Helicobacter pylori therapy: Present and future

Biomimetic cell membrane-coated poly(lactic-co-glycolic acid) nanoparticles for biomedical applications

Poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) are commonly used for drug delivery because of their favored biocompatibility and suitability for sustained and controlled drug release. To prolong NP circulation time, enable target-specific drug delivery and overcome physiological barriers, NPs camouflaged in cell membranes have been developed and evaluated to improve drug delivery. Here, we discuss recent advances in cell membrane-coated PLGA NPs, their preparation methods, and their application to cancer therapy, management of inflammation, treatment of cardiovascular disease and control of infection. We address the current challenges and highlight future research directions needed for effective use of cell membrane-camouflaged NPs.

Telephone-Based Reeducation of Drug Administration for Helicobacterpylori Eradication: A Multicenter Randomized Controlled Study

Poor adherence to treatment instructions may play an important role in the failure of Helicobacter pylori eradication. The aim of this study was to evaluate the effects of telephone-based reeducation on 14-day quadruple H. pylori eradication therapy. In total, 162 patients were randomly assigned (1 : 1) to either the intervention group (patients received telephone-based reeducation on the 4^th, 7^th, and 10^th days of the course) or the control group (patients received instructions only at the time of getting the prescriptions). All patients received a 14-day quadruple H. pylori eradication therapy. The primary outcome was the H. pylori eradication rate. The secondary outcomes included the symptom relief rates and the incidence rates of adverse events. Seventy-five patients in the reeducation group and 74 patients in the control group completed the follow-up. The H. pylori eradication rate in the reeducation group was statistically higher than that in the control group (intention-to-treat: 72.8% vs. 50.6%, P = 0.006; per-protocol: 78.7% vs. 55.4%, P = 0.003). However, the symptom relief rates and the adverse event rates in these two groups were not significantly different. Overall, the results from this study suggest that telephone-based reeducation can be potentially applied to improve the H. pylori eradication rate in clinical practice, without significantly increasing the adverse effects.

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

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

The C-terminal domain of HpDprA is a DNA-binding winged helix domain that does not bind double-stranded DNA

DNA-processing protein A, a ubiquitous multidomain DNA-binding protein, plays a crucial role during natural transformation in bacteria. Here, we carried out the structural analysis of DprA from the human pathogen Helicobacter pylori by combining data issued from the 1.8-Å resolution X-ray structure of the Pfam02481 domain dimer (RF), the NMR structure of the carboxy terminal domain (CTD), and the low-resolution structure of the full-length DprA dimer obtained in solution by SAXS. In particular, we sought a molecular function for the CTD, a domain that we show here is essential for transformation in H. pylori. Albeit its structural homology to winged helix DNA-binding motifs, we confirmed that the isolated CTD does not interact with ssDNA nor with dsDNA. The key R52 and K137 residues of RF are crucial for these two interactions. Search for sequences harboring homology to either HpDprA or Rhodopseudomonas palustris DprA CTDs led to the identification of conserved patches in the two CTD. Our structural study revealed the similarity of the structures adopted by these residues in RpDprA CTD and HpDprA CTD. This argues for a conserved, but yet to be defined, CTD function, distinct from DNA binding.

Integration of virtual screening and susceptibility test to discover active-site subpocket-specific biogenic inhibitors of Helicobacter pylori shikimate dehydrogenase

Shikimate dehydrogenase (HpSDH) (EC 1.1.1.25) is a key enzyme in the shikimate pathway of Helicobacter pylori (H. pylori), which catalyzes the NADPH-dependent reversible reduction of 3-dehydroshikimate to shikimate. Targeting HpSDH has been recognized as an attractive therapeutic strategy against H. pylori infection. Here, the catalytic active site in the crystal structure of HpSDH in complex with its substrate NADPH and product shikimate was examined in detail; the site can be divided into three spatially separated subpockets that separately correspond to the binding regions of shikimate, NADPH dihydronicotinamide moiety, and NADPH adenine moiety. Subsequently, a cascading protocol that integrated virtual screening and antibacterial test was performed against a biogenic compound library to identify biologically active, subpocket-specific inhibitors. Consequently, five, eight, and six promising compounds for, respectively, subpockets 1, 2, and 3 were selected from the top-100 docking-ranked hits, from which 11 compounds were determined to have high or moderate antibacterial potencies against two reference H. pylori strains, with MIC range between 8 and 93 μg/mL. It is found that the HpSDH active site prefers to accommodate amphipathic and polar inhibitors that consist of an aromatic core as well as a number of oxygen-rich polar/charged substituents such as hydroxyl, carbonyl, and carboxyl groups. Subpockets 1- and 2-specific inhibitors exhibit a generally higher activity than subpocket 3-specific inhibitors. Molecular dynamics simulations revealed an intense nonbonded network of hydrogen bonds, π-π stacking, and van der Waals contacts at the tightly packed complex interfaces of active-site subpockets with their cognate inhibitors, conferring strong stability and specificity to these complex systems. Binding energetic analysis demonstrated that the identified potent inhibitors can target their cognate subpockets with an effective selectivity over noncognate ones.

Rifabutin Triple Therapy is Effective in Patients With Multidrug-resistant Strains of Helicobacter pylori

INTRODUCTION

Eradicating Helicobacter pylori continues to be a challenge, and no treatment regimen is uniformly successful in all treated patients. Triple therapy with rifabutin and amoxicillin is a successful rescue therapy after consecutive treatment failures. We designed this study to test the efficacy of 12-day rifabutin-based triple therapy in patients infected with multidrug-resistant strains.

METHODS

Consecutive patients with dyspeptic symptoms after at least 1 antibiotic therapy course for H. pylori infection harboring triple-resistant (clarithromycin, metronidazole, levofloxacin) strains were enrolled. They received triple therapy with esomeprazole 40 mg bid, amoxicillin 1 g bid, and rifabutin 150 mg od for 12 days. Patients who failed rifabutin therapy were treated empirically on the basis of the judgment of the treating physician.

RESULTS

A total of 254 out of 756 tested patients were found to be infected with a triple-resistant H. pylori strains after at least 1 antibiotic therapy course. Overall, the infection was eradicated in 213 patients, corresponding to a cure rate of 82.9% (95% CI, 78.3-87.5) by intention-to-treat analysis and 88.7% (95% CI, 84.7-92.7) at per-protocol analysis. In multivariate analysis, no factor was identified as an independent predictor of bacterial eradication.

CONCLUSIONS

There is no current standard for the growing population of patients with multidrug-resistant strains of H. pylori. The 12-day low-dose rifabutin/high-dose proton pump inhibitor regimen is a safe and reliable option for patients infected with triple-resistant strains.

High primary antibiotic resistance of Helicobacter Pylori strains isolated from dyspeptic patients: A prevalence cross-sectional study in Spain

BACKGROUND

The rate of H. pylori resistance to different antibiotics is increasing and determines the selection of eradication therapy. The aim of this study was to determine the resistance patterns of H. pylori strains in our area.

METHODS

Biopsies from gastric corpus for microbiological culture and antibiotic resistance were obtained in patients undergoing upper gastrointestinal endoscopy for dyspepsia. Selective Agar Pylori for isolation of the bacteria and Agar Mueller-Hinton supplemented with blood to test the sensitivity to antibiotics were used. Presence of H. pylori was confirmed using direct observation with phase-contrast microscopy and/or smears stained with acridine orange. In vitro bacterial susceptibility to amoxicillin, clarithromycin, rifampicin, tetracycline, metronidazole, and levofloxacin was tested using diffusion MIC test strips. Minimum inhibitory concentration values were determined based on the 6th version of the EUCAST (European Committee on Antimicrobial Susceptibility Testing) Clinical Breakpoint (2016).

RESULTS

Two hundred and seventeen patients were included (58.1% female, median age 64 years, range 25-92). H. pylori was identified in 108 patients (49.8%); culture and antibiogram were completed in 77 of them (71.3% of H. pylori-positive patients). The resistance rates were as follows: levofloxacin 38.7%, rifampicin 33.3%, metronidazole 27% and clarithromycin 22.4%. No case of amoxicillin or tetracycline resistance was identified. Dual clarithromycin-metronidazole resistance was observed in 10% of strains, whereas multiple drug-resistant was observed in 14.2%.

CONCLUSIONS

Resistance rate of H. pylori to antibiotics is high in the northwest of Spain. The high resistance to levofloxacin and clarithromycin advises against their wide empirical use of these antibiotics in eradication regimens.

First-line therapies for Helicobacter pylori eradication: a critical reappraisal of updated guidelines

Helicobacter pylori (H. pylori) treatment remains a challenge for the clinician, as no available therapy is able to cure the infection in all treated patients. In the last two decades, several antibiotic combinations have been proposed, including triple therapies, bismuth-free therapies (sequential, concomitant, hybrid regimens), and bismuth-based quadruple therapy. Some national and international guidelines on H. pylori management have recently been updated, recommending or discouraging the use of each of these therapeutic approaches, based mainly on the presumed pattern of primary antibiotic resistance in different geographic areas. We examined the recommendations on first-line therapies in the most recently updated guidelines worldwide, taking into account other data affecting the efficacy of a therapy regimen beyond the primary resistance pattern. Although several guidelines highlighted that the results achieved by an eradication therapy are population-specific and not directly transferable, it emerged that some therapy regimens are recommended or discouraged with no mention of the vital need for national data.

Helicobacter pylori treatment: New perspectives using current experience

Infection with Helicobacter pylori plays an essential role in the development of duodenal and gastric ulcers as well as in the pathobiology of gastric adenocarcinoma. Thus, successful elimination of the bacterium can reduce the risk of development of these diseases. Currently, most guidelines recommend standard triple therapy (amoxicillin+clarithromycin+proton pump inhibitor), although its efficacy is rapidly falling. Notably, traditional first-line therapy fails in almost 32% of H. pylori-carrying cases, suggesting the importance of choosing the best formulation for first-line therapy. Hence, due to the decreasing effectiveness of first-line treatment, we should be prepared to confront increasing H. pylori therapeutic defeat. Owing to increasing reports of antibiotic resistance worldwide, newer approaches and directions are necessary for managing this problematic infection. Developing and providing better anti-H. pylori strategies (probiotics, antibiotic therapy and non-traditional medicine) without using current clinical experience in treating the infection is impossible. Furthermore, development and examination of new preventive vaccines may also be a new therapeutic direction. Taken together, with regard to current experience, clinicians are highly recommended to consider all alternatives to eradicate H. pylori until a universal vaccine becomes practically available. This article aims to give an overview regarding the current status of H. pylori treatment, accordingly designing an actual overview to gain optimal strategies against this infection.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

[Molecular genetic predictors of resistance to anti-Helicobacter pylori therapy]

In current clinical practice, there is no optimal empirical therapy for Helicobacter pylori (H. pylori) infection and there is a progressive decrease in the efficiency of classical eradication therapy (ET) regimens. The variability in the efficiency of ET in a specific patient is largely due to the heterogeneous molecular genetic mechanisms underlying the resistance of the microorganism to the components of the treatment regimens. The basis of the mechanisms for antibiotic resistance in H. pylori is mainly the point mutations in some genes, which determine alterations in the mechanisms of action of drugs, such as clarithromycin (domain V of 23S rRNA), metronidazole (rdxA, frxA), amoxicillin (pbp1A), tetracycline (16S rRNA), and levofloxacin (gyrA). The predictors of resistance to ET are also the CagA-negative status of the microorganism and the presence of the vacA s2 allele. There are a number of host genetic determinants (the CYP2C19 genotype (*1/*1, *1/*17, *17/*17) and the MDR1 3435 T/T genotype (in an Asian population)) that reduce the efficiency of ET, by altering the pharmacokinetics of proton pump inhibitors. In addition, the IL-1β-511 C/C polymorphism that affects gastric acid secretion is a predictor of the inefficiency of ET.

Molecular and Proteomic Analysis of Levofloxacin and Metronidazole Resistant Helicobacter pylori

Antibiotic resistance in bacteria incurs fitness cost, but compensatory mechanisms may ameliorate the cost and sustain the resistance even under antibiotics-free conditions. The aim of this study was to determine compensatory mechanisms of antibiotic resistance in H. pylori. Five strains of levofloxacin-sensitive H. pylori were induced in vitro to develop resistance. In addition, four pairs of metronidazole-sensitive and -resistant H. pylori strains were isolated from patients carrying dual H. pylori populations that consist of both sensitive and resistant phenotypes. Growth rate, virulence and biofilm-forming ability of the sensitive and resistant strains were compared to determine effects of compensatory response. Proteome profiles of paired sensitive and resistant strains were analyzed by liquid chromatography/mass spectrophotometry (LC/MS). Although there were no significant differences in growth rate between sensitive and resistant pairs, bacterial virulence (in terms of abilities to induce apoptosis and form biofilm) differs from pair to pair. These findings demonstrate the complex and strain-specific phenotypic changes in compensation for antibiotics resistance. Compensation for in vitro induced levofloxacin resistance involving mutations of gyrA and gyrB was functionally random. Furthermore, higher protein translation and non-functional protein degradation capabilities in naturally-occuring dual population metronidazole sensitive-resistant strains may be a possible alternative mechanism underlying resistance to metronidazole without mutations in rdxA and frxA. This may explain the lack of mutations in target genes in ~10% of metronidazole resistant strains.

Inhibitory effects of rHP-NAP IgY against Helicobacter pylori attachment to AGS cell line

Helicobacter pylori is a major human pathogen related to gastric adenocarcinoma and gastroduodenal diseases. Treatment of H. pylori infections is complicated by the rise of antibiotic resistance, necessitating investigation of alternative therapies. One such alternative is passive immunization by oral administration of antibacterial immunoglobulin. In the present study, chicken immunoglobulin (IgY) was used for passive immunotherapy against a major virulence factor of H. pylori, namely recombinant HP-Nap protein. Recombinant HP-Nap was prepared and used to immunize hens. IgY was purified from the eggs by polyethylene glycol precipitation method with a total IgY-HP-NAP yield of 30 mg per egg. The inhibitory effect of specific IgY on H. pylori attachment was investigated in AGS cell line infected by the bacteria. The results demonstrate the potent effect of IgY- HP-NAP in inhibition of H. pylori attachment to the AGS cells.

Novel anti-Helicobacter pylori therapies

Helicobacter pylori is a ubiquitous gastropathogen infecting more than half of the world population. It is associated with dyspepsia, gastritis, gastroduodenal ulcers, mucus-associated lymphoid tissue lymphoma and gastric carcinoma. Current recommended therapy does not eradicate infection in all treated cases and at least 20% post-treatment patients continue to suffer. Salvage therapy helps some of these nonresponders, but resistance to available antibiotics is mounting. Hence, its treatment still remains a daunting task for the practicing physician. Novel medications with improved efficacy and tolerability and with less chances of resistance are required. The present review attempts to discuss the newer patents in this field, which demonstrate a promising future role in the management of H. pylori infection and its consequent problems.

Treatment of Helicobacter pylori infection: Current and future insights

Helicobacter pylori (H. pylori) is an important major cause of peptic ulcer disease and gastric malignancies such as mucosa-associated lymphoid tissue lymphoma and gastric adenocarcinoma worldwide. H. pylori treatment still remains a challenge, since many determinants for successful therapy are involved such as individual primary or secondary antibiotics resistance, mucosal drug concentration, patient compliance, side-effect profile and cost. While no new drug has been developed, current therapy still relies on different mixture of known antibiotics and anti-secretory agents. A standard triple therapy consisting of two antibiotics and a proton-pump inhibitor proposed as the first-line regimen. Bismuth-containing quadruple treatment, sequential treatment or a non-bismuth quadruple treatment (concomitant) are also an alternative therapy. Levofloxacin containing triple treatment are recommended as rescue treatment for infection of H. pylori after defeat of first-line therapy. The rapid acquisition of antibiotic resistance reduces the effectiveness of any regimens involving these remedies. Therefore, adding probiotic to the medications, developing anti-H. pylori photodynamic or phytomedicine therapy, and achieving a successful H. pylori vaccine may have the promising to present synergistic or additive consequence against H. pylori, because each of them exert different effects.

Effects of daily telephone-based re-education before taking medicine on Helicobacter pylori eradication: A prospective single-center study from China

AIM: To investigate the effects of daily telephone-based re-education (TRE) before taking medicine for the eradication of Helicobacter pylori (H. pylori) on the compliance and the eradication rate in a Chinese patient population.

METHODS: A prospective, physician-blinded, randomized, controlled clinical study was conducted. The patients were randomly assigned to receive TRE every day before taking medicine (TRE group) or no TRE (control group). The patients in the TRE group received regular instructions before taking medicine for the eradication of H. pylori during the entire course of treatment through telephone calls. The patients in the control group received detailed instructions at the time of seeing a doctor for the guidance. The primary outcome was the H. pylori eradication rate after treatment. The secondary outcomes included the clinical remissions after treatment, adverse events, compliance, and patients’ satisfaction.

RESULTS: A total of 140 patients were randomized, 70 to the TRE group and 70 to the control group. As the primary outcome, the H. pylori eradication rates in the TRE and control groups were 62.7% and 71.2% in per protocol analysis (P = 0.230), and 52.9% and 52.9% in intention-to-treat analysis (P = 0.567), respectively. As the secondary outcomes, there were no significant differences in the patients’ satisfaction between the two groups (good, 79.7% vs 76.9%; fair, 13.6% vs 19.2%; poor, 6.7% vs 3.9%, for the TRE group and control group, respectively; P > 0.05 for all); the rates of adverse effects were 15.2% and 63.5% in the TRE and control groups, respectively (P < 0.001); the compliance rates in the TRE and control groups were 85.7% and 74.3%, respectively (P = 0.069).

CONCLUSION: Daily TRE before taking medicine had no significant impact on the patients’ compliance, satisfaction, or H. pylori eradication, but reduced the rate of adverse events.

Sequential vs. prolonged 14-day triple therapy for Helicobacter pylori eradication: the meta-analysis may be influenced by 'geographical weighting'

BACKGROUND

Sequential therapy is a first-line regimen obtaining satisfactory Helicobacter pylori eradication. Triple therapy prolongation improves the success rate even if a recent meta-analysis showed satisfying results only for the 14-day regimen. Studies from Africa and North America were unavailable in previous meta-analyses.

AIM

To perform a meta-analysis comparing sequential vs. prolonged 14-day triple therapy with regard to 'geographic weighting' by considering subgroups analysis according to metronidazole/clarithromycin low and high resistance areas.

METHODS

Based on PRISMA recommendations, we considered all first-line clinical studies from 2003 to November 2014. Randomised clinical trials (RCTs) were included by a search on PubMed, MEDLINE, Science Direct, EMBASE. Data on eradication rates were expressed as ITT. Risk ratio (RR), pooled RR and 95% confidence intervals were calculated by the Mantel-Haenszel method. Data were entered into RevMan 5.2 software (Nordic Cochrane Centre) using a random-effects model.

RESULTS

Databases identified 194 studies; seven met the inclusion criteria. Overall results showed a similar effectiveness of the two regimens considered (RR = 0.99; 95% CI = 0.94-1.05; p = 0.75). In areas with high resistance to clarithromycin, sequential was superior to 14-day triple therapy (RR = 0.95; 95% CI = 0.90-1.00; p = 0.03). In areas with high metronidazole resistance, sequential and 14-day triple therapy were equivalent (RR = 0.99; 95% CI = 0.91-1.08; p = 0.82).

CONCLUSIONS

'Geographic weighting' could be the main factor affecting the lack of differences between sequential and 14-day triple therapy outcomes.

Structural and biochemical characterization of GTP cyclohydrolase II from Helicobacter pylori reveals its redox dependent catalytic activity

GTP cyclohydrolase II (GCHII), catalyzes the conversion of GTP to 2,5-diamino-6-β-ribosyl-4(3H)-pyrimidinone-5'-phosphate and has been shown to be essential for pathogens. Here we describe the biochemical, kinetic and structural characterization of GCHII from Helicobacter pylori (hGCHII). The crystal structure of hGCHII, unlike other GCHII structures, revealed that cysteines at the active site existed in oxidized state forming two disulfide bonds and lacked Zn(2+) that was shown to be indispensable for catalytic activity in other species. However, incubation of hGCHII with hydrogen peroxide, an oxidizing agent, followed by PAR-assay showed that Zn(2+) was intrinsically present, indicating that all cysteines at the catalytic site remained in reduced state. Moreover, site directed mutagenesis of catalytic site cysteines revealed that only three, out of four cysteines were essential for hGCHII activity. These results, though, indicated that hGCHII crystallized in oxidized form, the expulsion of Zn(2+) upon oxidation of catalytic cysteines revealed its ability to act in response to the redox environment. Exploring further, incubation of hGCHII with reversible thiol modifying agent S-methyl-methane-thiosulfonate resulted in loss of GCHII activity due to oxidation of its cysteine residues as revealed by mass spectrometry studies. However, addition of reducing agent DTT partially restored the hGCHII catalytic activity. Taken together, these results demonstrate that hGCHII can regulate its catalytic activity depending on the redox environment, a function hitherto unknown for GCHII.

Primary antibiotic resistance of Helicobacter pylori strains isolated from patients with dyspeptic symptoms in Beijing: A prospective serial study

AIM: To determine the resistance patterns of Helicobacter pylori (H. pylori) strains isolated from patients in Beijing and monitor the change of antibiotic resistance over time.

METHODS: In this prospective, serial and cross-sectional study, H. pylori cultures were successfully obtained from 371 and 950 patients (never receiving eradication) during 2009-2010 and 2013-2014, respectively. Resistance to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin was determined by Epsilometer test.

RESULTS: The resistance rates of isolates obtained during 2009-2010 were 66.8%, 39.9%, 34.5%, 15.4%, 6.7%, and 4.9% to metronidazole, clarithromycin, levofloxacin, rifampicin, amoxicillin and tetracycline, respectively; and the corresponding rates for isolates during 2013-2014 were 63.4%, 52.6%, 54.8%, 18.2%, 4.4% and 7.3%, respectively. The resistance rates to clarithromycin and levofloxacin were significantly increased after four years. In 2009-2010, 14.6% of H. pylori isolates were susceptible to all tested antibiotics, with mono (33.7%), double (28.3%), triple (16.7%), quadruple (6.2%), quintuple (0.3%) and sextuple resistance (0.3%) also being detected. In 2013-2014, 9.4% were susceptible to all tested antibiotics, and mono (27.6%), double (28.4%), triple (24.9%), quadruple (7.3%), quintuple (2.3%) and sextuple resistance (0.1%) was also observed. More multiple resistant H. pylori isolates were found during 2013-2014. Gender (to levofloxacin and metronidazole), age (to levofloxacin) and endoscopic findings (to clarithromycin) were independent factors influencing antibiotic resistance.

CONCLUSION: H. pylori resistance to commonly used antibiotics in Beijing is high with increased multiple antibiotic resistance.

High-dose esomeprazole and amoxicillin dual therapy for first-line Helicobacter pylori eradication: a proof of concept study

BACKGROUND

The prevalence of resistance to clarithromycin and metronidazole has considerably increased, with a corresponding decrease in the eradication rate for Helicobacter pylori (H. pylori) infection. Primary resistance to amoxicillin is extremely low, and esomeprazole was found to exert a noteworthy antimicrobial activity in vitro against H. pylori. A dual therapy with high-dose of esomeprazole coupled with high-dose amoxicillin might be therefore an ideal first-line treatment for H. pylori eradication. We aimed to assess the efficacy of a first-line 10-day, high-dose dual therapy consisting of amoxicillin and esomeprazole to eradicate H. pylori infection.

METHODS

Consecutive naïve H. pylori-infected patients, who underwent an upper endoscopy in 4 Italian hospitals due to dyspeptic symptoms and found to be infected at routine histological assessment, were invited to participate. Patients enrolled received a 10-day, high-dose dual therapy comprising esomeprazole (40 mg t.i.d) and amoxicillin (1 g t.i.d.). At least 4 weeks after the end of the treatment a (13)C-urea breath test was performed to evaluate the eradication.

RESULTS

A total of 56 patients agreed to participate in the study and were all followed-up. The overall eradication was 87.5% (95% CI=78.8•96.2), without a statistically significant difference among centres. Overall, 5 (8.9%; 1.5•16.4%) patients complained of side-effects.

CONCLUSIONS

The 10-day, high-dose dual therapy with esomeprazole and amoxicillin might be an effective and safe first-line regimen. The efficacy of a longer 14-day regimen should be tested.

Prospective multi-region study on primary antibiotic resistance of Helicobacter pylori strains isolated from Chinese patients

BACKGROUND

Large-scale multi-region studies are urgently needed to provide comprehensive and up-to-date information on the antibiotic resistance of Helicobacter pylori that is critical for selecting the most optimal eradication regimens.

AIMS

To determine the resistance patterns of Helicobacter pylori strains isolated from dyspeptic patients.

METHODS

This is a prospective, multicentre, cross-sectional, observational study. Helicobacter pylori cultures were successful in 600 patients (never receiving eradication therapy) from Northern, Eastern, Middle, and Southern regions between 2008 and 2012. Resistance to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin was determined by Epsilometer test.

RESULTS

The overall resistance rate was highest for metronidazole (403, 67.2%), followed by clarithromycin (225, 37.5%), levofloxacin (201, 33.5%), rifampicin (85, 14.2%), amoxicillin (41, 6.8%), and tetracycline (21, 3.5%). There were 16.3% isolates susceptible to all tested antibiotics, followed by mono-resistance (34.2%), double resistance (27.0%), triple resistance (16.8%), quadruple resistance (4.7%), quintuple resistance (0.7%) and sextuple resistance (0.3%). Independent factors influencing antibiotic resistance were gender (to levofloxacin), age (to levofloxacin), and endoscopic finding (to clarithromycin, metronidazole, and levofloxacin). Among the clarithromycin-resistant isolates, 75.6% and 48.0% were also resistant to metronidazole and levofloxacin, respectively.

CONCLUSIONS

Helicobacter pylori resistance to commonly used antibiotics in China is a very serious issue, due to the high resistance rate and general multiple resistance.

High rate of levofloxacin resistance in a background of clarithromycin- and metronidazole-resistant Helicobacter pylori in Vietnam

Antimicrobial resistance in Helicobacter pylori has increased worldwide and has become a major cause of treatment failure in many countries, including Vietnam. It is advisable to perform an antibiogram to provide optimal regimens for H. pylori eradication. This study evaluated the rate of antibiotic resistance to the four commonly used antibiotics against H. pylori at a tertiary care hospital in Central Vietnam and analysed point mutations in genes related to clarithromycin (CLA) and levofloxacin (LFX) resistance. A total of 92 H. pylori strains from gastric biopsy specimens were tested; 42.4% were resistant to CLA (primary, 34.2%; secondary, 73.7%), 41.3% to LFX (primary, 35.6%; secondary, 63.2%), 76.1% to metronidazole (MTZ) and 1.1% to amoxicillin. Multidrug resistance was observed in 56.5% (primary, 50.7%; secondary, 78.9%) of isolates (P<0.05). The rate of resistance to LFX was significantly higher in females than males (P<0.05). Most of the CLA- and LFX-resistant strains harboured resistance-associated mutations, with common positions at A2143G and T2182C in the 23S rRNA gene and at Asn-87 or Asp-91 in GyrA. Minimum inhibitory concentrations (MICs) increased in strains carrying quadruple mutations in their 23S rRNA gene and in strains with Asn-87 GyrA mutation (P<0.05). One high-level LFX-resistant strain (MIC=32mg/L) had new mutations with a combination of N87A, A88N and V65I. High resistance rates to CLA, MTZ and LFX discourage standard and LFX-based triple therapies as first-line treatment in Vietnam.

Sequential, concomitant and hybrid first-line therapies for Helicobacter pylori eradication: a prospective randomized study

Helicobacter pylori eradication remains a challenge for physicians. Sequential, concomitant and the hybrid regimens have been proposed as novel, more effective therapies. We compare the efficacy of these therapies. Dyspeptic patients referred for upper endoscopy with H. pylori infection were enrolled. Patients were randomized to receive: (a) sequential therapy - 20 mg omeprazole and 1 g amoxicillin for 5 days, followed by 20 mg omeprazole, 500 mg clarithromycin and 500 mg tinidazole for the successive 5 days; (b) concomitant therapy - 20 mg omeprazole, 1 g amoxicillin, 500 mg clarithromycin and 500 mg tinidazole for either 5 days (5 day concomitant) or 14 days (14 day concomitant); or (c) hybrid therapy - 20 mg omeprazole and 1 g amoxicillin for 7 days, followed by 20 mg omeprazole, 1 g amoxicillin, 500 mg clarithromycin and 500 mg tinidazole for the successive 7 days. All drugs were given twice daily. Bacterial eradication was checked by using a [(13)C]urea breath test. In 'intention-to-treat' analysis, sequential therapy achieved the highest eradication rate, which was higher than that of 5 day concomitant therapy (90  vs 78.1 %; P = 0.02). The success rate did not statistically differ among the sequential and either 14 day concomitant (90  vs 86.3 %; P = not significant) or hybrid therapies (90  vs 82.7 %; P = not significant). The 10 day sequential, 14 day concomitant and 14 day hybrid therapies, but not the 5 day concomitant regimen, achieved similarly high eradication rates. The lower therapeutic cost coupled with the lower number of tablets needed would favour the sequential therapy as the first-line H. pylori treatment in clinical practice.

Triple therapy with high-dose proton-pump inhibitor, amoxicillin, and doxycycline is useless for Helicobacter pylori eradication: a proof-of-concept study

INTRODUCTION

Helicobacter pylori resistance to antibiotics is steadily increasing and multidrug-resistant strains are common and difficult to eliminate, mainly in countries where bismuth, tetracycline, furazolidone, and rifabutin are unavailable.

AIM

To evaluate the efficacy and safety of a triple therapy with proton-pump inhibitor (PPI), amoxicillin, and doxycycline in patients with multidrug-resistant H. pylori.

PATIENTS AND METHODS

This prospective study involved 16 patients (13 females; mean age - 50 ± 11.3 years) infected by H. pylori with known resistance to clarithromycin, metronidazole, and levofloxacin, but susceptibility to amoxicillin and tetracycline. All patients were previously submitted to upper endoscopy with gastric biopsies for H. pylori culture and susceptibility testing by Etest. Mutations in 23S rRNA and gyrA genes were determined by real-time PCR. A 10-day eradication regimen with PPI (double-standard dose b.i.d.), amoxicillin (1000 mg b.i.d.), and doxycycline (100 mg b.i.d.) was prescribed after pretreatment with PPI during 3 days. Eradication success was assessed by (13) C-urea breath test 6-10 weeks after treatment. Compliance and adverse events were determined through phone contact immediately after treatment and specific written questionnaires.

RESULTS

Only one patient did not complete treatment due to adverse events. Another four patients experienced mild side effects not affecting compliance. The control (13) C-urea breath test was positive in all patients. Per-protocol and intention-to-treat eradication rates were 0%.

CONCLUSIONS

Although safe, a triple-therapy protocol with high-dose PPI, amoxicillin, and doxycycline is useless for multidrug-resistant H. pylori eradication.

Helicobacter pylori: Future perspectives in therapy reflecting three decades of experience

The rising prevalence of antibiotic resistance has created a need to reassess the established Helicobacter pylori (H. pylori) eradication protocols, and to develop new ones. Various bacterial and host factors are evaluated, and their contribution to eradication failure is estimated. For a long time being considered the cornerstone eradication scheme, the standard triple therapy has been replaced with novel, more efficient regimens, namely sequential and concomitant, along with the emergence of a new design of bismuth quadruple therapy. A rescue levofloxacin based regimen has overcome the fear of therapy failure due to higher prevalence of dual resistant (clarithromycin and metronidazole) H. pylori. Culture-free and efficient susceptibility test are reestablishing the concept of tailored therapy, making eradication success close to originally desirable rates. Alleviating therapy side effects and improving patient compliance are as important as choosing appropriate eradication schemes, so various probiotic compound supplements are taken into consideration. Finally, we summarize the emerging efforts and obstacles in creating efficient H. pylori vaccine.

Choosing optimal first-line Helicobacter pylori therapy: a view from a region with high rates of antibiotic resistance

Helicobacter pylori is a gram-negative, microaerophilic spiral bacillus that is associated with life-threatening diseases such as gastric cancer, gastric MALT lymphoma, and peptic ulcer disease. The definition of an effective therapy is one that achieves at least a 90% eradication rate on a per-protocol basis with the first attempt. Eradication rates of H. pylori have declined to unacceptable levels worldwide, mostly due to antibiotic resistance and standard triple therapy gradually has lost its efficacy in most counties. However, bismuth quadruple therapy, when prescribed properly, has maintained its effectiveness. Alternative first-line regimens such as sequential and concomitant therapy were developed to substitute for standard triple therapy and were highly effective in the countries where they were developed, but proved susceptible to failure in regions with high rates of antibiotic resistance. Antibiotic resistance rates in Russia are high, however there is lack of data regarding comparative efficacy of first-line eradication options. The authors of this review extrapolate the knowledge of H. pylori first-line eradication options in Russia based on data from other countries, as well as from domestic studies. The available data support use of 14-day regimens with concomitant therapy, bismuth quadruple therapy, or furazolidone quadruple therapy for empiric use in adults. In addition, 14-day levofloxacin-containing therapies could be used if resistance is relatively low or lacking as triple therapy or possibly as a 5-day concomitant levofloxacin therapy.

Epidemiology and pattern of antibiotic resistance in Helicobacter pylori: scenario from Saudi Arabia

Helicobacter pylori is recognized as a major cause of gastritis, peptic ulcer, gastric cancer, and mucosa-associated lymphoma. Infection with this gram-negative microaerophile has been treated using combination of antibiotics and proton pump inhibitors for different gastrointestinal diseases. The most commonly used treatment is triple therapy which consists of administration of a proton pump inhibitor, clarithromycin, and amoxicillin. Many factors contribute to treatment failure, but one of the main reasons is development of bacterial antibiotic resistance. The percent prevalence of antibiotic resistance varies among different countries; it appears to be partly determined by the geographic factors and its ability to undergo frequent homologous recombination. The aim of this paper is to review the prevalence of H. pylori infection, association of clinical outcomes with H. pylori genotypes, and current status of antibiotic resistance in H. pylori in Saudi Arabia. It also discusses the different alternative approaches for the treatment of H. pylori using antibiotics. In addition, association of antibiotic resistance with H. pylori virulent genotypes in Saudi population and its underlying resistance mechanism will also be discussed.

First- and second-line Helicobacter pylori eradication with modified sequential therapy and modified levofloxacin-amoxicillin-based triple therapy

BACKGROUND

Helicobacter pylori (H. pylori) treatment remains a challenge for physicians. Although highly effective, the standard sequential therapy fails in a certain number of patients. Moreover, the cure rate following a levofloxacin-amoxicillin second-line triple therapy seems to be decreasing. We tested the efficacy of modified 10-day sequential therapy, and an intensified levofloxacin-amoxicillin regimen as first- and second-line therapy respectively.

METHODS

In this prospective, open label, multicenter, pilot study H. pylori-infected patients received a first-line modified 10-day sequential therapy regimen including rabeprazole 20 mg, and amoxicillin 1 g for the first 3 days, followed by rabeprazole 20 mg, clarithromycin 250 mg, and metronidazole 250 mg, for the remaining 7 days, all drugs given thrice daily. An 8-day therapy regimen with rabeprazole 20 mg, levofloxacin 250 mg, and amoxicillin 1 g, all thrice daily, was administered a second-line therapy.

RESULTS

A total of 99 and 15 patients were enrolled for first- and second-line therapy. The eradication rates were 85.9% (95% CI 80-93) and 93.4% (95% CI 88-98) according to ITT and PP analyses following modified sequential therapy, and 60% (95% CI 35-86) and 64.3% (95% CI 39-89) following the intensified second-line therapy.

CONCLUSION

A modified sequential 3- plus 7-day regimen with thrice daily drug administration failed to achieve very high eradication rate at ITT analysis. The intensified second-line regimen achieved disappointingly low eradication rate. Novel levofloxacin-free second-line therapies are urged in Italy.

Gastric MALT lymphoma: old and new insights

The stomach is the most frequent site of extranodal lymphoma. Gastric lymphoma originating from mucosa-associated lymphoid tissue (MALT) is typically a low-grade, B-cell neoplasia strongly associated with Helicobacter pylori (H. pylori) infection. Only certain H. pylori strains in some predisposed patients determine lymphoma development in the stomach, according to a strain-host-organ specific process. The clinical presentation is poorly specific, symptoms ranging from vague dyspepsia to alarm symptoms. Similarly, different endoscopy patterns have been described for gastric lymphoma. H. pylori eradication is advised as first-line therapy in early stage disease, and complete lymphoma remission is achieved in 75% of cases. Neoplasia stage, depth of infiltration in the gastric wall, presence of the API2-MALT1 translocation, localization in the stomach, and patient ethnicity have been identified as predictors of remission. Recent data suggests that H. pylori eradication therapy may be successful for gastric lymphoma treatment also in a small subgroup (15%) of H. pylori-negative patients. The overall 5-year survival and disease-free survival rates are as high as 90% and 75%, respectively. Management of patients who failed to achieve lymphoma remission following H. pylori eradication include radiotherapy, chemotherapy and, in selected cases, surgery.

How antibiotic resistances could change Helicobacter pylori treatment: A matter of geography?

Therapeutic management of Helicobacter pylori (H. pylori) remains an unsolved issue. Indeed, no therapeutic regimen is able to cure the infection in all treated patients, and in many the infection persists despite the administration of several consecutive standard therapies. Although antibiotic resistance reports describe alarming results, the outcome of therapeutic regimens does not seem to parallel this scenario in most cases, since a successful performance is often reached in more than 80% of cases. However, the phenomenon of increasing antibiotic resistance is being closely studied, and the results show controversial aspects even in the same geographic area. For the continents of Europe, America, Asia, Africa, and Oceania, minimal and maximal values of resistance to the main antibiotics (clarithromycin, amoxicillin, metronidazole, and levofloxacin) feature wide ranges in different countries. The real enigma is therefore linked to the several different therapeutic regimens, which show results that often do not parallel the in vitro findings even in the same areas. A first aspect to be emphasized is that some regimens are limited by their use in very small geographic districts. Moreover, not all therapeutic trials have considered bacterial and host factors affecting the therapeutic outcome. The additional use of probiotics may help to reduce adverse events, but their therapeutic impact is doubtful. In conclusion, the "ideal therapy", paradoxically, appears to be a "utopia", despite the unprecedented volume of studies in the field and the real breakthrough in medical practice made by the discovery and treatment of H. pylori. The ample discrepancies observed in the different areas do not encourage the development of therapeutic guidelines that could be valid worldwide. On these bases, one of the main challenges for the future might be identifying a successful solution to overcome antibiotic resistances. In this context, geography must be considered a relevant matter.

Concomitant, sequential, and hybrid therapy for H. pylori eradication: a pilot study

BACKGROUND AND OBJECTIVE

Since the efficacy of the standard triple therapies for Helicobacter pylori eradication has decreased, novel antibiotic regimens have been introduced, including concomitant, sequential, and hybrid therapies. We aimed to compare the cure rates achieved by these new therapy regimens.

METHODS

This was a multicenter, open-label, pilot study enrolling consecutive non-ulcer dyspepsia patients with H. pylori infection never previously treated for the infection. Patients were randomized to receive one of the following treatments: (a) concomitant therapy: omeprazole 20mg, amoxicillin 1g, clarithromycin 500 mg, and tinidazole 500 mg for 5 days; (b) sequential therapy: omeprazole 20mg and amoxicillin 1g for 5 days followed by omeprazole 20mg, clarithromycin 500 mg, and tinidazole 500 mg for 5 days; (c) hybrid therapy: omeprazole 20mg, and amoxicillin 1g for 7 days followed by omeprazole 20mg, amoxicillin 1g, clarithromycin 500 mg, and tinidazole 500 mg, for 7 days. All drugs were administered twice daily. Bacterial eradication was checked 6 weeks after treatment by using a (13)C-urea breath test. A 10-day, second-line therapy with omeprazole 20mg, levofloxacin 250 mg, and amoxicillin 1g, all given twice daily, was offered to the eradication failure patients.

RESULTS

Overall, 270 patients were enrolled, but 13 patients early interrupted treatment due to side effects. At intention-to-treat (ITT) and per-protocol analysis (PP), the eradication rates were 85.5% and 91.6% with the concomitant regimen, 91.1% and 92.1% with the sequential therapy, and 80% and 85.7% with the hybrid regimen. Differences were not statistically significant. H. pylori infection was cured in 10 (55.6%) patients with the second-line regimen.

CONCLUSION

In our study, both concomitant and sequential therapy, but not hybrid therapy, reached high eradication rates. The success rate of second-line levofloxacin-based triple therapy is decreasing.

Rare case of Helicobacter pylori-related gastric ulcer: Malignancy or pseudomorphism?

Helicobacter pylori (H. pylori) is a pathogen and the most frequent cause of gastric ulcers. There is also a close correlation between the prevalence of H. pylori infection and the incidence of gastric cancer. We present the case of a 38-year-old woman referred by her primary care physician for screening positron emission tomography-computed tomography (PET-CT), which showed a nodular strong accumulation point with standardized uptake value 5.6 in the gastric fundus. Gastroscopy was then performed, and a single arched ulcer, 12 mm in size, was found in the gastric fundus. Histopathological examination of the lesion revealed chronic mucosal inflammation with acute inflammation and H. pylori infection. There was an obvious mitotic phase with widespread lymphoma. Formal anti-H. pylori treatment was carried out. One month later, a gastroscopy showed a single arched ulcer, measuring 10 mm in size in the gastric fundus. Histopathological examination revealed chronic mucosal inflammation with acute inflammation and a very small amount of H. pylori infection. The mitotic phase was 4/10 high power field, with some heterotypes and an obvious nucleolus. Follow-up gastroscopy 2 mo later showed the gastric ulcer in stage S2. The mucosal swelling had markedly improved. The patient remained asymptomatic, and a follow-up PET-CT was performed 6 mo later. The nodular strong accumulation point had disappeared. Follow-up gastroscopy showed no evidence of malignant cancer. H. pylori-associated severe inflammation can lead to neoplastic changes in histiocytes. This underscores the importance of eradicating H. pylori, especially in those with mucosal lesions, and ensuring proper follow-up to prevent or even reverse early gastric cancer.