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

Randomised clinical trial: the efficacy of a 10-day sequential therapy vs. a 14-day standard proton pump inhibitor-based triple therapy for Helicobacter pylori in Korea

BACKGROUND

The eradication rates of Helicobacter pylori (H. pylori) using a proton pump inhibitor (PPI)-based triple therapy have declined due to antibiotic resistance worldwide.

AIM

To compare the eradication rate of the 10-day sequential therapy for H. pylori infection with that of the 14-day standard PPI-based triple therapy.

METHODS

This was a prospective, randomised, controlled study. A total of 409 patients with H. pylori infection were randomly assigned to receive either the 10-day sequential therapy regimen, which consisted of pantoprazole (40 mg) plus amoxicillin (1000 mg) twice a day for 5 days, then pantoprazole (40 mg) with clarithromycin (500 mg) and metronidazole (500 mg) twice a day for another five consecutive days or the 14-day PPI-based triple therapy regimen, which consisted of pantoprazole (40 mg) with amoxicillin (1000 mg) and clarithromycin (500 mg) twice a day for 14 days. The pre- and post-treatment H. pylori status were assessed by rapid urease test, urea breath test, or histology. Successful eradication was confirmed at least 4 weeks after finishing the treatment.

RESULTS

In the intention-to-treat analysis, the eradication rates of the 10-day sequential therapy and of the 14-day PPI-based triple therapy were 85.9% (176/205) and 75.0% (153/205), respectively (P = 0.006). In the per-protocol analysis, the eradication rates were 92.6% (175/205) and 85% (153/204), respectively (P = 0.019). There was no statistically significant difference between the two investigated groups regarding the occurrence of adverse event rates (18.9% vs. 13.3%, P = 0.143).

CONCLUSION

The 10-day sequential therapy achieved significantly higher eradication rates than the 14-day standard PPI-based triple therapy in Korea.

Mutations of Helicobacter pylori associated with fluoroquinolone resistance in Korea

BACKGROUND AND AIM

Fluoroquinolone resistance of Helicobacter pylori is known to be dependent on mutations in the QRDR of gyrA. This study was performed to investigate the distribution of gyrA point mutations and to evaluate the impact of the mutations on second-line H. pylori eradication therapy.

METHODS

After H. pylori isolation from gastric mucosal specimens, fluoroquinolone resistance was examined using the agar dilution method. DNA sequencing of the QRDR of gyrA was performed in 89 fluoroquinolone-resistant and 27 fluoroquinolone-susceptible isolates. Transformation experiments were performed to confirm mutations in the resistant strains. The eradication rates of moxifloxacin-containing triple therapy were evaluated depending on the resistance of fluoroquinolone.

RESULTS

The gyrA mutations were detected in 75.3% (55 of 73 strains) of the primary resistant strains and 100% (16 strains) of the secondary resistant strains. The most common mutations were Asp-91 (36.0%) and Asn-87 (33.7%). The MIC values in the transformed strains differed depending on the gyrA mutations, N87, and D91. Six patients with fluoroquinolone-resistant strains received moxifloxacin-containing triple therapy as the second-line therapy, and two of three patients with Asn-87 mutations (66.7%) failed in the eradication. By contrast, three patients with Asp-91 mutations had successful eradication treatment.

CONCLUSIONS

Fluoroquinolone resistance of H. pylori was caused by gyrA Asn-87 and Asp-91 point mutations. The Asn-87 mutation seems to be an important determinant of failure of fluoroquinolone-containing triple eradication therapy based on eradication results.

[Regional difference of antibiotic resistance of helicobacter pylori strains in Korea]

BACKGROUND/AIMS

This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea.

METHODS

H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method.

RESULTS

There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference.

CONCLUSIONS

There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.

Effects of multistrain probiotic-containing yogurt on second-line triple therapy for Helicobacter pylori infection

BACKGROUND AND AIMS

The adjuvant effects of probiotic-containing yogurt on second-line triple therapy for Helicobacter pylori (H. pylori) infection have not been evaluated.

METHODS

A total of 337 patients with persistent H. pylori infection, after first-line triple therapy, were randomly assigned to receive either triple therapy with (yogurt group, n=151) or without (control group, n=186) Will yogurt. Triple therapy consisted of 400 mg moxifloxacin q.d., 1000 mg amoxicillin b.i.d., and 20 mg esomeprazole b.i.d. for 14 days. Will yogurt contains Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium longum, and Streptococcus thermophilus. H. pylori eradication was evaluated by the (13)C-urea breath test, histology, or the rapid urease test.

RESULTS

The eradication rates by intention-to-treat analysis were 66.7% and 68.9% in the control and yogurt groups, respectively (P=0.667). The eradication rates by per-protocol analysis were 78.5% and 86% in the control and the yogurt groups, respectively (P=0.110). The adverse event rates were 25.3% and 28.5% in the control group and yogurt group, respectively (P=0.508).

CONCLUSIONS

The addition of yogurt containing probiotics to moxifloxacin-containing second-line treatment neither improved H. pylori eradication rates nor reduced the adverse events of treatment.