Predicting Helicobacter pylori eradication: how to teach an old dog new tricks!

Susceptibility patterns and virulence genotypes of Helicobacter pylori affecting eradication therapy outcomes among Egyptian patients with gastroduodenal diseases

BACKGROUND

Helicobacter pylori (H. pylori) is a significant human pathogen that is responsible for a variety of illnesses, including mucosa-associated lymphoid tissue lymphoma, gastric cancer, peptic ulcers, and gastritis.

AIM

To investigate the frequency of H. pylori infection and its resistance patterns among Egyptian patients and to determine the influence of H. pylori virulence genetic determinants on the eradication success of 14-d triple therapy regimen.

METHODS

H. pylori infections were investigated in 72 patients with gastroduodenal complications suggestive of H. pylori infection. The cagA and vacA genotypes of cultured strains were studied using polymerase chain reaction. The patients underwent 14 d of triple-therapy treatment. The treatment response was examined using histology and a rapid urease test 6 wk after therapy discontinuation.

RESULTS

The intention-to-treat eradication rate was 59.2% (95%CI: 48.2%-70.3%). Rates of H. pylori resistance to clarithromycin, amoxicillin, and metronidazole were 52.8%, 81.9%, and 100%, respectively. Successful eradication of H. pylori was more significantly associated with vacA s1-positive strains [adjusted odds ratio (aOR) = 0.507, 95%CI: 0.175-0.822]. A significant association was found between failed eradication rate and H. pylori strains resistant to clarithromycin (aOR = 0.204, 95%CI: -0.005 to 0.412) and amoxicillin (aOR = 0.223, 95%CI: 0.026-0.537).

CONCLUSION

This study's low H. pylori eradication rate following 14-d triple therapy is concerning and worrying. H. pylori pan-resistance to metronidazole followed by the high resistance to ciprofloxacin, amoxicillin, and clarithromycin in this research is challenging and of great concern.

Helicobacter pylori Eradication Efficacy of Therapy Based on the Antimicrobial Susceptibility in Children with Gastritis and Peptic Ulcer in Mekong Delta, Vietnam

Background: The efficacy of Helicobacter pylori (H. pylori) eradication therapy for children is currently low, and antibiotic resistance is a significant cause of treatment failure. The purpose of this study was to evaluate the H. pylori eradication efficacy of therapy based on antimicrobial susceptibility in pediatric patients with gastritis and peptic ulcer. Methods: This study was conducted at Can Tho Children’s Hospital and Can Tho University of Medicine and Pharmacy Hospital between March 2019 and April 2022. We performed an upper gastrointestinal endoscopy, cultured H. pylori from biopsies of gastric mucosa, determined antibiotic sensitivities to H. pylori by the E-test method, and treated eradication based on the antibiotic susceptibilities of bacteria. After at least 4 weeks of eradication therapy, we assessed the effectiveness of treatment with a breath test. Results: Among 237 children recruited in this study, 48.9% were boys and 51.1% were girls, and the mean age was 10.03 ± 2.53 years. We determined that 80.6% of H. pylori were resistant to clarithromycin, as well as amoxicillin, metronidazole, levofloxacin, and tetracycline, at 71.7%, 49.4%, 45.1%, and 11.4%, respectively. The overall eradication rate of H. pylori was 83.1% (172/207). Among therapies tailored to antimicrobial susceptibility, the bismuth quadruple regimen achieved the greatest success, but the efficacy of triple therapy with esomeprazole + AMX + CLR/MTZ was low. Conclusions: Tailored eradication therapy was highly successful in our study but did not achieve over 90%. We recommend that in countries with a high prevalence of antibiotic resistance in H. pylori strains, particularly where the amoxicillin-resistance rate of H. pylori is high, therapy tailored to antimicrobial susceptibility should be used as first-line therapy, and bismuth and tetracycline should be added to enhance the eradication efficacy in children.

Clinical Factors Implicated in Antibiotic Resistance in Helicobacter pylori Patients

Helicobacter pylori is a common gastric pathogen associated with multiple clinical syndromes, including cancer. Eradication rates of H. pylori remain suboptimal despite the progress made in the past few decades in improving treatment strategies. The low eradication rates are mainly driven by antibiotic resistance of H. pylori. Non-invasive molecular testing to identify patients with antibiotic-resistant H. pylori represents a promising therapeutic avenue, however this technology currently remains limited by availability, costs, and lack of robust validation. Moreover, there is insufficient evidence to demonstrate that resistance-testing-based treatment approaches are superior to appropriately designed empiric strategies. Consensus guidelines recommend use of proven locally effective regimens; however, eradication data are inconsistently generated in several regions of the world. In this review, we describe several clinical factors associated with increased rates of antibiotic resistant H. pylori, including history of previous antibiotic exposure, increasing age, female gender, ethnicity/race, extent of alcohol use, and non-ulcer dyspepsia. Assessment of these factors may aid the clinician in choosing the most appropriate empiric treatment strategy for each patient. Future study should aim to identify locally effective therapies and further explore the clinical factors associated with antibiotic resistance.

Helicobacter pylori eradication following first-line treatment failure in Europe: What, how and when chose among different standard regimens? A systematic review

Cure rate following standard first-line regimens for Helicobacter pylori eradication is decreasing so several patients require two or more treatments. Antibiotic susceptibility-based therapy, advised in current guidelines, is largely impracticable in clinical practice. Some 'standard' regimens (triple therapies based on either levofloxacin or rifabutin, bismuth-based quadruple therapies, sequential, concomitant and hybrid therapies) were empirically used as rescue therapies. We performed a systematic review on recent studies carried out in European countries dealing with these regimens. A total of 24 studies, with 3804 patients, were identified. As second-line therapy, Pylera (89.2%) and sequential therapy (92.5%) achieved significantly higher cure rates as compared to all the other regimens. As third-line therapy, levofloxacin-based therapy (84.1%) and Pylera (83.6%) achieved similarly high cure rates, whereas standard, bismuth-based quadruple therapy (64.1%) achieved the lowest. As a rescue therapy, the success rate was close to 75% following all therapies used, with data on rifabutin-based regimen consolidated in the larger sample size. Overall, levofloxacin-amoxicillin triple therapy achieved higher eradication rates when the 14- rather than 10-day regimen was used (87.1 vs. 72.2%; P = 0.003). Among bismuth-based therapies, Pylera achieved a significantly higher eradication rate than standard quadruple therapy (88 vs. 67%; P < 0.0001). These data suggest that a wise 'therapeutic package' following first-line therapy could be Pylera, levofloxacin- and rifabutin-based therapy, as long as Pylera therapy was not used as a first-line regimen and levofloxacin-based regimen was administered for 14 days.

Rescue Therapies for H. pylori Infection in Italy

Background/Aims: Curing Helicobacter pylori infection remains challenging for clinicians, as no proposed first-line therapy achieves bacterial eradication in all treated patients so that several patients need two or more consecutive treatments. Bacterial culture with antibiotics susceptibility testing is largely unachievable in Italy, and empiric second-line and rescue therapies are generally used. This study aimed to identify what eradication regimens perform better in Italy, following first-line therapy failure. Methods: We performed a literature search on PubMed for studies on standard therapy regimens used as second-line or rescue treatments performed in adult patients. Studies including modified drug combinations were not considered. Both intention-to-treat and per- protocol analyses were computed for each therapy subgroup. Results: Data from 35 studies with a total of 4830 patients were eventually considered. As a second-line therapy, Pylera® (90.6%) and a sequential regimen (89.8%) achieved eradication rates significantly higher than other therapies. For third-line therapy, a levofloxacin-based regimen and Pylera® achieved comparable eradication rates (88.2% vs. 84.7%; p = 0.2). Among therapies used as fourth (or more) attempts, Pylera® and a rifabutin-based therapy achieved 77.4% and 66.4% cure rates, respectively (p = 0.013). A therapy sequence based on the type of first-line therapy used was proposed. Conclusions: Data obtained through our review indicate that standard therapies for H. pylori eradication can be used when following an appropriate sequence, allowing clinicians to improve the cure rate without resorting to bacterial culture.

Antibiotic Resistance and Therapy for H. pylori Infection in Immigrant Patients Treated in Italy

Background: Helicobacter pylori (H. pylori) infection is the leading cause of both peptic ulcers and gastric tumors, including low-grade MALT-lymphoma and adenocarcinoma. Although it is decreasing in developed countries, H. pylori prevalence remains high in developing areas, mainly due to low socio-economic levels, and the potential consumption of contaminated water. Moreover, a different pattern of primary antibiotic resistance is expected in their H. pylori isolates, potentially affecting the efficacy of standard eradication therapies. Indeed, a previous study showed the eradication rate following triple therapy was distinctly lower in dyspeptic H. pylori infected immigrants living in Italy as compared to Italian patients. Aims: to evaluate the resistance pattern in H. pylori isolates from immigrant patients in Italy, and the success rate of first-line therapy in these patients. Materials and Methods: This retrospective study evaluated data of consecutive immigrant patients, diagnosed with H. pylori infection in a single center (Bologna, Italy) between January 2009 and January 2019. Patients underwent first-line therapy with either sequential or Pylera^® (Allergan USA, Inc. Madison, NJ, USA) therapy. Results: A total of 609 immigrants were diagnosed with H. pylori infection during the study period, but 264 previously received an eradication therapy. Therefore, the study was focused on 294 out of 345 naïve patients with a successful bacterial culture with antibiogram. Latin America immigrants had the highest overall resistance rate. Levofloxacin resistance rate was significantly higher in Latin Americans and Asians as compared with Europeans. Based on resistance patterns, sequential therapy showed a clear decreasing trend in eradication rates. Conclusions: while antibiotic resistance rates are generally increasing worldwide, Pylera^® seems to achieve a good performance as first-line treatment in all naïve foreigner patients, except for Africans.

Pylera and sequential therapy for first-line Helicobacter pylori eradication: a culture-based study in real clinical practice

BACKGROUND AND AIMS

Italian guideline suggests 10-day sequential or bismuth-based quadruple therapies for first-line Helicobacter pylori treatment. Comparison between these regimens is lacking. We assessed the efficacy of these therapies in clinical practice and evaluated the role of primary bacterial resistance toward clarithromycin and metronidazole.

PATIENTS AND METHODS

Consecutive patients with H. pylori infection were enrolled. Bacterial culture with antibiotics susceptibility testing was attempted in all cases. Patients received either a sequential therapy with esomeprazole 40 mg for 10 days plus amoxicillin 1000 mg for the first 5 days followed by clarithromycin 500 mg and tinidazole 500 mg (all twice daily) for the remaining 5 days, or bismuth-based therapy with esomeprazole 20 mg twice daily and Pylera 3 tablets four times daily for 10 days. H. pylori eradication was assessed by using C-urea breath test.

RESULTS

A total of 495 patients were enrolled. Following sequential (250 patients) and quadruple (245 patients) therapies, the eradication rate were 92 and 91%, respectively, at intention-to-treat analysis and 96 and 97%, respectively, at per protocol analysis. Overall, the pattern of bacterial resistance did not significantly affect the cure rate, but the presence of clarithromycin and metronidazole dual resistance tended to reduce the success rate of both sequential (84.8 vs. 90.1%; P=0.4) and quadruple (85 vs. 94.1%; P=0.06) therapies. Adverse events occurred more frequently with the quadruple than with sequential therapy (56.9 vs. 25.8%; P<0.001).

CONCLUSION

In our country, sequential and bismuth-based quadruple therapy achieved similarly high eradication rates as first-line treatments for H. pylori infection in clinical practice.

Antibiotic resistance pattern of Helicobacter pylori strains isolated in Italy during 2010-2016

PURPOSE

Bacterial resistance toward the most used antibiotics is increasing in Helicobacter pylori strains worldwide. Emergence of multidrug resistance significantly affects the efficacy of standard therapy regimens. Therefore, monitoring for primary antimicrobial resistance is essential for H. pylori management in clinical practice.

METHODOLOGY

H. pylori isolates obtained from patients consecutively observed in a single center were tested for primary resistance by using E-test method. Bacterial strains showing MIC values >0.5, >8 and >1 mg/L toward clarithromycin, metronidazole and levofloxacin, respectively, were considered resistant. The trend of antibiotic prevalence, either single or combined, during 2010-2016 was assessed.

RESULTS

Antibiotic susceptibility data were available in 1424 (82.3%) out of 1730 tested patients. The overall resistance for all the three antibiotics showed an increasing trend from 2010 to 2013 (clarithromycin: from 19% to 35.6%; metronidazole: from 33.6% to 45.3%; levofloxacin: from 19% to 29.7%; p < .001), when a plateau until 2016 was observed (clarithromycin: 35.9%; metronidazole: 40.2%; levofloxacin: 29.3%). A similar trend occurred for clarithromycin-metronidazole combined resistance rate (2010: 11.4%; 2013: 28.2%; 2016: 21.9%).

CONCLUSION

Our data suggest that prevalence of primary resistance in H. pylori isolates toward the most frequently used antibiotics probably reached a plateau in the last years.

First-line therapies for Helicobacter pylori eradication: a critical reappraisal of updated guidelines

Helicobacter pylori (H. pylori) treatment remains a challenge for the clinician, as no available therapy is able to cure the infection in all treated patients. In the last two decades, several antibiotic combinations have been proposed, including triple therapies, bismuth-free therapies (sequential, concomitant, hybrid regimens), and bismuth-based quadruple therapy. Some national and international guidelines on H. pylori management have recently been updated, recommending or discouraging the use of each of these therapeutic approaches, based mainly on the presumed pattern of primary antibiotic resistance in different geographic areas. We examined the recommendations on first-line therapies in the most recently updated guidelines worldwide, taking into account other data affecting the efficacy of a therapy regimen beyond the primary resistance pattern. Although several guidelines highlighted that the results achieved by an eradication therapy are population-specific and not directly transferable, it emerged that some therapy regimens are recommended or discouraged with no mention of the vital need for national data.

The internalization of Helicobacter pylori plays a role in the failure of H. pylori eradication

BACKGROUND

Helicobacter pylori (H. pylori) internalization involves invasion of cells by the bacterium. Several studies have shown that H. pylori can invade human gastric epithelial cells, immune cells, and Candida yeast in vivo and in vitro. Whether bacterial invasion plays a role in eradication failure is unclear.

AIM

To investigate the relationship between H. pylori invasion of GES-1 cells and H. pylori eradication failure.

MATERIALS AND METHODS

Forty-two clinical strains isolated from H. pylori-positive patients with different outcomes after treatment with furazolidone-based therapy were examined (17 failures and 25 successes). The H. pylori strains were shown to be susceptible to amoxicillin and furazolidone, and the patients also exhibited good compliance. Genotyping was performed for cagA and vacA (s and m). The antibiotic susceptibility of the strains to amoxicillin, furazolidone, clarithromycin, metronidazole, and levofloxacin was determined by E-tests. The levels of H. pylori invasion of GES-1 cells were detected by gentamicin colony-forming unit assays.

RESULTS

The internalization level in the eradication success group was 5.40±5.78 × 10^-3  cfu/cell, and the median was 6.194 × 10^-3  cfu/cell; the internalization level in the eradication failure group was 8.98±5.40 × 10^-3  cfu/cell, and the median was 10.28 × 10^-3  cfu/cell. The eradication failure group showed a greater invasion level than the eradication success group (P<.05). No significant difference was observed between the susceptible strains and the resistant strains when the internalization levels were compared (P>.05).

CONCLUSIONS

The results showed that H. pylori invasion of the gastric epithelia might play a role in eradication failure.

Primary Antimicrobial Susceptibility Changes in Children with Helicobacter pylori Infection over 13 Years in Northern Italy

The eradication therapy of Helicobacter pylori (H. pylori) infection is still a challenge for gastroenterologists. One of the main causes of failure in H. pylori eradication is the antibiotic resistance mainly to clarithromycin. Culture from biopsies is maybe the most used method among the antimicrobial susceptibility techniques. In this study, we compared the antimicrobial susceptibility changes in children with H. pylori infection over 13 years and we confirmed that clarithromycin resistance has been increased (16% versus 26%) though with no statistically signficant value. Therefore, clarithromycin should not be used in empiric treatment of H. pylori eradication therapy in children, but its use should be limited only to children with known antimicrobial susceptibility. On the other hand, metronidazole resistance has decreased over this time period in statistically significant manner (56% versus 33%, p = 0.014). Furthermore, ampicillin resistance has been confirmed to be very rare (3% versus 0%) in children with H. pylori infection. In conclusion, in H. pylori infection, if we do not know the antibiotic susceptibility of patients, we should recommend an eradication therapy based on the local distribution of antibiotic resistance rates trying to limit the therapeutic failures.

Use of a combination formulation of bismuth, metronidazole and tetracycline with omeprazole as a rescue therapy for eradication of Helicobacter pylori

BACKGROUND

Helicobacter pylori infection occurs in children and adults worldwide. Standard triple therapy of omeprazole, amoxicillin and clarithromycin (OAC) may not be optimal.

AIM

To evaluate quadruple therapy with bismuth subcitrate potassium, metronidazole and tetracycline hydrochloride, given with omeprazole in H. pylori infected subjects who failed previous OAC eradication therapy.

METHODS

This was a multicenter, open-label, single-arm, multinational study. Helicobacter pylori-positive subjects who had failed ≥1 previous course of OAC therapy with or without up to three supplemental treatments in the previous year. Subjects were treated for 10 days with a combination formulation containing bismuth subcitrate potassium 140 mg, tetracycline hydrochloride 125 mg, and metronidazole 125 mg, three capsules four times daily (q.d.s.), and omeprazole 20 mg twice daily (b.d.). The primary endpoint was H. pylori eradication rate defined as one negative (13) C-urea breath test ≥28 days post-treatment.

RESULTS

Helicobacter pylori eradication rates ranged from 93.2% to 93.8% in the intent-to-treat population (n = 49), and from 94.7% to 95.0% in the PP population (n = 40). No clinically meaningful differences were observed when analysed by country. Metronidazole resistance was observed in 16/49 (32.7%) subjects and clarithromycin resistance in 31/49 (63.3%) subjects. Thirty-three subjects (67.3%) reported 87 adverse events, and only one (2%) discontinued the study for an adverse event.

CONCLUSIONS

A quadruple regimen of bismuth, metronidazole and tetracycline plus omeprazole produces a high eradication rate in subjects previously failing H. pylori eradication regimens. This bismuth-based regimen offers an effective option as rescue therapy.

The problem of Helicobacter pylori resistance to antibiotics: a systematic review in Latin America

OBJECTIVES

Latin America has a high prevalence of Helicobacter pylori infection and associated diseases, including gastric cancer. Antibiotic therapy can eradicate the bacterial infection and decrease associated morbidity and mortality. To tailor recommendations for optimal treatments, we summarized published literature and calculated region- and country-specific prevalences of antibiotic resistance.

METHODS

Searches of PubMed and regional databases for observational studies evaluating H. pylori antibiotic resistance yielded a total of 59 independent studies (56 in adults, 2 in children, and 1 in both groups) published up to October 2013 regarding H. pylori isolates collected between 1988 and 2011. Study-specific prevalences of primary resistance to commonly prescribed antibiotics were summarized using random-effects models. Between-study heterogeneity was assessed by meta-regression. As a sensitivity analysis, we extended our research to studies of patients with prior H. pylori-eradication therapy.

RESULTS

Summary prevalences of antimicrobial primary resistance among adults varied by antibiotic, including 12% for clarithromycin (n=35 studies), 53% for metronidazole (n=34), 4% for amoxicillin (n=28), 6% for tetracycline (n=20), 3% for furazolidone (n=6), 15% for fluoroquinolones (n=5), and 8% for dual clarithromycin and metronidazole (n=10). Resistance prevalence varied significantly by country, but not by year of sample collection. Analyses including studies of patients with prior therapy yielded similar estimates. Pediatric reports were too few to be summarized by meta-analysis.

CONCLUSIONS

Resistance to first-line anti-H. pylori antibiotics is high in Latin American populations. In some countries, the empirical use of clarithromycin without susceptibility testing may not be appropriate. These findings stress the need for appropriate surveillance programs, improved antimicrobial regulations, and increased public awareness.

Second and third line treatment options for Helicobacter pylori eradication

Helicobacter pylori is a highly successful bacterium with a high global prevalence and the infection carries significant disease burden. It is also becoming increasingly difficult to eradicate and the main reason for this is growing primary antibiotic resistance rates in a world where antibiotics are frequently prescribed and readily available. Despite knowing much more about the bacterium since its discovery, such as its genomic makeup and pathogenesis, we have seen declining treatment success. Therefore, clinicians today must be prepared to face one, two or even multiple treatment failures, and should be equipped with sufficient knowledge to decide on the appropriate salvage therapy when this happens. This article discusses the factors contributing to treatment failure and reviews the second and third-line treatment strategies that have been investigated. Established empiric second line treatment options include both bismuth based quadruple therapy and levofloxacin based triple therapy. Antibiotic testing is recommended prior to initiating third line treatment. In the event that antibiotic susceptibility testing is unavailable, third line treatment options include rifabutin, rifaximin and sitafloxacin based therapies.

Helicobacter pylori: Future perspectives in therapy reflecting three decades of experience

The rising prevalence of antibiotic resistance has created a need to reassess the established Helicobacter pylori (H. pylori) eradication protocols, and to develop new ones. Various bacterial and host factors are evaluated, and their contribution to eradication failure is estimated. For a long time being considered the cornerstone eradication scheme, the standard triple therapy has been replaced with novel, more efficient regimens, namely sequential and concomitant, along with the emergence of a new design of bismuth quadruple therapy. A rescue levofloxacin based regimen has overcome the fear of therapy failure due to higher prevalence of dual resistant (clarithromycin and metronidazole) H. pylori. Culture-free and efficient susceptibility test are reestablishing the concept of tailored therapy, making eradication success close to originally desirable rates. Alleviating therapy side effects and improving patient compliance are as important as choosing appropriate eradication schemes, so various probiotic compound supplements are taken into consideration. Finally, we summarize the emerging efforts and obstacles in creating efficient H. pylori vaccine.

Standard triple and sequential therapies for Helicobacter pylori eradication: an update

H. pylori infection remains a worldwide spread disease with a definite morbidity and mortality. Unfortunately, no current therapy regimen is able to cure the infection in all treated patients. The efficacy of the widely recommended triple therapies is decreasing, and a novel 10-day sequential therapy has been proposed. Data of 3 previous meta-analyses showed a significantly higher eradication rate following the sequential as compared to the 7-10 days triple therapies. The sequential therapy achieved significantly better results than triple therapies in children, elderly patients, non-ulcer dyspepsia patients, and in those infected with resistant strains towards either clarithromycin or metronidazole. We identified further 10 randomized trials. By pooling data, H. pylori infection was cured in 2,454 (86%; 95% CI: 84.7-87.3) out of 2,853 patients with the sequential therapy and in 2,320 (75.3%; 95% CI: 73.8-76.9) out of 3,079 patients treated with standard triple therapies (p<0.001), corresponding to a number to treat (NNT) of 9. The comparison between the 10-day sequential regimen and 14-day triple therapies deserves further investigations.

Newer agents for Helicobacter pylori eradication

Helicobacter pylori infection remains widespread internationally, with a definite morbidity and mortality. The efficacy of standard 7–14 day triple therapies is decreasing, mainly due to increasing primary bacterial resistance to antibiotics. Currently, the most effective treatments are either the sequential regimen or the concomitant therapy. Different patents have been registered showing high bactericidal effects in vitro, some of which are active against clarithromycin- and metronidazole-resistant strains, even at low pH values. Among these novel molecules, benzimidazole-derivatives, polycyclic compounds, pyloricidin, and arylthiazole analogues seem to be the more promising. The identification of essential genes for either bacterial colonization or growth represents a route for potential target therapies in the near future.