One-week once-daily triple therapy with esomeprazole, moxifloxacin, and rifabutin for eradication of persistent Helicobacter pylori resistant to both metronidazole and clarithromycin

Aim: To investigate a 1‐week once‐daily triple therapy with esomeprazole, moxifloxacin, and rifabutin for rescue therapy of Helicobacter pylori infection. Methods: Consecutive patients (n = 103) with at least one previous treatment failure and H. pylori infection resistant to both metronidazole and clarithromycin were treated with esomeprazole 40 mg, moxifloxacin 400 mg, and rifabutin 300 mg, given once daily for 7 days. Eradication was confirmed by histology and culture. CYP2C19 status was determined by polymerase chain reaction‐restriction fragment length polymorphism. Results: Intention‐to‐treat and per‐protocol eradication rates were 77.7% (68.4–85.3) and 83.3% (74.4–90.2). Five patients discontinued prematurely (4.8%). Eradication was achieved in 93.1% of poor/intermediate metabolizers and in 78.8% of homozygous extensive metabolizers (p = .14). Eradication rates in patients with one, two, three, and four or more previous failures were 78.3%, 89.6%, 68.6%, and 88.9%, respectively (p = .21). The regimen was effective in seven of nine patients who previously failed quadruple therapy. Post‐treatment resistance to moxifloxacin and rifabutin was detected in two (12.5%) and five (31%) patients after treatment failure. Conclusion: Once‐daily triple therapy with esomeprazole, moxifloxacin, and rifabutin is a promising, safe, and convenient regimen for rescue therapy of H. pylori infection that may serve as a valuable alternative to quadruple therapy, particularly for patients with intolerance to amoxicillin.     

Modified sequential Helicobacter pylori therapy: proton pump inhibitor and amoxicillin for 14 days with clarithromycin and metronidazole added as a quadruple (hybrid) therapy for the final 7 days

Background: Ten‐day sequential therapy with a proton pump inhibitor (PPI) and amoxicillin followed by a PPI, clarithromycin, and an imidazole typically achieves Helicobacter pylori eradication rates of 90–94% (Grade B success). Aims: We tested whether prolonging treatment and continuing amoxicillin throughout the 14‐day treatment period would produce a ≥95% result. Methods: This was a multicenter pilot study in which H. pylori‐infected patients received a 14‐day sequential–concomitant hybrid therapy (esomeprazole and amoxicillin for 7 days followed by esomeprazole, amoxicillin clarithromycin, and metronidazole for 7 days). H. pylori status was examined 8 weeks after therapy. Success was defined as achieving ≥95% eradication by per‐protocol analysis. Results: One hundred and seventeen subjects received hybrid therapy. The eradication rate was 99.1% (95% confidence interval (CI), 97.3–100.0%) by per‐protocol analysis and 97.4% by intention‐to‐treat analysis (95% CI, 94.5–100.0%). Adverse events were seen in 14.5%; drug compliance was 94.9%. Conclusions: Fourteen‐day hybrid sequential–concomitant therapy achieved >95%H. pylori eradication (Grade A result). Further studies are needed 1, in regions with different patterns and frequencies of resistance to confirm these findings, and 2, to examine whether Grade A success is maintained with hybrid therapy shorter than 14 days.     

Analysis of antibiotic susceptibility patterns of Helicobacter pylori isolates from Malaysia

Background: The prevalence of antibiotic resistance varies in geographic areas. The information on the antibiotic susceptibility patterns of Helicobacter pylori (H. pylori) in our local setting is therefore relevant as a guide for the treatment options. Objective: This study was conducted to determine the primary resistance rates among H. pylori isolated from Malaysian patients. Materials and methods: Biopsy samples were obtained from the stomach antrum and corpus of 777 patients from September 2004 until 2007. H. pylori isolated from these patients were then subjected to minimum inhibitory concentration (MICs) determination using E‐test method, against metronidazole, clarithromycin, levofloxacin, ciprofloxacin, amoxicillin, and tetracycline. Results: From 777 patients, 119 were positive for H. pylori where a total of 187 strains were isolated. The resistance rates were noted to be 37.4% (metronidazole), 2.1% (clarithromycin), 1% (levofloxacin and ciprofloxacin), and 0% (amoxicillin and tetracycline). Different resistance profiles were observed among isolates from the antrum and corpus of 13 patients. Resistance to one type of antibiotic was observed in 36.4% of the strains where mono‐resistance to metronidazole was the most common. Resistance to ≥2 antibiotics was noted in 3.3% of isolates. High metronidazole MICs of ≥256 μg/mL were observed among the resistant strains. Conclusions: The resistance rates of the antibiotics used in primary treatment of H. pylori infections in Malaysia are low, and multi‐antibiotic‐resistant strains are uncommon. Infections with mixed populations of metronidazole‐sensitive and ‐resistant strains were also observed. However, the high metronidazole MIC values seen among the metronidazole‐resistant strains are a cause for concern.     

The evolution of Helicobacter pylori antibiotics resistance over 10 years in Beijing, China

Objectives: To evaluate Helicobacter pylori antibiotics resistance evolution from 2000 to 2009 to amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin and moxifloxacin in Beijing, China. Methods: A total of 374 H. pylori strains isolated from 374 subjects who had undergone upper gastrointestinal endoscopy from 2000 to 2009 were collected and examined by E‐test method for antibiotics susceptibility. Results: The average antibiotics resistance rates were 0.3% (amoxicillin), 37.2% (clarithromycin), 63.9% (metronidazole), 1.2% (tetracycline), 50.3% (levofloxacin) and 61.9% (moxifloxacin). Overall resistance to clarithromycin, metronidazole, and fluoroquinolone increased annually (from 14.8 to 65.4%, 38.9 to 78.8%, and 27.1 to 63.5%, in 2000 or 2006–2007 to 2009, respectively). The secondary resistance rates were much higher than primary rates to these antibiotics, which also increased annually in recent 10 years. Conclusions: The trend of clarithromycin, metronidazole, and fluoroquinolone resistance of H. pylori increased over time and the resistance to amoxicillin and tetracycline was infrequent and stable in Beijing. Clarithromycin, metronidazole, and fluoroquinolone should be used with caution for H. pylori eradication treatment.     

Evaluation of a four-drug, three-antibiotic, nonbismuth-containing "concomitant" therapy as first-line Helicobacter pylori eradication regimen in Greece

Background: The eradication rates of Helicobacter pylori (H. pylori) with standard treatments are decreasing worldwide as in Greece. Studies with new antibiotic combinations are needed to find better methods of eradication. Therefore, the aim of this study was to evaluate efficacy and tolerability of a 10‐day, four‐drug, three‐antibiotic, nonbismuth–containing concomitant regimen. Materials and Methods: This is a prospective, open‐label, multicenter study that included 131 patients infected with H. pylori. All patients were diagnosed with peptic ulcer disease or nonulcer dyspepsia by endoscopy. H. pylori infection was established by at least two positive tests among rapid urease test, gastric histology, and ¹³C‐urea breath test. For 10 days, all patients received esomeprazole 40 mg, amoxycillin 1000 mg, clarithromycin 500 mg, and metronidazole 500 mg, all b.d. eradication was assessed with ¹³C urea breath test 8 weeks after the start of treatment. Intention‐to‐treat and per‐protocol eradication rates were determined. Results: One hundred and twenty‐seven of the 131 patients completed the study. At intention‐to‐treat analysis, the eradication rate was 91.6% (95% confidence interval (CI), 85.5–95.7%). For the per‐protocol analysis, the eradication rate was 94.5% (95% CI, 89–97.8%). Adverse events were noted in 42 of 131 (32.1%); drug compliance was excellent with 96.9% of the patients taking more than 90% of the prescribed medication. Conclusion: A 10‐day concomitant regimen appears to be an effective, safe, and well‐tolerated treatment option for first‐line H. pylori eradication in Greece.     

Randomized trial on 14 versus 7 days of esomeprazole, moxifloxacin, and amoxicillin for second-line or rescue treatment of Helicobacter pylori infection

Background: Triple therapy with a proton pump inhibitor, moxifloxacin, and amoxicillin has been proven effective in first‐line treatment of Helicobacter pylori infection. Aim: To explore 1, the value of triple therapy with esomeprazole, moxifloxacin, and amoxicillin in second‐line or rescue treatment of Caucasian patients and 2, the impact of treatment duration on eradication success. Methods: H. pylori‐infected patients with at least one previous treatment failure were randomized to oral esomeprazole 20 mg b.i.d., moxifloxacin 400 mg o.d., and amoxicillin 1000 mg b.i.d. for either 7 (EMA‐7) or 14 days (EMA‐14). Eradication was confirmed by 13C urea breath test. Antimicrobial susceptibility testing was performed in all patients at baseline and in patients who failed treatment. Results: Eighty patients were randomized, and 60% had ≥2 previous treatment failures. Pretreatment resistance against clarithromycin and metronidazole was found in 70.5 and 61.5% of cases, respectively. The intention‐to‐treat eradication rate was significantly higher after EMA‐14 compared with EMA‐7 (95.0 vs 78.9%, p = .036). No independent risk factor for treatment failure could be identified. There were no serious adverse events. Five of the EMA‐14 patients (12.5%) compared with none of the EMA‐7 patients discontinued prematurely because of adverse events (p = .031). Post‐treatment resistance against moxifloxacin was found in one of seven patients with isolated organisms (14.3%). Conclusion: Second‐line/rescue H. pylori eradication therapy with esomeprazole, moxifloxacin, and amoxicillin is very effective and well tolerated. Fourteen days of treatment significantly increase the eradication rate but also the rate of adverse events.     

Eradication of Helicobacter pylori in children in Vietnam in relation to antibiotic resistance

Background: Low Helicobacter pylori eradication rates are common in pediatric trials especially in developing countries. The aim of the study was to investigate the role of antibiotic resistance, drug dosage, and administration frequency on treatment outcome for children in Vietnam. Materials and Methods: Antibiotics resistance of H. pylori was analyzed by the Etest in 222 pretreatment isolates from children 3–15 years of age who were originally recruited in a randomized trial with two treatment regiments: lansoprazole with amoxicillin and either clarithromycin (LAC) or metronidazole (LAM) in two weight groups with once‐ or twice‐daily administration. The study design was an observational study embedded in a randomized trial. Results: The overall resistance to clarithromycin, metronidazole, and amoxicillin was 50.9%, 65.3%, and 0.5%, respectively. In LAC, eradication was linked to the strains being susceptible to clarithromycin (78.2% vs 29.3%, p = .0001). Twice‐daily dosage of proton‐pump inhibitor (PPI) and clarithromycin was more effective for eradication than once‐daily dosage for resistant strains (50.0% vs 14.7%, p = .004) and tended to be so also for sensitive strains (87.5% vs 65.2%, p = .051). Exact antibiotic dose per body weight resulted in more eradication for resistant strains (45.3% vs 8.0%, p = .006). These differences were less pronounced for the LAM regimen, with twice‐daily PPI versus once daily for resistant strains resulting in 69.2% and 50.0% eradication (p = .096), respectively. Conclusions: Helicobacter pylori clarithromycin resistance was unexpectedly high in young children in Vietnam. Clarithromycin resistance was an important cause for eradication treatment failure. Twice‐daily administration and exact antibiotic dosing resulted in more eradicated infections when the strains were antibiotic resistant, which has implications for the study design in pediatric H. pylori eradication trials.     

A prospective,randomized study of quadruple therapy and high-dose dual therapy for treatment of Helicobacter pylori resistant to both metronidazole and clarithromycin

Background and Aim. Failure of primary anti‐H. pylori therapy results in a high rate of antimicrobial resistance. Here, we investigated the efficacy of high‐dose dual therapy and quadruple therapy as salvage treatments for eradication of H. pylori resistant to both metronidazole and clarithromycin. Patients and Methods. Patients with at least one treatment failure and infected with H. pylori resistant to both metronidazole and clarithromycin, were randomized to receive either omeprazole 4 × 40 mg and amoxicillin 4 × 750 mg; or omeprazole 2 × 20 mg, bismuthcitrate 4 × 107 mg, metronidazole 4 × 500 mg and tetracycline 4 × 500 mg. Both regimens were given for 14 days. In cases of persistent infection, a cross‐over therapy was performed. Results. Eighty‐four patients were randomized. Cure of H. pylori infection was achieved in 31 patients after dual therapy and in 35 patients after quadruple therapy (per protocol: 83.8% (95% CI, 67.9–93.8) and 92.1% (95% CI, 78.6–98.3), respectively (p = 0.71); intention to treat: 75.6% (95% CI: 59.7–87.6) and 81.4% (95% CI: 66.6–91.6), respectively (p = 0.60)). Cross‐over therapy was performed in six of nine patients, four of whom were cured of the infection. Conclusion. Both high‐dose dual therapy and quadruple therapy are effective in curing H. pylori infection resistant to both metronidazole and clarithromycin in patients who experienced previous treatment failures.     

The relationship between consumption of antimicrobial agents and the prevalence of primary Helicobacter pylori resistance

Background. Primary and acquired resistance to the antimicrobial agents is a primary reason for the failure of Helicobacter pylori eradication therapies. We assessed the primary antibiotic resistance rates of H. pylori to three different antibiotics and its relationship due to the annual antibiotic consumption in Japan during the period prior to approval of anti‐H. pylori therapy in Japan. Materials and Methods. Antibiotic susceptibility was tested using the agar dilution method for clarithromycin, amoxicillin and metronidazole. Isolates were considered resistant when the MIC value was > 8 mg/l for metronidazole, > 1 mg/l for clarithromycin and < 0.5 mg/l for amoxicillin. Results. Helicobacter pylori isolates were obtained from 593 Japanese patients from 1995 to 2000. Primary resistance of H. pylori to clarithromycin, metronidazole and amoxicillin was found in 11%, 9% and 0.3% strains, respectively. The proportion with clarithromycin resistance significantly increased from 7% in 1997–98 to 15.2% in 1999–2000 (p = .003). During the same period the metronidazole resistance rate also increased from 6.6% in 1997–98 to 12% in 1999–2000 (p = .02). The prevalence of clarithromycin and metronidazole was related to the annual consumption of these antimicrobial agents. Conclusion. Resistance rates for both clarithromycin and metronidazole appear to reflect the annual consumption of these agents. The high rate of clarithromycin resistance in Japan suggests that the effectiveness of clarithromycin‐based therapies may be compromised in the near future.     

High Helicobacter pylori resistance to metronidazole but zero or low resistance to clarithromycin, levofloxacin, and other antibiotics in Malaysia

Objective: Bacterial resistance to antibiotics is the single most important determinant of treatment success. The objective of this study was to determine the prevalence of Helicobacter pylori resistance to clarithromycin, amoxicillin, metronidazole, tetracycline, levofloxacin, rifabutin, and furazolidone in our local bacterial strains. Methods: Samples from consecutive ninety patients were obtained for culture and sensitivity testing. Resistance to individual antibiotics were tested using the E‐test and MIC₉₀ read from the strips. Resistance to rifampicin and nitrofurantoin were used as a surrogate for rifabutin and furazolidine. Results: There was a high prevalence of resistance to metronidazole 68/90 (75.5%). No male (34/45 (75.5%) versus female (35/45 (77.7%) difference in frequency of metronidazole resistance was noted (p = 1.000). There was zero resistance ₀ to clarithromycin, levofloxacin, amoxicillin, and nitrofurantoin/furazolidone. Resistance to rifampicin/rifabutin was for breakpoints of 1 and 4 μg/mL of 14.4 and 2.2% respectively. Conclusions: Although there was high bacterial resistance to metronidazole, the absence of resistance particularly to the key antibiotics used in H. pylori eradication therapy: clarithromycin and levofloxacin is reassuring to note. Continued monitoring of antibiotic resistance should be carried out.     

Antibiotic resistance of Helicobacter pylori in Mazandaran, North of Iran

Background: The aim of this study was to investigate the prevalence of resistances in Helicobacter pylori against commonly used antibiotics including metronidazole, clarithromycin, amoxicillin, and tetracycline in Iranian patients. Methods: H. pylori isolates were collected from gastric biopsies from patients referred for upper gastrointestinal endoscopy at Tooba Medical Center, Sari, Iran, from 2007 to 2010. None of them had been using antibiotics for at least 8 months. H. pylori was identified based on morphological shape and positive biochemical tests for catalase, oxidase, and urease activity. Antibiotic resistance for metronidazole, clarithromycin, amoxicillin, and tetracycline was investigated by using epsilometer test. Resistance was defined by minimal inhibitory concentration (MIC) > 0.5 mg/L for amoxicillin (AMX), >4 mg/L for tetracycline (TET), >8 mg/L for metronidazole (MTZ), and >1 mg/L for clarithromycin (CLR). Results: Strains were collected from 132 patients, mean age 45.8 years, 52 (39%) were women. Patients had diverse diagnoses: gastritis 42 (31.8%), duodenal ulcer 45 (34%), gastric cancer 15 (11.3%), or gastric ulcer 30 (22.7%). The prevalences of resistance of H. pylori strains isolated from the patients were 73.4% for metronidazole, 30% for clarithromycin, 6.8% for amoxicillin, and 9% for tetracycline. Twenty‐eight (21.2%) were double resistant to MTZ‐CLR, 16 (12.1%) showed triple resistance to MTZ‐CLR‐AMX, and 8 (6%) were resistant to all four tested antibiotics (MTZ‐CLR‐AMX‐TET). No associations were detected between multiple resistant strains and clinical manifestations (p > .05). Conclusions: The prevalence of H. pylori antibiotic resistance to metronidazole and clarithromycin was high in Iran consistent with the reported low success rates for H. pylori treatment in this country.     

Role of the preliminary susceptibility testing for initial and after failed therapy of Helicobacter pylori infection with levofloxacin, amoxicillin, and esomeprazole

BACKGROUND: Levofloxacin has been proposed as an alternative to classic therapy in secondary resistance to Helicobacter pylori. AIM: To evaluate primary and secondary resistance of H. pylori to levofloxacin, and to test the role of susceptibility test on the efficacy of levofloxacin-based triple therapy. METHODS: Eighty consecutive dyspeptic patients with positive (13)C-urea breath test never treated were randomly allocated into group A(1) (40 patients) and group B(1) (39 patients). Eighty-three patients already treated unsuccessfully with positive (13)C-urea breath test were divided into group A(2) (51 patients) and group B(2) (32 patients). Patients in group A(1) and group A(2) underwent upper gastrointestinal endoscopy for H. pylori susceptibility test to amoxicillin, clarithromycin, tinidazole, rifabutin, and levofloxacin. These patients were treated with levofloxacin (500 mg b.i.d.), amoxicillin (1 g b.i.d.) and esomeprazole (20 mg b.i.d.) for 10 days if sensitive to these two antibiotics. If H. pylori was found resistant to amoxicillin and/or levofloxacin the treatment was based on the indications of the susceptibility test. Patients in group B(1) and group B(2) were treated empirically with levofloxacin, amoxicillin, and esomeprazole at the same dose and duration as group A. All patients underwent (13)C-urea breath test 2 months after the end of therapy. RESULTS: The antibiotic resistance of H. pylori strains in group A(1) and group A(2) was (%): amoxicillin: 2.4, 10; clarithromycin: 21.9, 43.1; tinidazole: 31.7, 70; rifabutin: 2.4, 4; and levofloxacin: 9.7, 12.2, respectively. In group A(1) with susceptibility test-driven therapy, eradication was 97.2%, and in group B(1) with empirical treatment, 94.1% (n.s.). In group A(2) with susceptibility test, eradication was 97.5%, whereas in group B(2) with empirical treatment 81.2% (p < .01). CONCLUSION: Primary and secondary resistance of H. pylori to levofloxacin is approximately 10% of the tested strains. The susceptibility test does not influence therapeutic outcome of triple therapy with amoxicillin and levofloxacin in patients never treated, while it is determinant for patients who were previously treated without success.     

Whole genome sequencing reveals novel genetic mutations of Helicobacter pylori associating with resistance to clarithromycin and levofloxacin

Background

Detection of mutations in one or a couple of genes may not provide enough data or cover all the genomic DNA variance related to antibiotic resistance of Helicobacter pylori to clarithromycin (CLA) and levofloxacin (LVX). We aimed to perform whole genome sequencing to explore novel antibiotic resistance-related genes to increase predictive accuracy for future targeted sequencing tests.

Methods

Gastric mucosal biopsies were taken during upper endoscopy in 27 H. pylori-infected patients. According to culture-based antibacterial susceptibility test, H. pylori strains were divided into three groups, with nine strains in each group: CLA single-drug resistance (group C), LVX single-drug resistance (group L), and strains sensitive to all antibacterial drugs (group S). Based on whole genome sequencing with group S being the control, group C and group L group-specific single nucleotide variants and amino acid mutations were screened, and potential candidate genes related to CLA and LVX resistance were identified.

Results

The median age of study subjects was 35 years (IQR: 31–40), and 17 (63.0%) were male. All nine CLA-resistant strains had A2143G mutations in 23S rRNA, while none of nine sensitive strains had the mutation. Six of nine strains in group L and six of nine strains in group S had 87th or 91st mutation in gyrA. After comparing sequencing data of strains among the three groups, we identified five mutated positions belonging to four genes related to CLA resistance, and 31 mutated positions belonging to 20 genes related to LVX resistance. Novel genetic mutations were detected for CLA resistance (including fliJ and clpX) and LVX resistance (including fliJ, cheA, hemE, Val360Ile, and HP0568). Missense mutations in fliJ and cheA gene were mainly involved in chemotaxis and flagellar motility to facilitate bacterial escape of antibiotics, while the functions of other novel gene mutations underpinning antibiotic resistance remain to be investigated.

Conclusion

Whole genome sequencing detected potential novel genetic mutations conferring resistance of H. pylori to CLA and LVX including fliJ and cheA. Further studies to correlate these findings with treatment outcome should be performed.     

Correlation between substitutions in penicillin-binding protein 1 and amoxicillin resistance in Helicobacter pylori

The correlation between the substitutions of penicillin-binding protein 1 (PBP1) and amoxicillin resistance was studied for the determination of the substitutions in PBP1 which confer amoxicillin resistance in Helicobacter pylori. By the comparison of the amino acid sequences of PBP1 in the amoxicillinresistant (n=3), low-susceptible (n=3), and susceptible (n=13) H. pylori isolates, the substitution Asn562-->Tyr, which is adjacent to KTG motif (555-557), was common and specific to amoxicillin-resistant H. pylori. Additionally, all amoxicillin-resistant isolates had multiple substitutions such as Ser414-->Arg in the transpeptidase region of PBP1 of H. pylori. Furthermore all transformants obtained by the natural transformation using the pbp1 genes of amoxicillin-resistant H. pylori isolates had multiple substitutions including Asn562-->Tyr. These results suggest that multiple amino acid substitutions in the transpeptidase region of PBP1 are closely related to amoxicillin resistance in H. pylori.     

Helicobacter pylori infection: sequential therapy followed by levofloxacin-containing triple therapy provides a good cumulative eradication rate

Background: In the eradication of H. pylori infection, even today, the main international guidelines recommend the triple therapy as first‐line regimen, although its effectiveness is clearly decreasing. As second‐line treatment, the bismuth‐containing quadruple therapy is the most used regimen, although several other therapies are studied. The Italian guidelines recommend, alternatively, sequential therapy or triple therapy as first‐line treatment and levofloxacin‐containing triple therapy as second‐line regimen. We wanted to assess the overall eradication rate of Helicobacter pylori infection in two therapeutic rounds following the Italian guidelines in clinical practice. Materials and Methods: We treated 231 consecutive Helicobacter pylori‐positive patients by sequential therapy and we verified the eradication 8–10 weeks after treatment by stool antigen test. Patients positive for stool antigen test received levofloxacin‐containing triple therapy, as second‐line therapy, according to Italian Guidelines and they were again submitted to the fecal test 8–10 weeks after the end of treatment. Results: In the first‐line regimen, we obtained an eradication rate of 92.6%, in the second‐line of 75.0% and as cumulative result we achieved a 97.8% of eradication, in per‐protocol analysis. Conclusions: Sequential therapy as first‐line and levofloxacin‐containing triple therapy as second‐line represent a good combination to eradicate Helicobacter pylori infection in only two rounds.