Helicobacter pylori eradication rates in children upon susceptibility testing based on noninvasive stool polymerase chain reaction versus gastric tissue culture

Individualized diagnosis and eradication therapy for Helicobacter pylori infection based on gene detection of clarithromycin resistance in stool specimens: A systematic review and meta-analysis

BACKGROUND

Empiric therapy for Helicobacter pylori infection results in significantly increased antibiotic resistance and decreased eradication efficacy. The genotypic testing of clarithromycin resistance from stool specimens is a promising method for individualized diagnosis and treatment. This study aimed to determine the status of research and application on this method through a systematic review and meta-analysis.

METHODS

PubMed, Embase, MEDLINE, and WAN FANG database were searched for relevant literature. The quality of included diagnostic articles was evaluated using the quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate random-effect model was conducted to calculate the diagnostic accuracy of genotypic testing of clarithromycin resistance.

RESULTS

A total of 16 diagnostic-related were included and analyzed after exclusions. The pooled sensitivity and specificity of diagnostic meta-analysis were 0.93 (95% confidence interval [CI]: 0.90-0.96) and 0.98 (95% CI: 0.93-1.00), respectively. The area under the curve (AUC) of the summary receiver operating characteristic was 0.97 (95% CI: 0.95-0.98). The genotypic testing in stool samples had heterogeneous sensitivity (Q = 37.82, p < .01, I²  = 37.82) and specificity (Q = 60.34, p < .01, I²  = 93.72) in detecting clarithromycin resistance. Purification method, stool sample weight, real-time PCR, and antimicrobial susceptibility testing as reference accounted for the heterogeneity of pooled sensitivity, while patient age, purification method, stool sample weight, and real-time PCR for the heterogeneity of pooled specificity.

CONCLUSION

The genotypic testing of clarithromycin resistance from stool specimens is an accurate, convenient, noninvasive, and rapid detection technology, providing a definitive diagnosis of clarithromycin resistance and guiding the rational antibiotic selection.

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.

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.

Traditional and Modern Diagnostic Approaches in Diagnosing Pediatric Helicobacter pylori Infection

Helicobacter pylori (H. pylori) is the most common bacterial infection worldwide, is usually acquired during childhood and is related to gastric carcinogenesis during adulthood. Therefore, its early proper diagnosis and subsequent successful eradication represent the cornerstones of gastric cancer prevention. The aim of this narrative review was to assess traditional and modern diagnostic methods in terms of H. pylori diagnosis. Several invasive and non-invasive methods were described, each with its pros and cons. The invasive diagnostic methods comprise endoscopy with biopsy, rapid urease tests, histopathological exams, cultures and biopsy-based molecular tests. Among these, probably the most available, accurate and cost-effective test remains histology, albeit molecular tests definitely remain the most accurate despite their high costs. The non-invasive tests consist of urea breath tests, serology, stool antigens and non-invasive molecular tests. Urea breath tests and stool antigens are the most useful in clinical practice both for the diagnosis of H. pylori infection and for monitoring the eradication of this infection after therapy. The challenges related to accurate diagnosis lead to a choice that must be based on H. pylori virulence, environmental factors and host peculiarities.

Efficacy of Phenotype-vs. Genotype-Guided Therapy Based on Clarithromycin Resistance for Helicobacter pylori Infection in Children

BACKGROUND

Clarithromycin resistance reduces the eradication rate of Helicobacter pylori (H. pylori). Cultures with susceptibility testing and molecular determination of genotypes are recommended to guide-tailored therapy.

METHODS

We retrospectively enrolled patients aged 6 and 18 years with H. pylori infection, who underwent an endoscopy and agreed to undergo both culture and genetic testing for clarithromycin resistance. Patients receiving tailored therapy based on traditional culture results (phenotype-guided therapy) or genetic testing results (genotype-guided therapy) were included in the study. ¹³C-urea breath test was used to evaluate the success of eradication at least 4 weeks after the completion of treatment. We aimed to determine whether the eradication rate of phenotype- or genotype-guided therapy based on clarithromycin resistance is greater than 90% in children.

RESULTS

Between September 2017 and October 2020, 226 eligible patients were enrolled. There were 71 with clarithromycin-sensitive strains in the phenotype-guided therapy group and 87 without 23S rRNA point mutations (A2142G, A2142C, and A2143G) in the genotype-guided therapy group. Eradication rates were 70.4% (50/71, [95% CI: 58.4-80.7%] for phenotype-guided therapy and 92.0% (80/87, [95% CI: 84.1-96.7%]) for genotype-guided therapy (P < 0.01). The incidence of side effects was 4.2% (3/71) and 10.3% (9/87), with no major differences between these two groups (P = 0.15), respectively. The compliance rate was also similar (97.2 vs. 95.4%, P = 0.87).

CONCLUSION

Tailored therapy according to genetic testing results achieved eradication rates of 92% and was superior to tailored therapy guided by traditional culture results.

Pediatric Endoscopy, Update 2020

Optimal management of pediatric endoscopy requires a multidisciplinary approach. In most hospitals, endoscopy in pediatric patients is performed by conventional gastroenterologists and only a few centers have specialized pediatric gastroenterologists. This is due to the fact that the number of pediatric gastroenterologists is limited and not all of them are experienced in endoscopic techniques. However, there are also some pediatric centers offering a high-quality and high-volume endoscopy service provided by very experienced pediatric gastroenterologists. Up to now, the literature on pediatric endoscopy is rather sparse. In this article, we describe current knowledge and practice of endoscopic procedures in pediatric patients, which should be relevant for both the adult and pediatric gastroenterologists.

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.

Detection of Helicobacter pylori in dental plaque using a DNA biosensor for noninvasive diagnosis

H. pylori in dental plaque was detected with a DNA biosensor with results correlating well with the ¹³C urea breath test.

Appropriateness of Repeating Helicobacter pylori Culture and Susceptibility Testing Following Failure of Individualized Antibiotic Therapy

BACKGROUND

Current guidelines recommend direct Helicobacter pylori culture and antibiotic susceptibility testing following 2 failed eradication attempts. If this process is followed and yet subsequent treatment is unsuccessful, it is unclear whether susceptibility testing should be repeated. This is the first study to examine the appropriateness of repeated H. pylori culture and susceptibility testing following failure of individualized treatment.

METHODS

Between 2007 and 2014, consecutive patients who underwent at least 2 upper gastrointestinal endoscopies with H. pylori culture and susceptibility testing at our institution following several treatment failures were retrospectively identified. Antibiotic susceptibility was recorded and linked to demographic data.

RESULTS

A total of 68 cultures from 34 patients were included (12 (35.3%) men, 41.4 ± 16.6 years), and 20 (58.8%) cultures had a different antibiotic susceptibility profile on repeat testing (8 (23.5%) with new susceptibility and 13 (38.2%) with new resistance). Acquired resistance to clarithromycin, levofloxacin and metronidazole was observed in 9 (26.5%), 2 (5.9%) and 10 (29.4%) cultures, respectively. Subjects with resistance to ≤1 antibiotic at baseline were more likely to develop resistance to at least 1 antibiotic on subsequent culture, compared to subjects with resistance to ≥2 antibiotics at baseline (13 (100%) vs. 5 (23.8%), p < 0.01).

CONCLUSION

Repeating H. pylori culture and susceptibility testing usually yields new antimicrobial susceptibility data. However, the clinical usefulness of this approach remains unclear.

Helicobacter pylori infection - recent developments in diagnosis

Considering the recommended indications for Helicobacter pylori (H. pylori) eradication therapy and the broad spectrum of available diagnostic methods, a reliable diagnosis is mandatory both before and after eradication therapy. Only highly accurate tests should be used in clinical practice, and the sensitivity and specificity of an adequate test should exceed 90%. The choice of tests should take into account clinical circumstances, the likelihood ratio of positive and negative tests, the cost-effectiveness of the testing strategy and the availability of the tests. This review concerns some of the most recent developments in diagnostic methods of H. pylori infection, namely the contribution of novel endoscopic evaluation methodologies for the diagnosis of H. pylori infection, such as magnifying endoscopy techniques and chromoendoscopy. In addition, the diagnostic contribution of histology and the urea breath test was explored recently in specific clinical settings and patient groups. Recent studies recommend enhancing the number of biopsy fragments for the rapid urease test. Bacterial culture from the gastric biopsy is the gold standard technique, and is recommended for antibiotic susceptibility test. Serology is used for initial screening and the stool antigen test is particularly used when the urea breath test is not available, while molecular methods have gained attention mostly for detecting antibiotic resistance.

Virulence factors and antibiotic resistance in children with Helicobacter pylori gastritis

OBJECTIVES

There are limited data regarding the pattern of Helicobacter pylori (Hp) antibiotic resistance and virulence factors in children. Evaluation of prevalence of drug resistance and virulence-factor genotype in children with Hp gastritis and to investigate whether there is any relation between drug resistance and genotype were our aims in this study.

METHODS

Ninety-eight children with polymerase chain reaction-positive Hp gastritis were included. Antimicrobial susceptibility was tested by disc diffusion method and polymerase chain reaction assays were used for the determination of virulence factors.

RESULTS

The resistance rates to clarithromycin, metronidazole, and amoxicillin were 23.5%, 11.7%, and 3.9%, respectively. All strains carried vacA genotype, and 51%, 70.4%, 49%, 34.7%, and 25.5% were cagA-, cagE-, babA2-, iceA1-, and iceA2-positive, respectively. Of those 98 specimens, 81.6%, 19.4%, 38.8%, and 63.3% carried vacAs1, vacAs2, vacAm1, and vacAm2, respectively. Dominant vacA type was s1am2 (32.7%), followed by s1am1 (14.3%) and s2m2 (12.2%). Significant rates of clarithromycin resistance were observed in cagE-, iceA1-, babA2-, and vacAs1c-positive groups. In those with metronidazole resistance, vacAs1 and vacAs1c were more common (P < 0.05).

CONCLUSIONS

The cagE-positive and vacA s1a/m2 genotypes, which are correlated with increased antibiotic resistance, were predominant in our population. In countries where Hp infection is prevalent, studies focusing on virulence factors and antibiotic susceptibility may provide anticipation of the prognosis and may be helpful to reduce morbidity and mortality.

Detection of clarithromycin-resistant Helicobacter pylori by stool PCR in children: a comprehensive review of literature

BACKGROUND

Helicobacter pylori infection is acquired mainly during childhood. To eradicate H. pylori, clarithromycin-based triple therapy has been recommended in children and adults by the latest Maastricht Consensus. However, the prevalence of clarithromycin-resistant H. pylori was higher in children than that in adults. Therefore, rapid, reliable and noninvasive methods for detecting clarithromycin-resistant H. pylori strains should be developed for children.

MATERIALS AND METHODS

Studies on evaluating stool PCR in detecting clarithromycin-resistant H. pylori and epidemiological surveys of the prevalence of clarithromycin-resistant H. pylori in children were searched in PubMed (from 1966 to December, 2011) for reviewing.

RESULTS

The average rates of primary clarithromycin-resistant H. pylori ranged from less than 10% to more than 40% in different regions. The rates of secondary resistance to clarithromycin were higher than primary resistance in the same population. In H. pylori isolated from children, the frequent point mutations that are responsible for the clarithromycin resistance included A2143G, A2142G, A2142C and A2144G, and they varied geographically. Comparing with culture-based susceptibility tests, stool PCR performed excellently for their rapidity, independence of bacterial growth, reproducibility and easy standardization. However, stool PCR showed lower sensitivity but perfect specificity in detection of clarithromycin-resistant H. pylori in children. Methodology and mixed infections of resistant H. pylori strains might contribute to the considerable discrepancies of stool PCR results.

CONCLUSION

Detection of clarithromycin-resistant H. pylori by stool PCR for children are reliable, rapid, noninvasive methods that are worthy of further clinical promotion. However, more evaluations of stool PCR in detection of clarithromycin-resistant H. pylori in children need to be conducted.

Epidemiology and diagnosis of Helicobacter pylori infection

Medline, PubMed and the Cochrane databases were searched on epidemiology and diagnosis of Helicobacter pylori for the period of April 2011-March 2012. Several studies have shown that the prevalence of H. pylori infection is decreasing in adults and children in many countries. Various diagnostic tests are available, and most of them have high sensitivity and specificity. The Maastricht IV/Florence consensus report states that the urea breath test using (13)C urea remains the best test to diagnose H. pylori infection. Among the stool antigen tests, the ELISA monoclonal antibody test is recommended. All these tests were used, either as a single diagnostic test or in combination, to investigate H. pylori infection among different populations throughout the world. Of particular interest, current improvements in high-resolution endoscopic technologies enable increased diagnostic accuracy for the detection of H. pylori infection, but none of these techniques, at present, are specific enough for obtaining a real-time diagnosis of H. pylori infection.