Helicobacter pylori resistance to clarithromycin and fluoroquinolones in a pediatric population in Turkey: A cross-sectional study

Antibiotic resistance, heteroresistance, and eradication success of Helicobacter pylori infection in children

BACKGROUND

Antibiotic resistance is a well-known factor of Helicobacter pylori eradication failure. Heteroresistance indicates the coexistence of resistant and susceptible strains and might lead to underestimating antimicrobial resistance. This study aims to evaluate the susceptibility profile, the frequency of heteroresistance of H. pylori strains, and their effect on eradication success in a pediatric population.

MATERIALS AND METHODS

Children aged 2-17 years who underwent an upper gastrointestinal endoscopy from 2011 to 2019 with positive H. pylori status were included. Susceptibility was measured by disk diffusion and E-test. The difference in susceptibility profiles between isolates from the antrum and the corpus was used to detect heteroresistance. For those who received eradication treatment, we evaluated eradication rate and factors affecting treatment success.

RESULTS

Inclusion criteria were met by 565 children. Strains susceptible to all antibiotics were detected in 64.2%. Primary resistance rates for clarithromycin (CLA), metronidazole (MET), levofloxacin (LEV), tetracyclin (TET), and amoxicillin (AMO) were 11%, 22.9%, 6.9%, 0.4%, and 0% and secondary resistance rates were 20.4%, 29.4%, 9.3%, 0%, and 0%. Heteroresistance was present in untreated children in 2%, 7.1%, 0.7%, 0.7%, and 0% for CLA, MET, LEV, TET, and AMO. First-line eradication rates were 78.5% in intention-to-treat (ITT), 88.3% in full-analysis-set (FAS), and 94.1% in per-protocol (PP). Factors affecting eradication success were the duration of treatment when the triple-tailored treatment was used, the number of daily doses of amoxicillin administered, and the patient's adherence to treatment.

CONCLUSIONS

This study shows the presence of relatively low primary resistance rates for H. pylori isolates but demonstrates the presence of heteroresistance in our population. Routine biopsies from the antrum and corpus must be considered for susceptibility testing to allow tailored treatments and increase eradication rates. Treatment success is affected by treatment choice, correct dosing of medications, and adherence. All these factors should be considered when evaluating the efficacy of an eradication regimen.

Helicobacter pylori Infections in Children

In the context of epidemiology, host response, disease presentation, diagnosis, and treatment management, the manifestation of Helicobacter pylori (H. pylori) infection diverges between children and adults. H. pylori infection stands out as one of the most prevalent bacterial infections globally, and its prevalence in both children and adults is decreasing in many developing countries but some still struggle with a high prevalence of pediatric H. pylori infection and its consequences. The majority of infected children are asymptomatic and pediatric studies do not support the involvement of H. pylori in functional disorders such as recurrent abdominal pain. The pathophysiology of H. pylori infection relies on complex bacterial virulence mechanisms and their interaction with the host immune system and environmental factors. This interaction gives rise to diverse gastritis phenotypes, which subsequently influence the potential development of various gastroduodenal pathologies. In clinical settings, the diagnosis of this infection in childhood requires an upper gastrointestinal endoscopic exam with mucosal biopsy samples for histology and culture, or Polymerase Chain Reaction (PCR) at the very least. When warranted, eradication treatment should be given when good compliance is expected, and there should be systematic use of a treatment adapted to the antimicrobial susceptibility profile. To combat the burgeoning threat of multidrug resistance, vigilant surveillance of resistance patterns and strategic antibiotic management are paramount.

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

Turkey presents both a high prevalence of Helicobacter pylori infection and high prevalence of antibiotic resistance. In this study, we aimed to summarize recent data on H. pylori antibiotic resistance rates in this nation. After conducting searches in two national and international databases (ULAKBIM, EKUAL, and PubMed), a systematic review was conducted. A total of 197 original articles on antibiotic resistance of H. pylori in Turkey were collected. After screening for inclusion and exclusion criteria, to evaluate the H. pylori antibiotic resistance for the period 2005-2020, 20 eligible articles were included in the meta-analysis. Data analysis was performed using MedCalc 12.7.0. The number of isolated H. pylori strains in each study was weighted, and pooled proportion analysis was performed. This review included 20 Turkish studies, including 1,556 H. pylori strains. The overall resistance rates were as follows: clarithromycin (CLA), 26.7% (95% confidence interval [CI]: 20.5-33.5); metronidazole (MTZ), 28.4% (95% CI: 19.7-38.1); levofloxacin (LVX), 19.6% (95% CI: 9.9-31.7); tetracycline (TET), 0.7% (95% CI: 0.1-1.8); and amoxicillin (AMO), 1.3% (95% CI: 0.3-3.1). The reported results showed that Turkish H. pylori isolates are highly resistant to CLA, MTZ, and LVX, while exhibiting a low level of resistance toward AMO and TET.

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.

Assessment of Efficacy and Adverse Effects of Bismuth-Based Treatment Combined with Bifidobacterium Lactis for Eradication of Helicobacter Pylori in Turkish Children

Objective There are many adverse effects of drugs used to eradicate Helicobacter pylori, and reconstructing the microbiota by external ingestion of probiotics seems to have good effects on H. pylori eradication and prevents side effects.

Methods The study included 161 outpatients aged between 8 and 18 years diagnosed with H. pylori gastritis in the Gülhane Training and Research Hospital Pediatric Gastroenterology unit from June 1, 2018, through March 31, 2020, and patients were randomized into two groups. Eighty patients in the probiotic group (first group) received H. pylori eradication therapy for 14 days; additionally, Bifidobacterium lactis B94 was administered for 14 days for eradication of H. pylori. Eighty-one patients in the standard therapy group (second group) received the same eradication therapy but no probiotics. All patients were asked to complete a detailed questionnaire regularly, including changes in symptoms and side effects of drugs on days 0, 7, and 14 of treatment. The eradication success was checked with the H. pylori stool antigen test kit 8 weeks after completion of the treatment regimen.

Results The mean age of the patients was 14.2 ± 2.9 years, and 88 (64.7%) were female. The eradication rates were similar between the standard therapy and the probiotic groups by intention-to-treat analysis (p = 0.930). In order of frequency, the most common eradication treatment–related side effects were abdominal pain, taste abnormalities, and anorexia. In addition, therapy-related epigastric pain and flatulence were similar initially (p > 0.05) but seemed to be significantly lower in the probiotic group than in the standard therapy group on days 7 and 14 (p < 0.05).

Conclusions Our results suggest that additional probiotic supplementation has not changed the eradication rates but seems to reduce some specific gastrointestinal adverse events in children with H. pylori infections treated with a bismuth-based quadruple eradication regimen. More extensive randomized controlled trials are needed to explain probiotics' effects on H. pylori eradication and drug side effects.

Detection of A2143G, A2142C, and A2142G Point Mutations with Real-Time PCR in Stool Specimens from Children Infected with Helicobacter pylori

Reports have indicated an increasing prevalence of clarithromycin resistance in children relative to adults. Thus, it is important to investigate primary clarithromycin resistance before therapy to avoid treatment failure. A2142G, A2143G, and A2142C point mutations in the peptidyltransferase region of the 23S ribosomal RNA (rRNA) of Helicobacter pylori (H. pylori) strains isolated from children with gastrointestinal symptoms and asymptomatic children were evaluated via real-time polymerase chain reaction (RT-PCR) using fecal DNA samples. The presence of H. pylori was determined using a fecal H. pylori antigen enzyme-linked immunosorbent assay (ELISA) kit from the stools of children (n = 543). A2143G, A2142C, and A2142G point mutations were detected via RT-PCR and confirmed by sequencing the 23S rDNA. Fecal H. pylori antigen testing was positive in 101 symptomatic (49) and asymptomatic (52) children. A significant difference was found between the 0–5- and 5–18-year-old groups in terms of the A2143G and A2142G point mutations (p = 0.001). The A2142C mutation was not detected. There was a significant difference in the A2143G mutation between the symptomatic and asymptomatic 5–18-year-old children (p = 0.019). Macrolides are frequently used to treat upper respiratory tract infections in children due to their selective pressure effect. We suggest that H. pylori strains carrying mutations in the 23S RNA subunit conferring clarithromycin resistance may lead to an intense inflammatory response in the gastric epithelial cells, allowing them to proliferate more rapidly and causing possible diarrhea, halitosis, or abdominal pain in children.

Recent trends in the antibiotic resistance of Helicobacter pylori in patient with dyspepsia

The aim of this study was to determine the resistance status and to identify the point mutations conferring resistance to clarithromycin and fluoroquinolones among dyspeptic patients in Manisa, Turkey. The study included a sample of 140 patients with an indication for upper gastrointestinal endoscopy randomly selected from 2100 dyspeptic patients attending to the Gastroenterology and Endoscopy Unit at Manisa Celal Bayar University Hafsa Sultan Hospital between April 2016 and May 2018. A commercially available GenoType Helico DR test was used to detect the presence of Helicobacter pylori and mutations associated with resistance to clarithromycin and fluoroquinolones in biopsy specimens. In total, 116 (82.9%) of 140 biopsies obtained from the same number of dyspeptic patients were positive for H pylori and 82 (approximately 71%) of them harbored resistance mutations in 23SrRNA and/or gyrA. Resistance to clarithromycin, levofloxacin, or both were detected in 43.1% (50/116), 27.6% (32/116), and 16/116 (13.8%) of tested biopsies, respectively. The most common mutation conferring resistance to clarithromycin was A2147G (96%, 48/50). Resistance to fluoroquinolones was frequently due to mutation in codon 91 and the most common mutation detected was D91G (34.4%). Heteroresistance patterns were observed in 48.0% (24/50) of clarithromycin-resistant samples and 28.1% (9/32) of levofloxacin-resistant samples. The resistance rates and detected mutations in this study are in line with the country data. However, to achieve better H pylori eradication and to prevent the spread of multidrug-resistant strains in Turkey, the molecular-based susceptibility tests should be considered routinely. Further studies are needed to determine the various mutations among resistant strains.

Can Saccharomyces boulardii treat and eradicate Helicobacter pylori among children instead of bismuth?

Aim: The objective of this study is to compare the use of Saccharomyces boulardii (S. boulardii) in eradicating Helicobacter pylori (H. pylori) in children as an alternative to bismuth, which has a limited scope of application due to its side effects. Material and Method: Included in the study were 220 pediatric patients with symptomatic H. pylori gastritis. The patients were randomized into three treatment groups. Patients who received bismuth or S. boulardii in addition to the standard triple therapy for 14 days were compared with the control group who received only triple therapy. Results: Analysis of the bismuth, S. boulardii, and control groups’ treatment success showed that the H. pylori eradication rate was highest among study participants who received bismuth (95.2%), followed by patients who received S. boulardii (92.4%). The most frequent side effects were observed in the patient group that received bismuth (17.5%). Conclusion: Although bismuth continues to be successful in eradicating H. pylori, alternative treatment protocols are necessary because of its side effects and limited use in pediatric patients. S. boulardii can be administered instead when bismuth can not serve as alternative due to its side effects.

Heteroresistance to clarithromycin and metronidazole in patients with a Helicobacter pylori infection: a systematic review and meta-analysis

BACKGROUND

Antimicrobial resistance of H. pylori can lead to treatment failure. Importantly, several studies have reported on heteroresistance, i.e. the presence of resistant and susceptible H. pylori populations in the same sample and/or a difference in the susceptibility patterns between biopsy samples. This meta-analysis aims to provide comprehensive data on the prevalence of metronidazole and clarithromycin heteroresistance and the approaches to their detection.

MATERIAL AND METHODS

A systematic review was performed after the search of MEDLINE, Scopus and Web of Science. The study outcomes were the weighted pooled prevalence of heteroresistance to clarithromycin and metronidazole in H. pylori positive samples and/or isolates with a subanalysis by continent.

RESULTS

A total of 22 studies that had investigated 3852 H. pylori positive patients were included in the meta-analysis. Heteroresistance to clarithromycin was reported in 20 studies, with a weighted pooled prevalence of 6.8% (95% CI 5.1-8.6; 3654 H. pylori positive patients; the substantial heterogeneity I² = 55.6%). Heteroresistance to metronidazole was reported in 12 studies, with a weighted pooled prevalence of 13.8% (95% CI 8.9-18.6; 1670 H. pylori positive patients; the substantial heterogeneity I² = 60.9%). The weighted pooled prevalence of clarithromycin heteroresistance was similar in Asia and Europe (p = 0.174584), however, metronidazole heteroresistance was detected more often in Europe (p < 0.00001). Clarithromycin heteroresistance was detected more often by phenotype rather than by using genotyping methods (12 vs 8 studies), whereas heteroresistance to metronidazole was detected only by phenotype.

CONCLUSION

The prevalence of heteroresistance to clarithromycin and/or metronidazole is not negligible and can be detected in approximately 7 and 14% of H. pylori positive samples, respectively. These findings highlight the need to raise the awareness of gastroenterologists and microbiologists to the heteroresistance to clarithromycin and metronidazole in patients with a H. pylori infection.

Increased Antibiotic Resistance in Children with Helicobacter pylori Infection: A Retrospective Study

Children with recurrent abdominal pain may be suffering from a Helicobacterpylori (HP) infection. The gold standard for confirming HP gastritis is histological evaluation and microbiological tests performed on specimens collected by esophagogastroduodenoscopy (EGD). The aim of this study was to analyze HP positive cultures and antibiograms with regard to clinical and histopathological correlates. The data of 124 subjects with frequent gastrointestinal symptoms who underwent an EGD were retrospectively collected and analyzed. The mean age of the patients was 13 ± 3.6 years. The most frequent complaints were epigastric pain (84%; n = 100/119) and dyspepsia (79%; n = 94/119). HP gastritis was diagnosed in 54% (n = 67). Interestingly, 40% (n = 49) of the isolates were resistant to at least one antibiotic: amoxicillin (20%; n = 10/49), clarithromycin (45%; n = 22/49), or metronidazole (59%; n = 29/49). Isolates were resistant to two or more antibiotics in 16% (n = 20) of cases. In conclusion, we revealed remarkably high resistance rates to amoxicillin, metronidazole, and clarithromycin in our cohort. The presence of antibiotic resistance to more than one antibiotic was substantially increased in our HP-infected patients and this may negatively affect eradication treatment.

Phenotypic and Genotypic Analysis of Resistant Helicobacter pylori Strains Isolated from Children with Gastrointestinal Diseases

Antibiotic resistance of Helicobacter pylori is currently a global issue. The aim of this study was to analyze actual antibiotic resistance rates of H. pylori strains isolated from children with primary infections and to compare the incidence of mutations that determine resistance to clarithromycin (CH) and metronidazole (MET) in children with different clinical diagnoses. A total of 91 H. pylori strains were isolated from 108 children with primary infections. Drug susceptibility testing of the strains was performed using E-test method. Classical sequencing of DNA fragments was used to detect point mutations for CH and MET resistance. Resistance to CH was detected in 31% of isolated strains (28/91), while resistance to MET and CH was detected in 35% (32/91) of strains. A2143G was the most frequently detected mutation and was dominant among strains isolated from children with peptic ulcer disease (80%). Mutations in the rdxA gene were found significantly more frequently among MET-resistant strains than MET-sensitive strains (p = 0.03, Chi2 = 4.3909). In children, a higher frequency of H. pylori multiresistant strains was observed compared with the previous study in the same area. Differences were found in the occurrence of point mutations among H. pylori strains resistant to CH isolated from children with different clinical diagnoses.

Treatment of Helicobacter pylori infection in children: A systematic review

BACKGROUND

Helicobacter pylori (H. pylori) infection is predominantly acquired in childhood. When indicated, the most accepted treatment for H. pylori eradication in this age group is first-line triple therapy. However, the increasing resistance to clarithromycin and nitroimidazoles has been associated with treatment failure, and thus, alternative treatment regimens have been proposed.

AIM

To perform a systematic review of randomized controlled trials on treatment regimens for H. pylori infection in children.

METHODS

We surveyed relevant articles published in English from 2010 to April 2020 in the PubMed and MEDLINE databases. Keywords included “Helicobacter pylori”/”children or childhood”/”treatment or eradication.” The risk of bias was evaluated according to the Cochrane Handbook of Systematic Reviews for Interventions.

RESULTS

Among the 1144 records identified through the database, 20 articles were selected. Four studies compared the eradication rates of H. pylori infection between standard triple therapies, changing only the main antibiotic used. Seven studies evaluated the effectiveness of standard triple therapy with the addition of probiotics. One study investigated the relationship between the effectiveness in the eradication rates of standard triple therapy and vitamin E levels. Six studies analyzed the eradication rates of sequential therapy.

CONCLUSION

The findings suggest that although standard triple therapy is the most recommended regimen for children by the current guidelines, other therapeutic schemes have shown promising results and may also be recommended for clinical practice in the future.