Prevalence of Helicobacter pylori resistance to antibiotics in Northeast Italy: a multicentre study. GISU. Interdisciplinary Group for the Study of Ulcer

The nonadherence and risk factors of eradication failure by sequential therapy as first-line anti-Helicobacter pylori treatment in real-world clinical practice

BACKGROUND

The eradication rates of sequential therapy are high in clinical trials; however, the adherence for follow-up or the patient population in a real-world setting might be different from those in trails. This study investigates the effectiveness of sequential therapy in a real-world setting and the factors that lead to treatment failure.

MATERIALS AND METHODS

In this retrospective study, patients receiving sequential therapy as a first-line anti-Helicobacter pylori (H. pylori) treatment in a real-world setting were reviewed. The age adjusted Charlson Comorbidity Index (age-CCI) and baseline variety of medications were reviewed to determine factors correlated with nonadherence for post-treatment testing and H. pylori eradication failure.

RESULTS

A total of 1053 patients were reviewed. A total of 579 patients receiving sequential therapy were included in the analyses. Among them, 462 received post-treatment testing and were placed into the follow-up group. Thus, the post-treatment testing rate was 79.8%. Stroke was an independent factor of nonadherence for post-treatment testing. In the follow-up group, the eradication failure rate was 8.2%. Female sex (odds ratio [OR] 2.41 [95% CI 1.16-5.03], p = 0.02) and age-CCI ≥2 (OR 3.16 [1.05-9.48], p = 0.04) were independent factors of H. pylori eradication failure. The eradication failure rates were 14.4%, 7.8%, 7.1%, and 3.1% for the females with age-CCI ≥2, females with age-CCI <2, males with age-CCI ≥2, and males with age-CCI <2 subgroups, respectively (p = 0.027).

CONCLUSIONS

In a real-world setting, the adherence rate of post-treatment testing for sequential therapy as a first-line anti-H. pylori treatment was found to be suboptimal. Female sex and age-CCI ≥2 were independent factors of eradication failure.

Clinical Implications of Helicobacter pylori Antibiotic Resistance in Italy: A Review of the Literature

Helicobacter pylori (H. pylori) resistance to antibiotics has increased worldwide in recent decades, especially to clarithromycin. As a result, the World Health Organization (WHO) identified clarithromycin-resistant H. pylori as a "high priority" pathogen in 2017. As international guidelines recommend empirical therapy as first-line treatment, it is crucial to know local resistance rates and history of antibiotic use to determine the most appropriate first-line antibiotic treatment. Italy is one of the European countries with the highest prevalence of H. pylori infection and the highest percentage of antibiotic-resistant H. pylori. The aim of this review is to summarize all data on H. pylori antibiotic resistance in Italy in order to quantify the current rate and determine the most effective therapeutic approach. The study confirms an elevated level of resistance to clarithromycin, metronidazole, and levofloxacin in Italy. In addition, our results show a satisfactory eradication rate for a bismuth-based regimen when used as first- or second-line treatment. Naive patients are also successfully treated with clarithromycin-based quadruple therapies. Considering the good results of bismuth-based therapy as recovery therapy, this argues for the potential use of clarithromycin quadruple therapy as a first-line treatment.

Genotypic detection of metronidazole and clarithromycin resistance in dyspeptic patients with helicobacter pylori

In Egypt, antibiotic sensitivity analysis for Helicobacter pylori is not routinely performed. We aimed to identify the clarithromycin and metronidazole resistance directly from gastric biopsies for better guide treatment regimens. This cross-sectional descriptive study included 75 adult dyspeptic patients referred to the upper endoscopy unit in Suez Canal University Hospital, Ismailia, Egypt. Gastric biopsies were taken for rapid urease test (RUT) and cultured on brucella agar with antibiotic supplements. Genomic DNA was extracted directly from the specimen, and PCR was performed for direct detection of H. pylori. Also, to explore clarithromycin and metronidazole resistance, mutations in the 23S rRNA gene and the rdxA gene were investigated. We found that 60 samples were positive to RUT (80%), and only 4 samples were positive by culture. UreC gene was detected in 45 specimens. Meanwhile, 26 isolates were contained mutations at positions 2142 and 2143. Amplification of the metronidazole rdx gene was performed by conventional PCR. Out of 45 isolates, DNA sequence analysis of PCR product showed the wild type (ACA) in 9 isolates, while the mutant type (ATA) was detected in 28 isolates. We found a significant proportion of clarithromycin and metronidazole resistance among H. pylori infected patients in our region.

Clinical Factors Implicated in Antibiotic Resistance in Helicobacter pylori Patients

Helicobacter pylori is a common gastric pathogen associated with multiple clinical syndromes, including cancer. Eradication rates of H. pylori remain suboptimal despite the progress made in the past few decades in improving treatment strategies. The low eradication rates are mainly driven by antibiotic resistance of H. pylori. Non-invasive molecular testing to identify patients with antibiotic-resistant H. pylori represents a promising therapeutic avenue, however this technology currently remains limited by availability, costs, and lack of robust validation. Moreover, there is insufficient evidence to demonstrate that resistance-testing-based treatment approaches are superior to appropriately designed empiric strategies. Consensus guidelines recommend use of proven locally effective regimens; however, eradication data are inconsistently generated in several regions of the world. In this review, we describe several clinical factors associated with increased rates of antibiotic resistant H. pylori, including history of previous antibiotic exposure, increasing age, female gender, ethnicity/race, extent of alcohol use, and non-ulcer dyspepsia. Assessment of these factors may aid the clinician in choosing the most appropriate empiric treatment strategy for each patient. Future study should aim to identify locally effective therapies and further explore the clinical factors associated with antibiotic resistance.

Polysorbate 80 add-on therapy in the treatment of Helicobacter pylori infection: Polysorbate 80 and HP antibiotic resistance

Polysorbate 80, a sorbitan derivate, is a surfactant used as an emulsifier in some foods in concentrations of up to 0.5%. It was recently shown in vitro that polysorbate 80 decreases the minimum bactericidal concentrations of clarithromycin and metronidazole and may also revert antibiotic resistance. We report the case of an adult man, suffering from symptomatic Helicobacter pylori (HP) infection resistant to two courses of treatment with PPI plus amoxicillin and clarithromycin, and PPI plus clarithromycin and metronidazole. He was treated with a further antibiotic approach consisting of two-week administration of clarithromycin, metronidazole, PPI and polysorbate 80 as an add on therapy. Eradication of infection was confirmed by ¹³C-urea breath test two and five months after completion of the treatment course. Complete regression of symptoms was also achieved. To our knowledge, this is the first case of HP infection eradicated with a combination therapy based on polysorbate 80 added to antibiotics.

Antibiotic susceptibility, heteroresistance, and updated treatment strategies in Helicobacter pylori infection

In this review, we discuss the problem of antibiotic resistance, heteroresistance, the utility of cultures and antibiotic susceptibility tests in Helicobacter pylori (Hp) eradication, as well as the updated treatment strategies for this infection. The prevalence of antibiotic resistance is increasing all over the world, especially for metronidazole and clarithromycin, because of their heavy use in some geographical areas. Heteroresistance (simultaneous presence of both susceptible and resistant strains in different sites of a single stomach) is another important issue, as an isolate could be mistakenly considered susceptible if a single biopsy is used for antimicrobial tests. We also examined literature data regarding eradication success rates of culture-guided and empiric therapies. The empiric therapy and the one based on susceptibility testing, in Hp eradication, may depend on several factors such as concomitant diseases, the number of previous antibiotic treatments, differences in bacterial virulence in individuals with positive or negative cultures, together with local antibiotic resistance patterns in real-world settings. Updated treatment strategies in Hp infection presented in the guidelines of the Toronto Consensus Group (2016) are reported. These suggest to prolong eradication therapy up to 14 days, replacing the old triple therapy with a quadruple therapy based on proton pump inhibitor (PPI), bismuth, metronidazole, and tetracycline for most of the patients, or as an alternative quadruple therapy without bismuth, based on the use of PPI, amoxicillin, metronidazole, and clarithromycin. The new drug vonoprazan, a first-in-class potassium-competitive acid blocker recently approved in Japan, is also considered to be a promising solution for Hp eradication, even for clarithromycin-resistant strains. Furthermore, there is growing interest in finding new therapeutic strategies, such as the development of vaccines or the use of natural resources, including probiotics, plants, or nutraceuticals.

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).

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).

Review article: the global emergence of Helicobacter pylori antibiotic resistance

BACKGROUND

Helicobacter pylori is one of the most prevalent global pathogens and can lead to gastrointestinal disease including peptic ulcers, gastric marginal zone lymphoma and gastric carcinoma.

AIM

To review recent trends in H. pylori antibiotic resistance rates, and to discuss diagnostics and treatment paradigms.

METHODS

A PubMed literature search using the following keywords: Helicobacter pylori, antibiotic resistance, clarithromycin, levofloxacin, metronidazole, prevalence, susceptibility testing.

RESULTS

The prevalence of bacterial antibiotic resistance is regionally variable and appears to be markedly increasing with time in many countries. Concordantly, the antimicrobial eradication rate of H. pylori has been declining globally. In particular, clarithromycin resistance has been rapidly increasing in many countries over the past decade, with rates as high as approximately 30% in Japan and Italy, 50% in China and 40% in Turkey; whereas resistance rates are much lower in Sweden and Taiwan, at approximately 15%; there are limited data in the USA. Other antibiotics show similar trends, although less pronounced.

CONCLUSIONS

Since the choice of empiric therapies should be predicated on accurate information regarding antibiotic resistance rates, there is a critical need for determination of current rates at a local scale, and perhaps in individual patients. Such information would not only guide selection of appropriate empiric antibiotic therapy but also inform the development of better methods to identify H. pylori antibiotic resistance at diagnosis. Patient-specific tailoring of effective antibiotic treatment strategies may lead to reduced treatment failures and less antibiotic resistance.

Antibiotic Resistance of Helicobacter pylori Among Male United States Veterans

BACKGROUND & AIMS

The most recent information published on resistance of Helicobacter pylori to antibiotics in a large population in the United States is more than 10 years old. We assessed the susceptibility of H pylori to antibiotics among patients in a large metropolitan hospital, as well as demographic, clinical, and lifestyle factors associated with antimicrobial resistance.

METHODS

We performed a cross-sectional study of a random sample of 656 patients (90.2% men) from a cohort of 1559 undergoing esophagogastroduodenoscopy with collection of gastric biopsies from 2009 through 2013 at the Houston Veterans Affairs Medical Center. We performed culture analyses of gastric tissues to detect H pylori. The minimum inhibitory concentrations of amoxicillin, clarithromycin, metronidazole, levofloxacin, and tetracycline were determined by the Epsilometer test. Logistic regression analysis was performed to estimate the association between risk factors and antimicrobial resistance.

RESULTS

Biopsies from 135 subjects (20.6%) tested positive for H pylori; 128 of these were from men (94.8%). Only 65 strains were susceptible to all 5 antibiotics. The prevalence of resistance to levofloxacin was 31.3% (95% confidence interval [CI], 23.1%-39.4%), to metronidazole it was 20.3% (95% CI, 13.2%-27.4%), to clarithromycin it was 16.4% (95% CI, 9.9%-22.9%), and to tetracycline it was 0.8% (95% CI, 0.0%-2.3%). No isolate was resistant to amoxicillin. Clarithromycin resistance increased from 9.1% in 2009-2010 to 24.2% in 2011-2013. In multivariate analysis, prior treatment of H pylori infection and use of fluoroquinolones were significantly associated with clarithromycin and levofloxacin resistance, respectively.

CONCLUSIONS

H pylori resistance to clarithromycin increased between 2009 and 2013; resistance to metronidazole remains high in infected men in the United States. The high frequency of resistance to levofloxacin is a new and concerning finding.

The Helicobacter pylori resistance rate to clarithromycin in Iran

BACKGROUND

Clarithromycin is the most commonly suggested antibiotic in Helicobacter pylori eradication regimens. Increasing antibiotic resistance rate to clarithromycin is the main reason for therapeutic failure. The resistance is associated with mutations in the 23S rRNA gene.

AIM

The purpose of this study was to determine the clarithromycin resistance rate of isolated H. pylori strains from referral patients in Kashan, Iran.

METHODS

In total 95 H. pylori strains isolated from gastric mucosa of 246 patients with different clinical signs underwent gastroscopy in Kashan, Iran in 2013. The Epsilometer test was used to determine the minimum inhibitory concentrations (MICs) of clarithromycin (CLR) in isolated H. pylori strains. Occurrence of mutation in 23S rRNA gene of clarithromycin-resistant strains was investigated with polymerase chain reaction-sequencing method.

RESULTS

Antibiotic susceptibility pattern showed that 32 strains (33.7%) were resistant to clarithromycin (MICs ≥1 μg/ml), 33.7% were intermediate resistant, while 31 of H. pylori strains (32.6%) were susceptible. The 23S rRNA gene mutations at positions A2143G and A2142G were detected in H. pylori clarithromycin-resistant strains.

CONCLUSION

The resistance rate to clarithromycin in Iran is high. H. pylori clarithromycin-resistant strains were not associated with sex, age, and disease. The A2143G mutation in clarithromycin-resistant H. pylori strains was the predominant finding.

Primary clarithromycin resistance to Helicobacter pylori: Is this the main reason for triple therapy failure?

Conventional triple therapies for Helicobacter pylori (H. pylori) eradication have recently shown a disappointing reduction in effectiveness in many countries. The main reason for failure was found to be bacterial resistance to one of the most commonly used antibiotics, clarithromycin. An additional problem for conventional triple therapy is the high rate of resistance to metronidazole found in Europe, America and Asia. In Italy, in the last 15 years a 2-fold increase in resistance has occurred. A recent study of the whole of Italy included about 20 patients from each region at the first endoscopic diagnosis of H. pylori infection. The most surprising result was the patchy distribution of resistance, which was almost absent in two regions (one northern and one southern), although the highest prevalence was found in some regions of the South. In the paediatric population we found a 25% prevalence of resistance in a sample of H. pylori positive children observed between 2002 and 2007, mirroring data obtained in southern European countries. Clarithromycin resistance assessment is currently based on phenotypic detection performed after culture the agar dilution method or E-test, and genotypic methods based on polymerase chain reaction (PCR). In a recent comparative study we found a 71.2% agreement between the two methods. Culture-free techniques are highly accurate in finding even minimal traces of genotypically resistant strains. Moreover, PCR-based tools are accurate in detecting a heteroresistant status, defined as the co-existence of some strains that are susceptible and some resistant to the same antibiotic in an individual patient. Three point mutations, namely A2143G, A2142G and A2142C, are responsible for 90% of cases of primary clarithromycin resistance in H. pylori strains isolated in Western countries, although we previously demonstrated that the presence of the A2143G mutation, but not A2142G or A2142C, significantly lowered the H. pylori eradication rate. Treatment failure has considerable cost/benefit implications because of “waste” of National Health System and patient resources, in terms of drugs, further diagnostic tests and medical examination expenses. Therefore, in future it would be very useful to be able to test for clarithromycin resistance before starting conventional triple therapy. Hopefully, fast, effective non-invasive tests may soon be devised to determine this condition.

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

Background/Aims

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

Methods

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

Results

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

Conclusions

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

The status of antimicrobial resistance of Helicobacter pylori in Eastern Azerbaijan, Iran: comparative study according to demographics

Helicobacter pylori-associated infections are extremely common in Iran, but few data about antibiotic sensitivity of H. pylori are available for this region. The purpose of this study was to investigate the prevalence of resistance in isolates against commonly used antibiotics in Eastern Azerbaijan, Iran, and the dependence of prevalence on the sex and age of patients. H. pylori isolates were collected by culture from gastric biopsies. Antibiotic susceptibility of isolates was determined by use of the disk agar diffusion test, and the minimum inhibitory concentration of clarithromycin was established by use of the Etest. A total 395 of biopsy specimens were studied; 112 samples of H. pylori were isolated (28.3 %), 55 (49 %) from males and 57 (51 %) from females. The prevalence of resistance to clarithromycin, metronidazole, erythromycin, amoxicillin, ciprofloxacin, rifampin, nitrofurantoin, and tetracycline were 16 (14.3 %), 86 (76.8 %), 29 (26.0 %), 32 (28.6 %), 37 (33.0 %), 32 (28.6 %), 13 (11.6 %), and 21 (18.7 %), respectively. Antimicrobial resistance was not statistically significantly associated with sex or age. Furthermore, the prevalence of resistance to metronidazole was high and that to clarithromycin was reasonable, consistent with reported low success in H. pylori treatment in this area. Therefore, continuous surveillance of antibiotic resistance of H. pylori is essential.

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

BACKGROUND/AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Optimal management of peptic ulcer disease in the elderly

Recent data report that the incidence of peptic ulcer is decreasing in the general population; conversely, the rates of gastric and duodenal ulcer hospitalization and mortality remain very high in older patients. Two major factors that might explain this epidemiological feature in the elderly population are the high prevalence of Helicobacter pylori infection and the increasing prescriptions of gastroduodenal damaging drugs, including NSAIDs and/or aspirin (acetylsalicylic acid). The main goals for treating peptic ulcer disease in old age are to reduce recurrence of the disease and to prevent complications, especially bleeding and perforation. The available treatments for peptic ulcer are essentially based on gastric acid suppression with antisecretory drugs and the eradication of H. pylori infection. The aim of this article is to report the available data on clinical efficacy and tolerability of peptic ulcer treatments in elderly patients and provide recommendations for their optimal use in this special population. Proton pump inhibitor (PPI)-based triple therapies for 7 days are highly effective for the cure of H. pylori-positive peptic ulcers as well as for reducing ulcer recurrence. Antisecretory drugs are also the treatment of choice for NSAID- or aspirin-related peptic ulcers and are useful as preventive therapy in chronic users of NSAIDs and low-dose aspirin as antiplatelet therapy. Antisecretory PPI therapy has a favourable tolerability profile in geriatric patients; however, monitoring is suggested in older patients with frequent pulmonary infections, gastrointestinal malabsorption, unexplained chronic diarrhoea, osteoporosis or those taking concomitant cytochrome P450 2C19-metabolized medications. The overall approach to the geriatric patient should include a comprehensive geriatric assessment that ensures multidimensional evaluation of the patient in order to better define the clinical risk of adverse outcomes in the older patient with peptic ulcer and its complications.

Phenotypic and genotypic Helicobacter pylori clarithromycin resistance and therapeutic outcome: benefits and limits

INTRODUCTION

Primary clarithromycin resistance is increasing worldwide, and it has been regarded as the main factor reducing the efficacy of Helicobacter pylori therapy. However, the clinical consequence of either phenotypic or genotypic resistance still remains unclear. This study aimed to evaluate: (i) the concordance between phenotypic (culture) and genotypic (real-time PCR) tests in assessing primary clarithromycin resistance; and (ii) the role of both in therapeutic outcome.

METHODS

A post hoc subgroup study was selected from a double-blind, placebo-controlled trial, enrolling 146 patients with dyspepsia or peptic ulcers never previously treated. Real-time PCR and Etest on bacterial culture for assessing clarithromycin resistance were performed. [(13)C]urea breath test (UBT), histology and rapid urease tests at entry and UBT after 4-8 weeks were used to assess infection and eradication. All patients received a 10 day therapy.

RESULTS

Prevalence of clarithromycin phenotypic resistance was significantly lower as compared with genotypic resistance (18.4% versus 37.6%, P < 0.001). A concordance between the two methods was present in 71.2% of cases. A significant difference in the eradication rate was seen between clarithromycin-susceptible and -resistant strains, when assessed with either Etest (92.4% versus 55.5%, P < 0.001) or a PCR-based method (94.5% versus 70.9%; P < 0.001). Of note, the eradication rate showed the lowest value (30.7%) when phenotypic bacterial resistance was genetically linked to the A2143G point mutation.

CONCLUSIONS

This study showed that: (i) there is a relevant discordance between the two methods; and (ii) phenotypic clarithromycin resistance markedly reduces H. pylori eradication when it is linked to a specific point mutation.

Management and long-term follow-up of early stage H. pylori-associated gastric MALT-lymphoma in clinical practice: an Italian, multicentre study

BACKGROUND/AIM

Data on management and long-term follow-up of Helicobacter pylori-associated MALT-lymphoma in clinical practice are scanty. We evaluate the long-term efficacy of H. pylori eradication on low-grade MALT-lymphoma, and the efficacy of further therapies in refractory patients.

METHODS

This study enrolled patients with stages I-II(1) MALT-lymphoma and H. pylori infection. H. pylori eradication was attempted in all patients. Patients with lymphoma persistence or progression following H. pylori treatments received further lymphoma treatments. Both 5-year and disease-free survivals were calculated.

RESULTS

Sixty patients (stage I/II(1): 50/10) were followed up for a median time of 65 months (range 7-156). H. pylori infection was successfully eradicated in 53 (88.3%) patients following three consecutive therapeutic attempts, and lymphoma regressed in 42 (79.2%) of these patients. Sixteen patients received anti-neoplastic treatments due to either lymphoma persistence or progression, and lymphoma was cured in 14 (87.5%) cases. At follow-up, lymphoma relapsed in 13/42 (30.9%) patients within a median time of 19 months (range 3-41), and all but 1 patient were cured with further therapies. Overall, lymphoma regression was achieved in 56 patients (93.3%). The 5-year and disease-free survivals were 94.7% and 74.6%, respectively.

CONCLUSIONS

In clinical practice, a conservative approach with antibiotic eradication seems to be appropriate management for early-stage MALT-lymphoma, with oncologic therapy being reserved for those patients who fail to respond to H. pylori therapy.

Evaluation of clinical and socio-demographic risk factors for antibacterial resistance of Helicobacter pylori in Bulgaria

The aim of this study was to assess the clinical and socio-demographic risk factors for primary Helicobacter pylori antibacterial resistance. In total, 266 consecutive H. pylori strains, from untreated symptomatic adult patients who answered a questionnaire, were evaluated. Strain susceptibility to amoxicillin, metronidazole, clarithromycin and tetracycline was tested by a breakpoint susceptibility test. Metronidazole resistance was found in fewer (17.0 %) peptic ulcer patients than in non-ulcer subjects (28.3 %, P=0.037), as well as in fewer patients born in villages (12.7 %) than in those born in towns (27.6 %, P=0.016). Clarithromycin resistance varied from 8.8 to 23.4 % (P=0.009) within the hospital centres. The highest clarithromycin resistance rate was found in hospital centre A (23.4 %) compared to other centres (12.9 %, P=0.041). The factors sex, age, symptom duration, non-steroidal anti-inflammatory drug use, diabetes, type of profession and educational level were not associated with H. pylori resistance. Logistic regression revealed that the risk factors for metronidazole resistance were non-ulcer disease [odds ratio (OR) 1.95, 95 % confidence interval (95 % CI) 1.04-3.65] and a birthplace of a town (OR 2.64, 95 % CI 1.18-5.93). The hospital centre may be a risk factor (OR 2.07, 95 % CI 1.02-4.21) for clarithromycin resistance but further studies are required to verify this suggestion. In conclusion, the knowledge of the risk factors for H. pylori resistance to antibacterials could facilitate the treatment choice for H. pylori eradication.

Moxifloxacin-based triple therapy versus clarithromycin-based triple therapy for first-line treatment of Helicobacter pylori infection: a meta-analysis of randomized controlled trials

BACKGROUND

Moxifloxacin-based triple therapy has been suggested as an alternative first line therapy to clarithromycin-based triple therapy for Helicobacter pylori infection.

AIMS

To systematically review the efficacy and tolerance of moxifloxacin-based triple therapy, and to conduct a meta-analysis of studies comparing this regimen with clarithromycin-based triple therapy.

METHODS

A search of The Cochrane Library, PUBMED, EMBASE, EBM Review databases, Science Citation Index Expanded, and CMB (Chinese Biomedical Literature Database) was performed. Randomized controlled trials comparing moxifloxacin-based triple therapy to gold standard triple therapy in the first-line treatment of Helicobacter pylori infection were selected for meta-analysis. Relative risk was used as a measure of the effect of the two above-mentioned regimens with a fixed-effects model using the methods of DerSimonian and Laird.

RESULTS

Four randomized controlled trials totaling 772 patients were included. The meta-analysis showed that the mean eradication rate was 84.1 (318/378) in the moxifloxacin-based triple therapy group and 73.6 (290/394) in the clarithromycin-based triple therapy group; there was statistical significance between the two groups (RR, 1.13; 95% CI, 1.01, 1.27; P=0.04). There were no statistically significant difference in the overall side effects (RR, 0.61; 95% CI, 0.25, 1.48; P<0.28).

CONCLUSIONS

Moxifloxacin-based triple therapy is more effective and does not increase the incidence of overall side effects compared to clarithromycin-based triple therapy in the treatment of H. pylori infection.

Antibiotic resistance of Helicobacter pylori from patients in Ile-Ife, South-west, Nigeria

BACKGROUND

Helicobacter pylori has become recognized as a major cause of gastroduodenal diseases in man. Evidence indicates that once acquired, H. pylori persists, usually for life unless eradicated by antimicrobial therapy. Over the past few years, we have accumulated some knowledge of the epidemiology of H. pylori in Ile-Ife, South-West Nigeria. In one collaborative study, we detected H. pylori in 195 (73%) patients referred for endoscopy at Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC). Furthermore we have observed a variegated gastric inflammatory response and atrophy including atrophic pangastritis but are yet to demonstrate MALToma in any of our patients. In addition we have demonstrated that dental plaque is a possible source of gastric H. pylori infection and such an endogenous source could account for difficulty in eradication leading to re-infection. Presently, infected patients are treated with standard combination therapy made up of amoxycilin and ciprofloxacin with a proton pump inhibitor/bismuth. Reports however have shown that the incidence of antimicrobial resistance in Helicobacter pylori is a growing problem and which has been linked with failures in treatment and eradication. Given this situation it has become necessary to have information about the susceptibility of isolates to particular antimicrobial agents before the selection of an appropriate treatment regimen.

OBJECTIVES

More recently, we sought to study antimicrobial susceptibility of locally isolated H. pylori strains.

METHODS

We subjected 32 isolates to antimicrobial susceptibility testing against seven agents.

RESULTS

All the isolates showed multiple acquired antimicrobial resistance as they were all resistant to amoxicillin, clarithromycin, metronidazole, while 29/31, 27/31 showed resistance to rifampicin and tetracycline respectively. Five (15.6%) of these isolates showed resistance to ciprofloxacin.

CONCLUSIONS

Our findings suggest that H. pylori strains isolated within our study environment have acquired resistance to all the commonly prescribed antibiotics. On the basis of the findings it would be necessary to re-evaluate the eradication treatment regime in our setting.

Helicobacter pylori isolates recovered from gastric biopsies of patients with gastro-duodenal pathologies in Cameroon: current status of antibiogram

OBJECTIVE

To determine the prevalence of Helicobacter pylori in patients with gastro-duodenal pathologies and the susceptibility patterns of isolates to the currently recommended antibiotic treatment regimen used in Cameroon.

METHODS

Consecutive dyspeptic patients referred to Douala General Hospital, Cameroon for endoscopy were recruited in the study. Gastric biopsies were collected from the patients and H. pylori isolated and identified following standard microbiology and biochemical techniques. Antibiotic susceptibility was determined by disk diffusion and agar dilution methods against clarithromycin, tetracycline, amoxicillin and metronidazole. Data were analysed using chi-square test and significance considered at P < 0.05.

RESULTS

Seventy-one (92.2%) of the 77 patients (mean age 44.5 +/- 15.7, range 15-77 years) were positive for H. pylori. The antibiotic susceptibility rates were 56% for tetracycline, 55.3% for clarithromycin, 14.4% for amoxicillin and 6.8% for metronidazole. The prevalence of clarithromycin resistance in males vs. females was 42.1%vs. 46.7%, while for metronidazole it was 89.5%vs. 94.7% (P > 0.05). Antimicrobial susceptibility results also revealed 12 antibiotypes based on resistance to the antimicrobial agents investigated. The resistance pattern, amoxicillin and metronidazole (AMR(R) MET(R)) was the most common (23.7%) amongst the isolates. More than 60% of the isolates exhibited multi-drug resistance to three or four antibiotics.

CONCLUSION

Multi-drug resistance is common against the current treatment regimen in Cameroon and, therefore, calls for urgent studies involving newer and broad spectrum antibiotics to address the problem.

Antibiotic resistance of Helicobacter pylori

Helicobacter pylori are spiral-shaped, Gram-negative bacteria that colonize the stomachs of more than half the world's population. H. pylori colonization is the most common cause of chronic active gastritis and peptic ulcer disease, which directly related to gastric carcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. However, the efficacies of eradication therapies are not satisfying mainly because of bacterial resistance to antibiotics. This article makes a brief summary on the recent research related to the antibiotic resistance of H. pylori.

Changing antimicrobial susceptibility epidemiology of Helicobacter pylori strains in Japan between 2002 and 2005

Surveillance of Helicobacter pylori antimicrobial susceptibility reflecting the general population in Japan is limited. The antimicrobial susceptibilities of 3,707 H. pylori strains isolated from gastric mucosa samples of previously untreated patients diagnosed with gastroduodenal diseases at 36 medical facilities located throughout Japan between October 2002 and September 2005 were evaluated. Using an agar dilution method for antimicrobial susceptibility testing of H. pylori, the MIC distributions and trends during the study period for clarithromycin, amoxicillin, and metronidazole were studied. While the MIC(50) and MIC(90) for clarithromycin did not change during the 3-year period, the MIC(80) showed a 128-fold increase. Furthermore, the rate of resistance increased yearly from 18.9% (2002 to 2003) to 21.1% (2003 to 2004) and 27.7% (2004 to 2005). With a resistance rate of 19.2% among males compared to 27.0% among females, a significant gender difference was observed (P < 0.0001). Our study shows that in Japan, there is an evolving trend towards increased resistance to clarithromycin with geographical and gender differences as well as between clinical disease conditions. No significant changes in resistance were observed for amoxicillin and metronidazole during the period. While the benefit of H. pylori antimicrobial susceptibility testing has been debated in Japan, current empirical regimens are not based on susceptibility data representative of the general population. The development of an effective H. pylori eradication regimen in Japan will require continued resistance surveillance as well as a better understanding of the epidemiology of resistance.

Current management of Helicobacter pylori infections in the elderly

Helicobacter pylori infection is a chronic gastric gram-negative infection that increases with age worldwide. However, the percentage age of H. pylori-positive elderly patients who are tested and treated for their infection remains very low. It is now demonstrated that H. pylori infection induces a whole cascade of events leading to gastric pathologies, such as peptic ulcer diseases, gastric precancerous lesions and gastric cancer. Recent data also demonstrated that H. pylori chronic infection can play a role in gastric aging, appetite regulation and extradigestive diseases, such as Alzheimer's disease, in the elderly. The diagnosis of H. pylori infection remains difficult to realize in the very old population, and the urea breath test obtains the best performance in this population. 1-week proton pump inhibitor-based triple therapy regimens are highly effective and well tolerated in elderly patients, and antibiotic resistance remains very low. Low compliance is the main factor related to treatment failure in this population.

Clarithromycin resistance, tumor necrosis factor alpha gene polymorphism and mucosal inflammation affect H. pylori eradication success

Several bacterial and host-related factors concur in causing Helicobacter pylori eradication failure. We ascertained the role of bacterial virulence genes (cagA, vacA), clarithromycin resistance [Cla(R), 23S ribosomal RNA (rRNA) mutations], host polymorphism of CYP2C19 (polyphosphoinositide, PPI, metabolism) and of the cytokines IL-1B-31C>T, IL-1RN VNTR, IFN-gamma+874A>T, TNF-alpha-1031T>C, TNF-alpha-857C>T, TNF-alpha-376G>A, TNF-alpha-308G>A, TNF-alpha-238G>A, IL-10-1082A>G, IL-10-819C>T, IL-10-592C>A, IL-12A+6686G>A, IL-12B+15485A>C. Two groups of H. pylori-infected and H. pylori-treated patients were retrospectively identified: 45 not eradicated and 57 eradicated. Treatment failure was significantly correlated with Cla(R) (all resistant strains in non-eradicated patients); with TNF-alpha-238, IL10-819, IL10-592, IL-12B+15485 single nucleotide polymorphism (SNP); with IL10 ATA/ATA haplotype; and with antral inflammatory grade. On considering Cla(S)-infected patients only, logistic regression analysis (eradication = dependent; TNF-alpha-238, IL12B + 15485 genotypes, IL10 ATA/ATA as present or absent, antral gastritis grade = covariates) confirmed as significantly correlated with eradication antral gastritis grade only (Exp(B) = 6.48; 95% CI, 1.2-35.01). In conclusion, the bacterial determinant causing triple therapy failure is clarithromycin resistant, being virulence genes not involved. The host related factors that favor eradication are those linked to inflammation: a higher inflammatory infiltrate in the mucosa, possibly favored by genotypes able to down regulate the anti-inflammatory cytokine response, enhance the chance of eradication success.

High eradication rate of H. pylori with moxifloxacin-based treatment: a randomized controlled trial

INTRODUCTION

Eradication of Helicobacter pylori remains a problematic treatment issue in clinical practice. The intention is to find a treatment that achieves a high rate of eradication at a low price and treatment options that are now used give us the opportunity to achieve this goal. Recently published results showing a low rate of resistance and better compliance with moxifloxacin-based treatment regimens indicate the need to investigate its efficacy in H. pylori eradication. This study is based on proving the efficacy of moxifloxacin in H. pylori eradication within the triple therapy.

AIMS AND METHODS

The aim of the study was to compare the efficacy of one week of moxifloxacin-based treatment with the standard treatment for H. pylori eradication. Patients with H. pylori infection and non-ulcer dyspepsia (n = 277) were randomly divided into four groups to receive: moxifloxacin 400 mg/d, metronidazole 400 mg twice daily, lansoprazole 30 mg twice daily (MML group); moxifloxacin 400 mg/d, amoxicillin 1 g twice daily, lansoprazole 30 mg twice daily (MAL group); clarithromycin 500 mg twice daily, metronidazole 400 mg twice daily, lansoprazole 30 mg twice daily (CML group); clarithromycin 500 mg twice daily, amoxicillin 1 g twice daily, lansoprazole 30 mg twice daily (CAL group). The patients were assessed for prevalence of H. pylori using the CLO test, histology and culture on gastric biopsy samples obtained during upper gastrointestinal endoscopy before randomization and 4-6 weeks after completion of treatment. Bacterial sensitivity to clarithromycin and moxifloxacin was determined with the E-test.

RESULTS

265 (95.6%) patients completed the study forming the basis for PP analysis. Eradication rates of H. pylori in ITT and in PP analyses were: in the MML group 93.5% (58/62) and 96.7% (58/60), respectively; in the MAL group 86.4% (57/66) and 90.5% (57/63); in the CML group 70.4% (50/71) and 75.8% (50/66); and in the CAL group 78.2% (61/78) and 80.2% (61/76). Moxifloxacin treatment protocols were significantly more effective on both ITT and PP analyses than the clarithromycin based protocols with only one exception (MAL vs. CAL on ITT analysis). Among 238 patients (86% of the entire study group), strains showing primary resistance to clarithromycin were found in 10.8% and to moxifloxacin in 5.9%. Eradication of moxifloxacin sensitive/resistant strains was 98.1%/75% for MML (p < 0.01) and 91.1%/66.7% for MAL (p = n.s.); comparison of eradication of sensitive strains in MML and MAL regimens was 98.1%/91.1% (p < 0.05), and for resistant strains 75%/66.7% (p = n.s.). CML and CAL protocols did not differ in efficacy of eradication of clarithromycin sensitive or resistant strains.

CONCLUSION

Moxifloxacin-based triple therapies showed higher eradication rates with few side effects and good drug compliance when compared with standard H. pylori treatments. Moreover, the increased prevalence of clarithromycin resistance suggests that moxifloxacin-based regimens could be safe and effective options in treatment of H. pylori infection.

Primary antibiotic resistance in Helicobacter pylori strains isolated in northern and central Italy

BACKGROUND

Helicobacter pylori resistance to antibiotics is increasing worldwide, and it reduces the efficacy of therapy.

AIM

To assess current primary antibiotic resistance in H. pylori strains isolated in Italy.

METHODS

Between June 2004 and June 2006, H. pylori strains were isolated consecutively in the two participating centres (Bologna, northern Italy; Rome, central Italy) from patients never previously treated for the infection. Isolated strains were tested for primary clarithromycin, metronidazole and levofloxacin resistance using as break point the minimal inhibitory concentration >/=1, >/=8 and >/=1 mg/L for the three antibiotics, respectively.

RESULTS

Overall, 255 H. pylori strains were evaluated. The resistance rate was 16.9% for clarithromycin, 29.4% for metronidazole and 19.1% for levofloxacin. Clarithromycin resistance was significantly higher in non-ulcer dyspepsia than in peptic ulcer patients (19.1% vs. 0%, P = 0.02), metronidazole resistance was higher in foreign than Italian patients (50% vs. 22.9%, P = 0.0004) and levofloxacin resistance was higher in old than younger patients (28.4% vs. 14.4%, P = 0.048). Levofloxacin resistance was also more frequent in those strains with either clarithromycin or metronidazole resistance.

CONCLUSION

A very high rate of primary resistance towards the tested antibiotics was detected in our study.

Effective regimens for the treatment of Helicobacter pylori infection

Successful Helicobacter pylori eradication therapy remains a challenge in medical practice. Currently, a proton pump inhibitor-based triple therapy containing clarithromycin, amoxicillin or nitroimidazole for 7 days is the recommended first-line treatment approach with an expected eradication success rate of approximately 80%. As a second-line treatment option in the case of failure, a ranitidine bismuth citrate-based quadruple therapy is currently recommended curing another 80% of patients, leaving a subset of patients with persistent H. pylori infection. For these patients, promising rescue options have been evaluated including regimens that contain rifabutin, quinolones, furazolidone or high-dose amoxicillin. The role of susceptibility testing is still under discussion. It is not generally recommended prior to first-line treatment but guidelines propose a role for culture and antibiotic sensitivity testing after failure of the second attempt. Meanwhile, data on the geographic distribution of resistance pattern are available and may guide therapeutic decisions with regard to the combination of antibiotics chosen for the individual patients aiming at 100% cure rate in each individual patient.

Levofloxacin-based triple therapy in first-line treatment for Helicobacter pylori eradication

BACKGROUND

The standard first-line therapies for Helicobacter pylori eradication are based on clarithromycin and amoxicillin or metronidazole. Recent studies suggested levofloxacin as an alternative option for both first-and second-line H. pylori eradication treatment.

AIMS

To compare efficacy and tolerability of two different 7-day standard triple therapies versus 7-day levofloxacin-based triple therapy in first-line treatment for H. pylori infection.

METHODS

Three hundred consecutive H. pylori positive patients were randomized to receive: clarithromycin, amoxicillin, esomeprazole (Group A: N = 100); clarithromycin, metronidazole, esomeprazole (Group B: N = 100); or clarithromycin, levofloxacin, esomeprazole (Group C: N = 100). H. pylori status was rechecked by (13)C urea breath test 6 wk after the end of therapy.

RESULTS

Sixteen out of 300 patients discontinued treatment because of the occurrence of side effects (Group A, 5; Group B, 7; Group C, 4). The eradication rates in intention to treat (ITT) and per protocol (PP) analyses were: Group A, 75% and 79%; Group B, 72% and 77.4%; and Group C, 87% and 90.6%. The eradication rate achieved with levofloxacin-based triple therapy was significantly higher than that with standard therapies in either ITT (87%vs 75%, p <0.05; 87%vs 72%, p <0.01;) or PP analysis (90.6%vs 79%, p <0.05; 90.6 vs 77.4, p <0.05). No difference was found between standard triple therapies. The incidence of side effects was similar among groups.

CONCLUSIONS

A 7-day levofloxacin-based triple therapy can achieve higher H. pylori eradication rates than standard regimens. These data suggest levofloxacin-based regimens can be the most effective in first-line anti-H. pylori therapy, at least in the Italian population.

Bovine lactoferrin for Helicobacter pylori eradication: an open, randomized, multicentre study

BACKGROUND

Cure rates for eradication of Helicobacter pylori appear to be decreasing, thus more effective therapies must be identified.

AIM

To evaluate the efficacy of bovine lactoferrin in the treatment of H. pylori infection.

METHODS

In a multicentered prospective study, 402 (mean age 52.4, range 19-84 years) H. pylori-positive patients were assigned to one of three regimens: group A - esomeprazole 20 mg b.d., clarithromycin 500 mg b.d. and tinidazole 500 mg b.d. for 7 days; group B - lactoferrin 200 mg b.d. for 7 days followed by the same schedule of group A; group C - esomeprazole 20 mg b.d., clarithromycin 500 mg b.d. and tinidazole 500 mg b.d. plus lactoferrin 200 mg b.d. for 7 days.

RESULTS

Of the 402 patients, 389 completed the study. Six patients were discontinued due to side effects, one patient in group B died and six patients were lost to follow up. The eradication rate (intention-to-treat analysis) was 77% in group A (105/136), 73% in group B (97/132) and 90% in group C (120/134) (chi(2)-test P < 0.01). The incidence of side effects was 9.5% in group A, 9% in group B and 8.2% in group C (chi(2)-test P = 0.1).

CONCLUSION

This study demonstrates that bovine lactoferrin is an effective adjuvant to 7-day triple therapy for eradication of H. pylori infection.

Primary clarithromycin resistance in Italy assessed on Helicobacter pylori DNA sequences by TaqMan real-time polymerase chain reaction

BACKGROUND

Helicobacter pylori clarithromycin resistance is increasing worldwide and different mutations are involved in its mechanisms. Recently, molecular methods have been proposed to assess these mutations.

AIM

To assess prevalence of primary clarithromycin resistance in two Italian areas, and the distribution of involved mutations, by using a novel method for real-time polymerase chain reaction.

METHODS

Two hundred and thirty-two H. pylori-positive patients undergoing oesophagogastroduodenoscopy in two Italian towns (Rome, centre Italy; Foggia, south Italy) were enrolled. Helicobacter pylori infection was detected by histology, rapid urease and urea breath tests. Clarithromycin resistance was assessed by TaqMan real-time polymerase chain reaction on paraffin-embedded antral biopsies. Results Primary clarithromycin resistance was detected in 62 (26.7%) patients. Its prevalence did not differ between the two areas (31.5%, centre vs. 23.3%, south; P=0.17) and between non-ulcer dyspepsia and peptic ulcer patients (28.4% vs. 20.7%, P=0.2). The A2143G point mutation was detected in 35 (56.4%) patients, A2142G in 14 (22.6%), A2142C in eight (12.9%), whilst a double mutation (A2143G plus A2142C or A2142G) was present in the remaining five (8.1%) cases.

CONCLUSIONS

Our study found that primary clarithromycin resistance is highly prevalent in both central and southern Italy, and that A2143G is the most frequent point mutation involved in these areas.

Clarithromycin-resistant genotypes and eradication of Helicobacter pylori

BACKGROUND

Three point mutations (A2143G, A2142G, and A2142C) have been involved in Helicobacter pylori clarithromycin resistance.

OBJECTIVE

To compare the eradication rates among the different point mutations and the efficacy of triple therapy and a sequential regimen according to genotypic resistance.

DESIGN

Post hoc subgroup study from a multicenter, randomized trial.

SETTING

Two hospitals in central and southern Italy between January and December 2001.

PATIENTS

156 patients with H. pylori infection.

MEASUREMENTS

Real-time polymerase chain reaction for assessing clarithromycin resistance; histology, rapid urease test, and 13C-urea breath test at entry and after 4 to 6 weeks.

INTERVENTION

7-day triple therapy (20 mg of rabeprazole, 500 mg of clarithromycin, and 1 g of amoxicillin) in 75 patients or a 10-day sequential regimen (20 mg of rabeprazole plus 1 g of amoxicillin for 5 days and 20 mg of rabeprazole, 500 mg of clarithromycin, and 500 mg of tinidazole for the remaining 5 days) in 81 patients. All drugs were given twice daily.

RESULTS

Helicobacter pylori infection was eradicated in 11 of 23 patients (48%) with the A2143G mutation and in 14 of 15 patients (93%) with either A2142G or A2142C strains (difference, 45 percentage points [95% CI, 15 to 65 percentage points]; P = 0.004). The sequential regimen achieved a higher cure rate than triple therapy in A2143G mutate strains (difference, 49 percentage points [CI, 8 to 72 percentage points]; P = 0.024).

LIMITATIONS

The post hoc substudy design may require further confirmation. Other limitations are the accessibility to the tool and the cost of investigations (70 euros per patient).

CONCLUSIONS

The A2143G mutation seemed to be associated with a very low eradication rate. The sequential regimen achieved a higher cure rate than standard therapy even in patients with these strains.

One-week once-daily triple therapy with esomeprazole, levofloxacin and azithromycin compared to a standard therapy for Helicobacter pylori eradication

BACKGROUND

Primary antibiotic-resistance and poor compliance are the main causes of Helicobacter pylori eradication failure of standard regimens.

AIM

To investigate eradication rate, patient compliance and tolerability of a 1-week once-daily levofloxacin plus azithromycin triple therapy versus the standard twice-daily triple therapy.

PATIENTS AND METHODS

A total of 164 H. pylori-positive patients were randomised to either esomeprazole 20mg, levofloxacin 500 mg and azithromycin 500 mg once-daily (ELAz) or esomeprazole 20mg, clarithromycin 500 mg and amoxycillin 1g twice-daily (ECA) for 1 week. H. pylori infection was defined at entry by histology and urea breath test; cure of infection was determined both by negative urea breath test and H. pylori stool antigens.

RESULTS

H. pylori eradication rates of ELAz and ECA were similar at intention-to-treat (both 65%) and per-protocol analyses (70% versus 76%, respectively). Incidence of poor compliance was lower, although not significantly, in patients randomised to ELAz than to ECA (4% versus 10%); tolerability was significantly higher for ELAz than for ECA (88% versus 70%; P=0.01).

CONCLUSIONS

Once-daily levofloxacin plus azithromycin-based triple therapy achieves an H. pylori eradication rate comparable to that of standard twice-daily triple therapy, but is associated with higher patient compliance and might even be better tolerated.

Moxifloxacin-based strategies for first-line treatment of Helicobacter pylori infection

BACKGROUND

Standard anti-Helicobacter pylori therapy may not achieve a satisfactory eradication rate. Fluoroquinolones, such as moxifloxacin, are safe and promising agents for H. pylori eradication.

AIM

To compare the efficacy of two 1-week moxifloxacin-based H. pylori eradication regimens with two standard treatments.

METHODS

Three hundred and twenty H. pylori-positive subjects were randomized into four groups to receive: moxifloxacin, amoxicillin, esomeprazole (Group MAE); moxifloxacin, tinidazole and esomeprazole (Group MTE); standard triple therapies with clarithromycin, amoxicillin and esomeprazole (Group CAE) or tinidazole (Group CTE) for 7 days. H. pylori status was re-assessed 6 weeks after the end of therapy by 13C urea breath test.

RESULTS

Three hundred and twenty patients completed the efficacy analysis per protocol; H. pylori eradication rate in group MTE was 90% (72 of 80) and 92% (72 of 78), in group MAE was 88% (70 of 80) and 89%, (70 of 79) in Group CAE was 73% (58 of 80) and 78% (58 of 74), and in Group CTE was 75% (60 of 80) and 79% (60 of 76), respectively, in intention-to-treat and in per protocol analyses. Eradication rates of moxifloxacin-based triple therapies were significantly higher than that observed using standard triple schemes. The incidence of side effects was significantly lower in moxifloxacin groups than in control groups.

CONCLUSIONS

Seven-day moxifloxacin-based triple therapies provide optimal eradication rates with a good compliance when compared with the standard triple therapy schemes.

Impact of clarithromycin resistance on eradication of Helicobacter pylori in infected adults

The outcome of Helicobacter pylori infection was analyzed in 114 dyspeptic patients treated with triple-drug therapy including clarithromycin. Clarithromycin resistance (in 20.2% of our isolates) was mainly caused by an A2142G mutation in the 23S rRNA gene of H. pylori. H. pylori eradication was obtained in all patients with clarithromycin-susceptible isolates but not in any patients with clarithromycin-resistant isolates (P = 0.0001). Therefore, it would be useful to conduct H. pylori antimicrobial susceptibility testing of the first gastric biopsy culture before choosing the first three drugs for therapy of infected patients.

High levels of dual resistance to clarithromycin and metronidazole and in vitro activity of levofloxacin against Helicobacter pylori isolates from patients after failure of therapy

Current treatment for Helicobacter pylori infections generally includes two or more antimicrobials (amoxicillin, clarithromycin, nitroimidazoles, tetracycline, etc.), but treatment fails in 10-20% of all cases, often because of drug resistance. Levofloxacin has been proposed as an alternative for these refractory infections. We examined 67 H. pylori isolates from patients unsuccessfully treated with amoxicillin, clarithromycin, metronidazole and levofloxacin. Minimum inhibitory concentrations determined with the epsilometer test revealed clarithromycin and metronidazole resistance in 91 and 82.1% of the isolates, respectively; 52 (77.6%) were resistant to both drugs. All 67 isolates were susceptible to amoxicillin and tetracycline. Fifty-two isolates had levofloxacin MICs of 0.01-2 mg/l; the remaining 15 (22.4%), all clarithromycin- and metronidazole-resistant, had MICs >/= 8 mg/l. Levofloxacin may be an option for refractory H. pylori infections, but the choice should be based on in vitro susceptibility data, and physicians should consider local resistance patterns when treating these infections empirically.

Rifabutin based triple therapy for eradication of H. pylori primary and secondary resistant to tinidazole and clarithromycin

BACKGROUND

Rifabutin has been empirically used in Helicobacter pylori infections resistant to triple therapy. There are no data on primary and secondary resistance to rifabutin and its use in specific cases.

AIM

To analyse the susceptibility and resistance to rifabutin in H. pylori-positive patients with or without previous H. pylori therapy and to test the efficacy of rifabutin in H. pylori resistant to clarithromycin and tinidazole.

METHODS

Four hundred and twenty H. pylori-positive patients without previous exposure to triple therapy and 104 patients who had already received one course of triple therapy underwent upper endoscopy for dyspeptic symptoms and H. pylori susceptibility test. Amoxicillin, clarithromycin, tinidazole and rifabutin were evaluated for resistance and susceptibility. Forty patients with primary resistance to both clarithromycin and tinidazole and with susceptibility to amoxicillin and rifabutin, and 65 patients with secondary resistance and susceptibility to the same antibiotics were identified. All these patients received a 10-day triple therapy with pantoprazole amoxicillin and rifabutin. Treatment success was evaluated by the 13C-Urea Breath test.

RESULTS

In naive patients 23% of strains were resistant to clarythromycin, 35% to tinidazole, 9% to both antibiotics, and none was resistant to rifabutin In patients already treated the percentages of resistant strains were 76, 64.4, 62.5 and 1%, respectively. With rifabutin based triple therapy eradication rates were (Per Protocol and Intention-to-Treat analysis) 100 and 87.5% in primary resistance to clarithromycin and tinidazole and 82.2 and 78.5% in secondary resistance.

CONCLUSION

H. pylori primary and secondary resistances to clarithromycin and tinidazole are high in our geographic area, while resistance to rifabutin is rare. Rifabutin-based triple therapy, can be successfully used in primary and secondary resistance to clarithromycin and tinidazole according to the in vitro susceptibility test.

Laboratory diagnosis and susceptibility profile of Helicobacter pylori infection in the Philippines

Background

Helicobacter pylori diagnosis and susceptibility profile directs the applicability of recommended treatment regimens in our setting. To our knowledge, there is no published data on the culture and local susceptibility pattern of Helicobacter pylori in the Philippines.

Methods

52 dyspeptic adult patients undergoing endoscopy from the Outpatient Gastroenterology clinic of the University of the Philippines-Philippine General Hospital underwent multiple gastric biopsy and specimens were submitted for gram stain, culture, antimicrobial sensitivity testing, rapid urease test and histology. Antimicrobial susceptibility testing was done by Epsilometer testing (Etest) method against metronidazole, clarithromycin, amoxicillin, and tetracycline.

Results

Sixty percent (60%) of the study population was positive for H. pylori infection (mean age of 44 years ± 13), 70% were males. H. pylori culture showed a sensitivity of 45% (95% CI [29.5–62.1]), specificity of 98% (95%CI [81.5–100%]), positive likelihood ratio of 19.93 (95% CI [1.254–317.04]) and a negative likelihood ratio of 0.56 (95% CI [0.406–0.772]). All H. pylori strains isolated were sensitive to metronidazole, clarithromycin, amoxicillin and tetracycline.

Conclusion

Knowledge of the antibiotic susceptibility patterns in our setting allows us to be more cautious in the choice of first-line agents. Information on antibiotic susceptibility profile plays an important role in empiric antibiotic treatment and management of refractive cases.

Risk factors for primary Helicobacter pylori resistance in Bulgarian children

Risk factors for primary Helicobacter pylori resistance in 186 children with gastroduodenal diseases (44 from villages/small towns and 130 from large towns/cities) in 2000-2003 were tested. Susceptibility was tested by a limited agar dilution method. Overall resistance rates to metronidazole, clarithromycin, tetracycline and both metronidazole and clarithromycin were 14.5, 11.9, 3.3 and 4.3 %, respectively. No amoxycillin resistance was observed. Tetracycline resistance was found in six children aged 7-18 years. Clarithromycin resistance was more common in children from small towns/villages (22.7 %) than in those from large towns/cities (8.5 %, P < 0.05). There were no significant differences (P > 0.05) in resistance rates between children from northern Bulgaria and those from southern regions. Resistance rates in duodenal ulcer patients and other children were, respectively, 10.5 and 15 % (P > 0.20) for metronidazole and 10.5 and 12 % (P > 0.20) for clarithromycin. No combined resistance to metronidazole and clarithromycin was found in 22 children aged 1-7 years and in 34 children living in northern Bulgaria. There were no significant associations of resistance with sex and age group (1-7- versus 8-18-year-old children) for all antibacterial agents tested. In conclusion, primary H. pylori resistance was absent (for metronidazole + clarithromycin) or low (4.5 % for clarithromycin) in children aged 1-7 years. Place of residence was associated with clarithromycin resistance rates.

Identification of a novel mutation affecting domain V of the 23S rRNA gene in Helicobacter pylori

BACKGROUND

This study analyzes clarithromycin resistance status and 23S rRNA gene mutations in Helicobacter pylori strains from Central Italian patients.

MATERIALS AND METHODS

H. pylori strains from 235 dyspeptic patients (205 with no history of clarithromycin exposure and 30 referred for failure of eradication therapy) were tested for clarithromycin resistance by screening agar method and E-test. Resistant strains were analyzed for mutations of the 23S rRNA gene by PCR-RFLP and sequencing.

RESULTS

Primary resistance was observed in strains from 43/205 (21%) patients with no history of clarithromycin exposure and secondary resistance in 30/30 (100%) strains from previously treated patients. A single mutant strain was detected in 54/73 (74%) cases, a mixture of one or more mutant(s) plus the wild type in the remaining 19/73 (26%) cases. One 23S rRNA gene mutation (A-->T transversion at nucleotide 2144) in the peptidyltransferase region of domain V was novel.

CONCLUSIONS

This study shows: (a) a high prevalence of H. pylori strains with primary or secondary clarithromycin resistance in an urban area of Central Italy; (b) colonization by both mutant and wild-type H. pylori in the same patient; (c) a novel variant of the H. pylori 23S rRNA gene.

Helicobacter pylori infection and the prevention of peptic ulcer with proton pump inhibitors in elderly subjects taking low-dose aspirin

INTRODUCTION

The role of Helicobacter pylori infection on the risk of low-dose aspirin-related gastroduodenal damage and on the efficacy of the prevention therapy in elderly chronic users of low-dose aspirin is still controversial.

AIM

To evaluate in symptomatic elderly chronic users of low-dose aspirin: (1) the association between H. pylori infection and the prevalence of upper gastrointestinal lesions; and (2) the effect of H. pylori infection on the efficacy of proton pump inhibitors in the prevention of aspirin-related gastroduodenal lesions.

PATIENTS AND METHODS

Two hundred and forty-five symptomatic elderly who were taking aspirin 75-300 mg daily, at least during the last 3 months, were evaluated by endoscopy. A structured interview was carried out to evaluate gastrointestinal symptoms and the use of proton pump inhibitors. H. pylori infection was diagnosed according to histology and the rapid urease test on gastric biopsies.

RESULTS

One hundred and twelve patients were H. pylori-positive and 133 patients were H. pylori-negative. A significantly higher prevalence of peptic ulcers was observed in H. pylori-positive than in H. pylori-negative subjects (36.6% versus 15.8%, P = 0.0002). The use of proton pump inhibitors was associated with a significant decreased risk of peptic ulcer both in H. pylori-positive (absolute risk reduction, ARR = -36.2, 95% confidence interval: -51.2 to -21.3, P < 0.001) and H. pylori-negative patients (ARR = -12.6, 95% confidence interval: -23.9 to -1.2, P = 0.03). However, the number of patients who needed to be treated in order to gain a reduction of one peptic ulcer (number needed to treat, NnT) was lower in H. pylori-positive than in H. pylori-negative patients (NnT = 3 versus 8).

CONCLUSIONS

In symptomatic elderly chronic users of low-dose aspirin, H. pylori infection may influence the prevalence of peptic ulcers and the cost-effectiveness of the proton pump inhibitor prevention therapy.

Role of antibiotic sensitivity testing before first-line Helicobacter pylori eradication treatments

BACKGROUND

The resistance of Helicobacter pylori to antibiotics has been advocated as a major cause of treatment failure, and antimicrobial sensitivity testing has been proposed to improve efficacy; however, its role before first-line therapy has not been investigated in detail.

AIM

To assess whether antimicrobial sensitivity testing improves the eradication rate of first-line anti-Helicobacter treatments and to compare the effectiveness of ranitidine bismuth citrate and omeprazole in the presence of H. pylori resistance to antibiotics.

METHODS

Two hundred and forty-two patients were assigned to either empirical or antimicrobial sensitivity testing-based treatment; within each group, subjects were further randomized to receive ranitidine bismuth citrate, 400 mg b.d., tinidazole, 500 mg b.d., and clarithromycin, 500 mg b.d., or omeprazole, 20 mg b.d., clarithromycin, 500 mg b.d., and amoxicillin, 1 g b.d., for 1 week, with substitution of the resistant antibiotic in the antimicrobial sensitivity testing-based treatment group.

RESULTS

Eradication rates were 67% [confidence interval (CI), 55-79%] in the empirical treatment group and 76% (CI, 65-87%) in the antimicrobial sensitivity testing-based group (P=N.S.). The overall success rate was 60% (CI, 51-69%) with omeprazole and 82% (CI, 73-91%) with ranitidine bismuth citrate (P<0.03); the latter overcame antibiotic resistance in 12 of 15 strains vs. zero of eight strains by omeprazole.

CONCLUSIONS

Antimicrobial sensitivity testing before first-line treatment does not improve the eradication rate, which is greater when ranitidine bismuth citrate is included in the treatment.