Practical Aspects in Choosing a Helicobacter pylori Therapy

Genotypic detection of metronidazole and clarithromycin resistance in dyspeptic patients with helicobacter pylori

In Egypt, antibiotic sensitivity analysis for Helicobacter pylori is not routinely performed. We aimed to identify the clarithromycin and metronidazole resistance directly from gastric biopsies for better guide treatment regimens. This cross-sectional descriptive study included 75 adult dyspeptic patients referred to the upper endoscopy unit in Suez Canal University Hospital, Ismailia, Egypt. Gastric biopsies were taken for rapid urease test (RUT) and cultured on brucella agar with antibiotic supplements. Genomic DNA was extracted directly from the specimen, and PCR was performed for direct detection of H. pylori. Also, to explore clarithromycin and metronidazole resistance, mutations in the 23S rRNA gene and the rdxA gene were investigated. We found that 60 samples were positive to RUT (80%), and only 4 samples were positive by culture. UreC gene was detected in 45 specimens. Meanwhile, 26 isolates were contained mutations at positions 2142 and 2143. Amplification of the metronidazole rdx gene was performed by conventional PCR. Out of 45 isolates, DNA sequence analysis of PCR product showed the wild type (ACA) in 9 isolates, while the mutant type (ATA) was detected in 28 isolates. We found a significant proportion of clarithromycin and metronidazole resistance among H. pylori infected patients in our region.

Prevalence of CYP2C19 polymorphism in Bogotá, Colombia: The first report of allele *17

INTRODUCTION

Proton pump inhibitors (PPIs) are a group of drugs that are essential for the treatment of acid-related disorders, such as gastroesophageal reflux (GERD), dyspepsia, gastric ulcers and Helicobacter pylori (H. pylori) infection. PPIs such as omeprazole, esomeprazole, pantoprazole and lansoprazole are metabolized by the CYP2C19 enzyme, which is encoded by a polymorphic gene. Four polymorphisms have an impact on the speed of PPI metabolism: CYP2C19*1/*1 (extensive metabolizers), CYP2C19*2/*2 (intermediate metabolizers), CYP2C19*3/*3 (poor metabolizers) and CYP2C19*17/*17 (ultrarapid metabolizers). Extensive and ultrarapid metabolizers inactivate PPIs quickly, which consequently causes low plasma concentrations of PPIs, while intermediate or poor metabolizers have higher plasma concentrations of PPIs and, therefore, PPIs have greater therapeutic efficacy in individuals with these polymorphisms.

OBJECTIVE

To determine the frequency of genetic polymorphisms of the CPY2C19 enzyme in Bogotá, Colombia.

METHODS

This observational study was conducted in Bogotá between 2012 and 2015 and was part of a clinical trial (ID: NCT03650543). It included 239 subjects with dyspepsia, H. pylori infection, or GERD symptoms. CYP2C19 genotyping was performed on gastric biopsy samples. Polymorphisms *1, *2, and *3 were analyzed by real-time PCR (Roche®), and PCR-RFLP was used to determine the presence of polymorphism *17.

RESULTS

The distribution of different types of PPI metabolizers was as follows: extensive (70.7%), ultrarapid (12.9%), intermediate (8.8%) and poor (0.8%).

CONCLUSION

The population studied consisted mainly of extensive and ultrarapid PPI metabolizers. These findings show that it is necessary to increase PPI doses in this group of subjects or to use PPIs that are not metabolized by CYP2C19 (rabeprazole). This is the first Colombian work to identify ultrarapid metabolizers.

Compliance, adverse effects and effectiveness of first line bismuth-containing quadruple treatment (Pylera®) to eradicate Helicobacter pylori infection in 200 patients

INTRODUCTION AND OBJECTIVES

quadruple therapy with bismuth is recommended as a first line treatment for Helicobacter pylori (H. pylori) infection. The aim of this study was to evaluate the compliance, adverse effects and effectiveness of this treatment with the new galenic three-in-one capsule formulation containing bismuth subcitrate, metronidazole and tetracycline (Pylera®).

METHODS

a prospective, non-controlled, single center observational study was performed in a cohort of 200 consecutive patients with an untreated H. pylori infection; 58% were female. The subjects were treated for ten days with Pylera® of three capsules four times daily with meals and a proton pump inhibitor taken before breakfast and dinner. The Pylera® capsule contains 140 mg of bismuth subcitrate, 125 mg of metronidazole and 125 mg of tetracycline. The compliance and adverse effects of the treatment were evaluated via telephone contact and via an interview during the clinical revision. Eradication of infection was controlled for at least four weeks after treatment termination via the urea breath test, the stool antigen test with monoclonal antibodies or by histology.

RESULTS

treatment compliance was observed in 96% (192/200) of the patients. Only 28.5% (57/200) of the patients experienced adverse effects, which led to abandoning the treatment in only seven subjects. Severe adverse effects developed in only one case due to Clostridium difficile infection. The effectiveness based on intention to treat was 91.5% (183/200, 95% CI: 87.1-96.8) and per protocol was 95.2% (182/191, 95% CI: 90.9-98.9).

CONCLUSIONS

in our experience, Pylera® is an effective and safe treatment that should be considered as a first line therapeutic option for the eradication of H. pylori infection.

In Vitro Activity of Diphenyleneiodonium toward Multidrug-Resistant Helicobacter pylori Strains

Background/Aims

The increased resistance of Helicobacter pylori to antibiotics has increased the need to develop new treatments for this bacterium. The aim of our study was to identify new drugs with anti-H. pylori activity.

Methods

We screened a small molecule library—the library of pharmacologically active compounds (LOPAC), which includes 1,280 pharmacologically active compounds—to identify inhibitors of H. pylori growth. The minimal inhibitory concentrations (MICs) of antibiotics against multidrug-resistant H. pylori strains were determined using the agar dilution method.

Results

We identified diphenyleneiodonium (DPI) as a novel anti-H. pylori agent. The MIC values for DPI were <0.03 μg/mL against all tested H. pylori strains. DPI also exhibited strong antibacterial activity against common gram-negative and gram-positive pathogenic bacteria.

Conclusions

DPI may be a candidate anti-H. pylori drug for future development.

Ten-day empirical sequential or concomitant therapy is more effective than triple therapy for Helicobacter pylori eradication: A multicenter, prospective study

BACKGROUND

The resistance of Helicobacter pylori to antibiotics has increased the need for new empirical, first-line treatments. However, the efficacy of sequential therapy (ST) and concomitant therapy (CT) compared with triple therapy (TT) has not been adequately evaluated.

AIM

In this study, we evaluated the efficacy of these empirical three regimens.

METHODS

The 517 patients enrolled in the study were prospectively randomized to receive 10 days of TT (n=171), ST (n=170), and CT (n=176) at 5 university-affiliated hospitals from May 2013 to March 2015. The post-treatment H. pylori status was determined using the (13)C-urea breath test.

RESULTS

The baseline characteristics were similar among the three groups. The intention-to-treat eradication rates were 62.6%, 70.6%, and 77.8% in the TT, ST, and CT groups, respectively (p<0.01). The corresponding per-protocol eradication rates were 82.8%, 89.5%, and 94.4%, respectively (p<0.01). There were no significant differences in the compliance, side effects, and follow-up loss rates.

CONCLUSION

A higher eradication rate was achieved with empirical 10-day ST, and CT than with the TT regimen, with similar rates of compliance and treatment side effects.

Eradication of Helicobacter pylori Infection

Helicobacter pylori infects about 50 % of the world's population, causing at a minimum chronic gastritis. A subset of infected patients will ultimately develop gastric or duodenal ulcer disease, gastric adenocarcinoma, or MALT (mucosa-associated lymphoid tissue) lymphoma. Eradication of H. pylori requires complex regimens that include acid suppression and multiple antibiotics. The efficacy of treatment using what were once considered standard regimens have declined in recent years, mainly due to widespread development of antibiotic resistance. Addition of bismuth to standard triple therapy regimens, use of alternate antibiotics, or development of alternative regimens using known therapies in novel combinations have improved treatment efficacy in specific populations, but overall success of eradication remains less than ideal. Novel regimens under investigation either in vivo or in vitro, involving increased acid suppression ideally with fewer antibiotics or development of non-antibiotic treatment targets, show promise for future therapy.

IV Spanish Consensus Conference on Helicobacter pylori infection treatment

Helicobacter pylori approximately infect 50% of Spanish population and causes chronic gastritis, peptic ulcer and gastric cancer. Until now, three consensus meetings on H.pylori infection had been performed in Spain (the last in 2012). The changes in the treatment schemes, and the increasing available evidence, have justified organizing the IVSpanish Consensus Conference (March 2016), focused on the treatment of this infection. Nineteen experts participated, who performed a systematic review of the scientific evidence and developed a series of recommendation that were subjected to an anonymous Delphi process of iterative voting. Scientific evidence and the strength of the recommendation were classified using GRADE guidelines. As starting point, this consensus increased the minimum acceptable efficacy of recommended treatments that should reach, or preferably surpass, the 90% cure rate when prescribed empirically. Therefore, only quadruple therapies (with or without bismuth), and generally lasting 14 days, are recommended both for first and second line treatments. Non-bismuth quadruple concomitant regimen, including a proton pump inhibitor, clarithromycin, amoxicillin and metronidazole, is recommended as first line. In the present consensus, other first line alternatives and rescue treatments are also reviewed and recommended.