Change in antibiotic resistance of Helicobacter pylori strains and the effect of A2143G point mutation of 23S rRNA on the eradication of H. pylori in a single center of Korea

Seven-day triple therapy is a better choice for Helicobacter pylori eradication in regions with low antibiotic resistance

AIM: To investigate whether 7-d triple therapies are still valid in populations with low levels of resistance.

METHODS: A total of 1106 Helicobacter pylori (H. pylori)-positive patients were divided into three groups, each of which received one type of 7-d triple therapy. Therapeutic outcomes of the patients were assessed by the ¹³C-urea breath test at 8 wk after treatment. The susceptibility of H. pylori to antibiotics was determined by an agar-dilution method. Data analysis was performed by χ² tests.

RESULTS: The eradication rates in groups A, B and C were 90.71% (332/366), 90.46% (313/346) and 90.87% (189/208), respectively (P = 0.986). The resistance rates were 8.91% for clarithromycin, 14.78% for levofloxacin and 0% for amoxicillin. The eradication rate was significantly different between clarithromycin- and levofloxacin-resistant patients (P < 0.05) in group A. Patients whose treatment failed in group A also had a higher clarithromycin resistance rate than did successive patients (P = 0.034). However, levofloxacin resistance had no obvious influence on the eradication rate. Furthermore, three main antibiotics (clarithromycin, levofloxacin and amoxicillin) had lower DID (defined daily dose per 1000 inhabitants per day) in this city.

CONCLUSION: Clarithromycin resistance is the main reason for the failure of 7-d triple therapy. In populations with low levels of resistance, a 7-d triple therapy is a viable choice. The choice of therapy should not be influenced by conditions in high antibiotic resistance regions.

Clarithromycin Resistance Mutations in Helicobacter pylori in Association with Virulence Factors and Antibiotic Susceptibility of the Strains

Antibiotic resistance is the major cause for Helicobacter pylori eradication failure. H. pylori clarithromycin resistance mutations were evaluated in 84 (82 phenotypically clarithromycin resistant and 2 intermediately susceptible) strains by allele-specific PCR and 3'-mismatched PCR. Many (57.1%) of these strains were metronidazole resistant. Prevalence of cagA(+), cagE(+), vacA s1a, m1, i1, and i2 strains was 76.2%, 58.0%, 82.1%, 35.7%, 50.0%, and 50.0%, respectively. A2143G, A2142G, A2142C, and A2143G+A2142G mutation rates were 64.3%, 23.8%, 1.2%, and 10.7%, respectively. Strains harboring the A2142G mutation showed 5.3-fold higher clarithromycin MIC50 than those harboring the A2143G mutation. The A2143G mutation alone was 1.7-fold more common in vacA i2 strains compared with vacA i1 strains, while the A2142G mutation alone was 3-fold more frequent in vacA i1 strains than vacA i2 strains and 3.1-fold more common in metronidazole-susceptible compared with metronidazole-resistant strains. Briefly, clarithromycin resistance mutations were significantly linked to vacA i allele and metronidazole susceptibility. This is the first report about associations between the A2143G mutation and less virulent vacA i2 strains, and between the A2142G mutation and more virulent vacA i1 strains. As the 2143G mutation often predicts eradication failure by clarithromycin-based regimens, the results may be linked to the better eradication of more virulent strains compared with the less virulent strains.

Antibiotic treatment for Helicobacter pylori: Is the end coming?

Infection with the Gram-negative pathogen Helicobacter pylori (H. pylori) has been associated with gastro-duodenal disease and the importance of H. pylori eradication is underscored by its designation as a group I carcinogen. The standard triple therapy consists of a proton pump inhibitor, amoxicillin and clarithromycin, although many other regimens are used, including quadruple, sequential and concomitant therapy regimens supplemented with metronidazole, clarithromycin and levofloxacin. Despite these efforts, current therapeutic regimens lack efficacy in eradication due to antibiotic resistance, drug compliance and antibiotic degradation by the acidic stomach environment. Antibiotic resistance to clarithromycin and metronidazole is particularly problematic and several approaches have been proposed to overcome this issue, such as complementary probiotic therapy with Lactobacillus. Other studies have identified novel molecules with an anti-H. pylori effect, as well as tailored therapy and nanotechnology as viable alternative eradication strategies. This review discusses current antibiotic therapy for H. pylori infections, limitations of this type of therapy and predicts the availability of newly developed therapies for H. pylori eradication.

Trends in Helicobacter pylori eradication rates by first-line triple therapy and related factors in eradication therapy

BACKGROUND/AIMS

Trends in successful eradication of Helicobacter pylori using first-line triple therapy, consisting of a proton pump inhibitor, amoxicillin, and clarithromycin, have been understudied. We evaluated H. pylori eradication rates at a single center over the last 10 years and identified risk factors related to eradication failure.

METHODS

This study included 1,413 patients who were diagnosed with H. pylori infection and received 7 days of triple therapy between January 2003 and December 2012. We investigated H. pylori eradication rates retrospectively with respect to the year of therapy, as well as demographic and clinical factors. H. pylori eradication was confirmed by a (13)C-urea breath test or a rapid urease test at least 4 weeks after the completion of triple therapy.

RESULTS

The overall H. pylori eradication rate was 84.9%. Annual eradication rates from 2003 to 2012 were 93.5%, 80.0%, 87.2%, 88.5%, 92.0%, 88.3%, 85.7%, 84.1%, 83.7%, and 78.8%, respectively, by per-protocol analysis. The eradication rate with first-line triple therapy decreased during the last 10 years (p = 0.015). Multivariate analysis showed that female gender (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.12 to 2.55) and smoking (OR, 1.61; 95% CI, 1.05 to 2.47) were associated with the failure of H. pylori eradication therapy.

CONCLUSIONS

The efficacy of first-line triple therapy for H. pylori infection has decreased over the last 10 years, suggesting an increase in antibiotic-resistant H. pylori strains. Thus, other first-line therapies may be necessary for H. pylori eradication in the near future.

High Efficacy of Finafloxacin on Helicobacter pylori Isolates at pH 5.0 Compared with That of Other Fluoroquinolones

Finafloxacin is a novel fluoroquinolone with improved antimicrobial efficacy, especially in an acidic environment. The efficacy of finafloxacin for the inhibition of Helicobacter pylori infection was compared with the efficacies of levofloxacin and moxifloxacin at neutral and acidic pH. The impacts of gyrA point mutation on the efficacy of those three fluoroquinolones were also investigated. A total of 128 clinical H. pylori strains were utilized. MICs of levofloxacin, moxifloxacin, and finafloxacin were determined at pH 5.0 and pH 7.0 by the agar dilution method. The impact of gyrA point mutations that are responsible for fluoroquinolone resistance was analyzed; the results showed 50 strains with an Asn-87 point mutation, 48 strains with an Asp-91 point mutation, and the remaining 30 strains with no gyrA mutations. The use of finafloxacin led to MIC values at pH 5.0 that were lower than the values seen at pH 7.0 for 112 strains (112/128, 87.5%), and this proportion was higher than that seen with moxifloxacin (21/128, 16.4%, P < 0.001). Finafloxacin also demonstrated a rate of susceptibility (MIC, <1 μg/ml) (37.5%, 48/128) at pH 5.0 that was higher than that seen with moxifloxacin (2.3%, 3/128) (P < 0.001). The trends were similar regardless of which of the Asn-87, Asp-91, and A2143 point mutations were present. In conclusion, the superior antimicrobial efficacy of finafloxacin against H. pylori in an acidic environment suggests the possible use of finafloxacin for treatment of H. pylori infection, as has been proposed by its developer, Merlion Pharma.

Fourteen- vs seven-day bismuth-based quadruple therapy for second-line Helicobacter pylori eradication

AIM: To compare the efficacy of 14- and 7-d bismuth-based quadruple therapies as second-line eradication treatment for Helicobacter pylori (H. pylori) infection.

METHODS: Between 2004 and 2014, the medical records of 790 patients who had experienced failure of first-line proton pump inhibitor (PPI)-based eradication therapy and were then treated with bismuth-based quadruple therapy were retrospectively reviewed. Those who received bismuth-based quadruple therapy [PPI, bismuth, metronidazole, and tetracycline (PBMT)] for either 7 d or 14 d were assigned to a PBMT-7 group (n = 543) or a PBMT-14 group (n = 247), respectively. The eradication rates for both groups were determined by intention-to-treat (ITT) and per-protocol (PP) analyses. ITT analysis compared the treatment groups as originally allocated while the PP analysis including only those patients who had completed the treatment as originally allocated. Successful eradication therapy for H. pylori infection was defined as a negative ¹³C-urea breath test 4 wk after the end of eradication treatment.

RESULTS: The overall ITT eradication rate was 69.1% (546/790). Final ITT eradication rates were 67.4% (366/543; 95%CI: 63.1%-71.7%) in the PBMT-7 group and 72.8% (180/247; 95%CI: 67.4%-78.2%) in the PBMT-14 group (P = 0.028). The overall PP eradication rate was 80.0% (546/682), and the final PP eradication rates were 78.2% (366/468; 95%CI: 72.1%-84.0%) in the PBMT-7 group and 84.1% (180/214; 95%CI: 76.8%-90.8%) in the PBMT-14 group (P = 0.009). The H. pylori eradication rates in the PBMT-14 group were significantly higher than in the PBMT-7 group according to both ITT (P = 0.028) and PP analysis (P = 0.009). Compliance was similar in both groups (PBMT-7 group: 97.9%; PBMT-14 group: 96.4%). Adverse event rates were 10.7% (51/478) and 17.1% (38/222) in the PBMT-7 and PBMT-14 groups, respectively (P = 0.487).

CONCLUSION: The 14-d bismuth-based quadruple therapy is a significantly more effective second-line eradication treatment for H. pylori infection than the 7-d alternative.

Comparison of efficacy and safety of levofloxacin-containing versus standard sequential therapy in eradication of Helicobacter pylori infection in Korea

BACKGROUND

Declining of eradication rates for Helicobacter pylori in Korea may be partly from the increasing prevalence of antibiotic resistance, especially clarithromycin resistance.

AIM

To compare the efficacy and the safety of using 10-day standard sequential therapy and levofloxacin-containing sequential therapy as a first-line treatment for Helicobacter pylori eradication in Korea.

METHODS

A total of 200 patients with proven Helicobacter pylori infection randomly received 10-day standard sequential therapy (n = 100) or levofloxacin-containing sequential therapy (n = 100). The standard sequential therapy group received rabeprazole and amoxicillin for 5 days, followed by rabeprazole, clarithromycin, and metronidazole for 5 more days. The levofloxacin-containing sequential therapy group was treated with rabeprazole and amoxicillin for 5 days, followed by rabeprazole, levofloxacin, and metronidazole for 5 more days.

RESULTS

Intention-to-treat eradication rates were 79.0% and 78.0% for groups of standard sequential and levofloxacin-containing sequential therapy, respectively (P = 0.863). Per-protocol eradication rates were 84.9% and 81.3%, respectively, for these two therapies (P = 0.498). There were no significant differences between the groups in regard to the eradication rates and adverse events.

CONCLUSIONS

The 10-day levofloxacin-containing sequential regimen and the standard sequential regimen showed the similar eradication rates of Helicobacter pylori in Korea.

Concomitant therapy achieved the best eradication rate for Helicobacter pylori among various treatment strategies

AIM

To compare the Helicobacter pylori (H. pylori) eradication rate of clarithromycin-based triple therapy, metronidazole-based triple therapy, sequential therapy and concomitant therapy.

METHODS

A total of 680 patients infected with H. pylori were divided into 4 groups and each group was treated with a different eradication therapy. Clarithromycin-based triple therapy was applied to the first group [rabeprazole, amoxicillin and clarithromycin (PAC) group: proton pump inhibitor (PPI), amoxicillin, clarithromycin], whereas the second group was treated with metronidazole-based triple therapy [rabeprazole, amoxicillin and metronidazole (PAM) group: PPI, amoxicillin, metronidazole]. The third group was treated with rabeprazole and amoxicillin, followed by rabeprazole, clarithromycin and metronidazole (sequential group). The final group was simultaneously treated with rabeprazole, amoxicillin clarithromycin and metronidazole (concomitant therapy group). In the case of a failure to eradicate H. pylori, second-line quadruple and third-line eradication therapies were administered.

RESULTS

The per protocol (PP) analysis was performed on 143, 139, 141 and 143 patients in the PAC, PAM, sequential and concomitant groups, respectively. We excluded patients who did not receive a C(13)-urea breath test (22, 20, 23 and 22 patients, respectively) and patients with less than an 80% compliance level (5, 11, 6 and 5 patients, respectively). The eradication rates were 76.2% (109/143) in the PAC group, 84.2% (117/139) in the PAM group, 84.4% (119/141) in the sequential group and 94.4% (135/143) in the concomitant group (P = 0.0002). All 14 patients who failed second-line therapy were treated with third-line eradication therapy. Among these 14 patients, 6 infections were successfully eradicated with the third-line therapy. Both PP and intention-to-treat analysis showed an eradication rate of 42.9% (6/14). In the PAC group, 3 of 4 patients were successfully cured (3/4, 75%); 2 of 2 patients in the PAM group (2/2, 100%) and 1 of 5 patients in the sequential group (1/5, 20%) were also cured. In the concomitant group, all 3 patients failed (0/3, 0%).

CONCLUSION

The eradication rate for the concomitant therapy was much higher than those of the standard triple therapy or sequential therapy (ClinicalTrials.gov number NCT01922765).

High rate of levofloxacin resistance in a background of clarithromycin- and metronidazole-resistant Helicobacter pylori in Vietnam

Antimicrobial resistance in Helicobacter pylori has increased worldwide and has become a major cause of treatment failure in many countries, including Vietnam. It is advisable to perform an antibiogram to provide optimal regimens for H. pylori eradication. This study evaluated the rate of antibiotic resistance to the four commonly used antibiotics against H. pylori at a tertiary care hospital in Central Vietnam and analysed point mutations in genes related to clarithromycin (CLA) and levofloxacin (LFX) resistance. A total of 92 H. pylori strains from gastric biopsy specimens were tested; 42.4% were resistant to CLA (primary, 34.2%; secondary, 73.7%), 41.3% to LFX (primary, 35.6%; secondary, 63.2%), 76.1% to metronidazole (MTZ) and 1.1% to amoxicillin. Multidrug resistance was observed in 56.5% (primary, 50.7%; secondary, 78.9%) of isolates (P<0.05). The rate of resistance to LFX was significantly higher in females than males (P<0.05). Most of the CLA- and LFX-resistant strains harboured resistance-associated mutations, with common positions at A2143G and T2182C in the 23S rRNA gene and at Asn-87 or Asp-91 in GyrA. Minimum inhibitory concentrations (MICs) increased in strains carrying quadruple mutations in their 23S rRNA gene and in strains with Asn-87 GyrA mutation (P<0.05). One high-level LFX-resistant strain (MIC=32mg/L) had new mutations with a combination of N87A, A88N and V65I. High resistance rates to CLA, MTZ and LFX discourage standard and LFX-based triple therapies as first-line treatment in Vietnam.

A randomised clinical trial of 10-day concomitant therapy and standard triple therapy for Helicobacter pylori eradication

BACKGROUND

As a result of increased resistance to antibiotics, Helicobacter pylori eradication rates using standard triple therapy have been declining.

AIM

To validate the efficacy and tolerability of a concomitant regimen as a first-line treatment for H. pylori infection.

METHODS

A total of 348 naïve H. pylori-infected patients from six hospitals in Korea were randomly assigned to concomitant therapy and standard triple therapy groups. The concomitant regimen consisted of 30 mg of lansoprazole, 1g of amoxicillin, 500 mg of clarithromycin, and 500 mg of metronidazole, twice daily for 10 days. The standard triple regimen consisted of 30 mg of lansoprazole, 1g of amoxicillin, and 500 mg of clarithromycin, twice daily for 10 days.

RESULTS

Concomitant and standard eradication rates were 78.7% (137/174) vs. 70.7% (123/174) by intention-to-treat (p=0.084) and 88.7% (133/150) vs. 78.4% (120/153) by per-protocol (p=0.016), respectively. The two groups were similar with regard to the incidence of adverse events.

CONCLUSIONS

Although 10-day concomitant therapy was validated as a suboptimal treatment option for the treatment of H. pylori infection, this regimen is expected to be a promising starting point in the development of an optimal treatment regimen for H. pylori infection.

[Future trends of Helicobacter pylori eradication therapy in Korea]

The prevalence of Helicobacter pylori infection in Korea shows a decreasing trend and has changed to that of developed country, especially for those below 30 years old. However, the primary antibiotic resistance rates are higher than those of developed countries. The reason for the decrease in the efficacy of standard triple therapy is mainly due to the increase in the resistance against clarithromycin. Sequential therapy seems to be more effective than the standard triple therapy, but the intention-to-treat eradication rate of sequential therapy in Korea, which is mostly under 80.0%, is still not satisfactory. Therefore, a promising regimen is needed. Recently, the Japanese health insurance system admitted 'H. pylori-infected gastritis'as an indication of eradication. Furthermore, the Kyoto Consensus Meeting on H. pylori Gastritis held from January 30th to February 1st, 2014, proposed that 'all H. pylori positive patients should be offered to receive H. pylori eradication'. This suggests that the concept of eradication has been changed from 'treatment' to 'prevention'. Various individualized tailored therapy based on the polymorphism, age and other demographic factors and antibiotic resistance has been attempted to maximize H. pylori eradication therapy. The aim of this article is to review the current epidemiology, H. pylori resistance state, treatment guideline, and to assess the possible future strategy and treatment for H. pylori infection in Korea.

GenoType HelicoDR test in the determination of antimicrobial resistance of Helicobacter pylori in Korea

OBJECTIVE

Antimicrobial resistance of Helicobacter pylori is most important factor in eradication success. GenoType HelicoDR test has been developed for rapid detection of antimicrobial resistance. The present study evaluated the clinical usefulness of GenoType HelicoDR test in Korea.

MATERIALS AND METHODS

To detect 23S rRNA for clarithromycin resistance and gyrA mutations for fluoroquinolone resistance, both DNA sequencing after minimal inhibitory test (MIC) and GenoType HelicoDR test were performed in H. pylori isolates from the gastric mucosa of 101 patients. The eradication results of clarithromycin and moxifloxacin-containing triple therapy were evaluated by the 23S rRNA and gyrA mutations.

RESULTS

For 42 isolates with A2143G mutation by GenoType HelicoDR, 83.3% (35/42) of concordance rate was estimated with DNA sequencing method and 85.7% (36/42) for MIC test. For 43 isolates with N87K mutation by GenoType HelicoDR, 71.1% (31/43) of concordance rate was estimated with DNA sequencing and 88.4% (38/43) for MIC test. The sensitivity and specificity of GenoType HelicoDR test in determination of 23S rRNA mutation were 94.9% and 87.1%, and those of gyrA 98.2% and 80.0%. The sensitivity and specificity of GenoType HelicoDR test in determination of clarithromycin resistance based on MIC test were 55.0% and 80.0%, for fluoroquinolone 74.4% and 70.0%.

CONCLUSION

GenoType HelicoDR test is useful to determine mutations responsible for clarithromycin or fluoroquinolone-containing eradication failure but has a limitation for the clinical applicability in determination of resistance.

[Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition]

Since the Korean College of Helicobacter and Upper Gastrointestinal Research has first developed the guideline for the diagnosis and treatment of Helicobacter pylori infection in 1998, the revised guideline was proposed in 2009 by the same group. Although the revised guideline was made by comprehensive review of previous articles and consensus of authoritative expert opinions, the evidence-based developmental process was not applied in the revision of the guideline. This new guideline has been revised especially in terms of changes in the indication and treatment of H. pylori infection in Korea, and developed by the adaptation process as evidence-based method; 6 guidelines were retrieved by systematic review and the Appraisal of Guidelines for Research and Evaluation (AGREE) II process, 21 statements were made with grading system and revised by modified Delphi method. After revision, 11 statements for the indication of test and treatment, 4 statements for the diagnosis and 4 statements for the treatment have been developed, respectively. The revised guideline has been reviewed by external experts before the official endorsement, and will be disseminated for usual clinical practice in Korea. Also, the scheduled update and revision of the guideline will be made periodically.

Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition

The Korean College of Helicobacter and Upper Gastrointestinal Research first developed guidelines for the diagnosis and treatment of Helicobacter pylori (H. pylori) infection in 1998, and revised guidelines were proposed in 2009 by the same group. Although the revised guidelines were based on a comprehensive review of published articles and the consensus of expert opinions, the revised guidelines were not developed using an evidence-based process. The new guidelines presented in this study include specific changes regarding indication and treatment of H. pylori infection in Korea, and were developed through the adaptation process using an evidence-based approach. After systematic review of the literature, six guidelines were selected using the Appraisal of Guidelines for Research and Evaluation (AGREE) II process. A total of 21 statements were proposed with the grading system and revised using the modified Delphi method. After the guideline revisions, 11 statements about indication of test and treatment, four statements about diagnosis, and four statements about treatment of H. pylori infection were developed. The revised guidelines were reviewed by external experts before receiving official endorsement from the Korean College of Helicobacter and Upper Gastrointestinal Research, and disseminated to physicians and other medical professionals for use in clinical practice in Korea. The guidelines will continue to be updated and revised periodically.

Resistotype of Helicobacter pylori isolates: the impact on eradication outcome

Antibiotic resistance is increasing worldwide, and it has been regarded as the main factor reducing the efficacy of Helicobacter pylori therapy. The aim of this study was to determine the phenotype and genotype of antibiotic-resistant strains of H. pylori in the Malaysian population and to evaluate the impact of antibiotic resistance to eradication outcome. One hundred and sixty-one H. pylori isolates were analysed in this study. Metronidazole, clarithromycin, fluoroquinolone, amoxicillin and tetracycline susceptibilities were determined by Etest. PCR followed by DNA sequencing was carried out to determine mutations. The medical records of the patients infected with resistant strains were reviewed to determine the eradication outcome. Metronidazole resistance was encountered in 36.6 % of H. pylori isolates, whereas clarithromycin and fluoroquinolone resistance was observed in 1.2  and 1.9 % of isolates, respectively. All strains tested were susceptible to amoxicillin and tetracycline. Frameshift and nonsense mutations in rdxA and frxA genes resulting in stop codons contributed to metronidazole resistance, which leads to reduced eradication efficacy. A2142G and A2143G mutations of 23S rRNA were identified as causing failure of the eradication therapy. Mutation at either codon 87 or 91 of the gyrA gene was identified in fluoroquinolone-resistant strains. However, the effect of resistance could not be assessed. This study showed that frameshift and nonsense mutations in rdxA or frxA genes and point mutations in the 23S rRNA affected the efficacy of H. pylori eradication therapy.

Dual-priming oligonucleotide-based multiplex PCR using tissue samples in rapid urease test in the detection of Helicobacter pylori infection

AIM

To investigate whether tissue samples processed by the rapid urease test (RUT) kit are suitable for dual-priming oligonucleotide-based multiplex polymerase chain reaction (DPO-PCR) to detect Helicobacter pylori (H. pylori).

METHODS

A total of 54 patients with specific gastrointestinal symptom were enrolled in this study. During endoscopy, gastric biopsy specimens were taken for histology, RUT, and DPO-PCR. DPO-PCR was performed on gastric biopsy samples and tissue samples that were analyzed by RUT at 2 separate institutes. In detecting H. pylori, the concordance rate of the DPO-PCR tests between the tissue samples that had been submitted to RUT and the gastric biopsy samples was investigated.

RESULTS

H. pylori co-occurred with 76.0% (19/25) of gastric ulcers, 64.3% (9/14) of duodenal ulcers, and 33.3% (4/12) of gastritis cases. H. pylori infection was found in 100% (3/3) of the patients with both gastric and duodenal ulcers. Overall, H. pylori was detected in 35 of 54 (64.8%) patients. The diagnostic sensitivities of histology, RUT, and DPO-PCR were 85.7% (30/35), 74.3% (26/35), and 97.1% (34/35), respectively (P = 0.02). The positive predictive value (PPV) of DPO-PCR was 94.4%, whereas the negative predictive value (NPV) was 94.7%. In the rapid urease test (CLOtest)-negative cases, the frequency of positive DPO-PCR and histologic results was 20.0% (7/35). The concordance rate of the DPO-PCR tests between the tissue samples from the RUT kit and the gastric biopsy samples was 94.4% (51/54). The rate of DPO-PCR and silver stain positivity in the RUT-negative cases was 20.0% (7/35).

CONCLUSION

In diagnosing H. pylori infection, DPO-PCR can be performed on tissue samples that have been processed by the RUT kit. Particularly, in patients with RUT-negative results, DPO-PCR on these tissue samples could be helpful in detecting of H. pylori infection.

Factors affecting first-line triple therapy of Helicobacter pylori including CYP2C19 genotype and antibiotic resistance

BACKGROUND

Emerging evidence shows that the eradication rate of proton pump inhibitor (PPI)-based triple therapy for the first-line treatment of Helicobacter pylori (H. pylori) has decreased.

AIMS

To clarify the trend of eradication rate of PPI-based triple therapy and to assess the related factors in Korea during the past decade.

METHODS

We prospectively prescribed the triple regimen for seven days (PPI + amoxicillin 1.0 g + clarithromycin 500 mg, twice a day) from March 2003 to May 2013 in 2,202 H. pylori-positive patients. Antibiotic susceptibility tests were performed by the agar dilution method, and the CYP2C19 genotype was determined by the PCR method.

RESULTS

In the past decade, the annual eradication rate showed a decreasing trend in intention-to-treat and per-protocol analyses (P = 0.001, both). The antibiotic resistance was increased to amoxicillin (7.2-17.2%, P = 0.003) and clarithromycin (23.2-37.3%, P = 0.010) during the study period. The poor metabolizer genotype of CYP2C19 showed a high eradication rate compared to the extensive metabolizer (86.8 vs. 78.2%, P = 0.035). In addition, age ≥ 50 years, female gender, BMI < 25 kg/m(2), amoxicillin and/or clarithromycin resistance were associated with treatment failure on univariate analysis. However, on multivariate analysis, clarithromycin resistance was the only significant factor for treatment failure (OR, 12.76; 95% CI, 5.58-29.18; P < 0.001).

CONCLUSIONS

An increase in clarithromycin resistance has led to decreased eradication rate of first-line triple therapy, and; hence, a new strategy is needed to improve the eradication rate of H. pylori.

Optimal treatment strategy for Helicobacter pylori: Era of antibiotic resistance

Standard triple therapy, consisting of a proton pump inhibitor, plus amoxicillin and clarithromycin, has been the most commonly used first-line treatment regimen for Helicobacter pylori (H. pylori) eradication for many years worldwide. However, as a result of increased resistance to antibiotics, H. pylori eradication rates with use of standard triple therapy have been declining and recently reached < 80% in many countries. Several new strategies to enhance the eradication rate of H. pylori have been studied. Currently, among the alternative first-line eradication regimens, concomitant and hybrid regimens have shown excellent results and could be the optimal treatment option. Although clinical usefulness of rescue therapy for patients in whom eradication of H. pylori with non-bismuth quadruple regimen has failed is unclear, levofloxacin-based quadruple therapy has shown promise as a rescue treatment. The choice of third-line therapy depends on factors such as the local pattern of antibiotic resistance, drug availability, and previous treatment. We hope that a simple method for detection of antibiotic susceptibility using polymerase chain reaction would be a possible alternative to administration of “tailored treatment” in the era of increasing prevalence of antimicrobial resistance.

Meta-analysis of first-line triple therapy for helicobacter pylori eradication in Korea: is it time to change?

Proton pump inhibitor (PPI)-based triple therapy consisting of PPI, amoxicillin, and clarithromycin, is the recommended first-line treatment for Helicobacter pylori infection. However, the eradication rate of triple therapy has declined over the past few decades. We analyzed the eradication rate and adverse events of triple therapy to evaluate current practices in Korea. A comprehensive literature search was performed up to August 2013 of 104 relevant studies comprising 42,124 patients. The overall eradication rate was 74.6% (95% confidence interval [CI], 72.1%-77.2%) by intention-to-treat analysis and 82.0% (95% CI, 80.8%-83.2%) by per-protocol analysis. The eradication rate decreased significantly from 1998 to 2013 (P < 0.001 for both intention-to-treat and per-protocol analyses). Adverse events were reported in 41 studies with 8,018 subjects with an overall incidence rate of 20.4% (95% CI, 19.6%-21.3%). The available data suggest that the effectiveness of standard triple therapy for H. pylori eradication has decreased to an unacceptable level. A novel therapeutic strategy is warranted to improve the effectiveness of first-line treatment for H. pylori infection in Korea.

[New therapeutic strategies against Helicobacter pylori]

The standard therapy for Helicobacter pylori infection in Korea is a triple-drug regimen consisting of a proton pump inhibitor with two antibiotics such as clarithromycin, amoxicillin, and metronidazole. However, as the eradication rate of this regimen has declined over the past decade, this prompted the formulation of new therapeutic regimens. New therapeutic strategies against H. pylori infection that had been tried all over the world include sequential therapy, concomitant therapy, and tailored therapy This article will review the basic concepts and the results of previous clinical trials on the aforementioned new therapeutic regiments.

How antibiotic resistances could change Helicobacter pylori treatment: A matter of geography?

Therapeutic management of Helicobacter pylori (H. pylori) remains an unsolved issue. Indeed, no therapeutic regimen is able to cure the infection in all treated patients, and in many the infection persists despite the administration of several consecutive standard therapies. Although antibiotic resistance reports describe alarming results, the outcome of therapeutic regimens does not seem to parallel this scenario in most cases, since a successful performance is often reached in more than 80% of cases. However, the phenomenon of increasing antibiotic resistance is being closely studied, and the results show controversial aspects even in the same geographic area. For the continents of Europe, America, Asia, Africa, and Oceania, minimal and maximal values of resistance to the main antibiotics (clarithromycin, amoxicillin, metronidazole, and levofloxacin) feature wide ranges in different countries. The real enigma is therefore linked to the several different therapeutic regimens, which show results that often do not parallel the in vitro findings even in the same areas. A first aspect to be emphasized is that some regimens are limited by their use in very small geographic districts. Moreover, not all therapeutic trials have considered bacterial and host factors affecting the therapeutic outcome. The additional use of probiotics may help to reduce adverse events, but their therapeutic impact is doubtful. In conclusion, the "ideal therapy", paradoxically, appears to be a "utopia", despite the unprecedented volume of studies in the field and the real breakthrough in medical practice made by the discovery and treatment of H. pylori. The ample discrepancies observed in the different areas do not encourage the development of therapeutic guidelines that could be valid worldwide. On these bases, one of the main challenges for the future might be identifying a successful solution to overcome antibiotic resistances. In this context, geography must be considered a relevant matter.

[Clarithromycin-resistant Helicobacter pylori associated with 23S rRNA point mutations in Jeju Island]

BACKGROUND/AIMS

The point mutations in 23S rRNA gene accounts for the majority of the clarithromycin resistance of Helicobacter pylori. This study aimed to investigate the association between the clarithromycin-resistance of H. pylori and the failure of primary H. pylori eradication therapy in Jeju Island.

METHODS

Between April 2011 and October 2012, 6,937 patients underwent endoscopy, and H. pylori infection was evaluated in 2,287 patients (33.0%). Total of 110 patients with H. pylori infection were treated with proton pump inhibitor (PPI)-based triple therapy. The result of eradication was evaluated with urea breath test, histology and PCR which were conducted 4 weeks from the last dose of medicine.

RESULTS

The patients who had point mutations were 33 (26.0%). A2142G and A2143G mutations were observed in 10 patients (7.9%) and 23 patients (18.1%). Among 110 patients treated with PPI-based triple therapy, the success rate of the eradication therapy was 52.7% (58/110) and 70.7% (58/82) by intention-to-treat and per-protocol analysis, respectively. Fifteen of the 24 patients who failed the eradication therapy showed point mutations; 1 patient (4.2%) showed A2142G mutation and 14 patients (58.3%) showed A2143G mutation. Patients with A2143G mutation H. pylori showed higher failure rate of 87.5%. Patients with A2142G mutation H. pylori showed similar failure rate compared to those of the patients with wild type H. pylori.

CONCLUSIONS

In Jeju Island, the frequency of 23S rRNA point mutations is similar (26.0%) with other regions of Korea (15.8-31.3%). A2143G mutation is associated with the failure of H. pylori eradication.

Antibiotic resistance in Helicobacter pylori strains and its effect on H. pylori eradication rates in a single center in Korea

BACKGROUND

Clarithromycin, amoxicillin, metronidazole, tetracycline, and levofloxacin have been commonly used for the eradication of Helicobacter pylori. We compared the change in antibiotic resistance of H. pylori strains during two separate periods and investigated the effect of antibiotic resistance on H. pylori eradication.

METHODS

H. pylori strains were isolated from 71 patients between 2009 and 2010 and from 94 patients between 2011 and 2012. The distribution of minimal inhibitory concentration (MIC) of 5 antibiotics was assessed using the agar dilution method, and H. pylori eradication based on the antimicrobial susceptibility of the isolates was investigated retrospectively.

RESULTS

Antibiotic resistance rate against clarithromycin, amoxicillin, tetracycline, metronidazole, and levofloxacin for the 2009-2010 isolates were 7.0% (5/71), 2.8% (2/71), 0% (0/71), 45.1% (32/71), and 26.8% (19/71), respectively, and for the 2011-2012 isolates were 16.0% (15/94), 2.1% (2/94), 0% (0/94), 56.3% (53/94), and 22.3% (21/94), respectively. Multi-drug resistance for 2 or more antibiotics increased slightly from 16.9% (12/71) in the 2009-2010 isolates to 23.4% (22/94) in the 2011-2012 isolates. In follow-up testing of 66 patients, first-line treatment successfully eradicated H. pylori in 50 patients (75.8%) and failed in 4 of 7 patients (57.1%) in a clarithromycin-resistant and amoxicillin-susceptible group.

CONCLUSIONS

We observed an increase in resistance to clarithromycin and an overall increase in multi-drug resistance during the 2 study periods. The effectiveness of the eradication regimen was low with combinations of clarithromycin and amoxicillin, particularly in the clarithromycin-resistant group. Thus, eradication of H. pylori depends upon periodic monitoring of antimicrobial susceptibility.

Sequential Therapy for Helicobacter pylori Infection in Korea: Systematic Review and Meta-Analysis

BACKGROUND/AIMS

Sequential therapy (ST) for Helicobacter pylori infection in countries other than Korea has shown higher eradication rates than triple therapy (TT). The aim of this study was to evaluate the efficacy of ST in Korea by performing a meta-analysis.

METHODS

We performed a comprehensive literature search on the efficacy of ST as a first-line therapy. The odds ratios (ORs) of eradicating H. pylori infection after ST compared with TT were pooled. Pooled estimates of the eradication rates of ST and TT were also calculated.

RESULTS

A total of six studies provided data on 1,759 adult patients. The ORs for the intention to treat (ITT) and the per-protocol (PP) eradication rate were 1.761 (95% confidence interval [CI], 1.403 to 2.209) and 1.966 (95% CI, 1.489 to 2.595). Pooled estimates of the ITT and PP eradication rate were 79.4% (95% CI, 76.3% to 82.2%) and 86.4% (95% CI, 83.5% to 88.8%), respectively, for the ST group, and 68.2% (95% CI, 62.1% to 73.8%) and 78.9% (95% CI, 68.9% to 81.7%), respectively, for the TT group.

CONCLUSIONS

Although ST presented a higher eradication rate than TT in Korea, the pooled eradication rates were lower than expected. Further studies are needed to validate ST as a first-line treatment for H. pylori in Korea.

Clinical outcomes of two-week sequential and concomitant therapies for Helicobacter pylori eradication: a randomized pilot study

BACKGROUND

The eradication rate with PPI-based standard triple therapy for Helicobacter pylori infection has fallen considerably. One recent innovation is sequential therapy with PPI and three antibiotics, but the complexity of this regimen may reduce its usability. Concomitant administration of nonbismuth quadruple drugs (concomitant therapy) is also an effective treatment strategy. To investigate which regimen is a reasonable choice for Korean population, we performed two pilot studies with sequential and concomitant therapies.

METHODS

A total of 164 patients with proven H. pylori infection randomly received 14 days of sequential (n = 86) or concomitant (n = 78) therapies. The sequential group received 20 mg rabeprazole and 1 g amoxicillin (first week), followed by 20 mg rabeprazole, 500 mg clarithromycin, and 500 mg metronidazole (second week). The concomitant group received 20 mg rabeprazole, 1 g amoxicillin, 500 mg clarithromycin, and 500 mg metronidazole for 2 weeks. All drugs were administered BID. Helicobacter pylori status was confirmed 4 weeks later, after completion of treatment by (13) C-urea breath test.

RESULTS

The intention-to-treat and per-protocol eradication rates were 75.6% (95% CI, 66.3-84.9) and 76.8% (95% CI, 67.1-85.5) in the sequential group, and 80.8% (95% CI, 71.8-88.5) and 81.3% (95% CI, 71.6-90.7) in the concomitant group. There were no significant between-group differences, in regard to the eradication rates, compliance, or side effects. The most common side effects were bitter taste, epigastric soreness, and diarrhea.

CONCLUSIONS

Two-week concomitant and sequential therapies showed suboptimal efficacies. However, considering high antibiotics resistance, either of these two regimens may be a reasonable choice for Korean population.

Prevalence of primary and secondary antimicrobial resistance of Helicobacter pylori in Korea from 2003 through 2012

BACKGROUND

Antimicrobial resistance of Helicobacter pylori (H. pylori) affects the efficacy of eradication therapy. The aim of this study was to estimate the prevalence of primary and secondary resistance of H. pylori isolates to antibiotics and to characterize the risk factors associated with antimicrobial resistance in Korea.

MATERIALS AND METHODS

This study was performed during the period of 2003-2012. Primary resistance was evaluated from 347 patients without any history of eradication, and secondary resistance was evaluated in 86 patients from whom H. pylori was cultured after failure of eradication. Minimal inhibitory concentration test was performed for amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, levofloxacin, and moxifloxacin using agar dilution method. Primary and secondary resistance rates of H. pylori to 7 antibiotics were evaluated and risk factors for the antibiotic resistance were analyzed.

RESULTS

Increase in the primary resistance rate was found in amoxicillin (6.3-14.9%, p = .051), clarithromycin (17.2-23.7%, p = .323), and both of levofloxacin and moxifloxacin (4.7-28.1%, p = .002) during the study period. Secondary resistance rate significantly increased in metronidazole, levofloxacin, and moxifloxacin. Increase of resistance occurred after initial failure of eradication therapy in case of clarithromycin (p < .001), azithromycin (p < .001), levofloxacin (p = .011), and moxifloxacin (p = .020). Multivariable analyses showed that clarithromycin, azithromycin, levofloxacin, and moxifloxacin resistance was associated with previous eradication treatment history.

CONCLUSIONS

The increased primary and secondary antibiotic resistance of H. pylori in Korea is ongoing, and it will become a significant limitation for effective eradication of H. pylori in the future.

Helicobacter pylori eradication on iatrogenic ulcer by endoscopic resection of gastric tumour: a prospective, randomized, placebo-controlled multi-centre trial

INTRODUCTION

The role of Helicobacter pylori (H. pylori) eradication has not been clarified in the healing of iatrogenic ulcer after endoscopic resection of gastric neoplasm. The aim of this study was to evaluate whether H. pylori eradication could facilitate the healing of iatrogenic ulcer after endoscopic resection of gastric neoplasm.

METHODS

A total of 232 patients with H. pylori-positive early gastric cancer or gastric adenoma underwent endoscopic resection and were randomly allocated to eradication or placebo group in a prospective, double-blinded, and placebo-controlled manner. The primary outcome was measured by healing rate of ulcer, and the secondary outcomes by reduction rate of ulcer size, relief rate from ulcer-related symptoms, and adverse event rates.

RESULTS

The healing rate of ulcer was 53% in eradication group and 51.6% in placebo group, respectively (p value=0.95). The reduction rate of ulcer size, relief rate from ulcer-related symptoms and adverse event rates were also not different between two groups. In multivariate analysis, initial ulcer size more than 3 cm and histology of cancer were significant factors affecting iatrogenic ulcer healing.

CONCLUSIONS

H. pylori eradication did not facilitate iatrogenic ulcer healing at early and late phase after endoscopic resection of gastric neoplasm.

Trends in the eradication rates of Helicobacter pylori infection for eleven years

AIM

To evaluate the trends in the eradication rate of Helicobacter pylori (H. pylori) over the past 11 years in a single center.

METHODS

This retrospective study covered the period from January 2000 to December 2010. We evaluated 5746 patients diagnosed with gastric ulcers (GU), duodenal ulcers (DU), GU + DU, or nonpeptic ulcers associated with an H. pylori infection. We treated them annually with the 2 wk standard first-line triple regimen, proton pump inhibitor (PPI) + amoxicilin + clarithromycin (PAC; PPI, clarithromycin 500 mg, and amoxicillin 1 g, all twice a day). The follow-up test was performed at least 4 wk after the completion of the 2 wk standard H. pylori eradication using the PAC regimen. We also assessed the eradication rates of 1 wk second-line therapy with a quadruple standard regimen (PPI b.i.d., tripotassium dicitrate bismuthate 300 mg q.i.d., metronidazole 500 mg t.i.d., and tetracycline 500 mg q.i.d.) after the failure of the first-line therapy. Statistical analysis was performed with 95%CI for the differences in the annual eradication rates.

RESULTS

A total of 5746 patients [2333 males (58.8%), 1636 females (41.2%); mean age of males vs females 51.31 ± 13.1 years vs 52.76 ± 13.6 years, P < 0.05, total mean age 51.9 ± 13.3 years (mean ± SD)] were investigated. Among these patients, 1674 patients were excluded: 35 patients refused treatment; 18 patients ceased H. pylori eradication due to side effects; 1211 patients had inappropriate indications for H. pylori eradication, having undergone stomach cancer operation or chemotherapy; and 410 patients did not undergo the follow-up. We also excluded 103 patients who wanted to stop eradication treatment after only 1 wk due to poor compliance or the side effects mentioned above. Finally, we evaluated the annual eradication success rates in a total of 3969 patients who received 2 wk first-line PAC therapy. The endoscopic and clinical findings in patients who received the 2 wk PAC were as follows: gastric ulcer in 855 (21.5%); duodenal ulcer in 878 (22.1%); gastric and duodenal ulcer in 124 (3.1%), erosive, atrophic gastritis and functional dyspepsia in 2055 (51.8%); and other findings (e.g., MALToma, patients who wanted to receive the therapy even though they had no abnormal endoscopic finding) in 57 (0.5%). The overall eradication rate of the 2 wk standard first-line triple regimen was 86.5%. The annual eradication rates from 2000 to 2010 were 86.7%, 85.4%, 86.5%, 83.3%, 89.9%, 90.5%, 88.4%, 84.5%, 89.1%, 85.8%, and 88.3%, sequentially (P = 0.06). No definite evidence of a significant change in the eradication rate was seen during the past eleven years. The eradication rates of second-line therapy were 88.9%, 82.4%, 85%, 83.9%, 77.3%, 85.7%, 84.4%, 87.3%, 83.3%, 88.9%, and 84% (P = 0.77). The overall eradication rate of 1 wk quadruple second-line therapy was 84.7%. There was no significant difference in the eradication rate according to the H. pylori associated diseases.

CONCLUSION

This study showed that there was no trend change in the H. pylori eradication rate over the most recent 11 years in our institution.

Efficacy of Proton Pump Inhibitor-based Triple Therapy and Bismuth-based Quadruple Therapy for Helicobacter pylori Eradication in Korean Children

PURPOSE

The aim of this study was to assess and compare the efficacies of proton pump inhibitor-based triple therapy and bismuth-based quadruple therapy as first-line treatments for Helicobacter pylori eradication in Korean children.

METHODS

We retrospectively reviewed the data of children who had been diagnosed with H. pylori infection at the Seoul National University Bundang Hospital from March 2004 to August 2012. The patients were randomly assigned to receive either triple therapy consisting of omeprazole, amoxicillin, and clarithromycin for 2 weeks (OAC group) or quadruple therapy comprising omeprazole, amoxicillin, metronidazole, and bismuth salts for 1 week (OAMB group). The patients were evaluated for eradication of H. pylori infection at 4 weeks after the completion of the treatment.

RESULTS

Of the 129 children enrolled in this study, 118 (91.5%) were included in the final analysis. The eradication rates in OAC and OAMB groups were 67.7% (42/62) and 83.9% (47/56), respectively, which were significantly different between the 2 treatment groups (p=0.041). The eradication rates in the OAMB group during the periods 2004-2006, 2007-2009, and 2010-2012 were superior to those in the OAC group.

CONCLUSION

This study indicated that the 1-week bismuth-based quadruple therapy, compared with the standard 2-week triple therapy, was significantly more successful in eradicating H. pylori infection in Korean children.

Rifaximin Plus Levofloxacin-Based Rescue Regimen for the Eradication of Helicobacter pylori

Background/Aims

This study assessed the efficacy of a rifaximin plus levofloxacin-based rescue regimen in patients that had failed both triple and quadruple standard regimens for the eradication of Helicobacter pylori.

Methods

We treated patients for H. pylori between August 2009 and April 2011. The triple regimen consisted of combined treatment with amoxicillin, clarithromycin, and pantoprazole for 1 week. For failed cases, a quadruple regimen of tetracycline, metronidazole, bismuth dicitrate, and lansoprazole for 1 week was administered. The rescue regimen for persistently refractory cases was rifaximin 200 mg t.i.d., levofloxacin 500 mg q.d., and lansoprazole 15 mg b.i.d. for 1 week.

Results

In total, 482 patients were enrolled in this study. The eradication rates associated with the first and second regimens were 58% and 60%, respectively. Forty-seven out of 58 patients who failed with the second-line regimen received rifaximin plus levofloxacin-based third-line therapy. The eradication rate for the third regimen was 65%. The cumulative eradication rates were 58%, 85%, and 96% for each regimen, respectively.

Conclusions

A rifaximin plus levofloxacin-based regimen could be an alternative rescue therapy in patients with resistance to both triple and quadruple regimens for the eradication of H. pylori.

Ten-day sequential therapy is more effective than proton pump inhibitor-based therapy in Korea: a prospective, randomized study

BACKGROUND AND AIMS

The eradication rate of proton pump inhibitor (PPI)-based triple therapy for Helicobacter pylori (H. pylori) infection has decreased, mainly due to increasing antibiotic resistance, especially against clarithromycin. It has been reported that a 10-day sequential strategy can produce good outcomes. The aim of this prospective study was to assess the efficacy of sequential therapy as the first-line treatment for the eradication of H. pylori in Korea.

METHODS

A total of 116 patients with proven H. pylori infection received 10-day sequential therapy (20 mg rabeprazole and 1 g amoxicillin, twice daily for the first 5 days, followed by 20 mg rabeprazole, 500 mg clarithromycin, and 500 mg metronidazole, twice daily for the remaining 5 days); 130 patients received 7-day triple therapy (20 mg rabeprazole, 500 mg clarithromycin, and 1 g amoxicillin, twice daily for 7 days). Eradication was evaluated by the (13) C-urea breath test, 4 weeks after the completion of treatment. Compliance and adverse events were assessed.

RESULTS

The eradication rates of 10-day sequential therapy and PPI-based triple therapy were 79.3% (92/116) and 63% (82/130) by intention-to-treat analysis, respectively (P = 0.005), and 81.9% (91/111) and 64.5% (82/127) by per protocol analysis, respectively (P = 0.003). Mild adverse events occurred in both therapy groups (27.5% vs 23.8%), but both treatments were well tolerated.

CONCLUSION

The eradication rate of the 10-day sequential therapy regimen was significantly higher than that of PPI-based triple therapy in the Korean population. Ten-day sequential therapy might be effective as a first-line treatment for H. pylori infection in Korea.

Randomised clinical trial: a comparative study of 10-day sequential therapy with 7-day standard triple therapy for Helicobacter pylori infection in naïve patients

BACKGROUND

The eradication rates following standard triple therapy for Helicobacter pylori infection are declining worldwide. Recent studies have shown that sequential therapy for H. pylori infection yields high cure rates.

AIM

To compare the efficacy and tolerability of a sequential regimen as first-line treatment of H. pylori infection with a standard triple regimen.

METHODS

A total of 348 naïve H. pylori-infected patients from six hospitals in Korea were assigned randomly to standard triple or sequential therapy groups. Standard triple therapy consisted of 20 mg of rabeprazole, 1 g of amoxicillin and 500 mg of clarithromycin, twice daily for 7 days. Sequential therapy consisted of a 5-day dual therapy (20 mg of rabeprazole and 1 g of amoxicillin, twice daily) followed by a 5-day triple therapy (20 mg of rabeprazole, 500 mg of clarithromycin, and 500 mg of metronidazole, twice daily).

RESULTS

The intention-to-treat (ITT) and per-protocol (PP) eradication rates were 62.2% (95% CI 54.8-69.6%) and 76.0% (95% CI 68.5-83.5%) in the standard triple group, and 77.8% (95% CI 71.4-84.2%) and 87.9% (95% CI 82.3-93.5%) in the sequential group, respectively. The eradication rate was significantly higher in the sequential group compared with the standard triple group in both the ITT and PP populations (P = 0.002 and P = 0.013 respectively), whereas the incidence of adverse events was similar.

CONCLUSIONS

Ten-day sequential therapy is more effective and equally tolerated for eradication of H. pylori infection compared with standard triple therapy. Sequential therapy may have a role as first-line treatment for H. pylori infection.

[Primary antibiotic resistance of Helicobacter pylori strains and eradication rate according to gastroduodenal disease in Korea]

BACKGROUND/AIMS

This study was performed to evaluate whether the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates and the eradication rate of H. pylori could be different between cancer and non-cancer patients.

METHODS

H. pylori were isolated from gastric mucosal biopsy specimens obtained from 269 Koreans, who did not have any eradication therapy history and were diagnosed as one of the following diseases; chronic gastritis, benign gastric ulcer, duodenal ulcer or gastric cancer. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin were examined with the agar dilution method. In addition, eradication rate of H. pylori was evaluated.

RESULTS

There was no significant difference in the primary antibiotic resistance to above eight antibiotics among chronic gastritis, peptic ulcer disease and gastric cancer. Furthermore there was no difference of antibiotic resistance between cancer and non-cancer patients, and there was no difference of eradication rate of H. pylori according to disease.

CONCLUSIONS

Primary antibiotic resistance and H. pylori eradication rate were not different between cancer and non-cancer patients.

[Helicobacter pylori eradication therapy in Korea]

Helicobacter pylori (H. pylori) is known to be associated with many gastrointestinal diseases including peptic ulcer. In Korea, eradication of H. pylori is recommended for peptic ulcer disease, low grade gastric mucosa-associated lymphoid tissue lymphoma, and early gastric cancer. Standard triple therapy using proton pump inhibitor, clarithromycin, and amoxicillin and bismuth-containing quadruple therapy have been the main first-line and second-line therapy for H. pylori in Korea. Although eradication rate of second-line quadruple therapy remains similar to that of the past, the success rate of eradication with triple therapy has decreased with increasing antimicrobial resistance to H. pylori. There is no standard third-line therapy, and some regimens that incorporate levofloxacin, moxifloxacin, and rifabutin can be used. New regimens such as sequential or concomitant therapy are suggested as alternative treatment for H. pylori. We need more well designed randomized controlled studies to choose proper treatment for H. pylori infection.