Quinolone resistance in Helicobacter pylori isolates in Germany

Antibiotic Resistance of Helicobacter pylori in Patients with Peptic Ulcer

Background and Objectives: To determine the antibiotic resistance rate of H. pylori among patients with peptic ulcer. Materials and Methods: A cross-sectional monocentric study was conducted from January to December 2021 among patients aged from 16 years with gastrointestinal symptoms and esophagogastroduodenoscopy. Gastric mucosa biopsies were collected at the edges of the ulcer or at lesion sites for H. pylori culture. Five antibiotics (amoxicillin (AMX), clarithromycin (CLR), metronidazole (MTZ), levofloxacin (LEV), and tetracycline (TET)) were selected for antibiotic susceptibility testing. Results: One hundred and twenty-five patients were included, and the sex ratio was 0.6. Their mean age was 47.3 ± 14.2 years. All of the participants had gastritis, and 24.0% had duodenitis. A total of 21.6% of patients had a duodenal ulcer, and 12.8% had an antral ulcer. A total of 40 specimens have grown in H. pylori culture. The proportion of resistance to AMX, CLR, MTZ, LEV, and TET was 27.5%, 50%, 67.5%, 35%, and 5%, respectively. The proportion of multidrug resistance was 22.5%. The proportion of double resistance to AMX + CLR was 20.0%, AMX + MTZ was 15.0%, AMX + LEV was 2.5%, CLR + MTZ was 32.5%, and TET + MTZ was 5.0%. Conclusions: Our research results show that the treatment with MTX-TET or LVX-AMOX has the highest sensitivity rate. Therefore, practitioners should refer to these regimes to eradicate H. pylori in patients with gastric and duodenal ulcers. The reports on H. pylori eradication from different geographic areas show heterogeneous results. Therefore, continuous monitoring of antibiotic resistance of H. pylori in each population is very important. Having evidence helps clinicians to treat patients most effectively, reduce treatment costs, and limit the rate of antibiotic resistance.

Revisiting Therapeutic Strategies for H. pylori Treatment in the Context of Antibiotic Resistance: Focus on Alternative and Complementary Therapies

The prevalence of Helicobacter pylori infection remains significant worldwide and it depends on many factors: gender, age, socio-economic status, geographic area, diet, and lifestyle. All successful infectious diseases treatments use antibiotic-susceptibility testing, but this strategy is not currently practical for H. pylori and the usual cure rates of H. pylori are lower than other bacterial infections. Actually, there is no treatment that ensures complete eradication of this pathogen. In the context of an alarming increase in resistance to antibiotics (especially to clarithromycin and metronidazole), alternative and complementary options and strategies are taken into consideration. As the success of antibacterial therapy depends not only on the susceptibility to given drugs, but also on the specific doses, formulations, use of adjuvants, treatment duration, and reinfection rates, this review discusses the current therapies for H. pylori treatment along with their advantages and limitations. As an alternative option, this work offers an extensively referenced approach on natural medicines against H. pylori, including the significance of nanotechnology in developing new strategies for treatment of H. pylori infection.

Antimicrobial Resistance of Helicobacter pylori in Gastric Biopsy Samples from Lima/Peru

Background: Helicobacter pylori prevalence and gastric cancer rates are remarkably high in Peru. Effective antimicrobial regimens are essential for successful H. pylori eradication. We aimed at assessing antimicrobial resistance rates to first- and second-line therapeutic agents in H. pylori strains detected in gastric biopsy samples. Materials and Methods: Gastric biopsy samples (antrum and corpus) were collected from therapy-naive patients (n = 154). H. pylori presence in the samples was confirmed by histopathology. Genotypic resistance to clarithromycin and quinolones was determined by real-time PCR. Results: Histology results were 100% concordant with PCR results (97/154; 63% H. pylori-positive in both). In 6% (6/97) of the patients, we found discordant results of H. pylori infection in antrum and corpus samples from the same patient. Resistance rates to clarithromycin and quinolone were 34% (33/97) and 68% (56/82), respectively. Antimicrobial resistance to both antimicrobials was 30% (25/82). Conclusion: Antimicrobial resistance rates of H. pylori to clarithromycin and quinolones are very high in Lima, Peru. Many first- and second-line, empiric eradication regimens may not be recommended for Peruvian patients.

Helicobacter pylori: Multiple resistance in patients from Bogotá, Colombia

Introduction: The main cause for Helicobacter pylori infection treatment failure is antibiotic resistance, where clarithromycin and metronidazole play the main role. In Colombia, primary resistance as a consequence of the use of these two antibiotics and excessive levofloxacin use is above the accepted limit (13.6%, 83%, and 16%, respectively). Despite this fact, empirical therapies that include the combination of these antibiotics are used in patients with previous therapeutic failure. Objective: To determine antibiotic resistance in patients previously treated for H. pylori in Bogotá, Colombia. Materials and methods: We conducted a descriptive study that included ten isolates obtained from five patients with three or four previous failed treatments for H. pylori. Antibiotic resistance to amoxicillin, clarithromycin, levofloxacin, and metronidazole was investigated by agar dilution and confirmed by DNA sequencing (Magrogen, Korea). Results: Eight isolates were resistant to two or more antibiotics. All isolates were resistant to levofloxacin. Susceptibility patterns in isolates from the gastric antrum and the body of the stomach were different in three patients. Conclusion: As far as we know, this is the first evidence of multiple H. pylori resistance in Colombia in previously treated patients. Results demonstrated the consequences of using an ineffective antibiotic scheme and the need to assess antibiotic susceptibility in different anatomical sites of the stomach. The consequences of multiple resistance decrease possible antibiotic effectiveness to eradicate H. pylori in the future.

Helicobacter pylori antimicrobial resistance in a pediatric population

BACKGROUND

The increasing prevalence of Helicobacter pylori (H. pylori) antimicrobial resistance, primarily for clarithromycin decreases the success of treatment. The aim of this study is to determine the local pattern of first-line antimicrobials resistance and the eradication rate.

MATERIAL AND METHODS

Prospective cohort study of H. pylori infected patients (positive histological or cultural exams) treated at Centro Materno-Infantil do Norte from January of 2013 to October of 2017. Susceptibility to 4 antibiotics: amoxicilin, metronidazole, clarithromycin, and levofloxacin were analyzed by E-test (phenotypic resistance). The E-test was chosen because it is simple and cost-effective for routine susceptibility testing. Point mutations that confer clarithromycin resistance were surveyed (genotypic resistance). Eradication of H. pylori infection was defined by a negative urea breath test or fecal antigen 6-8 weeks after the end of treatment.

RESULTS

Of a total of 74 H. pylori infected patients, 16 were excluded because they had previous H. pylori treatment or severe systemic disease. Median age of infection cases was 15 years (3-17 years). Eradication regimen used in all patients combined the use of 3 antibiotics (amoxicillin and metronidazole or clarithromycin) and proton pump inibhitor for 14 days and was tailored according antimicrobial susceptibility. 79.5% of the patients completed the treatment. The resistance rate for metronidazole and clarithromycin was 3.3% and 23.3%, respectively. There was no resistance for amoxicilin and levofloxacin. The rate of genotypic resistance to clarithromycin was 37.2%. The eradication rate was 97.8%.

CONCLUSIONS

The authors found a high resistance rate of H. pylori for clarithromycin in this northern portuguese pediatric center. This factor should determine a change in local current treatment, contraindicating the use of clarithromycin as a first-line treatment for H. pylori infection in children. The high eradication rate maybe explained for the eradication treatment tailored according antimicrobial susceptibility.

Microarray-Based Detection and Clinical Evaluation for Helicobacter pylori Resistance to Clarithromycin or Levofloxacin and the Genotype of CYP2C19 in 1083 Patients

Background. Helicobacter pylori (H. pylori) is one of the most frequent and persistent bacterial infections that affect nearly half of the world's population. Antibiotic resistance is a constantly evolving process and local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy. The aim of this study was to establish a microarray-based detection to identify H. pylori infection, clarithromycin and levofloxacin susceptibility, and CYP2C19 genetic polymorphism and guide to potential choice of proton pump inhibitor (PPI), antibiotic administration for tailored H. pylori eradication therapy. Methods. By analyzing the sequence of human genomic CYP2C19⁎2 and CYP2C19⁎3 and mutations within the 23S rRNA and gyrA gene regions conferring clarithromycin and levofloxacin resistance, respectively, we developed a microarray for individual therapy detection of H. pylori infection. Plasmids were established as positive or limit of detection (LOD) reference materials. The specificity and sensitivity of the microarray had been performed. And a total of 1083 gastric biopsy samples were tested and the Kappa value had been calculated between the array and Sanger sequencing. We also analyzed the resistance to clarithromycin and levofloxacin in China, as well as the CYP2C19 polymorphisms. Results. The LOD of detecting H. pylori was 10³ CFU/mL and human genome DNA was 2 ng/μL. The detection results of 1083 gastric biopsy samples showed that 691 (63.80%) were H. pylori positive, of which 266 (38.49%) were resistant to clarithromycin, 192 (27.79%) were resistant to levofloxacin, and 61 (8.83%) were resistant to both of them. For the type of CYP2C19 polymorphism, 412 (38.04%) were homozygous fast type (HomEM), 574 (53%) were heterozygous EM (HetEM), and 97 (8.96%) were poor metabolizer (PM). Conclusions. The proposed microarray-based detection has high specificity, sensitivity, and reproducibility for detecting the resistance of clarithromycin or levofloxacin as well as CYP2C19 polymorphism, which may help to improve the clinical eradication rate of H. pylori.

Prospective multicentre clinical study on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori

OBJECTIVES

We report on a large prospective, multicentre clinical investigation on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori.

METHODS

Therapy-naive patients (n = 2004) who had undergone routine diagnostic gastroscopy were prospectively included from all geographic regions of Austria. Gastric biopsy samples were collected separately from antrum and corpus. Samples were analysed by histopathology and real-time PCR for genotypic resistance to clarithromycin and quinolones. Clinical and demographic information was analysed in relation to resistance patterns.

RESULTS

H. pylori infection was detected in 514 (26%) of 2004 patients by histopathology and confirmed in 465 (90%) of 514 patients by real-time PCR. PCR results were discordant for antrum and corpus in 27 (5%) of 514 patients, indicating inhomogeneous infections. Clarithromycin resistance rates were 17% (77/448) and 19% (84/455), and quinolone resistance rates were 12% (37/310) and 10% (32/334) in antrum and corpus samples, respectively. Combination of test results per patient yielded resistance rates of 21% (98/465) and 13% (50/383) for clarithromycin and quinolones, respectively. Overall, infection with both sensitive and resistant H. pylori was detected in 65 (14%) of 465 patients.

CONCLUSIONS

Anatomically inhomogeneous infection with different, multiple H. pylori strains is common. Prospective clinical study design, collection of samples from multiple sites and microbiologic methods that allow the detection of coinfections are mandatory for collection of reliable data on antimicrobial resistance patterns in representative patient populations. (ClinicalTrials.gov identifier: NCT02925091).

Surveillance of Helicobacter pylori Antibiotic Susceptibility in Indonesia: Different Resistance Types among Regions and with Novel Genetic Mutations

Information regarding Helicobacter pylori antibiotic resistance in Indonesia was previously inadequate. We assessed antibiotic susceptibility for H. pylori in Indonesia, and determined the association between virulence genes or genetic mutations and antibiotic resistance. We recruited 849 dyspeptic patients who underwent endoscopy in 11 cities in Indonesia. E-test was used to determine the minimum inhibitory concentration of five antibiotics. PCR-based sequencing assessed mutations in 23S rRNA, rdxA, gyrA, gyrB, and virulence genes. Next generation sequencing was used to obtain full-length sequences of 23S rRNA, infB, and rpl22. We cultured 77 strains and identified 9.1% with clarithromycin resistance. Low prevalence was also found for amoxicillin and tetracycline resistance (5.2% and 2.6%, respectively). In contrast, high resistance rates to metronidazole (46.7%) and levofloxacin (31.2%) were demonstrated. Strains isolated from Sumatera Island had significantly higher metronidazole resistance than those from other locations. Metronidazole resistant strains had highly distributed rdxA amino acid substitutions and the 23S rRNA A2143G mutation was associated with clarithromycin resistance (42.9%). However, one strain with the highest MIC value had a novel mutation in rpl22 without an A2143G mutation. Mutation at Asn-87 and/or Asp-91 of gyrA was associated with levofloxacin-resistance and was related to gyrB mutations. In conclusions, although this is a pilot study for a larger survey, our current data show that Indonesian strains had the high prevalence of metronidazole and levofloxacin resistance with low prevalence of clarithromycin, amoxicillin, and tetracycline resistance. Nevertheless, clarithromycin- or metronidazole-based triple therapy should be administered with caution in some regions of Indonesia.

Systematic review with meta-analysis: the efficacy of levofloxacin triple therapy as the first- or second-line treatments of Helicobacter pylori infection

BACKGROUND

Levofloxacin triple therapy has been used for the first-line and second-line treatment of Helicobacter pylori infection for more than 10 years.

AIMS

To systematically review the efficacy of levofloxacin triple therapy in the first- and second-line treatment, and to assess the time trend and factors that might affect its efficacy.

METHODS

Prospective trials reporting the efficacy of levofloxacin triple therapy in either the first-line or second-line treatment of H. pylori infection in adults were searched from the PubMed and Cochrane database from January 2000 to September 2015. Meta-analysis was performed to calculate the cumulative eradication rate and the efficacies in subgroups.

RESULTS

Of the 322 articles identified, a total of 4574 patients from 41 trials, including 16 trials in the first-line treatment and 25 trials in the second-line treatment were eligible for analysis. The cumulative eradication rate was 77.3% (95% confidence intervals, CI: 74.7-79.6) and was 80.7% (95% CI 77.1-83.7) in the first-line treatment and 74.5% (95% CI: 70.9-77.8) in the second-line treatment. The efficacies of levofloxacin triple therapy before 2008, between 2009 and 2011, and after 2012 were 77.4%, 79.6% and 74.8% respectively. The eradication rate was higher when levofloxacin was given once daily (80.6%, 95% CI: 77.1-83.7) than twice daily (73.6%, 95% CI: 69.7-77.2). The efficacy was significantly higher in levofloxacin-susceptible strains than resistant strains (81.1% vs. 36.3%, risk ratio 2.18, 95% CI: 1.6-3, P < 0.001).

CONCLUSION

The efficacy of levofloxacin triple therapy has been lower than 80% in many countries and it is not recommended when the levofloxacin resistance is higher than 5-10%.

Prevalence of Primary Antimicrobial Resistance of H. pylori in Turkey: A Systematic Review

BACKGROUND

The prevalence of clarithromycin resistance has increased to the 20% or more in different regions of the world. Clarithromycin resistance is known to be responsible for most of the treatment failures in Helicobacter pylori (H. pylori) infection. The aim of this systematic review was to summarize the prevalence of primary antibiotic resistance (amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline) of H. pylori strains in different geographical regions of Turkey.

MATERIAL AND METHODS

An Internet search was performed using PubMed and the ULAKBIM Turkish Medical Database. The terms "primary antibiotic resistance (separately; amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline) of H. pylori" with and without "Turkey" or "different geographical regions of Turkey" were searched among articles published in both English and Turkish language within the time span from 1999 to 2015. Data analysis was performed using MedCalc 12.7.0. Each article was weighted according to the number of isolated H. pylori strains. Pooled proportion analysis was performed.

RESULTS

Twenty-one Turkish studies including 1059 H. pylori strains were included in this review. The overall primary antibiotic resistance rates of H. pylori strains isolated in Turkey were as follows: amoxicillin 3 (0.971%), clarithromycin 425 (24.864%), metronidazole 75 (33.747%), tetracycline 2 (3.511%), and levofloxacin 31 (23.769%).

CONCLUSIONS

Primary antibiotic resistance against H. pylori in Turkey shows differences between geographical regions and population densities. There is an increase in primary resistance rates to clarithromycin and metronidazole in different years. The data are not sufficient for tetracycline, amoxicillin, and levofloxacin. High clarithromycin resistance rates were mostly detected in overpopulated cities like Ankara (north), Izmir (west), Istanbul (west), and Bursa (west).

The Association of Age and Antibiotic Resistance of Helicobacter Pylori: A Study in Jiaxing City, Zhejiang Province, China

The antibiotic resistance of Helicobacter pylori (H pylori) is steadily increasing worldwide, resulting in the low efficiency of the current therapeutic approaches for eradication. In this study, we investigated the relationship between antibiotic resistances, the year of sample collection, and the ages of the infected individuals.A total of 29,034 gastric mucosa biopsy samples were randomly collected from January 1, 2009 to December 9, 2014 in Jiaxing City, Zhejiang Province, China. An antibiotic susceptibility testing was determined using an agar-dilution method. The statistical significance was tested using the chi-squared (χ) test.A total of 9687 strains were isolated. The resistance rate to clarithromycin, levofloxacin, and metronidazole were 17.76%, 19.66%, and 95.5%, respectively. Resistance was rare against amoxicillin, gentamicin, and furazolidone. The metronidazole resistance rate stayed at a consistently high level. In contrast, the resistance rates of clarithromycin and levofloxacin increased rapidly from 2009 to 2011, gradually decreased from 2012 to 2013, and then increased again in 2014. Although patients ages 31 to 50 and 71 to 80 years had lower infection rates of H pylori, they also had higher resistance rates to clarithromycin and levofloxacin. The highest antibiotic resistance rate was observed in patients' ages 71 to 80 years old. Younger patients (below 30 years old) had a lower resistance to levofloxacin. Patients' ages 51 to 60 years old may thus represent an important category for the future study of H pylori infection.Age plays a key element in H pylori resistance to clarithromycin and levofloxacin. It is therefore necessary to consider individualized therapy for the optimized treatment of H pylori-infected patients.

Antimicrobial resistance of Helicobacter pylori strains to five antibiotics, including levofloxacin, in Northwestern Turkey

INTRODUCTION

Antibiotic resistance is the main factor that affects the efficacy of current therapeutic regimens against Helicobacter pylori. This study aimed to determine the rates of resistance to efficacy clarithromycin, amoxicillin, tetracycline, levofloxacin and metronidazole among H. pylori strains isolated from Turkish patients with dyspepsia.

METHODS

H. pylori was cultured from corpus and antrum biopsies that were collected from patients with dyspeptic symptoms, and the antimicrobial susceptibility of H. pylori was determined using the E-test (clarithromycin, amoxicillin, tetracycline, metronidazole and levofloxacin) according to the EUCAST breakpoints. Point mutations in the 23S rRNA gene of clarithromycin-resistant strains were investigated using real-time PCR.

RESULTS

A total of 98 H. pylori strains were isolated, all of which were susceptible to amoxicillin and tetracycline. Of these strains, 36.7% (36/98) were resistant to clarithromycin, 35.5% (34/98) were resistant to metronidazole, and 29.5% (29/98) were resistant to levofloxacin. Multiple resistance was detected in 19.3% of the isolates. The A2143G and A2144G point mutations in the 23S rRNA-encoding gene were found in all 36 (100%) of the clarithromycin-resistant strains. Additionally, the levofloxacin MIC values increased to 32 mg/L in our H. pylori strains. Finally, among the clarithromycin-resistant strains, 27.2% were resistant to levofloxacin, and 45.4% were resistant to metronidazole.

CONCLUSIONS

We conclude that treatment failure after clarithromycin- or levofloxacin-based triple therapy is not surprising and that metronidazole is not a reliable agent for the eradication of H. pylori infection in Turkey.

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

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

The evolution of Helicobacter pylori antibiotics resistance over 10 years in Greece

BACKGROUND

Increasingly, over time, antibiotic resistance is considered a problem for the efficacy of H. pylori eradication treatment. The aim of our study was to evaluate the changes in clarithromycin and levofloxacin resistance of H. pylori strains in Greek patients in two different time periods (in 2000 and in 2010).

METHODS

Gastric biopsies of consecutive H. pylori-positive patients were investigated retrospectively. Mutations in H. pylori 23S rRNA and gyrA genes associated with resistance to clarithromycin and quinolones, respectively, were determined by allelic specific polymerase chain reaction.

RESULTS

In the first time period (2000), H. pylori resistance patterns were evaluated in 50 and in the second period (2010) in 57 patients. During the first time period 30 and 0% of patients were infected with clarithromycin- or quinolone-resistant strains, respectively. In the second time period (2010), the percentage of patients infected with clarythromycin or quinolone resistance strains increased to 42 and 5.3%, respectively.

CONCLUSIONS

Our study showed an increase in the prevalence of both clarithromycin and quinolones resistance of H. pylori. Although the resistance rate to quinolones increased over the years, it is relatively low justifying its use for the eradication of H. pylori infections.

Prevalence of multiple drug-resistant Helicobacter pylori strains among patients with different gastric disorders in Iran

Emergence of multidrug-resistant (MDR) strains of Helicobacter pylori is a global health concern. This study was aimed to determine the frequency of MDR H. pylori strains in Iran. H. pylori isolates were obtained from cultured gastric biopsy samples on selective culture media after their characterization by PCR and conventional biochemical methods. The minimal inhibitory concentrations of rifampicin, ciprofloxacin, levofloxacin, ampicillin, clarithromycin, erythromycin, metronidazole, and tetracycline were determined for 111 strains that were isolated from 197 dyspeptic patients by the agar dilution method. The primary resistance rates were 61.3% (68/111) for metronidazole, 15.3% (17/111) for ampicillin, and 14.4% (16/111) for rifampicin. Resistance rates for other antimicrobials were as follows: macrolides (erythromycin or clarithromycin) 32.4% (36/111) and quinolones (levofloxacin or ciprofloxacin) 30.6% (34/111). Among the resistant strains, the rates of double and multiple drug resistance phenotypes were 22.6% (19/84) and 34.5% (29/84), respectively. The quadruple drug resistance phenotype encompasses 37.9% of the MDR strains, of which 90% of them was resistant to metronidazole. In conclusion, these results showed a high frequency of MDR phenotypes among the studied H. pylori strains in Iran. The eradication of the H. pylori strains presenting high resistance rates to macrolides, fluoroquinolones, or metronidazole could be achieved by approved tetracycline- or amoxicillin-containing regimens as alternative regimens to standard triple therapy.

Resistance to amoxicillin, clarithromycin and ciprofloxacin of Helicobacter pylori isolated from Southern Brazil patients

Introduction:Helicobacter pylori is a bacteria which infects half the world population and is an important cause of gastric cancer. The eradication therapy is not always effective because resistance to antimicrobials may occur. The aim of this study was to determine the susceptibility profile of H. pylori to amoxicillin, clarithromycin and ciprofloxacin in the population of Southern Brazil.

Material and methods: Fifty four samples of H. pylori were evaluated. The antibiotics susceptibility was determined according to the guidelines of the British Society for Antimicrobial Chemotherapy and the Comité de l'Antibiogramme de la Société Française de Microbiologie.

Results: Six (11.1%) H. pylori isolates were resistant to clarithromycin, one (1.9%) to amoxicillin and three (5.5%) to ciprofloxacin. These indices of resistance are considered satisfactory and show that all of these antibiotics can be used in the empirical therapy.

Conclusion: The antibiotics amoxicillin and clarithromycin are still a good option for first line anti-H. pylori treatment in the population of Southern Brazil.

Antimicrobial susceptibility testing for Helicobacter pylori in times of increasing antibiotic resistance

The gram-negative bacterium Helicobacter pylori (H. pylori) causes chronic gastritis, gastric and duodenal ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Treatment is recommended in all symptomatic patients. The current treatment options for H. pylori infection are outlined in this review in light of the recent challenges in eradication success, largely due to the rapid emergence of antibiotic resistant strains of H. pylori. Antibiotic resistance is a constantly evolving process and numerous studies have shown that the prevalence of H. pylori antibiotic resistance varies significantly from country to country, and even between regions within the same country. In addition, recent data has shown that previous antibiotic use is associated with harbouring antibiotic resistant H. pylori. Local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy. Antimicrobial resistance is assessed by H. pylori culture and antimicrobial susceptibility testing. Recently developed molecular tests offer an attractive alternative to culture and allow for the rapid molecular genetic identification of H. pylori and resistance-associated mutations directly from biopsy samples or bacterial culture material. Accumulating evidence indicates that surveillance of antimicrobial resistance by susceptibility testing is feasible and necessary to inform clinicians in their choice of therapy for management of H. pylori infection.

Practical treatment of Helicobacter pylori: a balanced view in changing times

Eradication rates of first-line triple therapy for Helicobacter pylori infection have fallen in the recent years. The main reasons for treatment failure are poor compliance due to complicated treatment regimens and the emergence of antibiotic-resistant strains of H. pylori. Treatment failure is a cause for concern with regard to the complications of H. pylori infection, which include gastric and peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. This review describes considerations for optimizing standard first-line triple therapy, as well as alternatives to the standard first-line treatment, such as bismuth quadruple therapy, sequential therapy, concomitant therapy and hybrid therapy. Studies using levofloxacin-based and rifabutin-based regimens for the treatment of multiresistant infections have also been reviewed. The current most up-to-date systematic reviews and meta-analyses comparing the efficacy of these treatments have been discussed, in light of the recent antimicrobial susceptibility testing data, regional antibiotic resistance rates and the Maastricht IV guidelines on the management of H. pylori infection.

Antibiotic susceptibility of Helicobacter pylori in central Germany and its relationship with the number of eradication therapies

OBJECTIVES

Helicobacter pylori eradication rates show a constant decline over the last few years. The main reason for H. pylori treatment failure is the increasing antibiotic resistance.We assessed antibiotic susceptibility of H. pylori in a region of mid-Germany and analyzed the relationship of antibiotic resistance with the number of eradication therapies over a period of 7 years (2005-2012).

METHODS

H. pylori strains were isolated from 436 patients who underwent gastroscopy for different clinical indications. Susceptibility to amoxicillin, clarithromycin, metronidazole, tetracycline, levofloxacin, and rifabutin was determined using the E-test.

RESULTS

Primary, secondary, and tertiary resistances against clarithromycin were 7.5, 63.2, and 75.4%, respectively. Primary, secondary, and tertiary resistances to levofloxacin were 11.7, 17.6, and 36.4% and to metronidazole were 32.7, 63.2, and 80.1%, respectively. The resistance rates against tetracycline and rifabutin were comparatively low (<5%), even in patients with previous exposure to these antibiotics. Resistance to rifabutin increased to 6.2% in patients who received more than two previous eradication therapies. Amoxicillin resistance was not detectable in all patients.

CONCLUSION

In our region, we observed a stable, but constantly increasing, resistance rate to antibiotics commonly used for the treatment of H. pylori infection. Knowledge of the local antibiotic resistance rates is essential for developing successful treatment strategies for H. pylori eradication.

Effect of fluoroquinolone resistance on 14-day levofloxacin triple and triple plus bismuth quadruple therapy

OBJECTIVE

Levofloxacin has been proposed to replace clarithromycin for Helicobacter pylori treatment. Seven- and 10-day fluoroquinolone triple therapies have generally failed to achieve cure rates of ≥90%, whereas 14-day therapy has achieved 95% success. The aim was to assess the efficacy and effect of fluoroquinolone resistance on 14-day levofloxacin-containing triple therapy with or without the addition of bismuth.

DESIGN

Helicobacter pylori-positive patients with functional dyspepsia or healed peptic ulcers were randomized to receive lansoprazole 30 mg b.i.d., amoxicillin 1000 mg b.i.d., and levofloxacin 500 mg daily with (B-LAL) or without (LAL) bismuth potassium citrate 220 mg b.i.d. for 14 days. Eradication was assessed by ¹³C-urea breath testing 4 weeks after completing treatment. Antimicrobial susceptibility was by the agar dilution method. Success was defined as PP success ≥90%.

RESULTS

A total of 152 of 161 patients (81 LAL and 80 B-LAL) enrolled completed treatment. The PP rates were 94.6% (70/74; 95% CI, 86.9-97.9%) with B-LAL and 85.9% (95% CI, 76.5-91.9%) with LAL (p = .07); the ITT eradication rates were 87.5% (95% CI, 78.5-93.1%) with B-LAL and 82.7% (95% CI, 73-89.4%) with LAL (p = .39). Levofloxacin resistance was present in 30.3%. Treatment success was excellent with susceptible strains (97.5%) versus resistant strains (70.6%) for B-LAL and 97.3% versus 37.5% for LAL, respectively.

CONCLUSIONS

Fourteen-day fluoroquinolone therapy was highly effective when fluoroquinolone resistance rates are <12%. The addition of bismuth maintained effectiveness with fluoroquinolone resistance as high as 25%.

Antibiotics resistance rate of Helicobacter pylori in Bhutan

AIM: To survey the antibiotic resistance pattern of Helicobacter pylori (H. pylori) strains isolated from Bhutanese population.

METHODS: We isolated 111 H. pylori strains from the gastric mucosa of H. pylori-infected patients in Bhutan in 2010. The Epsilometer test was used to determine the minimum inhibitory concentrations (MICs) of amoxicillin (AMX), clarithromycin (CLR), metronidazole (MNZ), levofloxacin (LVX), ciprofloxacin (CIP), and tetracycline (TET).

RESULTS: Nineteen of the isolated H. pylori strains were susceptible to all antibiotics tested. The isolated strains showed the highest rate of antibiotic resistance to MNZ (92/111, 82.9%). Among the 92 MNZ-resistant strains, 74 strains (80.4%) showed high-level resistance (MIC ≥ 256 μg/mL). Three strains were resistance to LVX (2.7%). These strains were also resistance to CIP. None of the strains showed resistance to CLR, AMX and TET.

CONCLUSION: CLR-based triple therapy is a more effective treatment approach over MNZ-based triple therapy for H. pylori infection in Bhutan.

The efficacy of moxifloxacin-based triple therapy in treatment of Helicobacter pylori infection: a systematic review and meta-analysis of randomized clinical trials

Recent evidence shows that moxifloxacin could exert an antimicrobial effect against Helicobacter pylori in both in vitro and in vivo models. To systematically evaluate whether moxifloxacin-containing triple therapy could improve eradication rates and reduce side effects in first-line or second-line anti-H. pylori treatment, eligible articles were identified by searches of electronic databases. We included all randomized trials comparing moxifloxacin-based triple therapy with standard triple or quadruple therapy during H. pylori eradication treatment. Statistical analysis was performed with Review Manager 5.0.10. Subanalysis/sensitivity analysis was also performed. We identified seven randomized trials (n=1263). Pooled H. pylori eradication rates were 79.03% (95%CI: 75.73-82.07) and 68.33% (95%CI: 64.44-72.04) for patients with moxifloxacin-based triple therapy or with standard triple or quadruple therapy, respectively (intention-to-treat analysis). The odds ratio (OR) was 1.82 (95%CI: 1.17-2.81), the occurrence of total side effects was 15.23% (95%CI: 12.58-18.20) and 27.17% (95%CI: 23.64-30.92) for groups with or without moxifloxacin, and the summary OR was 0.45 (95%CI: 0.26-0.77). In subgroup analyses, we noted that the second-line eradication rate in the moxifloxacin group was significantly higher than that in the quadruple therapy group (73.33 vs 60.17%, OR: 1.78, 95%CI: 1.16-2.73, P<0.001). However, there was no difference in first-line eradication treatment. Findings from this meta-analysis suggest that moxifloxacin-based triple therapy is more effective and better tolerated than standard triple or quadruple therapy. Therefore, a moxifloxacin-based triple regimen should be used in the second-line treatment of H. pylori infection.

Helicobacter pylori resistance rates for levofloxacin, tetracycline and rifabutin among Irish isolates at a reference centre

INTRODUCTION

Helicobacter pylori eradication rates using conventional triple therapies are falling, making viable second-line and rescue regimens necessary. Levofloxacin, tetracycline and rifabutin are three efficacious antibiotics for rescue therapy.

AIM

We aimed to assess the resistance rates for H. pylori against these antibiotics in an Irish cohort.

METHODS

Gastric biopsies were collected from 85 patients infected with H. pylori (mean age 46 years) in the Adelaide and Meath Hospital, Dublin in 2008 and 2009. Susceptibility to antibiotics was tested using the Etest. Clinical information was obtained from endoscopy reports and chart review.

RESULTS

50.6 % of patients were females. Mean age was 47 years. Ten had prior attempts at eradication therapy with amoxicillin-clarithromycin-PPI, two had levofloxacin-based second-line therapy. 11.7 % [95 % CI (6.5-20.3 %)] (N = 10) had strains resistant to levofloxacin. There were no strains resistant to rifabutin or tetracycline. Levofloxacin resistance in the under 45 age group was 2.6 % (1/38) compared to 19.1 % (9/47) of above 45 age group (p = 0.02).

DISCUSSION

The levofloxacin rates illustrated in this study are relatively low by European standards and in line with other studies from the United Kingdom and Germany, with younger patients having very low levels of resistance. Levofloxacin, tetracycline and rifabutin are all valid options for H. pylori eradication in Irish patients but the importance of compliance cannot be underestimated.

Molecular Detection of Antibiotic Resistance in South African Isolates of Helicobacter pylori

Rapid diagnosis and treatment of Helicobacter pylori (H. pylori) presents a challenge. We aimed at investigating the presence of H. pylori, susceptibility profile, and associated mutations in an effort to validate the effectiveness of GenoType HelicoDR assay in H. pylori typing in our environment. Two hundred and fifty-four biopsy specimens were cultured and DNA extracted from seventy-eight positive cultures using the Qiagen DNA extraction kit. The GenoType Helico DR which employs reverse hybridisation was used to confirm the presence of H. pylori, determination of its susceptibility to antimicrobials, and detection of mutations conferring resistance to clarithromycin and fluoroquinolones. The organism was isolated from 168/254 (66.1 %) of the specimens by culture. Of the 78 strains used for further investigation, 12/78 (15.38%) were resistant to clarithromycin while 66/78 (84.61%) were susceptible. For fluoroquinolone, 70/78 (89.74%) strains were susceptible while 8 (10.26%) were resistant. Mutations were observed in 17 strains with A2147G being the most prevalent; A2146C and D91N were the least. The reverse hybridisation assay is an easy and fast technique in confirming the presence of H. pylori, its antimicrobial profile, and associated mutations. Analysis regarding the suitability of this assay for H. pylori typing is warranted in other regions.

High secondary resistance to quinolones in German Helicobacter pylori clinical isolates

OBJECTIVES

The aim of this study was to update data on levofloxacin/ciprofloxacin and triple resistance (resistance to metronidazole, clarithromycin and levofloxacin/ciprofloxacin) in Helicobacter pylori clinical isolates and to identify the impact of prior eradication therapies on their development.

METHODS

We tested the antimicrobial susceptibility to amoxicillin, metronidazole, clarithromycin, levofloxacin/ciprofloxacin, tetracycline and rifampicin of 5296 clinical H. pylori strains isolated between 2006 and 2011. Information on prior eradication therapies was gathered and their impact on the development of antimicrobial resistance, in particular to levofloxacin/ciprofloxacin and triple resistance, was analysed.

RESULTS

From 2006 onwards, both levofloxacin/ciprofloxacin and triple resistance have steadily increased and peaked in 2011 with 29.1% and 18.6%, respectively. Unsuccessful prior eradication attempts proved a major risk factor for resistance development. Patients who had undergone unsuccessful eradication attempts harboured levofloxacin/ciprofloxacin- and triple-resistant isolates significantly more often than untreated individuals (26.7% and 18.1% versus 10.6% and 1.6%). Levofloxacin/ciprofloxacin and triple resistance occurred significantly more often in patients who had received quinolones when compared with patients who had not (44.5% versus 23.1% and 28.7% versus 15.6%). We did not observe any significant differences in resistance rates in the different German federal states.

CONCLUSIONS

Resistance to levofloxacin/ciprofloxacin and triple resistance have continuously risen and reached worrying numbers. Hence we strongly advise against the use of quinolones in empirical second-line therapies for H. pylori without prior susceptibility testing and/or a carefully taken patient medical history.

The incidence of primary antibiotic resistance of Helicobacter pylori in Vietnam

GOALS

To determine the susceptibility of Helicobacter pylori strains isolated from a Vietnamese population to 5 antibiotics.

BACKGROUND

The incidence of antibiotic resistance in H. pylori infection is increasing worldwide and has become a leading cause for failure of treatment. Antibiotic susceptibility testing is very important to provide optimal regimens in a clinical setting.

STUDY

We isolated 103 H. pylori strains from the gastric mucosa of H. pylori-infected patients from 2 areas in Vietnam (Ho Chi Minh and Hanoi) in 2008. Epsilometer test was used to determine the minimum inhibitory concentrations of amoxicillin, clarithromycin (CLR), metronidazole (MNZ), levofloxacin, and tetracycline.

RESULTS

Among the 103 strains, the resistance rates were 0% (amoxicillin), 33% (CLR), 69.9% (MNZ), 18.4% (levofloxacin), and 5.8% (tetracycline). The resistant strains showed a high-level of resistance (≥ 256 µg/mL) to CLR, 23.5% (8/34), and MNZ, 29.1% (21/72). The resistance rate for CLR was significantly higher in Ho Chi Minh than in Hanoi (49% vs. 18.5%, P=0.001). Resistance to both CLR and MNZ was most commonly observed (24.3%). Two strains (1.9%) were resistant to 4 of the 5 antibiotics. No significant association was observed between antibiotic resistance rates and age, sex, or clinical outcomes of the patients.

CONCLUSIONS

High incidence of resistance to CLR and MNZ suggests that standard triple therapies may not be useful as first-line treatment in Vietnam. Alternative strategies such as bismuth-based quadruple therapies or sequential therapy may be more effective in Vietnam.

Primary antibiotic resistance and associated mechanisms in Helicobacter pylori isolates from Senegalese patients

Background

Antibiotic combination therapy for Helicobacter pylori eradication must be adapted to local resistance patterns, but the epidemiology of H. pylori resistance to antibiotics is poorly documented in Africa. The aim was to determine the antibiotic resistance rates, as well as the associated molecular mechanisms, of strains isolated in Dakar, Senegal.

Methods

One hundred and eight H. pylori strains were isolated between 2007 and 2009 from 108 patients presenting with upper abdominal pain to the Gastroenterology Department of Le Dantec Hospital. Antimicrobial susceptibility testing was performed for amoxicillin, clarithromycin, metronidazole, levofloxacin and tetracyclin using the E-test method. Mutations in the 23S rRNA gene of clarithromycin-resistant strains and in gyrA and gyrB of levofloxacin-resistant strains were investigated.

Results

Isolates were characterized by no resistance to amoxicillin (0%), tetracycline (0%), and very low rate of resistance to clarithromycin (1%), but a high rate of resistance to metronidazole (85%). The clarithromycin-resistant strain displayed the A2143G mutation. A worrying rate of levofloxacin resistance was detected (15%). N87I and D91N were the most common mutations in the quinolone-resistance-determining region of gyrA.

Conclusions

The first-line empirical regimen for H. pylori eradication in Senegal should include clarithromycin. Increasing rates of fluoroquinolone resistance detected should discourage the use of levofloxacin-containing regimens without prior antimicrobial susceptibility testing.

Efficacy of 5-day levofloxacin-containing concomitant therapy in eradication of Helicobacter pylori infection

BACKGROUND & AIMS

Helicobacter pylori have become resistant to antimicrobial agents, reducing eradication rates. A 10-day sequential regimen that contains levofloxacin was efficient, safe, and cost saving in eradicating H pylori infection in an area with high prevalence of clarithromycin resistance. We performed a noninferiority randomized trial to determine whether a 5-day levofloxacin-containing quadruple concomitant regimen was as safe and effective as the 10-day sequential regimen in eradicating H pylori in previously untreated patients.

METHODS

We randomly assigned patients with H pylori infection to groups that were given 5 days of concomitant therapy (esomeprazole 40 mg twice daily, amoxicillin 1 g twice daily, levofloxacin 500 mg twice daily, and tinidazole 500 mg twice daily; n = 90) or 10 days of sequential therapy (esomeprazole 40 mg twice daily, amoxicillin 1g twice daily for 5 days followed by esomeprazole 40 mg twice daily, levofloxacin 500 mg twice daily, and tinidazole 500 mg twice daily for 5 more days; n = 90). Antimicrobial resistance was assessed by the E-test. Efficacy, adverse events, and costs were determined.

RESULTS

Intention-to-treat analysis showed similar eradication rates for concomitant (92.2%; 95% confidence interval [CI], 84.0%-95.8%) and sequential therapies (93.3%; 95% CI, 86.9%-97.3%). Per-protocol eradication results were 96.5% (95% CI, 91%-99%) for concomitant therapy and 95.5% for sequential therapy (95% CI, 89.6%-98.5%). The differences between sequential and concomitant treatments were 1.1% in the intention-to-treat study (95% CI; -7.6% to 9.8%) and -1.0% in the per-protocol analysis (95% CI; -8.0% to 5.9%). The prevalence of antimicrobial resistance and incidence of adverse events were comparable between groups. Concomitant therapy cost $9 less than sequential therapy.

CONCLUSIONS

Five days of levofloxacin-containing quadruple concomitant therapy is as effective and safe, and less expensive, in eradicating H pylori infection than 10 days of levofloxacin-containing sequential therapy.

Levofloxacin versus clarithromycin in a 10 day triple therapy regimen for first-line Helicobacter pylori eradication: a single-blind randomized clinical trial

BACKGROUND

There is growing evidence that the standard triple therapy against Helicobacter pylori infection is losing clinical effectiveness. A triple therapy regimen with levofloxacin, amoxicillin and a proton pump inhibitor has been reported to be effective and well tolerated, and this regimen has been suggested as an alternative first-line treatment. The aim of this single-blind randomized clinical trial was to compare the eradication success of two first-line triple therapy regimens in the north of Spain: clarithromycin, amoxicillin and omeprazole (CAO) versus levofloxacin, amoxicillin and omeprazole (LAO).

MATERIALS AND METHODS

A total of 250 consecutive patients diagnosed by conventional methods with H. pylori infection were randomized into one of two 10 day therapeutic regimens: standard CAO (n = 128) or LAO (n = 122). Eradication was confirmed by the (13)C-urea breath test. Adverse effects and compliance were also assessed. The clinical trial registration number was HPL08001HCLAD (EudraCT: 2008-001892-31).

RESULTS

Intention-to-treat cure rates were: CAO, 75.0% (96/128; 95% CI: 66.6%-82.2%) and LAO, 82.8% (101/122; 95% CI: 74.9%-89.0%). Per-protocol cure rates were: CAO, 78.0% (96/123; 95% CI: 69.7%-85.0%) and LAO, 83.1% (98/118; 95% CI: 75.0%-89.3%). There were no statistically significant differences in effectiveness between the two regimens. In addition, no relevant differences in compliance or adverse effects were demonstrated.

CONCLUSIONS

Levofloxacin-based treatment for H. pylori infection did not improve upon the eradication rate of the standard clarithromycin-based triple therapy in this study. This may reflect the progressive increase in in vitro resistance rates to levofloxacin observed in our region.

Is Helicobacter pylori antibiotic resistance surveillance needed and how can it be delivered?

BACKGROUND

Most patients are prescribed Helicobacter pylori treatment without culture and antibiotic susceptibility testing, as current guidance recommends that patients with recurrent dyspepsia should be tested for H. pylori using a non-invasive breath or faecal antigen test.

AIMS

To determine the prevalence of H. pylori antibiotic resistance in patients attending endoscopy in England and Wales, and the feasibility of an antibiotic resistance surveillance programme testing.

METHODS

We tested the antibiotic susceptibility of H. pylori isolates from biopsy specimens from 2063 of 7791 (26%) patients attending for endoscopy in Gloucester and Bangor, and 339 biopsy specimens sent to the Helicobacter Reference Unit (HRU) in London. Culture and susceptibility testing was undertaken in line with National and European methods.

RESULTS

Helicobacter pylori were cultured in 6.4% of 2063 patients attending Gloucester and Bangor hospitals. Resistance to amoxicillin, tetracycline and rifampicin/rifabutin was below 3% at all centres. Clarithromycin, metronidazole and quinolone resistance was significantly higher in HRU (68%, 88%, 17%) and Bangor isolates (18%, 43%, 13%) than Gloucester (3%, 22%, 1%). Each previous course of these antibiotics is associated with an increase in the risk of antibiotic resistance to that agent [clarithromycin: RR = 1.5 (P = 0.12); metronidazole RR = 1.6 (P = 0.002); quinolone RR = 1.8 (P = 0.01)].

CONCLUSIONS

Helicobacter pylori infection is now uncommon in dyspeptic patients at endoscopy. A surveillance system is feasible and necessary to inform dyspepsia management guidance. Clinicians should take a thorough antibiotic history before prescribing metronidazole, clarithromycin or levofloxacin for H. pylori.

Rescue Therapy for Helicobacter pylori Infection 2012

Helicobacter pylori infection is the main cause of gastritis, gastroduodenal ulcer disease, and gastric cancer. After 30 years of experience in H. pylori treatment, however, the ideal regimen to treat this infection has still to be found. Nowadays, apart from having to know well first-line eradication regimens, we must also be prepared to face treatment failures. In designing a treatment strategy, we should not only focus on the results of primary therapy alone but also on the final-overall-eradication rate. The choice of a "rescue" treatment depends on which treatment is used initially. If a first-line clarithromycin-based regimen was used, a second-line metronidazole-based treatment (quadruple therapy) may be used afterwards, and then a levofloxacin-based combination would be a third-line "rescue" option. Alternatively, it has recently been suggested that levofloxacin-based "rescue" therapy constitutes an encouraging 2nd-line strategy, representing an alternative to quadruple therapy in patients with previous PPI-clarithromycin-amoxicillin failure, with the advantage of efficacy, simplicity and safety. In this case, quadruple regimen may be reserved as a 3rd-line "rescue" option. Even after two consecutive failures, several studies have demonstrated that H. pylori eradication can finally be achieved in almost all patients if several "rescue" therapies are consecutively given.

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.

Effectiveness and safety of repeated quadruple therapy in Helicobacter pylori infection after failure of second-line quadruple therapy: repeated quadruple therapy as a third-line therapy

BACKGROUNDS

Quadruple therapy using a proton-pump inhibitor, bismuth, metronidazole, and tetracycline is a standard second-line therapy for Helicobacter pylori infection, achieving an eradication rate of about 80% in Korea. A standard third-line therapy is not currently established, although various protocols have been proposed. We performed this study to evaluate the effectiveness of a retrial with quadruple therapy before starting a third-line treatment with new drugs.

MATERIALS AND METHODS

In 80 of 746 patients treated with a second-line quadruple therapy at the Korea University Ansan Hospital between January 2002 and September 2010, treatment for H. pylori had failed, and 45 of these patients were eligible for this study. Eradication of H. pylori was assessed by repeated endoscopy or by the (13) C-urea breath test at least 4 weeks after therapy. The patients with treatment failure were treated again with quadruple regimen for 2 weeks and reevaluated for treatment effectiveness and safety.

RESULTS

The eradication rate with second-line quadruple therapy was 86.9%. Of the 80 patients who failed treatment for H. pylori with the initial second-line quadruple therapy, 64 patients were treated again with the same regimen. Of the 45 retreated patients in this study, three patients were lost to follow-up and two complied poorly with medication. The eradication rate in the 40 patients retreated was 75.0% at per-protocol analysis. Seventeen patients experienced mild adverse events.

CONCLUSIONS

A retrial of quadruple therapy before use of a third-line therapy may be safe and effective for patients who fail to respond to second-line quadruple therapy.

Antimicrobial susceptibility of Helicobacter pylori to six antibiotics currently used in Spain

BACKGROUND

Antibiotic resistance is directly related to the loss of efficacy of currently accepted Helicobacter pylori therapies. Knowledge of the antibiotic susceptibility in a local area can contribute to the design of specific 'à la carte' treatments. The aim of this study was to analyse the susceptibility of H. pylori isolates to six conventional antibiotics currently used in a northern region of Spain.

METHODS

Seventy-one isolates were obtained from gastric biopsies of 76 consecutive adult patients suffering from peptic ulcer disease, dyspepsia or familial gastric cancer and known to be infected with H. pylori by conventional methods. Susceptibility testing was performed for amoxicillin, ciprofloxacin, levofloxacin, clarithromycin, metronidazole and tetracycline using the Etest method.

RESULTS

The prevalence rates of resistance were as follows: amoxicillin, 1.4% [95% confidence interval (CI) 0.0-7.6]; clarithromycin, 14.7% (95% CI 7.3-25.4); ciprofloxacin, 14.3% (95% CI 7.1-24.7); levofloxacin, 14.5% (95% CI 7.2-25.0); metronidazole, 45.1% (95% CI 33.2-57.3); and tetracycline, 0% (95% CI 0.0-5.1).

CONCLUSIONS

Our study confirms an increasing rate of resistance to levofloxacin that equals that of clarithromycin in our healthcare area. This fact may reflect a wide and indiscriminate use of the former antibiotic and could account for a loss of clinical effectiveness of levofloxacin-containing regimens. Moreover, clarithromycin resistance rates remain stable, which could allow us to maintain its use in our area.

Quadruple therapy with medications containing either rufloxacin or furazolidone as a rescue regimen in the treatment of Helicobacter pylori-infected dyspepsia patients: a randomized pilot study

BACKGROUND

The eradication rates of first-line treatment for Helicobacter pylori infection are not satisfactory. Various regimens including quadruple therapies have been recommended as rescue therapies after the first H. pylori eradication attempt failed.

AIMS

To compare the efficacy and safety between quadruple therapies with medications containing either rufloxacin or levofloxacin in the Chinese nonulcer dyspepsia patients infected with H. pylori.

METHODS

One hundred and thirty-eight patients after an unsuccessful 10-day standard triple therapy were enrolled in this study. They were randomized to receive a 14-day quadruple therapy with pantoprazole, bismuth citrate, and furazolidone in combination with either rufloxacin (Group Ruf, n=70) or levofloxacin (Group Lev, n=68). The H. pylori eradication was evaluated by (13) C-urea breath test 4 and 12 weeks after therapy was completed.

RESULTS

One hundred and twenty-seven patients (65 in Group Ruf and 62 in Group Lev) completed the study. The H. pylori eradication rates in Group Ruf were 81.4% for intention-to-treat (ITT) analysis and 87.7% for per-protocol (PP) analysis. The rates were statistically significantly higher than those in Group Lev (66.2% and 72.6%) (p<0.05). There were no severe adverse effects found in these two groups.

CONCLUSIONS

Fourteen-day quadruple therapy with a combination of proton-pump inhibitor, bismuth citrate, furazolidone, and rufloxacin is considered an effective and safe rescue therapy for H. pylori eradication after failure of standard triple treatment.

Isolation of Helicobacter pylori in gastric mucosa and susceptibility to five antimicrobial drugs in Southern chile

Helicobacter pylori colonizes more than 50% of the world population thus, it is considered an important cause of gastric cancer. The aim of this study was to determine the isolation frequency of H. pylori in Southern Chile from patients with symptomatology compatible with gastritis or gastric ulcer and to correlate these findings with demographic parameters of infected patients and the susceptibility profiles of the isolated strains to the antimicrobial drugs used in the eradication treatments. A total of 240 patients were enrolled in the study. Each gastric biopsy was homogenized and seeded onto blood agar plates containing a selective antibiotics mixture (DENT supplement). Plates were incubated at 37° C in a microaerophilic environment for five days. The susceptibility profiles to amoxicillin, ciprofloxacin, clarithromycin, tetracycline and metronidazole were determined using the E-test method. H. pylori was isolated from 99 patients (41.3%) with slightly higher frequency in female (42% positive cultures) than male (40.2% positive cultures). With regard to age and educational level, the highest isolation frequencies were obtained in patients between 21-30 (55%) and 41-50 (52.6%) years old, and patients with secondary (43.9%) and university (46.2%) educational levels. Nineteen (21.6%) strains showed resistance to at least one antimicrobial drug. Tetracycline was the most active antimicrobial in vitro, whereas metronidazole was the less active. One strain (5.3%) showed resistance to amoxicillin, clarithomycin and metronidazole, simultaneously.

Should quinolones come first in Helicobacter pylori therapy?

New generations of fluoroquinolones, like levofloxacin and moxifloxacin, exhibit a broad-spectrum activity against Gram-positive and Gram-negative bacteria, and have been successfully introduced into the treatment of Helicobacter pylori infection. Based on a large body of evidence, current guidelines recommend the use of levofloxacin- or moxifloxacin-containing proton-pump inhibitor (PPI) triple therapies in second-line or rescue treatment of H. pylori infection. The efficacy of standard PPI triple therapies has substantially declined during the last decade, mainly due to increasing resistance against the key antibiotics clarithromycin and metronidazole. Therefore, alternative strategies for first-line therapy of H. pylori infection have been evaluated in a considerable number of clinical trials including sequential regimens, nonbismuth quadruple regimens, and quinolone-containing PPI triple therapy regimens. The aim of this paper is to summarize the current body of evidence of levofloxacin- and moxifloxacin-containing regimens in first-line treatment of H. pylori infection, and to discuss the risks and benefits of these strategies in the light of increasing resistance of H. pylori to quinolones.

Mutant prevention concentrations of fluoroquinolones against Helicobacter pylori

AIM: To compare the mutant prevention concentrations (MPC) of four fluoroquinolones against fluoroquinolone-susceptible clinical Helicobacter pylori (H.pylori) isolates.

METHODS: Sixteen clinical isolates of H.pylori were enriched in broth and adjusted to 10¹⁰ colony-forming units per milliliter. The minimal inhibitory concentration (MIC) and provisional MPC (MPCpr) of moxifloxacin, gatifloxacin, levofloxacin and ciprofloxacin were determined using the agar plate dilution method. The 50% MIC (MIC₅₀), 90% MIC (MIC₉₀), and 90% provisional MPC (MPCpr₉₀) for fluoroquinolone-susceptible H.pylori isolates were then calculated.

RESULTS: When the breakpoints for fluoroquinolone resistance were defined as >1.0 mg/L, there were 2, 1, 4 and 2 H.pylori strains resistant to moxifloxacin, gatifloxacin, levofloxacin and ciprofloxacin, respectively. The MIC₅₀ of moxifloxacin, gatifloxacin, levofloxacin and ciprofloxacin for fluoroquinolone-susceptible H.pylori isolates were 0.13, 0.13, 0.25 and 0.50, respectively, while the MIC₉₀ were 0.50, 0.50, 1.00 and 0.50 mg/L, respectively. The MPCpr₉₀ of moxifloxacin, gatifloxacin, levofloxacin and ciprofloxacin were 8.0, 2.0, 8.0 and 2.0 mg/L, and the ratios of MPCpr₉₀ to MIC₉₀ were 16.0, 4.0, 8.0 and 4.0, respectively.

CONCLUSION: The anti-H.pylori activity of gatifloxacin and moxifloxacin might be stronger than that of levofloxacin and ciprofloxacin, and the capacity of gatifloxacin and ciprofloxacin restricting the selection of resistant mutants appears to be stronger than that of moxifloxacin and levofloxacin in the treatment of H.pylori infection.

Two-decade trends in primary Helicobacter pylori resistance to antibiotics in Bulgaria

Evaluating long-term trends in antibiotic resistance can predict earlier the short-term changes in resistance patterns. The aim of the present study was to compare primary resistance rates in 501 Helicobacter pylori strains in 2007 to 2009 to those in 1990 to 1995 (179 strains) and the antibiotic MICs to detect the 20-year resistance evolution. In 2007 to 2009, strains from children exhibited lower resistance rates to metronidazole (16.4%) and ciprofloxacin (2.7%) than those from adults (27.3% and 10.3%, respectively). In 2008 to 2009, more children (29.3%) harbored clarithromycin-resistant strains compared to the adults (17.4%). Overall clarithromycin resistance rate (19.4%) in 2007 to 2009 was much higher than that in 1990 to 1995 (6.2%). MIC(90) of erythromycin in 1990 to 1995 was 142.2-fold lower than that of clarithromycin in 2007 to 2009. Clarithromycin MIC(90) increased >42-fold since 2001 to 2004. Quinolone resistance rate increased 7.7-fold, being 9.2% in 2007 to 2009 versus 1.2% in 1990 to 1995, with a 5-fold increase in MIC(90). Conversely, the amoxicillin resistance decreased from 3.2% in 1996 to 1999 to 0.4% in 2007 to 2009. The MIC(90)'s of tetracycline remained stable but MIC(50)'s of both metronidazole and tetracycline before 1996 decreased about 4-fold to 2007 to 2009. In conclusion, associations between the resistance evolution and patients' age groups as well as the national outpatient antibiotic use have been found. H. pylori resistance to antibiotics showed many long-term changes, with a more rapid evolution for clarithromycin than for the other antibiotics. Metronidazole and tetracycline did not show a resistance evolution but exhibited a decrease in MIC(50) since 1990. The significant increase in ciprofloxacin resistance was found only by extending the study period to 20 years.

In vitro activity of nemonoxacin, tigecycline, and other antimicrobial agents against Helicobacter pylori isolates in Taiwan, 1998-2007

The minimum inhibitory concentrations (MICs) of 330 nonduplicate Helicobacter pylori isolates to nemonoxacin, tigecycline, and eight other antimicrobial agents were determined by using the agar dilution method. Sequencing the quinolone resistance-determining regions (QRDRs) in the gyrA gene of these isolates was also performed. Resistance to clarithromycin showed an increasing trend during the ten-year study period and was highest (38%) in 2005. Tigecycline had potent in vitro activities against all isolates, with an MIC(90) of 0.06 μg/ml. Among the quinolones tested, nemonoxacin (MIC(50) of 0.12 μg/ml and MIC(90) of 0.25 μg/ml) and gemifloxacin had one to two-fold better in vitro activities than ciprofloxacin, levofloxacin, and moxifloxacin. Among the nine isolates (2.7%) with levofloxacin resistance, four (44.4%) were also resistant to metronidazole, three (33.3%) to clarithromycin, and two (22.2%) to amoxicillin. Isolates with levofloxacin resistance exhibited one or two of three amino acid alterations (Ser-70, Asn-87, and Asp-91) involved in QRDRs in the gyrA gene. A double mutation at Ser70Cys and Asn87Ile had a higher level of resistance. The results of this study suggest a potentially useful role of nemonoxacin and tigecycline in the treatment of infections caused by H. pylori. The gyrA mutation at Ser-70 is a novel finding and has an impact on levofloxacin resistance.

Geographic map and evolution of primary Helicobacter pylori resistance to antibacterial agents

Antibiotic resistance in Helicobacter pylori is the major cause of eradication failure. Primary H. pylori susceptibility patterns, however, are becoming less predictable. Currently, high (> or =20%) clarithromycin resistance rates have been observed in the USA and in developed countries in Europe and Asia, while the highest (> or =80%) metronidazole-resistance rates have been reported in Africa, Asia and South America. Primary quinolone-resistance rates of 10% or more have already been reported in developed countries in Europe and Asia. Primary amoxicillin resistance has been low (0 to <2%) in Europe but higher (6-59%) in Africa, Asia and South America. Similarly, tetracycline resistance has been absent or low (<5%) in most countries and higher (9-27%) in Asia and South America. The increasing clarithromycin and quinolone resistance, and multidrug resistance detected in 0 to less than 5% in Europe and more often (14.2%) in Brazil are worrying. Growing resistance often parallels national antibiotic consumption and may vary within patient groups according to the geographic region, patient's age and sex, type of disease, birthplace, other infections and other factors. The geographic map and evolution of primary H. pylori resistance are clinically important, should be considered when choosing eradication regimens, and should be monitored constantly at national and global levels in an attempt to reach the recently recommended goal of eradication of more than 95%.

Time trends of Helicobacter pylori resistance to antibiotics in children living in Vienna, Austria

BACKGROUND

Increase of antibiotic resistance is a worldwide problem. Within the 4 years before the turn of the millennium Helicobacter pylori strains isolated in children living in Vienna, Austria, showed a primary clarithromycin and metronidazole resistance of 20% and 16%, respectively. The aim of this retrospective follow-up survey was to assess the further development and current antimicrobial resistance status.

METHODS

Children having undergone upper endoscopy between March 2002 and March 2008 at the same two co-operating pediatric gastroenterology units which had also been collaborating on the prior assessment were included. H. pylori infection was diagnosed by rapid urease test, histology, and culture. If the latter was positive, susceptibility testing to amoxicillin, clarithromycin and metronidazole by E-test followed. From March 2004 onwards, susceptibility to levofloxacin, tetracycline and rifampin was additionally assessed.

RESULTS

Out of 897 children, 153 had a proven infection with H. pylori and no history of prior eradication treatment. Their median age was 11.5 years (range 0.5-20.9 years). Primary resistance to clarithromycin and metronidazole were 34% and 22.9%, respectively; dual resistance was found in 9.8% of the strains; 0.9% was resistant to tetracycline and rifampin, respectively. No case of amoxicillin resistance was detected. The only independent risk factor for clarithromycin resistance turned out to be the origin of a child from Austrian parents.

CONCLUSIONS

In the last decade, the rate of primary resistance of H. pylori to clarithromycin continued to rise. No significant change was found regarding primary resistance to metronidazole or dual resistance to metronidazole and clarithromycin, respectively.

Antimicrobial resistance of H. pylori to the outcome of 10-days vs. 7-days Moxifloxacin based therapy for the eradication: a randomized controlled trial

Introduction

Antibiotic resistance decreases success of Helicobacter pylori (Hp) eradication. Recently published results show low rate of resistance and better compliance with moxifloxacin based regiments.

Aims&methods

Whether 7 days moxifloxacin with lansoprasole and amoxycillin can be compared with 10 days moxifloxacin with lansoprasole and amoxycillin according to moxifloxacin resistance. Patients with non-ulcer dyspepsia who had culture and histology positive Hp infection (n = 150) were randomly assigned into two groups. The first group (n = 75) received moxifloxacin 400 mg/d during 7 days and the other (n = 75) received moxifloxacin 400 mg/d during 10 days. All patients received amoxycillin 1 g twice daily, lansoprasole 30 mg twice daily. All Hp cultures were tested for sensitivity to moxifloxacin.

Results

138 patients (92%) completed the study, 68 in the first group and 70 in the second. Eradication rates were 84% (57/68) and 76% (57/75) in the 7 days moxifloxacin group and 90% and 84% in the second group (63/70, 63/75) according to the PP and ITT analysis; p = n.s. Among 129 patients (86% of study group), 6% of strains were primary resistant to moxifloxacin.

Eradication of moxifloxacin sensitive/resistant strains was 98%/66%, p < 0.05

Conclusion

According to our results we recommend 7 days moxiflixacin based triple therapy.

High level of antimicrobial resistance in French Helicobacter pylori isolates

BACKGROUND

Helicobacter pylori is a human pathogen responsible for serious diseases including peptic ulcer disease and gastric cancer. The recommended triple therapy included clarithromycin but increasing resistance has undermined its effectiveness. It is therefore important to be aware of the local prevalence of antimicrobial resistance to adjust treatment strategy.

MATERIALS AND METHODS

Overall, 530 biopsies were collected between 2004 and 2007. The antimicrobial susceptibility of H. pylori was determined by E-test and molecular methods.

RESULTS

Among these, 138/530 (26%) strains were resistant to clarithromycin, 324/530 (61%) to metronidazole and 70/530 (13.2%) to ciprofloxacin. Whereas no resistance against amoxicillin and tetracycline was observed, only one strain was resistant to rifampicin. Compared to the patients never treated for H. pylori infection, the prevalence of resistance was significantly higher in patients previously treated (19.1% vs 68% for clarithromycin; 13.2% vs 53.3% for both clarithromycin and metronidazole). The trend analysis revealed an increase of primary resistance to ciprofloxacin between 2004 and 2005 (7.3%) vs 2006-2007 (14.1%) (p = .04) and the secondary resistance reached 22.7% in 2007. Interestingly, 27 biopsies (19.6%) contained a double population of clarithromycin-susceptible and -resistant strains.

CONCLUSIONS

The reported high prevalence of clarithromycin and multiple resistances of H. pylori suggest that the empiric therapy with clarithromycin should be abandoned as no longer pretreatment susceptibility testing has assessed the susceptibility of the strain. As culture and antibiogram are not routinely performable in most clinical laboratories, the use of molecular test should be developed to allow a wide availability of pretreatment susceptibility testing.

An African perspective on Helicobacter pylori: prevalence of human infection, drug resistance, and alternative approaches to treatment

Helicobacter pylori is a Gram-negative, micro-aerophilic, motile, curved rod that inhabits the gastric mucosa of the human stomach. It chronically infects thousands of millions of people world-wide, and is one of the most genetically diverse of bacterial species. Infection with the bacterium leads to chronic gastritis, peptic ulceration, gastric cancers and gastric mucosa-associated lymphoid-tissue (MALT) lymphoma. The prevalence of infection appears to be partly determined by geographical and socio-demographic factors, being higher in Africa than elsewhere. Current treatment, based on potent combinations that each consist of a proton-pump inhibitor and two antibiotics, is successful in 80%-90% of patients. Some undesirable side-effects, poor patient compliance and drug resistance are, however, associated with significant levels of treatment failure and with contra-indications for some patients. Antibiotic resistance in H. pylori is a growing global concern that merits the urgent attention of public-health authorities. Numerous pieces of clinical evidence have revealed that eradication of the organism from a patient results in improvement of gastritis and drastically decreases the frequency of relapse of gastric and duodenal ulcers. Natural products, including medicinal plants and honey, may offer useful alternatives in the treatment of H. pylori-related infections.

Sequential therapy or triple therapy for Helicobacter pylori infection: systematic review and meta-analysis of randomized controlled trials in adults and children

OBJECTIVES

Eradication rates with triple therapy (TT) for Helicobacter pylori infection have declined to unacceptable levels. Sequential therapy (ST) is a novel treatment that has shown promise in several controlled trials. Our aim was to assess the efficacy of ST in adults and children compared with that of TT by performing a systematic review and meta-analysis.

METHODS

We performed an electronic search of the following: Cochrane Trial Register (until Issue 4, 2008), MEDLINE (1966 to 21 October 2008), EMBASE (1980 to 21 October 2008), and abstracts from the major US, European, and Asian gastroenterology conferences. Randomized controlled trials (RCTs) and controlled clinical trials with a parallel group design comparing the ST with a TT lasting at least 7 days were used.

RESULTS

Ten RCTs enrolled 3,006 adult patients and the odds ratio (OR) for eradication of H. pylori with ST compared with TT was 2.99 (95% confidence interval (CI): 2.47-3.62), giving a number needed to treat (NNT) of 6 (95% CI: 5-7) favoring ST. There was no publication bias. The OR for eradication with ST compared with 10-day TT was 2.92 (95% CI: 1.95-4.38), yielding an NNT of 8 (95% CI: 6-12), favoring ST. In patients with clarithromycin resistance, the OR for eradication with ST was 10.21 (95% CI: 3.01-34.58) compared with TT, but the numbers studied are small. Three RCTs enrolled 260 children and adolescents, and the OR for eradication was 1.98 (95% CI: 0.96-4.07). There was no difference in the rate of side effects between the ST and the TT (OR, 1.01; 95% CI: 0.78-1.30).

CONCLUSIONS

ST appears to be better than TT in the eradication of H. pylori. This is a promising therapy, but further trials are needed in other European countries and North America before it can be recommended as a first-line treatment.