High Helicobacter pylori resistance to metronidazole and clarithromycin in Brazilian children and adolescents

Antimicrobial Resistance of Helicobacter pylori Isolated From Latin American Children and Adolescents (2008-2023): A Systematic Review

BACKGROUND

Latin America has a high prevalence of Helicobacter pylori in children that may lead to peptic ulcer disease and eventually gastric cancer in adulthood. Successful eradication is hindered by rising antimicrobial resistance. We summarize H. pylori resistance rates in Latin American children from 2008 to 2023.

MATERIAL AND METHODS

Systematic review following PRISMA guidelines and National Heart, Lung, and Blood Institute checklist to assess risk of bias (PROSPERO CRD42024517108) that included original cross-sectional observational studies reporting resistance to commonly used antibiotics in Latin American children and adolescents. We searched in PubMed, LILACS, and SciELO databases.

RESULTS

Of 51 studies, 45 were excluded. The quality of the six analyzed studies (297 H. pylori-positive samples) was satisfactory. Phenotypic methods (N = 3) reported higher resistance rates than genotypic studies (N = 3). Clarithromycin resistance ranged from 8.0% to 26.7% (6 studies; 297 samples), metronidazole from 1.9% to 40.2% (4 studies; 211 samples), amoxicillin from 0% to 10.4% (3 studies; 158 samples), tetracycline resistance was not detected (3 studies; 158 samples), and levofloxacin resistance was 2.8% (1 study; 36 samples).

CONCLUSION

Scarce Latin American studies on H. pylori resistance, along with methodological heterogeneity, hinder conclusive findings. Clarithromycin and metronidazole (first-line drugs) resistance is worrisome, likely impacting lower eradication rates. Urgent systematic surveillance or individual testing before treatment is necessary to enhance eradication.

Molecular Mechanisms of Antibiotic Resistance and Novel Treatment Strategies for Helicobacter pylori Infections

Helicobacter pylori infects approximately 50% of the world's population and is considered the major etiological agent of severe gastric diseases, such as peptic ulcers and gastric carcinoma. Increasing resistance to standard antibiotics has now led to an ever-decreasing efficacy of eradication therapies and the development of novel and improved regimens for treatment is urgently required. Substantial progress has been made over the past few years in the identification of molecular mechanisms which are conducive to resistant phenotypes as well as for efficient strategies to counteract strain resistance and to avoid the use of ineffective antibiotics. These involve molecular testing methods, improved salvage therapies, and the discovery of novel and potent antimicrobial compounds. High rates of prevalence and gastric cancer are currently observed in Asian countries, including Japan, China, Korea, and Taiwan, where concomitantly intensive research efforts were initiated to explore advanced eradication regimens aimed at reducing the risk of gastric cancer. In this review, we present an overview of the known molecular mechanisms of antibiotic resistance and discuss recent intervention strategies for H. pylori diseases, with a view of the research progress in Asian countries.

Current Worldwide Trends in Pediatric Helicobacter pylori Antimicrobial Resistance

Helicobacter pylori (H. pylori) has acquired several resistance mechanisms in order to escape the currently used eradication regimens such as mutations that impair the replication, recombination, and transcription of DNA; the antibiotics capability to interact with protein synthesis and ribosomal activity; the adequate redox state of bacterial cells; or the penicillin-binding proteins. The aim of this review was to identify the differences in pediatric H. pylori antimicrobial-resistance trends between continents and countries of the same continent. In Asian pediatric patients, the greatest antimicrobial resistance was found to metronidazole (>50%), probably due to its wide use for parasitic infections. Aside from the increased resistance to metronidazole, the reports from different Asian countries indicated also high resistance rates to clarithromycin, suggesting that ciprofloxacin-based eradication therapy and bismuth-based quadruple therapy might be optimal choices for the eradication of H. pylori in Asian pediatric population. The scarce evidence for America revealed that H. pylori strains display an increased resistance to clarithromycin (up to 79.6%), but not all studies agreed on this statement. Pediatric patients from Africa also presented the greatest resistance rate to metronidazole (91%), but the results in terms of amoxicillin remain contradictory. Nevertheless, the lowest resistance rates in most of the African studies were found for quinolones. Among European children, the most frequent antimicrobial resistance was also noticed for metronidazole and clarithromycin (up to 59% and 45%) but with a predominance for clarithromycin as compared to other continents. The differences in antibiotic use among continents and countries worldwide is clearly responsible for the discrepancies regarding H. pylori antimicrobial-resistance patterns, emphasizing the crucial role of global judicious antibiotic use in order to control the increasing resistance rates worldwide.

The prevalence of clarithromycin-resistant Helicobacter pylori isolates: a systematic review and meta-analysis

Background

Knowledge of global clarithromycin (CLA)-resistant rates of Helicobacter pylori (H. pylori) is crucial for decision of the most appropriate eradication therapies with good clinical outcomes. Therefore, this review and meta-analysis aimed to evaluate the global prevalence of the CLA resistance in H. pylori to provide some guidance for selecting the first-line antibiotics.

Method

A comprehensive search was performed for relevant literature until April 2021 in PubMed, Embase, and Web of Science databases. Freeman-Tukey double arcsine transformation was performed to estimate the weighted pooled prevalence of resistance.

Results

The meta-analysis included 248 articles. The prevalence of CLA-resistant H. pylori was 27.53% (95% CI [25.41-29.69]). The heterogeneity between reports was significant (I² = 97.80%, P < 0.01). The resistance rate increased from 24.28% in 2010-2017 to 32.14% in 2018-2021 (P < 0.01). Iran, with 38 articles, has the most report. Nevertheless, Switzerland, Portugal, and Israel had the highest resistance rates (67.16%, 48.11%, and 46.12%, respectively). The heterogeneity between the continents and the antimicrobial susceptibility methods also interpreted standard guidelines and breakpoints was insignificant (P > 0.05).

Conclusion

Overall CLA resistance rate was 27.53%, worldwide. The difference in CLA resistance rate among the included studies can be due to several reasons such as differences in antibiotic prescription rates in various geographic areas, use of different breakpoints or inaccurate criteria in performed studies, and the emergence of multidrug-resistant (MDR) strains.

Unravelling the In Vitro and In Vivo Anti-Helicobacter pylori Effect of Delphinidin-3-O-Glucoside Rich Extract from Pomegranate Exocarp: Enhancing Autophagy and Downregulating TNF-α and COX2

Fruits containing antioxidants, e.g., anthocyanins, exhibit antimicrobial activities. The emergence of drug resistance represents a major challenge in eradicating H. pylori. The current study aims to explore the effect of pomegranate exocarp anthocyanin methanol extract (PEAME) against H. pylori isolates recovered from antral gastric biopsies. The UPLC-PDA-MS/MS and 1H NMR analyses indicated delphinidin-3-O-glucoside as the major anthocyanin in the extract. The PEAME showed activity against all tested resistant isolates in vitro recording minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 128 and 256 µg/mL, respectively. In vivo investigation included evaluation of the rat gastric mucosa for malondialdehyde (MDA), catalase activity, COX2, TNF-α, and key autophagy gene expression. The combination of pomegranate with metronidazole markedly reduced the viable count of H. pylori and the level of COX2, with alleviation of H. pylori-induced inflammation and oxidative stress (reduction of MDA, p-value < 0.001; and increase in catalase activity, p-value < 0.001). Autophagy gene expression was significantly upregulated upon treatment, whereas TNF-α was downregulated. In conclusion, we comprehensively assessed the effect of PEAME against H. pylori isolates, suggesting its potential in combination with metronidazole for eradication of this pathogen. The beneficial effect of PEAME may be attributed to its ability to enhance autophagy.

Prevalence of antibiotic heteroresistance associated with Helicobacter pylori infection: A systematic review and meta-analysis

BACKGROUND

Heteroresistance is a general term to describe diverse responses to specific antibiotics that can occur due to infection with either multiple bacterial strains or microevolution of a single strain during chronic infection. Due to limited information regarding heteroresistance Helicobacter pylori (H. pylori) infection, the current study was carried out to evaluate the prevalence of this phenomenon.

METHODS

For this study, all potential relevant studies were collected by searching international databases such as ISI Web of Science, PubMed, Scopus, ScienceDirect, ProQuest, Embase, DOAJ, China National Knowledge Infrastructure (CNKI), and Google Scholar. Finally, the frequency of heteroresistance H. pylori infection was measured using the event rate corresponding to 95% confidence intervals.

RESULTS

A total of 26 studies met our criteria; the eligible studies were related to the years 2001-2022. Our results showed that the prevalence of heteroresistance H. pylori strains was 60.1% to clarithromycin, 61.1% to metronidazole, 46.1% to levofloxacin, 3.8% to amoxicillin, and 21.1% to tetracycline. Our literature review also showed discrepancy of antimicrobial susceptibility test in strains isolated from different anatomical sites of the stomach. Heteroresistance H. pylori infection in developing countries is mostly due to infection with multiple H. pylori strains, while in developed countries it is due to microevolution of a single H. pylori strain in response to antibiotic pressure.

CONCLUSIONS

Heteroresistance H. pylori infection interferes with successful therapy and eventually can lead to the treatment failure. If a biopsy is taken from only one gastric site, resistant strains of H. pylori may be underestimated. Considering the role of heteroresistance H. pylori infection in treatment failure, it is very important for gastroenterologists to improve their knowledge about this fact. Regardingly, new guidelines should be developed and designed for the management and treatment of heteroresistance H. pylori infection.

Antibiotic Resistance of Helicobacter pylori in Children with Gastritis and Peptic Ulcers in Mekong Delta, Vietnam

Background: Helicobacter pylori (H. pylori) infection causes gastritis, duodenal and gastric ulcers, and gastric cancer. H. pylori eradication efficacy is low worldwide, and antibiotic resistance is the leading cause of therapy failure; therefore, this study was performed to determine the characteristics of antibiotic resistance of H. pylori in children with gastritis, duodenal and gastric ulcer. Methods: A cross-sectional study was conducted on 237 pediatric patients diagnosed with gastroduodenal inflammation and ulcer at two hospitals in Vietnam from March 2019 to April 2022. Pediatric patients with positive H. pylori tests continued to do E-tests to measure the minimum inhibitory concentration of the antibiotic so that we could prescribe effective antibiotics based on the sensitivity. Results: In 237 pediatric patients (51.1% males) with a median age of 10.3 years (range 5–16 years), endoscopic images showed that inflammatory lesions and peptic ulcers accounted for 69.2% and 30.8%, respectively. Resistance rates of H. pylori were 80.6% to clarithromycin (CLR), 71.7% to amoxicillin (AMX), 49.4% to metronidazole (MTZ), 45.1% to levofloxacin (LEV), and 11.4% to tetracycline (TET); dual resistance to AMX + CLR was 64.2%, AMX + LEV 35%, AMX + MTZ 33.3%, CLR + MTZ 32.5%, and TET + MTZ 7.2%. The frequency of clarithromycin resistance was significantly increased, particularly in pediatric patients who had received prior H. pylori treatment. The percentage of amoxicillin resistance increased with age; amoxicillin resistance of H. pylori was more prevalent among pediatric patients with peptic ulcers than those with gastroduodenal inflammation and higher in males than females. Conclusions: The proportions of resistance to CLR, AMX, MTZ, and LEV were extremely high, in contrast to TET, which was lower in pediatric patients. Our study suggests that the standard triple therapy with CLR should be limited as the empiric therapy for pediatric patients, and we should consider using eradication regimens with TET for children over 8 years of age if the medical facility is not qualified to perform antibiotic susceptibility tests of H. pylori in the Mekong Delta.

The Challenges of Eradicating Pediatric Helicobacter pylori Infection in the Era of Probiotics

Helicobacter pylori (H. pylori), the most common infection of childhood, results in life-threatening complications during adulthood if left untreated. Most of these complications are related to H. pylori-induced chronic inflammation. The dysbiosis caused by H. pylori is not limited to the gastric microenvironment, but it affects the entire gastrointestinal tract. Eradication of H. pylori has recently become a real challenge for clinicians due to both the persistent increase in antibiotic resistance worldwide and the wide spectrum of side effects associated with the eradication regimens resulting; therefore, there is an urgent need for more effective and less noxious treatment options. Thus, probiotics might be a promising choice in both adults and children with H. pylori infection since their role in improving the eradication rate of this infection has been proved in multiple studies. The positive effects of probiotics might be explained by their abilities to produce antimicrobial compounds and antioxidants, alter local gastric pH, and subsequently decrease H. pylori colonization and adherence to gastric epithelial cells. Nevertheless, if used alone probiotics do not considerably increase the eradication rate.

Probiotics as the live microscopic fighters against Helicobacter pylori gastric infections

Background

Helicobacter pylori (H. pylori) is the causative agent of stomach diseases such as duodenal ulcer and gastric cancer, in this regard incomplete eradication of this bacterium has become to a serious concern. Probiotics are a group of the beneficial bacteria which increase the cure rate of H. pylori infections through various mechanisms such as competitive inhibition, co-aggregation ability, enhancing mucus production, production of bacteriocins, and modulating immune response.

Result

In this study, according to the received articles, the anti-H. pylori activities of probiotics were reviewed. Based on studies, administration of standard antibiotic therapy combined with probiotics plays an important role in the effective treatment of H. pylori infection. According to the literature, Lactobacillus casei, Lactobacillus reuteri, Lactobacillus rhamnosus GG, and Saccharomyces boulardii can effectively eradicate H. pylori infection. Our results showed that in addition to decrease gastrointestinal symptoms, probiotics can reduce the side effects of antibiotics (especially diarrhea) by altering the intestinal microbiome.

Conclusion

Nevertheless, antagonist activities of probiotics are H. pylori strain-specific. In general, these bacteria can be used for therapeutic purposes such as adjuvant therapy, drug-delivery system, as well as enhancing immune system against H. pylori infection.

Phenotypic and Genotypic Antibiotic Resistance Patterns in Helicobacter pylori Strains From Ethnically Diverse Population in México

Helicobacter pylori strains carry a range of mutations in genes that confer antimicrobial resistance and restrict the available options to treat the infection. Latin America is a region that conserve a large number of indigenous communities relatively isolated that practice a traditional medicine without consumption of drugs. We hypothesized that rates of antibiotic resistance are lower in these communities. Recent progress in whole-genome sequencing has allowed the study of drug susceptibility by searching for the known mutations associated with antibiotic resistance. The aim of this work was to study trends of antibiotic resistance over a 20-year period in Mexican H. pylori strains and to compare susceptibility between strains from Mexican mestizos and from indigenous population; we also aimed to learn the prevalence of mutational patterns in genes gyrA, gyrB, rdxA, frxA, rpsU, omp11, dppA, and 23S rRNA and its association with phenotypic tests. Resistance to clarithromycin, metronidazole, amoxicillin and levofloxacin was determined in167 H. pylori isolates by E-test, and the occurrence of mutational patterns in specific genes was determined by whole genome sequencing (WGS). The trend of resistance over 20 years in mestizo isolates showed significant resistant increase for clarithromycin and levofloxacin to frequencies that banned its clinical use. Resistance in H. pylori isolates of native communities was lower for all antibiotics tested. Phenotypic resistance showed good to moderate correlation with genotypic tests. Genetic methods for characterizing antibiotic resistance require further validation in each population.

Bacterial Resistance in Surgical Infections in Low-Resource Settings

Background: There is an alarming increase in antimicrobial resistance (AMR) globally, complicating management of surgical infections, especially in low-resource settings. Of particular concern for surgeons are third generation cephalosporin-resistant and carbapenem-resistant Enterobacteriaceae. Methods: The published literature was searched to identify the scope and causative factors of emerging bacterial resistance in low- and middle-income countries (LMICs). Results: Antimicrobial resistance impacts economics, human development, health equity, health security, and food production. Factors that contribute to AMR include use of antibiotic agents in livestock, antibiotic agents in wastewater and sewage, poor sanitation, and overprescribing or unregulated use of antibiotic agents. Because the factors influencing AMR globally are multi-factorial, solutions must be addressed at multiple levels. In LMICs, these can occur through national initiatives, at the facility level, or at the community level with coordination engaging government agencies, the private sector, civil service, and professional groups. Conclusions: There is a growing recognition of the need for national AMR prevention programs. Meanwhile, infection prevention and control programs and antimicrobial stewardship remain cornerstones of management at the facility level.

Increasing antimicrobial resistance to clarithromycin and metronidazole in pediatric Helicobacter pylori infection in southern Taiwan: A comparison between two decades

BACKGROUND

Antimicrobial resistance of Helicobacter pylori reduces the eradication rate. This study aimed to investigate changes in antimicrobial susceptibility of H pylori isolated from children in Taiwan in the past two decades.

METHODS

This study enrolled children receiving esophagogastroduodenoscopy for upper gastrointestinal diseases in a national tertiary referring hospital from 1998 to 2018. H pylori infection was diagnosed by culture. The minimal inhibitory concentrations (MICs) of antibiotics were tested using the E test. The antibiotic resistance rates and MICs of amoxicillin, clarithromycin, metronidazole, levofloxacin, and tetracycline were compared between 1998-2008 and 2009-2018.

RESULTS

A total of 70 Helicobacter pylori isolates (29 from 1998 to 2008 and 41 from 2009 to 2018) were identified. The esophagogastroduodenoscopy findings included duodenal ulcers (n = 31), gastric ulcers (n = 9), and gastritis (n = 30). The overall antimicrobial resistance rates of clarithromycin and metronidazole were 22.9% and 21.4%, respectively. The dual resistance rate of clarithromycin and metronidazole was 10%. Resistance rates of levofloxacin and amoxicillin were 8.3% and 2.9%, respectively. None of the isolates were resistant to tetracycline. Compared with the isolates from 1998 to 2008, those from 2009 to 2018 had higher MICs and resistance rates of clarithromycin (26.8% vs 17.2%, P = 0.35) and metronidazole (26.8% vs 13.8%, P = 0.19), but not levofloxacin (9.8% vs 5.3%, P = 1.0) or coresistance to clarithromycin and metronidazole (12.2% vs 6.9%, P = 0.69).

CONCLUSIONS

The antimicrobial resistance rates of pediatric H pylori isolates to clarithromycin and metronidazole increased during the past decade. The selection of antimicrobial agents other than clarithromycin and metronidazole is crucial to increase pediatric H pylori eradication rates.

A Helicobacter pylori screening and treatment program to eliminate gastric cancer among junior high school students in Saga Prefecture: a preliminary report

BACKGROUND

To present the strategies and preliminary findings of the first 3 years after implementing a Helicobacter pylori screening and eradication program to prevent gastric cancer in Saga Prefecture.

METHODS

A screening and treatment program to eradicate H. pylori from third-grade junior high students was started in Saga Prefecture in 2016, using local governmental grants. Screening was with urinary anti-H. pylori antibody tests, followed by H. pylori stool antigen tests for students who were antibody positive. Those positive on both tests underwent H. pylori eradication by triple therapy based on a potassium-competitive acid blocker.

RESULTS

From 2016 to 2018, the participation rate was 83.1% and the H. pylori infection rate was 3.1% (660/21,042). The participation rates were higher in 2017 (85.4%) and 2018 (85.9%) compared with 2016 (78.5%) (P < 0.0001), and the infection rate also decreased in a time-dependent manner (2016: 3.6%, 2017: 3.3%, 2018: 2.5%, P = 0.0001). In total, 501 students positive for H. pylori received eradication therapy (85.1% success) and adverse events occurred in 20 of these (4.0%). However, no serious complications occurred.

CONCLUSIONS

The H. pylori screening and eradication project for school students in Saga Prefecture has started successfully and we have seen both a steady increase in the participation rate and a steady decrease in the infection rate, without major safety concerns.

The antibiotic resistance of Helicobacter pylori to five antibiotics and influencing factors in an area of China with a high risk of gastric cancer

Background

H. pylori exhibits antibiotic resistance with regional differences. In this paper, we explored antibiotic resistance of H. pylori to five antibiotics in an area with a high risk of gastric cancer.

Results

H. pylori resistance rates to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were 78.0, 56.0, 31.0, 9.0, and 15.0%, respectively. Double, triple, quadruple, and quintuple resistance rates were 23, 20, 6, and 4%, respectively. The clarithromycin and multidrug resistance rates were significantly higher in males than females (clarithromycin: 44.4% vs 15.2%, respectively, P = 0.002; multidrug: 75.5% vs 37.2%, respectively; P < 0.001). During the three periods of 1998–1999, 2002–2004 and 2016–2017, the resistance rates to levofloxacin and amoxicillin were increasing (OR: 2.089, 95%CI: 1.142–3.821, P = 0.017; and OR: 5.035, 95%CI: 1.327–19.105, P = 0.018, respectively). The antibiotic resistance rates were unassociated with the host disease state. Metronidazole resistance was lower in the vacAs1m1/m2 group than the vacAs1m1m2 group (65% vs 85.7%, respectively; P = 0.026). As for levofloxacin resistance, it was higher with cagA⁺ than cagA⁻ (60.9% vs 23.1%, respectively; P = 0.020) but lower with slyD⁺ than slyD⁻ (41.4% vs 68.5%, respectively; P = 0.009). Clarithromycin had a lower resistance rate with iceA⁺⁺ than iceA⁻⁺ (19.7% vs 52.4%, respectively; P = 0.017). For amoxicillin, the iceA⁺⁺ group had a lower resistance rate than the iceA⁻⁻ group (1.6% vs 27.8%, respectively; P = 0.009).

Conclusions

The total resistance rates of H. pylori to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were high in Zhuanghe. The resistanc rates to levofloxacin and amoxicillin increased over time. Clarithromycin resistance was associated with male and iceA. The resistance of metronidazole was related to vacA. Levofloxacin resistance was concerned with cagA and slyD and amoxicillin resistance was concerned with iceA. While, the antibiotic resistance of H. pylori had nothing to do with the status of gastric disease.

Helicobacter pylori: Multiple resistance in patients from Bogotá, Colombia

Introduction: The main cause for Helicobacter pylori infection treatment failure is antibiotic resistance, where clarithromycin and metronidazole play the main role. In Colombia, primary resistance as a consequence of the use of these two antibiotics and excessive levofloxacin use is above the accepted limit (13.6%, 83%, and 16%, respectively). Despite this fact, empirical therapies that include the combination of these antibiotics are used in patients with previous therapeutic failure. Objective: To determine antibiotic resistance in patients previously treated for H. pylori in Bogotá, Colombia. Materials and methods: We conducted a descriptive study that included ten isolates obtained from five patients with three or four previous failed treatments for H. pylori. Antibiotic resistance to amoxicillin, clarithromycin, levofloxacin, and metronidazole was investigated by agar dilution and confirmed by DNA sequencing (Magrogen, Korea). Results: Eight isolates were resistant to two or more antibiotics. All isolates were resistant to levofloxacin. Susceptibility patterns in isolates from the gastric antrum and the body of the stomach were different in three patients. Conclusion: As far as we know, this is the first evidence of multiple H. pylori resistance in Colombia in previously treated patients. Results demonstrated the consequences of using an ineffective antibiotic scheme and the need to assess antibiotic susceptibility in different anatomical sites of the stomach. The consequences of multiple resistance decrease possible antibiotic effectiveness to eradicate H. pylori in the future.

Prevalence of Antibiotic Resistance in Helicobacter pylori: A Systematic Review and Meta-analysis in World Health Organization Regions

BACKGROUND & AIMS

In 2017, the World Health Organization (WHO) designated clarithromycin-resistant Helicobacter pylori a high priority for antibiotic research and development. However, there are no clear data on the global distribution of resistance or its clinical effects. We performed a systematic review and meta-analysis to assess the distribution of H pylori resistance to commonly used antibiotics and to measure the association between antibiotic resistance and treatment failure.

METHODS

We searched publication databases for studies that assessed rates of H pylori resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, or tetracycline. Pooled estimates of primary and secondary resistance and 95% confidence intervals (CIs) were grouped by WHO region. The association between antibiotic resistance and treatment failure was measured by extracting data on treatment efficacy in patients with resistant and susceptible isolates and pooling odds ratios with 95% CIs.

RESULTS

We identified 178 studies, comprising 66,142 isolates from 65 countries. Primary and secondary resistance rates to clarithromycin, metronidazole, and levofloxacin were ≥15% in all WHO regions, except primary clarithromycin resistance in the Americas (10%; 95% CI, 4%-16%) and South-East Asia region (10%; 95% CI, 5%-16%) and primary levofloxacin resistance in the European region (11%; 95% CI, 9%-13%). There was considerable heterogeneity (I2 > 75%) among all analyses-this might have resulted from the grouping of resistance rates by country. Increasing antibiotic resistance was observed in most WHO regions. Resistance to clarithromycin was significantly associated with failure of clarithromycin-containing regimens (odds ratio, 6.97; 95% CI, 5.23-9.28; P < .001).

CONCLUSIONS

Resistance of H pylori to antibiotics has reached alarming levels worldwide, which has a great effect on efficacy of treatment. Local surveillance networks are required to select appropriate eradication regimens for each region.

Antibiotic Resistance of Helicobacter pylori in Iranian Children: A Systematic Review and Meta-Analysis

Antibiotic therapy for children infected with Helicobacter pylori is important. However, resistance to antibiotics is one of the main causes of treatment failure. This study was designed to evaluate the prevalence pattern of antibiotic resistance of H. pylori in Iranian children using a systematic review and meta-analysis of literature. A computerized search (until June 10, 2017) using related keywords in the national and international databases was performed. A total of 261 original articles on antibiotic resistance of H. pylori in Iranian children were collected. After screening for inclusion and exclusion criteria, six eligible articles were included in the meta-analysis. Resistance rates of H. pylori to different antibiotics were as follows: metronidazole: 71%, clarithromycin: 12.2%, amoxicillin: 20.4%, tetracycline: 8.4%, ampicillin: 21.4%, rifampin: 28.6%, furazolidone: 8.4%, ciprofloxacin: 16.2%, azithromycin: 19%, erythromycin: 15.3%, and nitrofurantoin: 0%. The prevalence of H. pylori resistance to metronidazole, amoxicillin, ampicillin, and rifampin among Iranian children was high. Therefore, a careful monitoring of antibiotic resistance to select the best treatment options and prevent treatment failure is required. Although resistance to some antibiotics such as clarithromycin, tetracycline, furazolidone, and ciprofloxacin was less prevalent, frequent consumption of these drugs in children should be controlled owing to their known adverse events.

Development and validation of a whole-cell ELISA for serologically diagnosing Helicobacter pylori infection in Brazilian children and adults: a diagnostic accuracy study

BACKGROUND

Serological tests are practical, with low cost, but no noninvasive tests are available for diagnosing Helicobacter pylori (H. pylori) infection in Brazil. The aim here was to develop and validate enzyme-linked immunosorbent assay (ELISA) serological tests to detect anti-H. pylori immunoglobulin G antibodies, based on cultured strains from Brazilian patients.

DESIGN AND SETTING

Cross-sectional, diagnostic accuracy study comparing a locally developed and validated ELISA and invasive tests among dyspeptic patients at two public hospitals in São Paulo, Brazil.

METHODS

An ELISA test was prepared using whole-cell antigen from 56 strains. After genotypic characterization, it was standardized and optical density (OD) cutoffs were determined based on the serum antibody response of 100 H. pylori-negative samples, compared with 82 H. pylori-positive samples. Validation was performed on 174 symptomatic patients.

RESULTS

The optimal OD cutoffs established (for monoclonal and polyclonal tests, respectively) were 0.167 and 0.164; overall ELISA sensitivity: 84.3%, 78.9%; specificity: 88.6%, 90.6%; positive predictive value (PPV): 75.4%, 80%; negative predictive value (NPV): 93.1%, 81.8%; accuracy: 87.3%, 86.2%; child and adolescent ELISA sensitivity: 74.2%, 81.8%; specificity: 90.8%, 86.7%; PPV: 66.6%, 84.3%; NPV: 95.8%, 84.8%; accuracy: 88.5%, 84.6; adult ELISA sensitivity: 84.4%, 75%; specificity: 86.9%, 93%; PPV: 81.8%, 78.3%; NPV: 88.9%, 91.8%; accuracy: 85.9%, 88.5%.

CONCLUSION

The polyclonal serological test developed using local strains presented better diagnostic performance among children and adolescents, while the monoclonal test was better among adults. The results from both tests suggest that these in-house serological tests could be used to detect anti-H. pylori antibodies in our population, for screening purposes.

Antibiotics resistance of Helicobacter pylori in children with upper gastrointestinal symptoms in Hangzhou, China

BACKGROUND

The decreasing eradication rate of Helicobacter pylori is mainly because of the progressive increase in its resistance to antibiotics. Studies on antimicrobial susceptibility of H. pylori in children are limited. This study aimed to investigate the resistance rates and patterns of H. pylori strains isolated from children.

MATERIALS AND METHODS

Gastric mucosa biopsy samples obtained from children who had undergone upper gastrointestinal endoscopy were cultured for H. pylori, and susceptibility to six antibiotics (clarithromycin, amoxicillin, gentamicin, furazolidone, metronidazole, and levofloxacin) was tested from 2012-2014.

RESULTS

A total of 545 H. pylori strains were isolated from 1390 children recruited. The total resistance rates of H. pylori to clarithromycin, metronidazole, and levofloxacin were 20.6%, 68.8%, and 9.0%, respectively. No resistance to amoxicillin, gentamicin, and furazolidone was detected. 56.1% strains were single resistance, 19.6% were resistant to more than one antibiotic, 16.7% for double resistance, and 2.9% for triple resistance in 413 strains against any antibiotic. And the H. pylori resistance rate increased significantly from 2012-2014. There was no significant difference in the resistance rates to clarithromycin, metronidazole, and levofloxacin between different gender, age groups, and patients with peptic ulcer diseases or nonulcer diseases.

CONCLUSIONS

Antibiotic resistance was indicated in H. pylori strains isolated from children in Hangzhou, and it increased significantly during the 3 years. Our data strongly support current guidelines, which recommend antibiotic susceptibility tests prior to eradication therapy.

Helicobacter pylori treatment: antibiotics or probiotics

Treatment of Helicobacter pylori infection is important for the management of gastrointestinal disorders such as peptic ulcer and gastric cancer. Due to the increase in the prevalence of H. pylori resistance to antibiotics, triple therapy with clarithromycin is no longer the best treatment for H. pylori, especially in some areas where the local resistance to this antibiotic is higher than 20%. Alternative treatments have been proposed for the eradication of H. pylori. Some of them including novel antibiotics or classical ones in different combinations; these treatments are being used in the regular clinical practice as novel and more effective treatments. Others therapies are using probiotics associated to antibiotics to treat this infection.The present article is a revision of H. pylori eradication treatment, focusing on emerging approaches to avoid the treatment failure, using new therapies with antimicrobials or with probiotics.

Resistance of Helicobacter pylori to furazolidone and levofloxacin: A viewpoint

In their review, Arslan et al^[1] did not describe the status of Helicobacter pylori (H. pylori) treatment with furazolidone and the resistance to this antibiotic. We have presented different surveys showing the resistance of H. pylori to furazolidone from Asia and South America. The resistance rates varied but were mostly low (< 5%). There are not enough data on its efficacy and resistance in the United States and Europe. H. pylori mutations occurring in the oorD gene, including A041G, A122G, C349A(G), A78G, A112G, A335G, C156T and C165T, and in the porD gene, including G353A, A356G, C357T, C347T, C347G and C346A, have been indicated to be possibly related to the observed resistance. Additionally, to complete Arslan et al’s statement regarding levofloxacin resistance, it should be noted that compound mutations of N87A, A88N and V65I at codon Asn-87 were recently observed in the gyrA gene for the first time. However, the results on these topics are not sufficient, and more worldwide studies are suggested.

Eradication rate of Helicobacter Pylori infection is directly influenced by adherence to therapy in children

BACKGROUND

Current commonly accepted strategies to eradicate Helicobacter pylori in children are a 10-day sequential treatment or a triple therapy for 7-14 days. To avoid further expensive and possibly risky investigations as well as induction of secondary antimicrobial resistance, a success rate of elimination strategies over 90% in a per-protocol analysis is the target goal but rates observed in clinical trials are lower. Antimicrobial resistance is a well-recognized risk factor for treatment failure; therefore, only a treatment tailored to susceptibility testing should be recommended. Adherence to therapy is also a risk factor for treatment failure but that has been poorly studied. The purpose of this study was to evaluate the influence of adherence to therapy on the elimination rates obtained with different treatment regimens.

METHODS

Cohort study analysis of children, aged 2-17 years, treated for Helicobacter pylori infection between October 2011 and December 2013. As a routine clinical practice, children infected with a strain susceptible to clarithromycin and to metronidazole received either a sequential regimen or a 10-day triple therapy while children infected with a strain resistant to clarithromycin or metronidazole received a 10-day triple regimen tailored to antimicrobial susceptibility. The eradication rate was assessed by a negative ¹³ C-urea breath test performed at least 8 weeks after the end of the treatment and adherence evaluated using a diary.

RESULTS

One hundred forty-five children (67 girls/78 boys, median age 9.7 years) fulfilled the inclusion criteria, 118 being infected with a strain susceptible to both clarithromycin and metronidazole, 10 with a clarithromycin resistant, and 17 with a metronidazole resistant strain. A sequential regimen was prescribed in 44, a triple therapy containing clarithromycin in 84 and containing metronidazole in 17. Follow-up data were available for 130/145 and clearance of the infection observed in 105 of them. A concordance of more than 90% between the prescribed and the ingested drugs was observed in 109 children, between 50 and 90% in eight, less than 50% in 11 while these data were unknown for 2/130. A successful eradication was achieved for 89.9% of patients that received at least 90% of the prescribed drugs, whereas the eradication rate for nonadherent patients was 36.6%. Adherence above 90% was significantly higher in the absence of chronic concomitant disease, in the absence of adverse event and results in a significantly higher eradication rate. With the proposed strategy and an adherence higher than 90%, eradication was obtained in 98/109 children, the rate being only significantly superior to 90% with the sequential regimen.

CONCLUSION

Adherence to therapy is a very important factor for the outcome and has to be assessed when evaluating the outcome of an H. pylori eradication regimen in order to understand the reasons of treatment failure. As we treated only after evaluation of the resistance of the H. Pylori strains, we were expecting to reach the given objective of 90% successful treatment. Children with adherence to treatment above 90% had a successful outcome of 89,9%, whereas nonadherent had a successful outcome of 36,8%. This is the first time that adherence has been assessed accurately.

Increasing metronidazole and rifampicin resistance of Helicobacter pylori isolates obtained from children and adolescents between 2002 and 2015 in southwest Germany

BACKGROUND

Increasing antibiotic resistance has been reported for Helicobacter pylori, but data on the prevalence of antibiotic resistance of H. pylori in pediatric patients and the development of resistance over time are sparse.

METHODS

Data for 610 H. pylori isolates obtained between 2002 and 2015 from gastric biopsies of 582 (mainly treatment-naïve) pediatric patients from southwest Germany were analyzed retrospectively regarding the antibiotic susceptibility determined by Etest and patients' characteristics.

RESULTS

Overall resistance to metronidazole, clarithromycin, and rifampicin was 28.7%, 23.2%, and 13.3%, respectively, while resistance to amoxicillin was rare (0.8%). Simultaneous resistance to metronidazole and clarithromycin was observed for 7.7% of the isolates, and 2.3% were resistant to metronidazole, clarithromycin, and rifampicin. Differences between primary vs secondary resistance existed for metronidazole (24.7% vs 38.8%, P=.01) and clarithromycin (17.2% vs 54.1%, P=.0001). From 2002-2008 to 2009-2015, resistance to metronidazole increased from 20.8% to 34.4% (P=.003) and to rifampicin from 3.9% to 18.8% (P=.0001); this was not associated with increased numbers of patients previously treated for H. pylori infection in the second study period. In contrast, resistance to clarithromycin did not change significantly over time. Resistance was not associated with age, sex, or family origin in Europe.

CONCLUSIONS

The considerable antibiotic resistance of H. pylori isolates argues for standard antibiotic susceptibility testing of H. pylori in pediatric patients prior to the initiation of antibiotic therapy.

Sequential Therapy for Helicobacter pylori Infection in Treatment-naïve Children

The goal of first-line Helicobacter pylori therapy is to reach an eradication rate of 90% to avoid further investigations, antibiotic use, and spreading of resistant strains.

AIM

To evaluate the eradication rate of high-dose sequential therapy in treatment-naïve children and to assess factors associated with failure.

METHODS

Prospective data assessed in a registry from nine European centers between October 2009 and December 2011. Children with biopsy-proven Helicobacter pylori infection were prescribed 5 days of esomeprazole and amoxicillin, followed by 5 days of esomeprazole, clarithromycin, and metronidazole according to bodyweight. Eradication was assessed after 8-12 weeks. Primary endpoint was the eradication rate in children who received at least one dose and had follow-up data. Multivariate analysis evaluated potential factors for treatment success including sex, age, center, migrant status, antibiotic resistance, and adherence to therapy.

RESULTS

Follow-up was available in 209 of 232 patients (age range 3.1-17.9 years, 118 females). Primary resistance occurred for clarithromycin in 30 of 209 (14.4%), for metronidazole in 32 (15.3%), for both antibiotics in 7 (3.3%), and culture failed in 6 (2.9%). Eradication was achieved in 168 of 209 children (80.4%, 95% CI 75.02-85.78), in 85.8% with no resistance, 72.6% with single resistance, and 28.6% with double resistance. Independent factors affecting eradication rate included resistance to clarithromycin (adjusted ORs 0.27 (0.09-0.84), p = .024), to metronidazole (0.25 (0.009-0.72), p = .010) or to both (0.04 (0.01-0.35), p = .004), and intake of ≤ 90% of prescribed drugs (0.03 (0.01-0.18), p < .001).

CONCLUSION

A high-dose 10-day sequential therapy cannot be recommended in treatment-naïve children.

Prevalence of antibiotic resistance in Helicobacter pylori: A recent literature review

AIM: To review previous studies (the last 6 years) about the Helicobacter pylori (H. pylori) antibiotic resistance in order to evaluate the trend in antibiotic resistance.

METHODS: In this study, the PubMed, MEDLINE, Science Direct, Google Scholar and Scielo manuscripts were reviewed from 2009 to 2014.

RESULTS: On the whole rates of H. pylori antibiotic resistance were 47.22% (30.5%-75.02%) for metronidazole, 19.74% (5.46%-30.8%) for clarithromycin, 18.94% (14.19%-25.28%) for levofloxacin, and 14.67% (2%-40.87%) for amoxicillin, 11.70% (0%-50%) for tetracycline, 11.5% (0%-23%) for furazolidon and 6.75% (1%-12.45%) for rifabutin. The frequency of tetracycline, metronidazole and amoxicillin resistance was higher in Africa, while clarithromycin and levofloxacin resistance was higher in North America and Asian, respectively.

CONCLUSION: The most sensitive drug is rifabutin and the lowest sensitive drug is metronidazole in the world. The worldwide H. pylori antibiotic resistance to clarithromycin and levofloxacin has increased during the last 6 years. The present systematic review show alarming results and a novel plan is needed for eradication therapy of H. pylori infections.

Loop-Mediated Isothermal Amplification as a Fast Noninvasive Method of Helicobacter pylori Diagnosis

BACKGROUND

Helicobacter pylori infection is etiologically associated with some important health problems such as gastric cancer. Because of the high clinical importance of H. pylori infection, development of a noninvasive test for the detection of H. pylori is desirable.

METHODS

In this study, a loop-mediated isothermal amplification (LAMP) targeted ureC of H. pylori was evaluated on 100 stool specimens and compared with a stool antigen test. Culture and rapid urease test were considered as gold standards.

RESULTS

The overall detection rate of the fecal antigen test and LAMP was 58% and 82%, respectively. The analytical sensitivity of the fecal antigen test and LAMP was 500 and 10 H. pylori cells/g and 10 fg DNA/reaction, which is equal to six H. pylori genome.

CONCLUSION

LAMP technique has been characterized by high sensitivity and low detection limit for the detection of H. pylori in stool specimen. Clinical diagnostic performance of LAMP was better than the stool antigen test.

Antimicrobial susceptibility testing for Helicobacter pylori isolates from Brazilian children and adolescents: comparing agar dilution, E-test, and disk diffusion

Antimicrobial susceptibility testing for Helicobacter pylori is increasingly important due to resistance to the most used antimicrobials agents. Only agar dilution method is approved by CLSI, but it is difficult to perform routinely. We evaluated the reliability of E-test and disk diffusion comparing to agar dilution method on Helicobacter pylori antimicrobial susceptibility testing. Susceptibility testing was performed for amoxicillin, clarithromycin, furazolidone, metronidazole and tetracycline using E-test, disk-diffusion and agar dilution method in 77 consecutive Helicobacter pylori strains from dyspeptic children and adolescents. Resistance rates were: amoxicillin - 10.4%, 9% and 68.8%; clarithromycin - 19.5%, 20.8%, 36.3%; metronidazole - 40.2%33.7%, 38.9%, respectively by agar dilution, E-test and disk diffusion method. Furazolidone and tetracycline showed no resistance rates. Metronidazole presented strong correlation to E-test (r = 0.7992, p < 0.0001) and disk diffusion method (r=-0.6962, p < 0.0001). Clarithromycin presented moderate correlation to E-test (r = 0.6369, p < 0.0001) and disk diffusion method (r=−0.5656, p < 0.0001). Amoxicillin presented weak correlation to E-test (r = 0.3565, p = 0.0015) and disk diffusion (r=−0.3565, p = 0.0015). Tetracycline presented weak correlation with E-test (r = 0.2346, p = 0.04) and furazolidone to disk diffusion (r=−0.0288, p = 0.8038). E-test presented better agreement with gold standard. It is an easy and reliable method for Helicobacter pylori susceptibility testing. Disk diffusion method presented high disagreement and high rates of major errors.

In vitro and in vivo activities of HPi1, a selective antimicrobial against Helicobacter pylori

A high-throughput screen (HTS) was performed to identify molecules specifically active against Helicobacter pylori, the causative agent of peptic ulcer and gastric carcinoma. Currently, treatment of H. pylori infection is suboptimal, with failure rates approaching 25%, despite triple therapy with two broad-spectrum antibiotics and a proton pump inhibitor or quadruple therapy with added bismuth. The HTS was performed in 384-well plates, and reduction of the metabolic indicator resazurin was used as a reporter for cell growth. Diverse molecules from commercial sources were identified as hits, and in vitro validations included measurements of MIC and time-dependent killing as well as anaerobic susceptibility testing against a panel of gut microbes. In vivo validation included testing in the mouse model of H. pylori infection. The small molecule HPi1 (3-hydrazinoquinoxaline-2-thiol) had excellent potency, with an MIC of 0.08 to 0.16 μg/ml and good selectivity for H. pylori compared to a panel of commensal bacteria. HPi1 was also effective in a mouse model of H. pylori infection, reducing colony counts to below the limit of detection after oral dosing of 25 mg/kg/day for 3 days. HPi1 is a promising lead in the search for more effective and specific H. pylori therapeutics.

Antibiotics resistance of Helicobacter pylori and treatment modalities in children with H. pylori infection

Pediatric infection with Helicobacter pylori may occur early in childhood and persist lifelong. Global pediatric clinical studies have reported a decreasing tendency in the overall rate of H. pylori eradication. In pediatric patients with H. pylori infection, pediatric patients with peptic ulcer, and the first-degree relatives of patients with a history of gastric cancer, it is commonly recommended that H. pylori strains be eradicated. Antibiotic drug resistance to H. pylori, which has been reported to vary widely between geographic regions, is mainly associated with treatment failure in these patients. It is therefore imperative that the antibiotic resistance rates of H. pylori in children and adolescents be meticulously monitored across countries and throughout geographic regions. This paper particularly focuses on the antibiotic drug resistance of H. pylori and the thearpy of pediatric H. pylori infection cases.

A review of Helicobacter pylori diagnosis, treatment, and methods to detect eradication

Helicobacter pylori (H. pylori) affects nearly half of the world’s population and, thus, is one of the most frequent and persistent bacterial infections worldwide. H. pylori is associated with peptic ulcer disease, gastric ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Various diagnostic methods exist to detect infection, and the choice of one method or another depends on several factors, such as accessibility, advantages and disadvantages of each method, cost, and the age of patients. Once H. pylori infection is diagnosed, the clinician decides whether treatment is necessity, according to the patient’s clinical condition. Typically, eradication of H. pylori is recommended for treatment and prevention of the infection. Cure rates with the standard triple therapy are acceptable, and effective quadruple therapies, sequential therapies, and concomitant therapies have been introduced as key alternatives to treat H. pylori infection. In this work, we review the main diagnostic methods used to identify H. pylori infection and to confirm eradication of infection. In addition, key factors related to treatment are reviewed.

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.

Helicobacter pylori in pediatrics

This review concerned the important pediatric studies published between April 2012 and March 2013. Symptomatology in Helicobacter pylori-positive children is nonspecific, except for those suffering from peptic ulcer diseases. Investigation of H. pylori status in children and adolescents with sideropenic anemia is recommended, and it is the aim of several studies worldwide. Associations of H. pylori with plasma ghrelin levels as well as the negative association of H. pylori with atopic disease were interesting objectives for several studies this year. Success rates of sequential therapy tended to be lower in recent studies than in previous trials, which probably reflects the increase in macrolide resistance. A beneficial effect of probiotics was reported although not all trials supported this result in children. Intrafamilial transmission and young age could be major risk factors associated with reinfection in children.