

Surface Grafted MSI-78A Antimicrobial Peptide has High Potential for Gastric Infection Management

As we approach the end of the antibiotic era, newer therapeutic options, such as antimicrobial peptides (AMPs), are in urgent demand. AMP surface grafting onto biomaterials has been described as a good strategy to overcome problems associated with their in vivo stability. Helicobacter pylori is among the bacteria that pose greatest threat to human health, being MSI-78A one of the few bactericidal AMPs against this bacterium. Here, we report that MSI-78A grafted onto model surfaces (Self-Assembled Monolayers –SAMs), in a concentration of 30.3 ± 1.2 ng/cm² determined by quartz crystal microbalance with dissipation (QCM-D), was able to kill, by contact, 98% of planktonic H. pylori in only 2 h. This fact was not verified against the control bacteria (Staphylococcus epidermidis), although the minimal inhibitory concentration (MIC) of MSI-78A in solution is much lower for S. epidermidis (2 μg/mL) than for H. pylori (64 μg/mL). Our results also demonstrated that, in opposite to other bacteria, H. pylori cells were attracted to ethylene glycol terminated (antiadhesive) surfaces, which can explain the high bactericidal potential of grafted MSI-78A. This proof of concept study establishes the foundations for development of MSI-78A grafted nanoparticles for gastric infection management within a targeted nanomedicine concept.

Peptic Ulcer Disease: A Brief Review of Conventional Therapy and Herbal Treatment Options

Peptic ulcer is a chronic disease affecting up to 10% of the world's population. The formation of peptic ulcers depends on the presence of gastric juice pH and the decrease in mucosal defenses. Non-steroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori (H. pylori) infection are the two major factors disrupting the mucosal resistance to injury. Conventional treatments of peptic ulcers, such as proton pump inhibitors (PPIs) and histamine-2 (H2) receptor antagonists, have demonstrated adverse effects, relapses, and various drug interactions. On the other hand, medicinal plants and their chemical compounds are useful in the prevention and treatment of numerous diseases. Hence, this review presents common medicinal plants that may be used for the treatment or prevention of peptic ulcers.

Natural Products for the Prevention and Management of Helicobacter pylori Infection

Helicobacter pylori is the main pathogen that induces chronic gastritis, peptic ulcers, atrophic gastritis, and other gastric disorders, and it is classified as a group I carcinogen. To eradicate H. pylori infection, triple therapy consisting of two antibiotics and a proton pump inhibitor is the most widely recommended first-line therapeutic strategy. Antimicrobial resistance to antibiotics contained in triple therapy could lead to therapeutic regimen failures. Recent studies showed that many natural products, including fruits, vegetables, spices, and medicinal plants, possess inhibitory effects on H. pylori, indicating their potential to be alternatives to prevent and manage H. pylori infection. This review summarizes the effects of natural products on H. pylori infection and highlights the mechanisms of action.

Comparison of gastric juice soluble triggering receptor expressed on myeloid cells and C-reactive protein for detection of Helicobacter pylori infection

Background and aim

Triggering receptor expressed on myeloid cells (TREM-1) is a receptor on phagocytes that is triggered by infectious agents. The soluble form of it (sTREM-1) can be elevated in gastric juice by Helicobacter pylori (H. pylori) infection of gastric mucosa. The aim of this study was to compare the diagnostic values of sTREM-1 and C-reactive protein (CRP) for detection of H. pylori infection in gastric mucosa.

Methods

In this diagnostic accuracy study on cases who underwent endoscopy from March 2015 to July 2016 in Shahid Beheshti Hospital, Kashan, Iran, gastric juice sTREM-1 and CRP concentrations were measured by enzyme-linked immunosorbent assays (ELISA) and their diagnostic values were compared to detect H. pylori infection. Gold standard test was histopathology. Data were entered into SPSS software version 16. Statistical analysis was made by Kolmogorov-Smirnov, Chi-square, Independent-samples t-test, Kruskal-Wallis, Mann-Whitney U, Pearson product-moment correlation, Receiver operating characteristic curve (ROC), Brier score, Nagelkerke R square and scaled reliability test.

Results

Of a total of 160 cases, 81 (50.6%) were H. pylori-positive based on pathology. The level of sTREM-1 in H. pylori-positive patients was significantly higher than H. pylori-negative patients (p=0.000), but no significant difference between CRP concentrations was shown between groups (p=0.7). Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and accuracy of sTREM-1 were 82%, 75%, 3.3, 0.25, 78% and for CRP were 62%, 40%, 1.02, 0.98, 51% respectively for diagnosis of H. pylori infection. True positive and negative rates were 66 (81.5%) and 59 (74.7%) for sTREM-1 and 50 (61.7%) and 31 (39.2%) for CRP. The levels of sTREM-1 and CRP were not significantly different between endoscopic finding groups (p=0.97, p=0.2 respectively).

Conclusion

Despite CRP, sTREM-1 was a relatively acceptable indicator of H. pylori infection of gastric mucosa.

High efficacy of gemifloxacin-containing therapy in Helicobacter Pylori eradication: A pilot empirical second-line rescue therapy

BACKGROUND

Helicobacter pylori (H pylori) is a common gastric pathogen which is associated with chronic gastritis, peptic ulcer, and gastric cancer. It has worldwide distribution with higher incidence in developing countries. Gemifloxacin is a fluoroquinolone antibiotic with documented in vitro activity against H pylori. Considering that there is no clinical data to verify gemifloxacin efficacy in H pylori eradication, this pilot clinical trial was designed.

METHODS

This prospective pilot study was performed during February 2014 to February 2015. A regimen of gemifloxacin (320 mg single dose) plus twice daily doses of amoxicillin1g, bismuth 240 mg, and omeprazole 20 mg for 14 days were prescribed for H pylori infected patients in whom a first-line standard quadruple therapy (clarithromycin-amoxicillin-bismuth-omeprazole) had failed. To confirm H pylori eradication a 13C-urea breath test was performed 4 weeks after treatment.Compliance and incidence of adverse effects were evaluated by questionnaires.

RESULTS

A total of 120 patients were enrolled consecutively; out of which 106 patients achieved H pylori eradication; per-protocol and intention-to-treat eradication rates were 91.4% (95% CI: 85.5-97.6) and 88.3% (95% CI: 75.4-92.4) respectively. Three patients (2.5%) failed to take at least 80% of the drugs and excluded from the final analysis. Adverse effects were reported in 42% of patients, most commonly including nausea (15%) and diarrhea (13.3%), which was intense in 1 patient and led to the discontinuation of treatment. In total, 96.7% (116/120) of the patients took the medications correctly.

CONCLUSION

This study revealed that gemifloxacin-containing quadruple therapy provides high H pylori eradication rate (≥90% PP cure rate), and this agent can be included in the list of second-line H pylori therapeutic regimens.

Efficacy of microencapsulated lactic acid bacteria in Helicobater pylori eradication therapy

BACKGROUND

Probiotic delivery systems are widely used nutraceutical products for the supplementation of natural intestinal flora. These delivery systems vary greatly in the effectiveness to exert health benefits for a patient. This study focuses on providing probiotic living cells with a physical barrier against adverse environmental conditions.

MATERIALS AND METHODS

Microencapsulation of the selected lactic acid bacteria (LAB) using chitosan and alginate was performed. Physical examination of the formulated LAB microcapsules was observed using phase contrast inverted microscope and scanning electron microscope (SEM). Finally, the survival of microencapsulated and noncapsulated bacteria was cheeked in the simulated human gastric tract (GT). The potential antimicrobial activity of the most potent microencapsulated LAB strain was in vivo evaluated in rabbit models.

RESULTS

Microencapsulated L. plantarum, L. acidophilus, and L. bulgaricus DSMZ 20080 were loaded with 1.03 × 10(10) CFU viable bacteria/g, 1.9 × 10(10) CFU viable bacteria/g, and 5.5 × 10(9) CFU viable bacteria/g, respectively. The survival of microencapsulated cells was significantly higher than that of the free cells after exposure to simulated gastric juice (SGJ) at pH 2. Additionally, in simulated small intestine juice (SSJ), larger amounts of the selected LAB cells were found, whereas in simulated colon juice (SCJ), the released LAB reached the maximum counts. In vivo results pointed out that an 8-week supplementation with a triple therapy of a microencapsulated L. plantarum, L. acidophilus, and L. bulgaricus DSMZ 20080 might be able to reduce H. pylori.

CONCLUSION

Microencapsulated probiotics could possibly compete with and downregulate H. pylori infection in humans.

Effect of Native Gastric Mucus on in vivo Hybridization Therapies Directed at Helicobacter pylori

Helicobacter pylori infects more than 50% of the worldwide population. It is mostly found deep in the gastric mucus lining of the stomach, being a major cause of peptic ulcers and gastric adenocarcinoma. To face the increasing resistance of H. pylori to antibiotics, antimicrobial nucleic acid mimics are a promising alternative. In particular, locked nucleic acids (LNA)/2'-OMethyl RNA (2'OMe) have shown to specifically target H. pylori, as evidenced by in situ hybridization. The success of in vivo hybridization depends on the ability of these nucleic acids to penetrate the major physical barriers-the highly viscoelastic gastric mucus and the bacterial cell envelope. We found that LNA/2'OMe is capable of diffusing rapidly through native, undiluted, gastric mucus isolated from porcine stomachs, without degradation. Moreover, although LNA/2'OMe hybridization was still successful without permeabilization and fixation of the bacteria, which is normally part of in vitro studies, the ability of LNA/2'OMe to efficiently hybridize with H. pylori was hampered by the presence of mucus. Future research should focus on developing nanocarriers that shield LNA/2'OMe from components in the gastric mucus, while remaining capable of diffusing through the mucus and delivering these nucleic acid mimics directly into the bacteria.

Atomic force microscopy measurements reveal multiple bonds between Helicobacter pylori blood group antigen binding adhesin and Lewis b ligand

The strength of binding between the Helicobacter pylori blood group antigen-binding adhesin (BabA) and its cognate glycan receptor, the Lewis b blood group antigen (Le(b)), was measured by means of atomic force microscopy. High-resolution measurements of rupture forces between single receptor-ligand pairs were performed between the purified BabA and immobilized Le(b) structures on self-assembled monolayers. Dynamic force spectroscopy revealed two similar but statistically different bond populations. These findings suggest that the BabA may form different adhesive attachments to the gastric mucosa in ways that enhance the efficiency and stability of bacterial adhesion.

Structural Basis for the Inhibition of Helicobacter pylori α-Carbonic Anhydrase by Sulfonamides

Periplasmic α-carbonic anhydrase of Helicobacter pylori (HpαCA), an oncogenic bacterium in the human stomach, is essential for its acclimation to low pH. It catalyses the conversion of carbon dioxide to bicarbonate using Zn(II) as the cofactor. In H. pylori, Neisseria spp., Brucella suis and Streptococcus pneumoniae this enzyme is the target for sulfonamide antibacterial agents. We present structural analysis correlated with inhibition data, on the complexes of HpαCA with two pharmacological inhibitors of human carbonic anhydrases, acetazolamide and methazolamide. This analysis reveals that two sulfonamide oxygen atoms of the inhibitors are positioned proximal to the putative location of the oxygens of the CO₂ substrate in the Michaelis complex, whilst the zinc-coordinating sulfonamide nitrogen occupies the position of the catalytic water molecule. The structures are consistent with acetazolamide acting as site-directed, nanomolar inhibitors of the enzyme by mimicking its reaction transition state. Additionally, inhibitor binding provides insights into the channel for substrate entry and product exit. This analysis has implications for the structure-based design of inhibitors of bacterial carbonic anhydrases.

Helicobacter pylori infection: A brief overview on alternative natural treatments to conventional therapy

Helicobacter pylori is a human gastric pathogen considered as the etiologic agent of several gastric disorders, that may range from chronic gastritis to more severe outcomes, including gastric cancer. The current therapeutic scheme relies on the combination of several pharmacological substances, namely antibiotics and proton pump inhibitors. However, the cure rates obtained have been declining over the years, mostly due to bacterial resistance to antibiotics. In this context, the use of non-antibiotic substances is of the utmost importance regarding H. pylori eradication. In this review, we present different classes of compounds obtained from natural sources that have shown to present anti-H. pylori potential; we briefly highlight their possible use in the context of developing new therapeutic approaches.

Ten-day Quadruple therapy comprising proton-pump inhibitor, bismuth, tetracycline, and levofloxacin achieves a high eradication rate for Helicobacter pylori infection after failure of sequential therapy

BACKGROUND

Sequential therapy has been recommended in the Maastricht IV/Florence Consensus Report as the first-line treatment for Helicobacter pylori eradication in regions with high clarithromycin resistance. However, it fails in 5-24% of infected subjects, and the recommended levofloxacin-containing triple rescue therapy only achieves a 77% eradication rate after failure of sequential therapy.

AIM

To investigate the efficacy of a novel quadruple therapy comprising proton-pump inhibitor, bismuth, tetracycline, and levofloxacin for rescue treatment of sequential therapy.

METHODS

This was a multicenter study in which H. pylori-infected patients who had failed sequential therapy received a 10-day quadruple therapy (esomeprazole (40 mg b.d), tripotassium dicitrato bismuthate (120 mg q.d.s.), tetracycline (500 mg q.d.s.), and levofloxacin (500 mg o.d.) for 10 days). H. pylori status was examined 6 weeks after the end of treatment.

RESULTS

From July 2007 to June 2012, twenty-four subjects received 10-day quadruple therapy. The eradication rates according to intention-to-treat and per-protocol analyses were both 95.8% (23 of 24; 95% confidence interval, 87.8-103.8%). Adverse events were seen in 25.0% (6 of 24) of the patients. Drug compliance was 100.0% (24/24).

CONCLUSIONS

The 10-day quadruple therapy comprising proton-pump inhibitor, bismuth, tetracycline, and levofloxacin achieves a very high eradication rate for H. pylori infection after failure of sequential therapy. It is well tolerated and has great potential to become a good choice of rescue treatment following non-bismuth-containing quadruple therapy in regions with high clarithromycin resistance.

Bacterial-binding chitosan microspheres for gastric infection treatment and prevention

Helicobacter pylori (H. pylori) colonizes the gastric mucosa of over 50% of the world population, causing several pathologies, such as gastric ulcers and gastric cancer. Since current antibiotic treatments are inefficient in 20% of cases alternative therapies are needed. This work reports the ability of chitosan microspheres to adhere to H. pylori and prevent/remove H. pylori colonization. Adhesion of H. pylori strains with different functional adhesins (BabA and/or SabA) to chitosan microspheres (diameter 167 ± 27 μm) occurs at both pH 2.6 and 6.0, but is higher at pH 6.0. Bacterial adhesion to a gastric cell line expressing sialylated carbohydrates (SabA receptors) was performed at the same pH values using H. pylori strains with and without SabA. At both pH values addition of microspheres to gastric cells before and after pre-incubation with H. pylori decreased bacterial adhesion to cells. Furthermore, the chitosan microspheres were non-cytotoxic. These findings reveal the potential of chitosan microspheres as an alternative or complementary treatment for H. pylori gastric eradication or prevention of H. pylori colonization.

Bioengineered surfaces promote specific protein-glycan mediated binding of the gastric pathogen Helicobacter pylori

Helicobacter pylori colonizes the gastric mucosa of half of the worlds population and persistent infection is related with an increase in the risk of gastric cancer. Adhesion of H. pylori to the gastric epithelium, which is essential for infection, is mediated by bacterial adhesin proteins that recognize specific glycan structures (Gly-R) expressed in the gastric mucosa. The blood group antigen binding adhesin (BabA) recognizes difucosylated antigens such as Lewis B (Leb), while the sialic acid binding adhesin (SabA) recognizes sialylated glycoproteins and glycolipids, such as sialyl-Lewis x (sLex). This work aimed to investigate whether these Gly-Rs (Leb and sLex) can attract and specifically bind H. pylori after immobilization on synthetic surfaces (self-assembled monolayers (SAMs) of alkanethiols on gold). Functional bacterial adhesion assays for (Gly-R)-SAMs were performed using H. pylori strains with different adhesin protein profiles. The results demonstrate that H. pylori binding to surfaces occurs via interaction between its adhesins and cognate (Gly-R)-SAMs and bound H. pylori maintains its characteristic rod-shaped morphology only during conditions of specific adhesin-glycan binding. These results offer new insights into innovative strategies against H. pylori infection based on the scavenging of bacteria from the stomach using specific H. pylori chelating biomaterials.

Global eradication rates for Helicobacter pylori infection: systematic review and meta-analysis of sequential therapy

OBJECTIVE

To do a systematic review and meta-analysis of studies comparing sequential therapy for eradication of Helicobacter pylori with pre-existing and new therapies, thus providing a glimpse of eradication success worldwide.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, and Cochrane Central Register of Controlled Trials up to May 2013; abstract books of major European, American, and Asian gastroenterological meetings.

STUDY SELECTION

Randomised controlled trials in previously untreated adults, in which sequential therapy was compared with a pre-existing or new therapy.

RESULTS

46 randomised controlled trials were reviewed and analysed. 5666 patients were randomised to sequential therapy and 7866 to other (established and new) treatments. The overall eradication rate of sequential therapy was 84.3% (95% confidence interval 82.1% to 86.4%). Sequential therapy was superior to seven day triple therapy (relative risk 1.21, 95% confidence interval 1.17 to 1.25; I(2)=29.3%; number needed to treat 6, 95% confidence interval 5% to 7%), marginally superior to 10 day triple therapy (1.11, 1.04 to 1.19; I(2)= 67.2%; NNT 10, 7 to 15), but not superior to 14 day triple therapy (1.00, 0.94 to 1.06; I(2)=54.3%), bismuth based therapy (1.01, 0.95 to 1.06; I(2)=21.1%), and non-bismuth based therapy (0.99, 0.94 to 1.05; I(2)=52.3%). Data on eradication according to pre-treatment antimicrobial susceptibility testing were available in eight studies, and sequential therapy was able to eradicate 72.8% (61.6% to 82.8%) of the strains resistant to clarithromycin.

CONCLUSIONS

Eradication rates with pre-existing and new therapies for H pylori are suboptimal. Regional monitoring of resistance rates should help to guide treatment, and new agents for treatment need to be developed.

Effect of gastric environment on Helicobacter pylori adhesion to a mucoadhesive polymer

Helicobacter pylori infection has been associated with several gastric diseases. This bacterium colonizes the gastric mucosa of half of the world's population, and available treatments are unsuccessful in practically one in every five patients. Mucoadhesive polymers, such as chitosan, are being investigated as gastric drug delivery systems. However, since chitosan is also known for its antimicrobial properties, this work aims to evaluate H. pylori interactions with chitosan under simulated gastric environments, namely using various pHs (2.6, 4 and 6), pepsin and urea. To enable the visualization of adherent bacteria, ultrathin chitosan films were produced by spin-coating on gold/glass surfaces, cross-linked with genipin and characterized by Fourier transform infrared reflection absorption spectroscopy, ellipsometry and electrokinetic analysis. Films with homogeneous thickness of 11.7±0.6 nm were produced, and were stable and protonated at all the pHs used. Furthermore, they adsorbed pepsin in all these pHs, in contrast to urea, of which a small adsorption was only observed at pH 6. H. pylori binding to chitosan was higher at pH2.6 although most of adherent bacteria were dead. The presence of pepsin decreased bacterial adhesion, but increased its viability while in a more stressed morphology (coccoid form). The presence of urea did not affect the amount, morphology or viability of chitosan-adherent bacteria. In suspension, the decrease in pH changed H. pylori zeta potential from negative to positive. Moreover, bacteria were only culturable when incubated in pH 6 with and without urea (without pepsin). This work demonstrates that chitosan has the capacity to bind and kill H. pylori in a range of pHs independently of urea. This opens new perspectives for the application of chitosan-based materials to the elimination of H. pylori gastric colonization, though pepsin might appear to be an obstacle.

Docosahexaenoic acid inhibits Helicobacter pylori growth in vitro and mice gastric mucosa colonization

H. pylori drug-resistant strains and non-compliance to therapy are the major causes of H. pylori eradication failure. For some bacterial species it has been demonstrated that fatty acids have a growth inhibitory effect. Our main aim was to assess the ability of docosahexaenoic acid (DHA) to inhibit H. pylori growth both in vitro and in a mouse model. The effectiveness of standard therapy (ST) in combination with DHA on H. pylori eradication and recurrence prevention success was also investigated. The effects of DHA on H. pylori growth were analyzed in an in vitro dose-response study and n in vivo model. We analized the ability of H. pylori to colonize mice gastric mucosa following DHA, ST or a combination of both treatments. Our data demonstrate that DHA decreases H. pylori growth in vitro in a dose-dependent manner. Furthermore, DHA inhibits H. pylori gastric colonization in vivo as well as decreases mouse gastric mucosa inflammation. Addition of DHA to ST was also associated with lower H. pylori infection recurrence in the mouse model. In conclusion, DHA is an inhibitor of H. pylori growth and its ability to colonize mouse stomach. DHA treatment is also associated with a lower recurrence of H. pylori infection in combination with ST. These observations pave the way to consider DHA as an adjunct agent in H. pylori eradication treatment.

Sequential therapy achieves a higher eradication rate than standard triple therapy in Taiwan

BACKGROUND AND AIMS

Most clinical trials concerning sequential therapy have been conducted in Italy. The efficacy of sequential therapy for Helicobacter pylori (H. pylori) eradication in Asia remains unclear. The aim of this study was to compare the efficacy of sequential therapy with standard triple therapy in Taiwan.

METHODS

From January 2005 to December 2009, 233 H. pylori-infected patients receiving either a 10-day sequential therapy (40 mg pantoprazole and 1 g amoxicillin, twice daily, for the initial 5 days, followed by 40 mg pantoprazole, 500 mg clarithromycin, and 500 mg metronidazole, twice daily, for the subsequent 5 days, n = 118) or a 7-day standard triple therapy (40 mg pantoprazole, 500 mg clarithromycin, and 1 g amoxicillin twice daily for 7 days, n = 115) were included in the retrospective study. All the patients underwent a follow-up endoscopy with a rapid urease test and histological examination or a urea breath test at 8 weeks after the end of anti-H. pylori therapy to assess H. pylori status.

RESULT

Intention-to-treat analysis demonstrated a significantly higher eradication rate for the sequential group than for the triple group (93% vs 80%, respectively, P = 0.003). Per-protocol analysis also showed similar results (93% vs 80%, P = 0.005). Both groups had similar frequencies of adverse events (29% vs 22%) and drug compliance (98% vs 97%).

CONCLUSION

Sequential therapy achieves a higher eradication rate than standard triple therapy in Taiwan. The novel treatment can be used as a first-line therapy for H. pylori infection for Taiwanese.

Randomised clinical trial: the efficacy of a 10-day sequential therapy vs. a 14-day standard proton pump inhibitor-based triple therapy for Helicobacter pylori in Korea

BACKGROUND

The eradication rates of Helicobacter pylori (H. pylori) using a proton pump inhibitor (PPI)-based triple therapy have declined due to antibiotic resistance worldwide.

AIM

To compare the eradication rate of the 10-day sequential therapy for H. pylori infection with that of the 14-day standard PPI-based triple therapy.

METHODS

This was a prospective, randomised, controlled study. A total of 409 patients with H. pylori infection were randomly assigned to receive either the 10-day sequential therapy regimen, which consisted of pantoprazole (40 mg) plus amoxicillin (1000 mg) twice a day for 5 days, then pantoprazole (40 mg) with clarithromycin (500 mg) and metronidazole (500 mg) twice a day for another five consecutive days or the 14-day PPI-based triple therapy regimen, which consisted of pantoprazole (40 mg) with amoxicillin (1000 mg) and clarithromycin (500 mg) twice a day for 14 days. The pre- and post-treatment H. pylori status were assessed by rapid urease test, urea breath test, or histology. Successful eradication was confirmed at least 4 weeks after finishing the treatment.

RESULTS

In the intention-to-treat analysis, the eradication rates of the 10-day sequential therapy and of the 14-day PPI-based triple therapy were 85.9% (176/205) and 75.0% (153/205), respectively (P = 0.006). In the per-protocol analysis, the eradication rates were 92.6% (175/205) and 85% (153/204), respectively (P = 0.019). There was no statistically significant difference between the two investigated groups regarding the occurrence of adverse event rates (18.9% vs. 13.3%, P = 0.143).

CONCLUSION

The 10-day sequential therapy achieved significantly higher eradication rates than the 14-day standard PPI-based triple therapy in Korea.

Second-line levofloxacin-based triple therapy's efficiency for Helicobacter pylori eradication in patients with peptic ulcer

OBJECTIVES

First-line standard eradication efficacy with lansoprazole, amoxicillin and clarithromycin regressed over 10 years. The aim of this study was to evaluate the efficacy and tolerability of a levofloxacin-based regimen in patients with peptic ulcer after failure of the standard first-line H.pylori eradication therapy in a country with a high rate of infection.

METHODS

A total of 91 peptic ulcer patients who were diagnosed H.pylori positive proven by rapid urease test and histology between November 2005 to March 2008 were given lansoprazole 30 mg bid, amoxicillin 1 g bid and clarithromycin 500 mg bid (LAC) for 14 days. After three months from the first line eradication treatment omeprazole 20 mg bid, levofloxacin 500 mg bid, amoxicillin 1 g bid (OLA) 7 day treatment regimen was recommended as a second-line therapy for 37 patients who failed at first-line standard triple therapy.

RESULTS

Eradication rates for LAC regimen were found to be 57.14% (52/91) for intention to treat and 58.42% (52/89) for per protocol analysis. Eradication rates for OLA regimen were found to be 37.83% (14/37) for ITT and 41.17% (14/34) for PP analysis.

CONCLUSION

OLA regimen eradication rate was successful only in 40% of patients who failed in the first-line eradication. New eradication treatment strategies must be performed, at least in Turkey.

Clarithromycin-resistant genotypes and eradication of Helicobacter pylori

OBJECTIVE

To compare the eradication rates among the different point mutations and the efficacy of triple therapy and a sequential regimen according to genotypic resistance.

STUDY DESIGN

Post hoc retrospective cohort study in a tertiary referral center for pediatric gastroenterology in southern Italy. All 168 children who were positive for Helicobacter pylori were enrolled. Patients had received clarithromycin-based 7-day triple therapy (73 children) or 10-day sequential therapy regimen (95 children). Real-time polymerase chain reaction for assessing clarithromycin resistance was performed on sections of paraffin-embedded gastric biopsy samples.

RESULTS

H pylori eradication was achieved in 16 of 32 (50%) children with the A2143G mutation, in 8 of 10 patients with either A2142G or A2142C strains (80%), and in 112 of 116 children with susceptible strains (88.9%). The presence of A2143G mutation was associated with a lower cure rate compared with the rate in the absence of this mutation (50% vs. 89%; P = .001). The sequential regimen achieved a higher cure rate than triple therapy in patients with A2143G mutant strains (80% vs nil; P < .001).

CONCLUSIONS

The A2143G mutation confers higher risk of treatment failure. Sequential regimen has higher efficacy than standard therapy, even in children with A2143G mutatant strains.

Comparison of azithromycin and metronidazole in a quadruple-therapy regimen for Helicobacter pylori eradication in dyspepsia

BACKGROUND/AIM

Helicobacter pylori (H pylori) plays an important role in the pathogenesis of chronic gastritis, peptic ulcer disease, and gastric neoplasms . Therefore, it is necessary to select an effective regimen for H pylori eradication . The aim of this study was to compare the efficacy of two quadruple-therapy regimens-one with azithromycin and the other with metronidazole-for H pylori eradication in patients with dyspepsia.

MATERIALS AND METHODS

In this double-blind randomized clinical trial conducted in Rasoule-Akram Hospital in 2006, we included 60 patients (aged 15-70 years) who had dyspepsia and H pylori infection as diagnosed by upper gastrointestinal endoscopy and rapid urease test. Patients were randomly assigned to receive a quadruple-therapy regimen for 2 weeks: 1) the MAO-B group (n = 30) received metronidazole 500 mg b.i.d, amoxicillin 1g b.i.d, omeprazole 20 mg b.i.d, and bismuth 240 mg b.i.d and 2) the AAO-B group (n = 30) received azithromycin 500 mg once daily for 1 week and amoxicillin 1g b.i.d, omeprazole 20 mg b.i.d, and bismuth 240 mg b.i.d for 2 weeks). H pylori eradication was assessed by the rapid urease test (RUT) 2 months after the cessation of treatment .

RESULTS

H pylori was eradicated in 68% and 69% of patients in the MAO-B and AAO-B groups, respectively. There was no significant difference in H pylori eradication rates between the two groups (P = 0.939).

CONCLUSION

No significant difference exists between the two quadruple-therapy regimens that were tested.

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.

Comparative study of Helicobacter pylori eradication rates of twice-versus four-times-daily amoxicillin administered with proton pump inhibitor and clarithromycin: a randomized study

BACKGROUND

Proton pump inhibitor (PPI)-containing triple therapy with clarithromycin and amoxicillin is now a standard regimen for Helicobacter pylori eradication in Korea. Amoxicillin has time-dependent bactericidal activity against H. pylori; we therefore assumed a dosing schedule of amoxicillin would affect the eradication rate of H. pylori. The purpose of this study was to evaluate and compare the efficacy of different amoxicillin dosing schedules for the eradication of H. pylori.

MATERIALS AND METHODS

One hundred and eighty-six patients with H. pylori infection were eligible for this study. Patients were randomly assigned to one of two regimens: amoxicillin 1000 mg with clarithromycin 500 mg and omeprazole 20 mg twice daily for 2 weeks (BID group, n = 93), or amoxicillin 500 mg four times daily with clarithromycin 500 mg and omeprazole 20 mg twice daily for 2 weeks (QID group, n = 93). The success of H. pylori eradication was evaluated 4-5 weeks after completing treatment.

RESULTS

Overall eradication rate was 90.3%, and eradication rates were 91.4% in the BID group and 89.2% in the QID group (p = 0.62). Compliances was 95.7% in the BID group and 93.5% in the QID group (p = 0.516); this was the only factor that significantly affected H. pylori eradication in this study. Side effects in both groups were generally mild.

CONCLUSIONS

Amoxicillin regimens with PPI and clarithromycin are found to be equally effective and safe in both the BID and QID groups for H. pylori eradication. Therefore, considering patient's comfort, we recommend a twice daily amoxicillin regimen.

13C-urea breath test values and Helicobacter pylori eradication

Delta over baseline (DOB) values of 13C-urea breath test (UBT) have been shown to be predictive of H. pylori eradication following therapy. This was a post hoc analysis of a large, double-blind, randomized trial. Consecutive patients with a positive UBT underwent upper endoscopy. H. pylori strains were tested for clarithromycin resistance. All patients received an eradication therapy with either a standard 10-day triple therapy or a 10-day sequential regimen. The infection was considered cured when two consecutive UBTs were negative. Basal DOB values were categorized as low (<16), intermediate (16-35), or high (>35). A total of 282 patients were selected. Eradication rates did not differ between patients with high and low DOB values. No significant difference in DOB values emerged between patients infected with clarithromycin-susceptible and clarithromycin-resistant strains. Under multivariate analysis, DOB values did not influence the bacterial eradication, which was significantly affected only by the presence of clarithromycin resistance. This large analysis failed to demonstrate a role for DOB value in H. pylori eradication with either a 10-day triple or sequential therapy.

Preoperative versus postoperative Helicobacter pylori eradication therapy in gastric cancer patients: a randomized trial

OBJECTIVES

Helicobacter pylori (H. pylori) eradication is strongly recommended for gastric cancer patients who undergo subtotal gastrectomy. The efficacy of proton pump inhibitor-based triple therapy for H. pylori eradication has not been adequately assessed in the gastric remnant. The aim of this study was to compare the efficacy of postoperative versus preoperative H. pylori eradication therapy.

METHODS

A total of 138 distal gastric cancer patients with H. pylori infection were randomized to receive either preoperative (preop, N = 68) or postoperative (postop, N = 70) proton pump inhibitor-based triple therapy for H. pylori eradication. The regimen consisted of rabeprazole 10 mg, clarithromycin 500 mg, and amoxicillin 1,000 mg, all twice daily for 7 days. Eradication was assessed by rapid urease test and histology 12 wk after surgery.

RESULTS

By intention-to-treat (ITT) analysis, H. pylori eradication rates were 84.6% (95% CI 73.5-92.4) in the preop group and 83.1% (95% CI 71.7-91.2) in the postop group (P= 0.99). By per protocol (PP) analysis, the rates were 87.3% (95% CI 76.5-94.4) in the preop group and 86.9% (95% CI 75.8-94.2) in the postop group (P= 0.99). In the postop group, eradication rates did not differ with reconstruction method (Billroth I vs II, 80.4%[95% CI 66.1-90.6]vs 89.5%[95% CI 66.9-98.7] by ITT analysis (P= 0.49), and 85.7%[95% CI 71.5-94.6]vs 89.5% (95% CI 66.9-98.7) by PP analysis, P= 0.99).

CONCLUSIONS

In distal gastric cancer patients, the effect of proton pump inhibitor-based triple therapy for H. pylori eradication was not different whether given postoperatively or preoperatively.

Isolated H. pylori duodenal colonization and idiopathic duodenal ulcers

OBJECTIVE

To evaluate whether some duodenal ulcers (DU) classified as idiopathic according to standard criteria may be causally related to isolated duodenal colonization by H. pylori.

METHODS

We studied consecutive ambulatory patients undergoing upper gastrointestinal endoscopy in a secondary care setting. Gastric and duodenal biopsies for diagnosing H. pylori infection were taken from all patients. Independently from the findings of duodenal biopsies, DU patients without gastric infection were classified as having idiopathic ulcers, and underwent urea C13 breath test and subsequent eradication therapy. Endoscopy was repeated 6 months after eradication treatment.

RESULTS

Among 608 DU patients, 42 (6.9%) were classified as idiopathic: 24 (3.9%) were free from gastric and duodenal infection (group A) and 18 (3.0%) (group B) had isolated duodenal colonization. Urea C13 breath test was positive in one (4.2%) group A patient and in 3 (16.7%) group B patients. After eradication therapy, DU were detected in 14 out of 20 group A patients (70%) (four patients did not perform control endoscopy) and in 2 group B patients (11.1%): OR 18.66, 95% CI 3.23-107.82, P= 0.002. The difference was still detectable after multivariate analysis taking into account possible confounding factors: OR 15.79, 95% CI 2.48-100.53, P= 0.001.

CONCLUSIONS

Isolated duodenal colonization by H. pylori is detectable in a substantial proportion of patients with so-called idiopathic DU, and eradication therapy is effective in these patients.

Modified allele-specific primer-polymerase chain reaction method for analysis of susceptibility of Helicobacter pylori strains to clarithromycin

BACKGROUND AND AIM

Most clarithromycin-resistant strains of Helicobacter pylori have a mutation from adenine (A) to guanine (G) at position 2142 or 2143 of the 23S rRNA gene. Our aim in this study was to develop a polymerase chain reaction (PCR)-based assay that could determine these mutations in a single reaction tube.

METHODS

We designed the forward primer FP2143G and the reverse primer RP2142G, which specifically anneal with the 2143G- and 2142G-mutated sequences, respectively, of the 23S rRNA gene of H. pylori. We also designed the forward primer FP-1 and reverse primer RP-1 upstream and downstream from the positions 2142 and 2143, respectively, to distinguish the wild-type A2142G and A2143G mutations from each other by amplicon sizes. DNA was extracted from 292 gastric tissue samples positive for rapid urease test, and the DNA underwent the PCR reaction. The results were compared with minimum inhibitory concentrations (MIC) for clarithromycin.

RESULTS

Helicobacter pylori strains with A2142G, A2143G and wild type could be distinguished by amplicon sizes by a single PCR reaction. The genotyping results were correlated well with the MIC values for clarithromycin. The median MIC for clarithromycin of the wild-type strains was <0.015 microg/mL. Those of strains with 2142G or 2143G were > or =1.0 microg/mL.

CONCLUSION

Our new PCR-based assay for 23S rRNA mutations of H. pylori is a useful method for detecting clarithromycin-resistant strains of H. pylori easily.

Helicobacter pylori: testing and treatment

Helicobacter pylori is an important pathogen worldwide. Accurate diagnosis and appropriate therapy is important in clinical practice. Invasive tests that accurately identify current infection include the biopsy urease test and histology. The best noninvasive tests for diagnosis include the urea breath test and stool antigen testing. Proton pump inhibitor therapy can lead to false-negative H. pylori test results, and treatment should be stopped for 1-2 weeks prior to testing if possible. In the setting of bleeding peptic ulcer disease, urea breath testing is recommended to rule out a false-negative biopsy test result if needed. The current recommendations for when to test for H. pylori vary around the world. Well-accepted indications include active and past ulcer disease, and gastric-mucosa associated lymphoid tissue lymphoma. There is no universal agreement regarding whether all patients with functional dyspepsia should be tested and treated, although this is an evidence-based recommendation. There is also evidence that H. pylori eradication prevents peptic ulcer disease in those starting NSAIDs long term. Primary treatment remains triple therapy with 10-14 days probably being superior to shorter courses of therapy. Quadruple therapy is recommended if standard triple therapy fails. Salvage therapies with levofloxacin, rifabutin or furazolidone have been identified. Novel approaches to treatment include sequential therapy and use of adjuvants.

Evidence for the role of gastric mucosa at the secretion of soluble triggering receptor expressed on myeloid cells (strem-1) in peptic ulcer disease

AIM: To investigate the role of gastric mucosa at the secretion of sTREM-1 in peptic ulcer.

METHODS: Seventy two patients were enrolled; 35 with duodenal, 21 with gastric ulcer and 16 with chronic gastritis. Patients were endoscoped and gastric juice was aspirated. Patients with duodenal and gastric ulcer underwent a second endoscopy post-treatment. Biopsies were incubated in the absence/presence of endotoxins or gastric juice. Supernatants were collected and sTREM-1 and TNFα were measured by enzyme immunoabsorbent assays. Scoring of gastritis was performed before and after treatment according to updated Sydney score.

RESULTS: Patients with duodenal and gastric ulcer and those with chronic gastritis had similar scores of gastritis. sTREM-1 was higher in supernatants of tissue samples of H pylori-positive than of H pylori-negative patients with gastric ulcer. Median (± SE) sTREM-1 was found increased in supernatants of patients with gastric ulcer before treatment (203.21 ± 88.91 pg/1000 cells) compared to supernatants either from the same patients post-treatment (8.23 ± 5.79 pg/1000 cells) or from patients with chronic gastritis (6.21 ± 0.71 pg/1000 cells) (P < 0.001 and < 0.001, respectively). Similar differences for sTREM-1 were recorded among LPS-stimulated tissue samples of patients (P = 0.001). Similar differences were not found for TNFα. Positive correlations were found between sTREM-1 of supernatants from patients with both duodenal and gastric ulcer before treatment and the degree of infiltration of neutrophils and monocytes.

CONCLUSION: sTREM-1 secreted by the gastric mucosa is an independent mechanism connected to the pathogenesis of peptic ulcer. sTREM-1 was released at the presence of H pylori from the inflamed gastric mucosa in the field of gastric ulcer.

Eradication therapy for Helicobacter pylori

Eradication therapy for Helicobacter pylori is recommended in a number of clinical conditions. In this article, we discuss the epidemiology and cellular mechanisms that result in antimicrobial resistance, the results of current eradication therapies, and new approaches to the management of Helicobacter pylori infection.

Treatment of Helicobacter pylori

Triple therapy, consisting of two antibiotics, clarithomycin and amoxicillin or metronidazole in combination with a proton pump inhibitor (PPI) has become the first-line option for infection with Helicobacter pylori and has been recommended at several consensus conferences. In clinical practice, approximately 20% of patients will fail to obtain H. pylori eradication with the recommended treatment regimens. Major causes of treatment failure are insufficient patient compliance and antibiotic resistance. Because of antibiotic resistance, bismuth-based quadruple therapy has also become a first-line regimen in areas with exceedingly high rates of clarithromycin and metronidazole resistance, and is the preferred second-line option otherwise. Triple therapies based on levofloxacin and/or rifabutin mainly with combination of amoxicillin are options if multiple eradication failure occurs. However, following therapy failure beyond a second treatment attempt requires antibiotic resistance testing. New drugs and adjuvant agents have been reported but their efficacy needs further evaluation.

How to proceed in Helicobacter pylori-positive chronic gastritis refractory to first- and second-line eradication therapy

Helicobacter pylori is a widespread disease causing most of the peptic ulcer diseases and low-grade mucosa-associated lymphoreticular tissue (MALT) lymphoma. Moreover, H. pylori is a proven environmental risk factor for gastric carcinoma and it has been recognized as a type 1 carcinogen factor. A combination of drugs has been proposed, using a proton pump inhibitor (PPI), amoxicillin, clarithromycin, metronidazole and tetracycline to treat the infection. Since 1996, according to the European guidelines, the first-line approach using PPI, amoxicillin and clarithromycin or metronidazole has been suggested. Seven days of quadruple therapy with PPI (or ranitidine), tetracycline, bismuth salts and metronidazole has been reserved as second-line treatment. To improve the eradication rate of the triple therapy, a different combination of the available antibiotics has been proposed, consisting of a 10-day sequential regimen. A second-line levofloxacin-amoxicillin-based triple therapy given for 10 days has been proposed, obtaining a high eradication rate, suggesting this regimen to be a suitable retreatment option in eradication failure. A third-line treatment with rifabutin-based regimen has been proposed.

Upper gastrointestinal bleeding

PURPOSE OF REVIEW

This review provides an update on the management of upper gastrointestinal bleeding with special attention to patient preparation, sedation, hemostatic techniques, and postprocedure care.

RECENT FINDINGS

In a large multicenter clinical trial, nurse-administered propofol sedation had a complication rate of less than 0.2%. The optimal management for an ulcer with adherent clot was confirmed by a meta-analysis to be clot removal and endoscopic treatment of the underlying lesion. A number of prospective studies have demonstrated that capsule endoscopy is the most sensitive imaging modality for identifying lesions in the small bowel and that double-balloon enteroscopy is the least invasive modality available for the management of these lesions.

SUMMARY

This update describes many recent advances in the diagnosis and management of upper gastrointestinal bleeding. However, clearly, much work needs to be done in this field. Since propofol is not available for use in all endoscopy units, is there a better alternative for deep sedation? Rebleeding occurs in 20% of patients after endoscopic therapy, and so can we provide better outcomes with newer technologies (endoscopic suturing devices)? Finally, what is the best management for Helicobacter pylori-negative, nonsteroidal antiinflammatory drug-negative ulcer patients?

Peptic ulcer disease

PURPOSE OF REVIEW

This review attempts to contextualize some of the clinically important publications of the last 2 years as they relate to the broad topic of dyspepsia and peptic ulcer disease, both Helicobacter pylori and nonsteroidal anti-inflammatory drug-related.

RECENT FINDINGS

This review includes findings which provide insight with regard to the triaging of dyspeptic subjects, information on new proton pump inhibitor drugs and H. pylori eradication 'rescue regimens'. The 'COX-2 debacle' is discussed and new data relating to the efficacy of co-therapy strategies for the prevention of nonsteroidal anti-inflammatory drug gastropathy are presented, while the use of antiplatelet agents as 'safe' substitutes for aspirin cardioprophylaxis is questioned. The important issue of proton pump inhibitor safety and nonsteroidal anti-inflammatory drug enteropathy are addressed.

SUMMARY

The review provides a summary and interpretation of literature pertaining to the above issues, and should provide a point of departure for clinical decision-making relevant to these issues.