Minimum inhibitory concentrations of commonly used antibiotics against Helicobacter Pylori: A multicenter study in South China.

AIM: To determine the minimum inhibitory concentrations (MICs) of commonly used antibiotics against Helicobacter Pylori (H. pylori) in South China and compare their resistance rates by using EUCAST breakpoints and other breakpoints. METHODS: Patients who had not previously received H. pylori treatment in clinical centers in South China were enrolled in this study from 2017 to 2020. Gastric biopsies were obtained for H. pylori culture. The MICs of amoxicillin (AMX), clarithromycin (CLA), metronidazole (MTZ), levofloxacin (LEV), tetracycline (TET) and furazolidone (FZD) were tested by broth microdilution method and assessed by two different breakpoints. ATCC43504 standard strain served as a control. RESULTS: A total of 208 H. pylori strains were isolated from patients' biopsy samples. The MICs of AMX, CLA, MTZ, LEV, TET and FZD for H. pylori were 0.0156-256mg/L (MIC50 0.125mg/L, MIC90 4mg/L), 0.0156- >256 mg/L (MIC50 0.0312mg/L, MIC90 64mg/L), 0.0156- >256mg/L (MIC50 8mg/L, MIC90 256mg/L), 0.0156-256mg/L (MIC50 0.25mg/L, MIC90 16mg/L), 0.0156-256mg/L (MIC50 0.0625mg/L, MIC90 4mg/L), and 0.0156- >256mg/L (MIC50 0.0312mg/L, MIC90 2mg/L), respectively. The MICs of AMX, CLA, MTZ, LEV, TET and FZD for ATCC43504 strain were 0.25mg/L, 0.0625mg/L, 64mg/L, 0.5mg/L, 1mg/L and 0.25mg/L, respectively. The resistance rate of FZD was 11.05%. The overall resistance rates according to EUCAST breakpoints and other breakpoints were 57.21% and 14.90% for AMX (p<0.001), 38.94% and 38.94% for CLA (p = 1), 39.42% and 50.96% for MTZ (p<0.001), 12.98% and 10.58% for TET (p = 0.025), 35.10% and 35.10% for LEV (p = 1), respectively. CONCLUSIONS: Our results demonstrate that AMX, FZD, and TET, but not MTZ, CLR or LEV, showed good anti-H. pylori activity in vitro in South China. When different breakpoints were used, similar results were found with CLA, and LEV, but not with AMX, MTZ, or TET.

Modified sequential therapy vs quadruple therapy as initial therapy in patients with Helicobacter infection.

AIM: To evaluate the efficacy and safety of modified sequential therapy and to compare modified sequential therapy with standard quadruple therapy for Helicobacter pylori (H. pylori) eradication. METHODS: In total, 200 consecutive patients who were diagnosed with H. pylori-infected chronic gastritis by electronic endoscopy and rapid urease testing from December 2012 to October 2013 were enrolled in this study. The patients had not previously received H. pylori eradication treatment, and were randomized into two groups. The patients in Group A (n = 101) were treated with ilaprazole + bismuth potassium citrate + amoxicillin and clavulanate potassium + levofloxacin, and the patients in Group B (n = 99) were administered a modified sequential therapy composed of ilaprazole at 5 mg bid and amoxicillin and clavulanate potassium at 914 mg for the first five days followed by ilaprazole at 5 mg bid, furazolidone at 100 mg bid and levofloxacin at 500 mg qid for the next five days. Four to six weeks after the end of treatment, a 14C-urea breath test was performed for all the subjects to confirm the eradication of H. pylori. The intention-to-treat and per-protocol eradication rates were determined. RESULTS: A total of 190 of the 200 patients completed the study. All 200 patients were included in the intention-to-treat analysis, whereas 190 patients were included in the per-protocol analysis. In the intention-to-treat analysis, the rates of H. pylori eradication in Groups A and B were 85.15% (86/101) and 81.82% (81/99), respectively. In the per-protocol analysis, the H. pylori eradication rates in Groups A and B were 88.66% (86/97) and 87.09% (81/93), respectively. No significant difference was observed (χ(2) = 0.109, P = 0.741) in the eradication rate between Groups A and B. The rates of adverse effects observed in the groups were similar at 6.19% (6/97) for Group A and 7.53% (7/93) for Group B (P > 0.05). No mortality or major morbidities were observed in any of the patients. Symptomatic improvements in the presentation of stomachache, acid regurgitation, and burning sensation were not significantly different between the two groups. CONCLUSION: Ilaprazole-based 10-d standard quadruple therapy does not offer an incremental benefit over modified sequential therapy for the treatment of H. pylori infection, as both treatment regimens appear to be effective, safe, and well-tolerated as initial treatment options.