Seven-day genotypic resistance-guided triple Helicobacter pylori eradication therapy can be highly effective

Efficacy of genotypic susceptibility-guided tailored therapy for Helicobacter pylori infection: A systematic review and single arm meta-analysis

BACKGROUND AND AIM

The prevalence of antibiotic resistance for Helicobacter pylori (H. pylori) has been increasing over the year, making it more difficult for traditional empirical therapy to successfully eradicate H. pylori. Thus, tailored therapy (TT) guided by molecular-based antibiotic susceptibility testing (AST) has been frequently recommended. We conducted a single-arm meta-analysis to determine the efficacy of tailored therapy guided by molecular-based AST.

METHODS

A systematic literature review was performed on multiple databases, and studies on molecular-based TT were included. The eradication rates of TT by intention-to-treat (ITT) and per-protocol (PP) analyses were pooled respectively.

RESULTS

A total of 35 studies from 31 literature (4626 patients) were included in the single-arm meta-analysis. Overall, the pooled eradication rate of TT was 86.9% (95% CI:84.7%-89.1%) by the ITT analysis, and 91.5% (95% CI:89.8%-93.2%) by PP analysis. The pooled eradication rates of first-line TT and rescue TT were 86.6% and 85.1% by ITT analysis and 92.0% and 87.9% by PP analysis, respectively. When tailored rescue therapy was based on the genotypic resistance to at least four antibiotics, the pooled eradication rates reached 89.4% by ITT analysis and 92.1% by PP analysis. For genotype-susceptive strains, the pooled eradication rate of TT with targeted antibiotics was 93.1% (95% CI:91.3%-94.9%), among which the pooled eradication rate of tailored bismuth quadruple therapy was the highest (94.3%). Besides, the eradication rate of 7-day TT or tailored triple therapy without bismuth for genotype-susceptive strains could both reach more than 93.0%.

CONCLUSION

Tailored therapy guided by molecular-based AST can achieve somewhat ideal therapeutic outcomes. TT with a 7-day duration or without bismuth for genotype-susceptible strains can achieve good eradication efficacy. The effectiveness of TT can be improved to some extent by expanding the coverage of AST or by adding bismuth.

Antibiotic resistance of Helicobacter pylori isolated from children in Chongqing, China

The resistance of Helicobacter pylori (H. pylori) to antibiotics has been increasing worldwide and varies across different geographic areas and times. Limited studies reported the prevalence of antibiotic resistance and its related gene mutations in children in Chongqing, a city located in southwest China. We collected 112 H. pylori strains isolated from gastric biopsies of 156 children at Children's Hospital of Chongqing Medical University and calculated resistance rates of these strains to six antibiotics. The A2143G and A2142G mutations in 23S rRNA gene, which are related to clarithromycin resistance, and Asn87 and Asp91 mutations in gyrA gene, which are related to levofloxacin resistance, were investigated in 102 strains. The resistance rates to clarithromycin, metronidazole, and levofloxacin were 47.3% (53/112), 88.4% (99/112), and 18.8% (21/112), respectively. No resistance to amoxicillin, tetracycline, and furazolidone was observed. Dual and triple resistance percentages were 37.5% (42/112) and 10.7% (12/112), respectively. The detection rate of A2143G mutation in 23S rRNA gene was 83.3% (40/48). The detection rates of mutations of Asn87 and Asp91 in gyrA gene were 52.6% (10/19) and 36.8% (7/19), respectively. Conclusion: The prevalence of H. pylori resistance to clarithromycin, metronidazole, and levofloxacin was high in children in Chongqing, China. The A2143G mutation was detected in most clarithromycin-resistant strains, and Asn87 and Asp91 of gyrA mutation points were common in levofloxacin-resistant strains. In clinical practice, anti-H. pylori therapy should be individualized based on a susceptibility test.  What is Known: • The resistance of H. pylori to antibiotics changes with the geographic areas and that in Asia the resistance rate is high. • Mutation plays a vital role in antibiotics resistance of H. pylori. What is New: • High resistance rates to single and multiple antibiotics in children of Chongqing, a city located in southwest China, were observed. • Molecular assays showed good conformance with susceptibility test results to direct antibiotic resistance of H. pylori.

Study on the value of antibiotic-resistant gene detection in Helicobacter pylori in China

The aim of the present study was to explore the value of detecting antibiotic-resistant genes in Helicobacter pylori (H. pylori) and the association between genotype and antibiotic resistance. Two gastric mucosa samples from each H. pylori-positive patient were collected. Each patient's H. pylori sample was cultured in vitro, and the agar plate dilution method was conducted. In addition, all patient samples were analyzed for the detection of antibiotic resistance-related mutant genes and VacA gene genotypes. The association between VacA genotypes and antibiotic resistance was also determined and the value of mutant gene detection in predicting H. pylori resistance to antibiotics was evaluated. In total, 133 H. pylori-positive patients were enrolled. A total of 22 strains of H. pylori failed to grow in in vitro culture and 25 strains were negative in a H. pylori gene test. Among 108 strains detected by PCR, a total of 39 VacA s1m1 strains, 69 VacA s1m2 strains and no VacA s2 strain were identified. There was no significant association between VacA genotypes and antibiotic resistance. The mutation rates of G616A in the rdxA gene, T87A, G91A, A91G and G91T in the gyrA gene and A2143G and A2142G in the 23S rRNA gene were 32.1, 32.3, 22.6, 12.9, 6.5, 81.8 and 0.0%, respectively. Among these mutant sites, the mutation coincidence rates were as follows, according to the agar plate dilution method: rdxA G616A (81.8%), gyrA G91T (66.7%), gyrA G91A (54.5%), 23 S rRNA A2143G (49.1%), gyrA T87A (45.5%), gyrA A91G (33.3%), penicillin-binding protein 1 (PBP1) C556G (0.0%), PBP1 A562T (0.0%), PBP1 A562G (0.0%) and 16 S rRNA 926-927 (AT-GT) (0.0%). VacA m subtypes were not associated with H. pylori antibiotic resistance. In conclusion, the present findings suggested that the detection of related mutant genes had a clinical application value in predicting the antibiotic resistance of H. pylori, particularly resistance to clarithromycin and levofloxacin.

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.

Identification of antibiotic resistance patterns in Helicobacter pylori strains isolated from gastric biopsies using real-time PCR and genotypic analysis

BACKGROUND

Helicobacter pylori (H. pylori) is associated with dyspepsia, mucus-associated lymphoid tissue lymphoma, gastritis, and peptic ulcer disease. Treatment in Malta consists of triple therapy, which consists of a proton pump inhibitor and 2 of the antibiotics amoxicillin, clarithromycin, metronidazole and fluoroquinolones. We aimed to determine the resistance rates for clarithromycin and fluoroquinolones in patients with H. pylori, and its incidence, in patients undergoing an esophagogastroduodenoscopy (EGD) using real-time polymerase chain reaction (RT-PCR).

METHODS

Patients undergoing an EGD were recruited. A rapid urease test (RUT) was performed, and 4 gastric biopsies were also taken (2 from antrum, 2 from corpus) and analyzed using RT-PCR. Positive samples were tested for antibiotic resistance using amplification and reverse hybridization techniques.

RESULTS

Two hundred patients (mean age 53.6 [range 20-92] years; 53.1% female) were recruited; the majority were (78%) non-smokers. H. pylori was identified in 21.0% of the patients. Fluoroquinolone resistance was detected in 21.4% of the patients. Clarithromycin resistance was observed in 26.2%, with dual resistance identified in 4.8% of the patients. A high concordance was present with patients testing negative for H. pylori with both RUT and RT-PCR (94.3%). Only 57.6% of patients tested positive with both tests. However, 92.9% of RT-PCR positive patients had a positive genotype HelicoDR test.

CONCLUSIONS

This data demonstrates a high rate of H. pylori resistance to both clarithromycin and fluoroquinolones. These should be avoided when treating H. pylori by utilizing different treatment regimes. Furthermore, we derived important data on the role of RT-PCR, which may be implemented in routine clinical practice.

Clinical Evaluation of a Real-Time PCR Assay for Simultaneous Detection of Helicobacter pylori and Genotypic Markers of Clarithromycin Resistance Directly from Stool

Helicobacter pylori infection is mainly diagnosed noninvasively, with susceptibility testing traditionally requiring endoscopy. Treatment is empirical, with clarithromycin-based triple therapy recommended where resistance rates are below 15%. Rising rates of clarithromycin resistance, resulting in high clarithromycin-based therapy failure rates, are seen worldwide, but U.S. data are limited. We developed a real-time PCR assay for simultaneous detection of H. pylori and genotypic markers of clarithromycin resistance directly from stool specimens. The assay was validated by testing 524 stool samples using an H. pylori stool antigen test as the reference method for detection accuracy and Sanger sequencing to confirm genotypic susceptibility results. A separate set of 223 antigen-positive stool samples was tested and retrospective medical record review conducted to define clinical utility. PCR resulted in 88.6% and 92.8% sensitivity in the validation and clinical study sets, respectively. Sequencing confirmed correct detection of clarithromycin resistance-associated mutations in all positive validation samples. The PCR-predicted clarithromycin resistance rate was 39% in the clinical data set overall and 31% in treatment-naive patients; the clarithromycin-based triple therapy eradication rate in treatment-naive patients was 62%. The clarithromycin-based triple therapy success was lower when resistance was predicted by PCR (41%) than when no resistance was predicted (70%; P = 0.03). PCR results were positive in 98% of antigen-positive stools from patients tested for eradication. The described PCR assay can accurately and noninvasively diagnose H. pylori, provide genotypic susceptibility, and test for eradication. Our findings support the need for susceptibility-guided therapy in our region if a clarithromycin-based regimen is considered.

Rifabutin for the Treatment of Helicobacter Pylori Infection: A Review

Nowadays, apart from having to know first-line Helicobacter pylori eradication regimens well, we must also be prepared to face treatment failures. The aim of this review is to summarize the role of rifabutin in the management of H. pylori infection. Bibliographical searches were performed in PubMed. Data on resistance and efficacy of rifabutin-containing regimens on H. pylori eradication were meta-analyzed. Mean H. pylori rifabutin resistance rate (39 studies, including 9721 patients) was 0.13%; when studies only including patients naïve to H. pylori eradication treatment were considered, this figure was even lower (0.07%). Mean H. pylori eradication rate (by intention-to-treat) with rifabutin-containing regimens (3052 patients) was 73%. Respective cure rates for second-, third-, fourth- and fifth-line therapies, were 79%, 69%, 69% and 72%. Most studies administered rifabutin 300 mg/day, which seemed to be more effective than 150 mg/day. The ideal length of treatment remains unclear, but 10–12-day regimens are generally recommended. Adverse events to rifabutin treatment in H. pylori studies were relatively infrequent (15%), and severe adverse events were exceptional (myelotoxicity was the most significant, although always reversible). In summary, rifabutin-containing therapy represents an encouraging strategy generally restricted, at present, to patients where previous (usually multiple) eradication regimens have failed.

Best Helicobacter pylori Eradication Strategy in the Era of Antibiotic Resistance

Antibiotic resistance is the major reason for Helicobacter pylori treatment failure, and the increasing frequency of antibiotic resistance is a challenge for clinicians. Resistance to clarithromycin and metronidazole is a particular problem. The standard triple therapy (proton pump inhibitor, amoxicillin, and clarithromycin) is no longer appropriate as the first-line treatment in most areas. Recent guidelines for the treatment of H. pylori infection recommend a quadruple regimen (bismuth or non-bismuth) as the first-line therapy. This treatment strategy is effective for areas with high resistance to clarithromycin or metronidazole, but the resistance rate inevitably increases as a result of prolonged therapy with multiple antibiotics. Novel potassium-competitive acid blocker-based therapy may be effective, but the data are limited. Tailored therapy based on antimicrobial susceptibility test results is ideal. This review discussed the current important regimens for H. pylori treatment and the optimum H. pylori eradication strategy.

Hellenic consensus on Helicobacter pylori infection

The Hellenic Society of Gastroenterology recently organized the “Hellenic consensus on Helicobacter pylori (H. pylori) infection”. The aim of this publication is to report the guidelines in order to aid the national gastroenterology community in the management of H. pylori infection. Forty-one delegates from all Greek regions, including gastroenterologists, pathologists, clinical microbiologists, epidemiologists and basic scientists, were invited to this meeting. The participants were allocated to 1 of the 4 main topics of the meeting: i.e., H. pylori diagnosis and association with diseases; H. pylori and gastric cancer; H. pylori and extragastric associated disorders; and H. pylori treatment. The results of each subgroup were submitted to a final consensus vote that included all participants. Relevant data based on international and Greek publications were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded. The cutoff level of 70% was considered as acceptance for the final statement. It is hoped that the recommendations and conclusions of this report will guide Greek doctors in their daily practice concerning the management of H. pylori infection.