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

Insights into Helicobacter pylori macrolide resistance: a comprehensive systematic review and meta-analysis

Background

Helicobacter pylori infection is a primary global health concern. However, the widespread use of antibiotics, particularly macrolides such as clarithromycin, has increased resistance among H. pylori strains. This study aimed to investigate the prevalence of macrolide resistance in H. pylori in different world regions.

Methods

This systematic literature search was performed using the appropriate search syntax after searching PubMed, Embase, Web of Science, and Scopus databases between May 2015 and December 2023. Statistical analysis was performed using Pooled and random effects model in R and the metafor package.

Results

A total of 7,768 articles were retrieved. After a thorough evaluation, 155 studies (by 178 reports) were finally eligible for inclusion in this systematic review and meta-analysis. According to the results, the majority of studies (178 reports from 43 countries) assessed clarithromycin susceptibility, with a pooled prevalence of 33.3% and high heterogeneity between studies (I 2 = 98.57%, p < 0.001). The rate of erythromycin resistance was moderate (22.8%, 10 reports), while azithromycin resistance was 34.4% (4 reports). Subgroup analysis revealed significant differences in the prevalence of resistance based on geographic location, continent, and year of publication. Clarithromycin resistance increased from 29.1% (2015-2019) to 36.5% (2020-2023).

Conclusion

This study highlights the critical challenges of macrolide resistance in treating H. pylori infection. The high prevalence and geographic variation underscore the need for tailored treatment strategies based on regional resistance patterns. Furthermore, continuously monitoring resistance trends and investigating contributing factors are essential to optimize treatment.

Systematic review registration

https://www.crd.york.ac.uk/prospero; CRD42024557749.

Antibiotic resistance and virulence genes in Helicobacter pylori strains isolated from children in Shanghai, China (2019-2022)

BACKGROUND

The increasing prevalence of antibiotic-resistant Helicobacter pylori strains poses a significant threat to children's health. This study investigated antibiotic resistance rates in Helicobacter pylori strains isolated from children in Shanghai and analyzed the presence of virulence genes in these strains.

METHODS

We obtained 201 Helicobacter pylori strains from pediatric patients with upper gastrointestinal symptoms who underwent gastrointestinal endoscopy between 2019 and 2022. Subsequently, we performed antibiotic susceptibility tests and virulence gene PCR assays on these strains.

RESULTS

Helicobacter pylori resistance rates of 45.8%, 15.4%, 1.0%, and 2.5% were detected for metronidazole, clarithromycin, amoxicillin, and levofloxacin, respectively. Among all isolates, 64.7% exhibited resistance to at least one antibiotic. Resistance to metronidazole and clarithromycin increased from 2019 to 2022. The predominant vacA gene subtype was vacA s1a/m2. The prevalence of vacA m2 and dupA exhibited an upward trend, while oipA presented a decreasing trend from 2019 to 2022. The prevalence of dupA was significantly higher in gastritis than peptic ulcer disease, and in non-treatment compared to treatment groups.

CONCLUSIONS

Helicobacter pylori antibiotic resistance remains high in children and has risen in recent years. Therefore, the increasing use of metronidazole and clarithromycin requires increased monitoring in children. No association was observed between antibiotic resistance and virulence gene phenotypes.

Global Primary Antibiotic Resistance Rate of Helicobacter pylori in Recent 10 years: A Systematic Review and Meta-Analysis

INTRODUCTION

Due to irregular antibiotic use, the rate of antibiotic resistance to Helicobacter pylori (H. pylori) is increasing and varies from region to region. Therefore, for the purpose of further clarifying the changes in antibiotic resistance rates nowadays, we conducted a systematic review and meta-analysis to update and assess the 10-year trend of primary H. pylori antibiotic resistance rate to the commonly prescribed antibiotics worldwide.

MATERIALS AND METHODS

According to the PRISMA statement, we systematically searched electronic databases for studies that assessed rates of H. pylori resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, or tetracycline published from 2013 to 2023. AHRQ was adopted to estimate methodological quality and publication bias in the included studies, and statistical analysis was performed using Stata 17.0.

RESULTS

We identified 163 studies, comprising 47,002 isolates from 36 countries. The meta-analysis showed that the primary antibiotic resistance rate of H. pylori varied widely among antibiotics. Subgroup analysis showed higher rates of antibiotic resistance in the adult population than in children, and a general trend of increased resistance was observed from 2013 to 2023. There was considerable heterogeneity (I2 > 75%) among all analyses, which may be due to high variability in resistance rates across the global regions.

CONCLUSIONS

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

Exploring virulence factors of Helicobacter pylori isolated from gastric biopsy

BACKGROUND

Helicobacter pylori (H. pylori) colonizes human gastric mucosa and is classified as class one carcinogenic bacteria. In this regard, this study aimed to detect major virulence factors in H. pylori strains recovered from gastric biopsy in patients referred to Aras Clinique in Ardabil, northwest of Iran (2019-2021).

MATERIALS AND METHODS

In this descriptive-cross sectional study, 287 dyspeptic patients were included. For bacterial isolation, gastric biopsy specimens (n=287) were taken from gastric antrum, then aseptically were cultured on the selective medium and incubated at 37C in microaerophilic conditions for 3-5 days.

RESULTS

25.18% of all (n = 70) patients were found to be infected with H. pylori upon endoscopy. Of them, 9 patients (12.857%) and 2 patients (2.875%) had peptic ulcer disease and gastric cancer respectively. According to the different patterns of virulence factors, 57 virutypes were identified in which oipA-vacAs1-vacAm2 (3, 4.28% n =) and oipA-vacAs1-vacAs2-vacAm2 (3, 4.28% n =) were the most common patterns. The simultaneous presence of vacAS2, vacAm2 and hopQ2 genes was observed in both patients with gastric cancer. OipA (n = 562.5%), VacAs1 (n = 6.75%), VacAs2 (n = 6.75%), and VacAm2 (n = 787.5%) were found to be the most prevalent virulence factor.

CONCLUSION

According previous studies, it is confirmed that the cagPAI gene cluster and vacA gene alleles are strongly correlated with gastritis and gastrointestinal tract adenocarcinomas. Our study indicated that 50% of the indigenous strains of H. pylori harbor these oncogenic genes and they are hypervirulent.

Efficacy of a 2-week therapy with levofloxacin concomitant versus a levofloxacin sequential regimen for Helicobacter pylori infection in the Syrian population: a study protocol for randomized controlled trial

BACKGROUND

Treating Helicobacter pylori is becoming increasingly difficult with the development of bacterial resistance to many established treatment regimens. As a result, researchers are constantly looking for novel and effective treatments. This trial aims to establish the efficacy of levofloxacin-based sequential treatment regimen and concomitant levofloxacin-based regimen as empirical first-line therapy in the Syrian population.

METHOD

This is an open-label, prospective, single-center, parallel, active-controlled, superiority, randomized clinical trial. The recruitment will target Helicobacter pylori-positive males and females between the ages of 18 and 65 to evaluate the efficacy of empirical first-line therapy in the Syrian population. We are planning to recruit up to 300 patients which is twice the required sample size. One hundred fifty individuals will be randomly assigned to undergo either a sequential levofloxacin-based treatment regimen or a concomitant levofloxacin-based regimen. High-dose dual therapy (proton-pump inhibitor and amoxicillin) will be the rescue therapy in the event of first-line failure. The first-line eradication rate in both groups is the primary outcome, and one of the secondary outcomes is the overall eradication rate of high-dose dual therapy in the event of first-line treatment protocol failure. Intention-to-treat analysis and per-protocol analysis will be used to evaluate the eradication rates of Helicobacter pylori for first-line treatment protocols.

DISCUSSION

For the first time in the Syrian population, this randomized controlled trial will provide objective and accurate evidence about the efficacy of a sequential levofloxacin-based treatment regimen.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06065267 . Registered on October 3, 2023. Prospective registered. Enrollment of the first participant has not started yet.

Antibiotic resistance of Helicobacter pylori in Chinese children: A multicenter study from 2016 to 2023

BACKGROUND

To investigate the antibiotic resistance of Helicobacter pylori (H. pylori) strains to clarithromycin, metronidazole, amoxicillin, levofloxacin, furazolidone, and tetracycline in Chinese children.

MATERIALS AND METHODS

This multicenter, retrospective study was conducted from January 2016 through May 2023. Gastric mucosa biopsies were obtained from pediatric participants who underwent upper gastrointestinal endoscopy at 96 hospitals in northern, southwestern, and southeastern China. The susceptibility of H. pylori to six commonly used antibiotics was determined by agar dilution method.

RESULTS

Among the 3074 H. pylori isolates, 36.7% were resistant to clarithromycin, 77.3% to metronidazole, 16.6% to levofloxacin, and 0.3% to amoxicillin. No strains were detected to be resistant to furazolidone or tetracycline. During the 8-year study period, resistance to clarithromycin and metronidazole showed a significant upward trend, while the resistance pattern of the other antibiotics demonstrated a slight but nonsignificant fluctuation. Significant regional differences were found in the distribution of clarithromycin resistance among the northern (66.0%), southwestern (48.2%), and southeastern (34.6%) regions. The metronidazole resistance rate was significantly lower in the southeastern coastal region (76.3%) than in the other two regions (88.2% in the north and 87.7% in the southwest). Multi-drug resistance for two or more antibiotics was detected in 36.3% of the H. pylori strains, and the predominant multi-resistance pattern was the dual resistance to clarithromycin and metronidazole.

CONCLUSIONS

The prevalence of H. pylori resistance to clarithromycin and metronidazole is rather high in Chinese children and has been increasing over time. A relatively high resistance rate to levofloxacin was also noticed in children, while almost all strains were susceptible to amoxicillin, furazolidone, and tetracycline. It will be of great clinical significance to continuously monitor the antibiotic-resistance patterns of H. pylori in the pediatric population.

Antibiotic resistance and heteroresistance in Helicobacter pylori isolates from symptomatic Vietnamese children: A prospective multicenter study

BACKGROUND

Antibiotic resistance of Helicobacter pylori (H. pylori) is increasing worldwide, with geographical variations, impacting the treatment outcomes. This study assessed the antibiotic resistance patterns of H. pylori in Vietnamese children.

MATERIALS AND METHODS

Symptomatic children undergoing gastroduodenoscopy at two tertiary Children's Hospitals in Ho Chi Minh City were recruited. Antral and corpus biopsies were obtained and cultured separately. Susceptibility to amoxicillin (AMO), clarithromycin (CLA), metronidazole (MET), levofloxacin (LEV), and tetracycline (TET) was determined using E-test. Polymerase chain reaction was performed on another antral biopsy to detect the urease gene, cytotoxin-associated gene A (cagA), vacuolating cytotoxin A (vacA) genotypes, and 23S rRNA mutations conferring CLA resistance.

RESULTS

Among 123 enrolled children, a high primary resistance rate was found for CLA (68.5%, 61/89), followed by LEV (55.1%), MET (31.5%), AMO (25.8%), and TET (1.1%). Secondary resistance rates were 82.1% (7/28), 71.4%, 53.6%, and 3.6% for CLA, LEV, MET, and TET, respectively. Multidrug resistance was frequent (67.7%), with common patterns including CLA + LEV (20.3%) and CLA + MTZ + LEV (15.2%). Heteroresistance was detected in eight children (6.5%). The A2143G mutation was detected in 97.5% (119/122) of children. 86.1% of children had positive cagA strains and 27.9% had multiple vacA genotypes. No factor was significantly associated with antibiotic resistance.

CONCLUSIONS

The alarming rate of antibiotic resistance for H. pylori, especially for CLA, with emerging multi- and hetero-resistant strains, pose a major treatment challenge that precludes CLA use as empirical therapy. Biopsies from both antrum and corpus can improve H. pylori culture, allowing tailored treatment based on antimicrobial susceptibility.

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.

Jinghua Weikang capsule for helicobacter pylori eradication: A systematic review and meta-analysis with trial sequential analysis

Background: Helicobacter pylori (H. pylori) infection is one of the most common chronic bacterial infections worldwide. The resistance of H. pylori to antibiotics may increase the risk of treatment failure. Complementary and alternative regimens are still needed. This study aimed to critically assess the efficacy and safety of Jinghua Weikang capsule (JWC) for H. pylori eradication. Materials and methods: PubMed, Embase, Web of Science, Cochrane library, China National Knowledge Infrastructure, Wanfang Digital Periodicals, and Chinese Science and Technology Periodicals database were searched from inception to April 2022. Randomized controlled trials (RCTs) comparing a combination of JWC and conventional treatments with conventional treatments alone or combined with a placebo for H. pylori eradication were considered for inclusion. The primary outcome was H. pylori eradication rate. The meta-analysis and trial sequential analysis (TSA) were conducted where possible. Results: A total of 34 studies were included in the statistical analysis. A pooled result showed that JWC with the duration of 2 weeks combined with the triple/quadruple therapy could significantly increase the H. pylori eradication rate compared with the triple/quadruple therapy alone (RR: 1.13, 95% CI: 1.05 to 1.21, p = 0.0008). However, the evidence of benefit was not confirmed by TSA. Another pooled result showed that JWC with the duration of 4 weeks combined with the triple/quadruple therapy could significantly increase the H. pylori eradication rate compared with the triple/quadruple therapy alone (RR: 1.21, 95% CI: 1.15 to 1.27, p < 0.00001). The evidence of benefit was confirmed by TSA. There were no statistically significant differences in the incidence of adverse reactions between the two groups. Conclusion: The present study suggests that JWC with the duration of 4 weeks can significantly improve the H. pylori eradication rate and should be considered as a complementary treatment to conventional regimens for H. pylori eradication. However, more high-quality RCTs are still needed to confirm these findings.

Prevalence, Virulence Genes, Phylogenetic Analysis, and Antimicrobial Resistance Profile of Helicobacter Species in Chicken Meat and Their Associated Environment at Retail Shops in Egypt

Helicobacter pylori (H. pylori) and Helicobacter pullorum (H. pullorum) are frequently reported pathogens in humans and poultry, respectively. Nevertheless, the source of H. pylori is still unclear. This study aimed to detect Helicobacter spp. in chicken carcasses and to assess the antibiogram and the virulence genes of Helicobacter isolates. Three hundred chicken meat samples (100 each of chicken breast, liver, and gizzard), besides 60 swab samples from chicken processing surfaces, were collected from retail shops in Qalyubia Governorate, Egypt, and examined for the prevalence of H. pylori and H. pullorum. The 16S rRNA of three H. pylori and two H. pullorum isolates were sequenced to determine the genetic relationship between these two Helicobacter spp. Of the 300 chicken samples tested, 16 (5.33%) and 14 (4.67%) were positive for H. pylori and H. pullorum, respectively. Multiplex PCR revealed that the virulence genes vacuolating cytotoxin A (vacA)s1, cytotoxin-associated gene A (cagA), and restriction endonuclease-replacing gene A (hrgA) were detected in 66.7%, 77.8%, and 100% of H. pylori strains tested, respectively. H. pylori showed the highest resistance for clarithromycin, while H. pullorum exhibited the highest resistance towards erythromycin and ciprofloxacin. The study concluded that the chicken meat and giblets are potential sources of the virulent and antimicrobial-resistant strains of H. pylori of human origin.

Treatment of Pediatric Helicobacter pylori Infection

Helicobacter pylori infection can cause gastritis, gastric or duodenal ulcers, mucosa-associated lymphoid tissue lymphoma, gastric cancer, and extra-gastrointestinal manifestations. Ideal treatment should be guided by antibiotic susceptibility testing. However, this is not feasible in many regions, so the treatment generally relies on clinical experience and regional culture sensitivity profiles. We aimed to integrate the treatment of pediatric H. pylori infection through a systematic literature review. Databases including PubMed, Cochrane Library, EMBASE, and Scholar were searched using terms containing (Helicobacter OR Helicobacter pylori OR H. pylori) AND (child OR pediatric) for all relevant manuscripts and guidelines, published from January 2011 to December 2021. The eradication rate for pediatric H. pylori infection was not satisfactory using triple therapy, sequential therapy, concomitant therapy, bismuth-based quadruple therapy, or adjuvant therapy with probiotics as the first-line therapy. Most therapies could not achieve the recommended eradication rate of >90%, which may be attributed to varying regional antibiotic resistance and possible poor children’s compliance. More studies are required to establish a best practice for pediatric H. pylori infection treatment.

FBPAII and rpoBC, the Two Novel Secreted Proteins Identified by the Proteomic Approach from a Comparative Study between Antibiotic-Sensitive and Antibiotic-Resistant Helicobacter pylori-Associated Gastritis Strains

Helicobacter pylori infection is the leading cause of chronic gastritis, which can develop into gastric cancer. Eliminating H. pylori infection with antibiotics achieves the prevention of gastric cancer. Currently, the prevalence of H. pylori resistance to clarithromycin and metronidazole, and the dual resistance to metronidazole and clarithromycin (C_R, M_R, and C/M_R, respectively), remains at a high level worldwide. As a means of exploring new candidate proteins for the management of H. pylori infection, secreted proteins from antibiotic-susceptible and antibiotic-resistant H. pylori-associated gastritis strains were obtained by in-solution tryptic digestion coupled with nano-liquid chromatography tandem mass spectrometry (nano-LC-MS/MS). A total of 583, 582, 590, and 578 differential expressed proteins were identified from C_R, M_R, C/M_R, and antibiotic-sensitive strain (S_S) samples, respectively. Of these, 23 overlapping proteins were found by Venn diagram analysis. Based on heat map analyses, the most and least differing protein expressions were observed from C/M_R strains and S_S strains, respectively. Of the proteins secreted by the S_S strain, only nine were found. After predicting the protein interaction with metronidazole and clarithromycin via the STITCH database, the two most interesting proteins were found to be rpoBC and FBPAII. After quantitative real-time reverse transcription PCR (qRT-PCR) analysis, a downregulation of rpoB from M_R strains was observed, suggesting a relationship of rpoB to metronidazole sensitivity. Inversely, an upregulation of fba from C_R, M_R, and C/M_R strains was noticed, suggesting the paradoxical expression of FBPAII and the fba gene. This report is the first to demonstrate the association of these two novel secreted proteins, namely, rpoBC and FBPAII, with antibiotic-sensitive H. pylori -associated gastritis strains.

Metronidazole-resistant Helicobacter pylori isolates without rdxA mutations obtained from Iranian dyspeptic patients

Antibiotic resistance is now accepted as an inevitable factor in Helicobacter pylori treatment failure, so a survey on the antibiotic susceptibility profile of H. pylori is welcomed. In addition, the main molecular mechanism of antibiotic resistance in H. pylori is not fully determined, particularly for metronidazole. Our single-centre study was designed to evaluate the local antibiotic resistance profile of H. pylori strains recovered from individuals with dyspepsia. Gastric biopsy specimens from 200 individuals underwent bacterial culture for H. pylori, and bacterial identification was confirmed by positive reports from biochemical and genotypic universal protocols. Antibiotic susceptibility tests were performed on the 73 isolates obtained, by both disc diffusion and E-test methods. DNA extraction was carried out on single colonies of H. pylori confirmed by biochemical tests, then PCR was used to amplify the rdxA and 23srRNA genes. Metronidazole and clarithromycin resistance phenotypes were checked to detect possible mutations at rdxA and 23SrRNA genes. Successful bacterial culture was reported for 73 of the 200 patients (27 male (36%) and 46 female (63%) with an age range from 25 to 80 years (mean 54 years)). None of the patients reported pre-treatment. Among the 73 biochemically and genotypically confirmed H. pylori isolates in this analysis, antibiotic resistance rates were 45% (33/73) for metronidazole and 23% (17/73) for clarithromycin. Additionally, ten H. pylori isolates were multidrug resistant (13%). According to the antibiogram analysis, 13/17 (76%) had the A2142G mutation, although 3/17 (17%) samples also showed A2143G. None of the resistant isolates were carrying the A2142C and A2144G mutations. Moreover, none of the metronidazole-resistant strains showed any of the point mutations. Identification of H. pylori isolates without the rdxA mutation reveals the need for an urgent investigation to select an effective antibiotic before drug prescription by gastroenterologists.

Phenotypic and Genotypic Assessment of Antibiotic Resistance and Genotyping of vacA, cagA, iceA, oipA, cagE, and babA2 Alleles of Helicobacter pylori Bacteria Isolated from Raw Meat

BACKGROUND

Foodstuffs with animal origins, particularly meat, are likely reservoirs of Helicobacter pylori.

PURPOSE

An existing survey was accompanied to assess phenotypic and genotypic profiles of antibiotic resistance and genotyping of vacA, cagA, cagE, iceA, oipA, and babA2 alleles amongst the H. pylori bacteria recovered from raw meat.

METHODS

Six-hundred raw meat samples were collected and cultured. H. pylori isolates were tested using disk diffusion and PCR identification of antibiotic resistance genes and genotyping.

RESULTS

Fifty-two out of 600 (8.66%) raw meat samples were contaminated with H. pylori. Raw ovine meat (13.07%) had the uppermost contamination. H. pylori bacteria displayed the uppermost incidence of resistance toward tetracycline (82.69%), erythromycin (80.76%), trimethoprim (65.38%), levofloxacin (63.46%), and amoxicillin (63.46%). All H. pylori bacteria had at least resistance toward one antibiotic, even though incidence of resistance toward more than eight antibiotics was 28.84%. Total distribution of rdxA, pbp1A, gyrA, and cla antibiotic resistance genes were 59.61%, 51.92%, 69.23%, and 65.38%, respectively. VacA s1a (84.61%), s2 (76.92%), m1a (50%), m2 (39.13%), iceA1 (38.46%), and cagA (55.76%) were the most generally perceived alleles. S1am1a (63.46%), s2m1a (53.84%), s1am2 (51.92%), and s2m2 (42.30%) were the most generally perceived genotyping patterns. Frequency of cagA-, oipA-, and babA2- genotypes were 44.23%, 73.07%, and 80.76%, respectively. A total of 196 combined genotyping patterns were also perceived.

CONCLUSION

The role of raw meat, particularly ovine meat, in transmission of virulent and resistant H. pylori bacteria was determined. VacA and cagA genotypes had the higher incidence. CagE-, babA2-, and oipA- H. pylori bacteria had the higher distribution. Supplementary surveys are compulsory to originate momentous relations between distribution of genotypes, antibiotic resistance, and antibiotic resistance genes.

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.

Helicobacter pylori and some aspects of gut microbiota in children

Helicobacter pylori infection in children differs from infection in adults in many aspects. The rate of infection, epidemiology, clinical presentations and complications, the applicability of diagnostic tests, antibiotic resistance, treatment options, and success rates differ significantly. Due to all these differences, management guidelines for children and adults differ also substantially. In 2017, the Updated ESPGHAN and NASPGHAN Guidelines on the management of H. pylori infection in children were published, emphasizing the differences in clinical presentation and indications for treatment, stating that the primary goal of clinical investigation in children is to identify the cause of upper gastrointestinal symptoms rather than the presence of H. pylori infection. Therefore, the diagnosis should be based on upper endoscopy, and the "test and treat strategy" should not be used in children. Due to an increasing rate of antibiotic resistance worldwide, the updated guidelines recommend broader use of antimicrobial susceptibility testing for H. pylori strains in order to tailor eradication treatment accordingly. Moreover, treatment in children should be prescribed only when indicated and should be based on the rate of eradication in local populations aiming for treatment success above 90%. During the last two decades there has been a steady decrease in the rate of H. pylori infection in both children and adults in the Western world. Two recent publications studying the incidence of H. pylori infection confirmed that early childhood is a time for acquisition of infection both in industrialized and nonindustrialized countries. In addition, they showed that H. pylori could be acquired outside the family. In respect to the inverse association between H. pylori and allergy, a longitudinal study demonstrated that early exposure to H. pylori at any age was inversely associated with atopy and allergic conditions.