Frequency of antibiotic resistance in Helicobacter pylori strains isolated from the northern population of Iran

The prevalence of clarithromycin-resistant Helicobacter pylori isolates: a systematic review and meta-analysis

Background

Knowledge of global clarithromycin (CLA)-resistant rates of Helicobacter pylori (H. pylori) is crucial for decision of the most appropriate eradication therapies with good clinical outcomes. Therefore, this review and meta-analysis aimed to evaluate the global prevalence of the CLA resistance in H. pylori to provide some guidance for selecting the first-line antibiotics.

Method

A comprehensive search was performed for relevant literature until April 2021 in PubMed, Embase, and Web of Science databases. Freeman-Tukey double arcsine transformation was performed to estimate the weighted pooled prevalence of resistance.

Results

The meta-analysis included 248 articles. The prevalence of CLA-resistant H. pylori was 27.53% (95% CI [25.41-29.69]). The heterogeneity between reports was significant (I² = 97.80%, P < 0.01). The resistance rate increased from 24.28% in 2010-2017 to 32.14% in 2018-2021 (P < 0.01). Iran, with 38 articles, has the most report. Nevertheless, Switzerland, Portugal, and Israel had the highest resistance rates (67.16%, 48.11%, and 46.12%, respectively). The heterogeneity between the continents and the antimicrobial susceptibility methods also interpreted standard guidelines and breakpoints was insignificant (P > 0.05).

Conclusion

Overall CLA resistance rate was 27.53%, worldwide. The difference in CLA resistance rate among the included studies can be due to several reasons such as differences in antibiotic prescription rates in various geographic areas, use of different breakpoints or inaccurate criteria in performed studies, and the emergence of multidrug-resistant (MDR) strains.

Evaluation of antibiotic resistance of Helicobacter pylori bacteria obtained from gastric biopsy samples: A cohort study

Objective

Helicobacter pylori infection is associated with a wide range of gastrointestinal diseases and is very common in developing countries. Overuse and self-prescribed antibiotics have led to antibiotic resistance and failure of complete eradication of the bacterium. The aim of this study is to evaluate the antibiotic resistance of h. pylori from samples obtained from gastric biopsy.

Methods

In this descriptive-analytical study was performed on 205 patients’ samples positive for h. pylori infection. Following h. pylori testing, the sample were culture with different antibiotics to obtain data regarding the resistance. Demographic information of the patients such as age, sex, employment status, area of residence and patient-related factors such as reason for referral, and previous history of treatment were obtained and evaluated for the correlation with antibiotic resistance.

Results

In this study, the mean age of the subjects was 42.32 ± 16.65 years. The most common reason for referral of patients in the present study was epigastric pain in 49.3% (101 patients). Antibiotic resistance to amoxicillin was 46.8%, tetracycline was 41%, metronidazole was 33.2%, clarithromycin was 70.7%. levofloxacin was 36.1% and bismuth was 19.5%. Sex, age, type of living (rural or urban), employment, reason for referral and history of treatment was not associated with any antibiotic resistance, p > 0.05.

Conclusion

Our study showed that clarithromycin resistance is the most common in our population followed by amoxicillin and tetracycline. Excessive use of these antibiotics and self-prescription should be analyzed in future studies and public-awareness programs might be required.

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H.pylori infection is associated with a wide range of gastrointestinal diseases.

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Self-prescribed antibiotics have led to antibiotic resistance and failure of complete eradication.

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Clarithromycin resistance is the most common in our population followed by amoxicillin and tetracycline.

Comparing the Effect of Two Low-dose and High-dose Four-drug Regimens of Furazolidone in Eradicating Helicobacter Pylori

BACKGROUND Antibiotic resistance is a major cause of Helicobacter pylori (H. pylori ) treatment failures. The increased resistance to clarithromycin and metronidazole has reduced the ability of this therapeutic regimen and prompted researchers to look for other drugs. One of the antibiotics of interest in this regard is furazolidone because of its low drug resistance. The aim of this study is compare two-drug regimens including low-dose and high-dose furazolidone in the treatment of H. pylori. METHODS This study is a clinical trial in which the studied subjects were categorized into two groups. The first group underwent treatment with amoxicillin 1000 mg-BD, furazolidone 100 mg-BD, omeprazole 20 mg-BD, and bismuth subcitrate 240 mg-BD for two weeks (low-dose OFAB). The second group received furazolidone 200 mg-BD (high-dose OFAB). Then eight weeks after completion of the treatment, they were examined in terms of eradication via the UBT test. RESULTS 85 participants completed the study in each group. The response to treatment was 76% and 83% in the low and high-dose groups, respectively, based on intention to treat analysis. Based on per protocol analysis the response to treatment was 78% and 84%, respectively, if excluded patients had completed their protocol and had response to treatment, and 72% and 79%, respectively, if excluded patients had completed their protocol and did not have response to treatment (p = 0.298). In the low-dose and high-dose groups, 16.5% and 24.7% of the participants suffered the complications of treatment with furazolidone (p = 0.18), respectively. Three patients in the high-dose group and one in the low-dose group did not complete the treatment because of the medication's bad taste (p = 0.03). CONCLUSION Low doses of furazolidone had a comparable therapeutic effect compared with high doses, but patients experienced significantly lower levels of bad taste, which was a major cause of reluctance to continue treatment. Therefore, we think four-drug low-dose furazolidone treatment is a good choice in eradicating H. pylori.

The increasing antimicrobial resistance of Helicobacter pylori in Iran: A systematic review and meta-analysis

BACKGROUND

Antimicrobial resistance of Helicobacter pylori can result in eradication failure. Metadata on the antimicrobial resistance of H pylori in Iran could help to formulate H pylori eradication strategies in Iran.

METHODS

A systematic review was performed after searching in MEDLINE, Scopus, Embase, Web of Science, and the Cochrane Library. A meta-analysis was performed, and a comparison of the rates between children and adults; time periods (1999-2010, 2011-2016, 2017-2019); and the methods used was carried out.

RESULTS

A total of 66 studies investigating 5936 H pylori isolates were analyzed. The weighted pooled resistance (WPR) rates were as follows: clarithromycin 21% (95% CI 16-26), metronidazole 62% (95% 57-67), clarithromycin in combination with metronidazole 16% (95% CI 10-23), ciprofloxacin 24% (95% CI 15-33), levofloxacin 18% (95% CI 9-30), erythromycin 29% (95% CI 12-50), furazolidone 13% (95% CI 4-27), tetracycline 8% (95% CI 5-13), and amoxicillin 15% (95% CI 9-22). During the three time periods, there was an increased resistance to amoxicillin, clarithromycin, ciprofloxacin, furazolidone, and tetracycline (P ˂ .05). Furazolidone and a clarithromycin/metronidazole combination had the higher resistance rates in children (P ˂ .05).

CONCLUSION

An increasing rate of resistance to amoxicillin, clarithromycin, ciprofloxacin, furazolidone, and tetracycline in Iranian H pylori isolates was identified. In children, the resistance to furazolidone and a combination of clarithromycin and metronidazole is higher compared to adults. As a stable, high resistance to metronidazole was found in children and adults in all Iranian provinces, we suggest that metronidazole should not be included in the Iranian H pylori eradication scheme.

Management of antibiotic-resistant Helicobacter pylori infection: current perspective in Iran

Helicobacter pylori is a common gastric bacterial pathogen implicated in the pathogenesis of many digestive tract disorders. H. pylori infection prevalence has been reported alarmingly in Iran. A plethora of studies have been conducted to evaluate the efficiency of first-line and second-line eradication attempts in patients diagnosed with H. pylori infections in Iran. The present study, was evaluated the efficacy of first-line and second-line therapy in H. pylori infections in Iran. We aimed to consider the literature review of the various library and electronic databases (Science Direct, PubMed, and Google Scholar) until 2020. The frequency of bacterial resistance to tetracycline, ampicillin, trimethoprim, erythromycin, ofloxacin, and metronidazolewas found to be high in Iran, while the most effective antibiotics were clarithromycin, rifampin, rifampicin, tetracycline, amoxicillin, ciprofloxacin, levofloxacin, moxifloxacin, and azithromycin. The therapeutic choice for H. pylori eradication in Iran could be quadruple therapy using two antibiotics amoxicillin and metronidazole/clarithromycin for the first-line regimen, and a combination of furazolidone plus tetracycline/amoxicillin and bismuth plus proton pump inhibitor for the second-line regimen. Due to increased antibiotic resistance in our region, empirical therapy must be replaced by more targeted treatment based on antimicrobial drug resistance profiles obtained from patients. Although we limited our investigation on the H. pylori eradication regimens in Iran, the results can be generalized to any region as long as the patterns of resistance are the same.

Genetic basis for metronidazole and clarithromycin resistance in Helicobacter pylori strains isolated from patients with gastroduodenal disorders

BACKGROUND

The aim of this study was to evaluate the antimicrobial resistance and genetic basis for metronidazole (Mtz) and clarithromycin (Cla) resistance in strains of Helicobacter pylori, isolated from patients with gastroduodenal disorders.

PATIENTS AND METHODS

A total of 157 H. pylori isolates (from 22 gastric cancer, 38 peptic ulcer disease, and 97 non-ulcer dyspepsia patients) were analyzed for drug susceptibility to Mtz and Cla, by gradient diffusion test (E-test, MAST). The PCR and sequence analysis of the rdxA and frxA for Mtz-resistant strains and the 23S rRNA for Cla-resistant strains were used to determine the genetic basis of drug resistance in H. pylori strains. Increased expression of TolC homologous genes (hefA) that upregulates efflux pump activity was determined in multidrug-resistant (MDR) strain of H. pylori by real-time PCR technique.

RESULTS

Among 157 H. pylori isolates, 32 (20.4%) strains were resistant to at least one of the antimicrobial agents. The highest resistance rate was attributed to Mtz (n=69, 43.94%). Among the resistant strains of H. pylori, 15 cases (9.55%) were detected as MDR. Mutations in the rdxA (85.5%) and A2143G point mutations (63.1%) in the 23S rRNA were the most common cause of resistance to Mtz and Cla in strains of H. pylori, respectively. In MDR strains, the rdxA mutation and A2143G-point mutation in the 23S rRNA were the most abundant mutations responsible for drug resistance. The relative expression of hefA in MDR strains (mean 3.706) was higher than the susceptible strains (mean 1.07).

CONCLUSION

Mutational inactivation and efflux pump overexpression are two mechanisms that increase the resistance to H. pylori antimicrobial agents and the rate of MDR strains. In Iran, the mutations of rdxA and frxA in Mtz-resistant strains and A2143G and A2142G of the 23S rRNA in Cla-resistant strains were significant. The screening for these mutations could help to prevent antibiotic resistance, and to determine the most effective anti-H. pylori drugs.

Comparison of Levofloxacin-Based, 10-day Sequential Therapy with 14-day Quadruple Therapy for Helicobacter Pylori Eradication: A Randomized Clinical Trial

BACKGROUND

Considering the importance of Helicobacter pylori (H. pylori) eradication, this clinical trial was designed to prospectively evaluate the efficacy of levofloxacin-based, sequential therapy in comparison with quadruple therapy for eradicating H. pylori.

METHODS

Overall 156 patients with dyspepsia and H. pylori infection were included in this study and were randomly allocated to either 10-day sequential therapy group (group A) to receive pantoprazole (40 mg twice daily), amoxicillin (1 gr twice daily), levofloxacin (500 mg twice daily), and tinidazole (500 mg twice daily) (PALT) or 14-day quadruple therapy group (group B) to receive pantoprazole, clarithromycin, bismuth subcitrate, and amoxicillin (PABC). At the end of the study the eradication rate in each group was assessed by urea breath test (UBT).

RESULTS

Age range of the participants was 18-65 years (average 36.9 years) and 50% of them (78 patients) were men. 78 patients were allocated to group A and 78 patients to groupe B. After antibiotic therapy, all the patients received acid suppression therapy with Proton Pump Inhibitor (PPI) for 4 weeks and then the eradication rate was confirmed by UBT (Heli FAN plus 13C, Germany). Before performing UBT, all the participants were requested to halt consumption of PPI for at least 1 week. During the treatment there was not any major complication but in group A (sequential therapy), two patients complained of minor complications including musculoskeletal pain. None of the patients in group B had any complaint or side effect. The rate of H. pylori eradication in group A was 78.2% (61 patients) while this rate in group B was 83.3% (65 patients) with no significant difference between the two groups (p = 0.42). In subgroup analysis, the rate of eradication among men in group A and B were 76.9% and 89.7%, respectively (p = 0.22) while the eradication rate among women were 79.4% and 76.9%, respectively (p = 1.00).

CONCLUSION

It seems that levofloxacin base sequential therapy does not have any advantage in comparison with quadruple regimen and until finding any more effective short course therapy for H. Pylori eradication; we encourage quadruple regimen to be used as the first line therapy.

Efficacy and Tolerability of Two Quadruple Regimens: Bismuth, Omeprazole, Metronidazole with Amoxicillin or Tetracycline as First-Line Treatment for Eradication of Helicobacter Pylori in Patients with Duodenal Ulcer: A Randomized Clinical Trial

AIM

To evaluate the efficacy and tolerability of tetracycline vs. high-dose amoxicillin in bismuth-based quadruple therapy for Helicobacter pylori(H. pylori) eradication.

METHODS

This randomized, open-label clinical trial included 228 patients with H.pylori infection and duodenal ulcer without a history of H.pylori treatment. Patients were randomly divided into two groups. The amoxicillin group received metronidazole 500mg, bismuth subcitrate 240mg, and amoxicillin 1000mg, all three times a day, plus omeprazole 20 mg twice a day, for 14 days. The tetracycline group received metronidazole 500mg three times a day; bismuth subcitrate240mg and tetracycline HCl 500mg, both four times a day; and omeprazole 20 mg twice a day, for 14 days. Evaluation for compliance and drug-relatedadverse effects were evaluated at the end of two weeks. Eight weeks after the end of treatment, the rate of H.pylori eradication was assessed by the C13urease breath test.

RESULTS

There were no significant demographic differences between the two groups. Eradication rate was higher with the amoxicillin-containing regimen than the tetracycline-containing regimen: 105/110 (95.51%; 95% confidence interval, 91.5%-99.3%) vs. 88/105 (83.8%; 95%CI, 76.7%-90.8%) by per-protocol analysis (p = 0.005) and 92.9% (95%CI, 88.1%-97.6%) vs. 76.5% (95%CI, 68.7%-84.2%) by intention-to-treat analysis (ITT, p = 0.001). Adverse effects were significant higher in the tetracycline groupthan in the amoxicillin group (65.2% vs. 43.4%; p = 0.001).

CONCLUSION

Bismuth-based quadruple therapy including high-dose amoxicillin and metronidazole achieved an acceptable rate of H.pylori infection eradication with good tolerance in patients with duodenal ulcer. This regimen can overcome treatment resistance in areas with high prevalence of metronidazole and clarithromycin resistance.

TRIAL REGISTRATION

The Thai Clinical Trial Registry (TCTR) 20170623004.

Resistance of Helicobacter pylori to furazolidone and levofloxacin: A viewpoint

In their review, Arslan et al^[1] did not describe the status of Helicobacter pylori (H. pylori) treatment with furazolidone and the resistance to this antibiotic. We have presented different surveys showing the resistance of H. pylori to furazolidone from Asia and South America. The resistance rates varied but were mostly low (< 5%). There are not enough data on its efficacy and resistance in the United States and Europe. H. pylori mutations occurring in the oorD gene, including A041G, A122G, C349A(G), A78G, A112G, A335G, C156T and C165T, and in the porD gene, including G353A, A356G, C357T, C347T, C347G and C346A, have been indicated to be possibly related to the observed resistance. Additionally, to complete Arslan et al’s statement regarding levofloxacin resistance, it should be noted that compound mutations of N87A, A88N and V65I at codon Asn-87 were recently observed in the gyrA gene for the first time. However, the results on these topics are not sufficient, and more worldwide studies are suggested.

Eradication of Helicobacter Pylori in Iran: A Review

Helicobacter pylori (H. pylori) infection is one of the most common bacterial infections, affecting almost half of the world’s population. It is associated with peptic ulcer disease, gastric adenocarcinoma, and lymphoma. In Iran, the prevalence of H. pylori infection has been reported to be between 36% and 90% in different geographic regions.

Several studies have assessed the efficacy of different therapeutic options for firstline and second-line H. pylori eradication in Iran; however, the results are conflicting. Therefore, we conducted a review to evaluate different studies in order to select the best options and to provide recommendations for H. pylori eradication in Iran. Accordingly, we searched through PubMed to obtain relevant randomized clinical trials published in English language up to June 2017.

According to our study, among first-line eradication regimens, bismuth-based furazolidone- or clarithromycin-containing quadruple therapies, hybrid regimen, and concomitant therapy seem to be appropriate options. Also, 10- or 14-day clarithromycin-containing triple therapy can be used if local H. pylori resistance to clarithromycin is known to be less than 15%.

For second-line H. pylori eradication, bismuth-based quadruple therapies and 14-day levofloxacin-based triple therapy can be used, provided that antibiotics other than those used in the first-line regimen are used. Third-line H. pylori eradication regimens have not been addressed in Iranian studies. However, most guidelines recommend treatment according to the results of culture and susceptibility testing.

Although we limited our investigation to H. pylori eradication regimens in Iran, the results are transferrable to any region as long as the patterns of antibiotic resistance are the same.

Resistance to clarithromycin and gastroenterologist’s persistence roles in nomination for Helicobacter pylori as high priority pathogen by World Health Organization

Due to the increasing prevalence of clarithromycin resistance, future of management of Helicobacter pylori (H. pylori) infections need to be recognized. To now, clarithromycin was the best effective, well-tolerated and safe antibiotic used in treatment of the bacterium, but, increasing trend of resistance reduced efficacy of recommended regimens. Indeed, gastroenterologists are mostly unable to start appropriate therapy-according to the sensitivity profile-due to the certain difficulties in routine H. pylori culture procedure and being time consuming method. This announcement by World Health Organization (WHO) was an onset to reconsider current challenging dilemma about H. pylori clarithromycin resistant isolates. Therefore, investigating of various factors affecting this nomination by WHO is highly welcomed. In fact, WHO enumerated more than 16 pathogens which seriously threats human life and public health, thus better management or effective guidelines are necessary. Here for the first time, we nominated this phenomenon as ‘‘gastroenterologist’s persistence’’ which should be equally investigated as antibiotic resistance. The ability of gastroenterologists to win the game against H. pylori infections is highly influenced by their collaboration with diagnostic laboratories to apply susceptibility patterns before any prescription. In conclusion, closer collaboration between two important partners (gastroenterologists and microbiologists) in management of H. pylori infection may hopefully trigger an era to remedy current crisis in clarithromycin resistance, a later gastric cancer can be practically preventable.

Clarithromycin versus Gemifloxacin in Quadruple Therapeutic Regimens for Helicobacter Pylori Infection Eradication

BACKGROUND Helicobacter pylori (H. pylori) infection is a major casual factor in any peptic diseases. Clarithromycin as one of the drugs recommended for the infection eradication regimen has shown different levels of resistance. The present study is comparing the effectiveness of clarithromycin- and gemifloxacin - based quadruple regimens in H. pylori eradication. METHODS This was a prospective double blind randomized clinical trial on patients with clear indication of H. pylori eradication. The patients were randomly divided into two groups: "BPAC group" treated with bismuth subcitrate (240 mg), pantoprazole (20 mg), amoxicillin (1 gr), and clarithromycin (500 mg), all twice daily, and the "BPAG group" treated with bismuth subcitrate, pantoprazole, and amoxicillin with same doses as "BPAC group" and gemifloxacin (320 mg daily) all for 10 days. Three months after the end of therapy, 14C-Urea breath test was performed to confirm the eradication. All the patients were assessed for compliance and drug side effects. Based on per-protocol (PP) and intention-to-treat (ITT) methods, data were analyzed and a P value<0.05 was considered as statistically significant. This project has been registered in the Iranian registry of clinical trials (IRCT). RESULTS Three patients were excluded from the survey and finally, 179 patients (89 patients in BPAC group and 90 patients in BPAG group) including 71(39.66%) men with the mean age of 46.4±12.3 years completed the treatment period. The incidence of side effects between the two study groups did not differ significantly. The success rate of BPAC regimen eradication was remarkably greater than BPAG regimen (ITT analysis; 89% vs 77%, respectively; CI 95%: 1.072-5.507, P<0.015 and PP analysis; 91% vs 77.8% respectively; CI 95%: P<0.015). There was no significant relationship between the demographic features and the eradication results. CONCLUSION The results showed that gemifloxacin is not a good alternative for clarithromycin in H. pylori eradication regimens in our region.

Management of Helicobacter pylori infections

BACKGROUND

Infection with Helicobacter pylori is associated with severe digestive diseases including chronic gastritis, peptic ulcer disease, and gastric cancer. Successful eradication of this common gastric pathogen in individual patients is known to prevent the occurrence of peptic ulcer disease and gastric cancer.

DISCUSSION

With half of the world's population being infected with H, pylori and only few antibiotics result in an effective eradication, a successful antibiotic driven worldwide eradication program seems unlikely. In addition, H. pylori eradication is not always beneficial as it has been described that eradication can be associated with an increased frequency of other disorders such as pediatric asthma, inflammatory bowel diseases and Barrett's Esophagus. We have to accept that eradication of this infection is a two-edged sword that is both useful and harmful and we should therefore focus our H. pylori eradication policy toward selectively identify and destroy only the virulent strains.

CONCLUSION

In order to still be able to effectively treat H. pylori infections in the future we need an alternative diagnostic/treatment algorithm. This would involve a shift towards more precise and enhanced disease predicting diagnosis that tries to identify patients with chance of developing severe diseases such as gastric cancer, rather than the current regime that is geared towards find and destroy all H. pylori.

Vaccine against Helicobacter pylori: Inevitable approach

Over three decades have passed since the discovery of Helicobacter pylori (H. pylori), and yet many questions about its treatment remain unanswered. For example, there is no certainty regarding continued use of current antibiotic therapy against H. pylori. The bad news is that even combined regimens are also unable to eradicate bacterial colonization. The worst problem with H. pylori chemotherapy is that even if we identify the most successful regimen, it cannot eliminate the risk of re-infection. This problem is further complicated by the fact that clinicians have no information as to whether probiotics are useful or not. Moreover, to date, we have no large scale produced vaccine effective against H. pylori. Due to the relatively rapid and abundant dissemination of guidelines globally reported concerning management of gastric cancer prevention and therapeutic regimens, clinicians may choose a vaccine as better effective weapon against H. pylori. Therefore, a radical shift in adopted strategies is needed to guide ultimate decisions regarding H. pylori management. In light of failures in vaccine projects, we should identify better vaccine design targeting conserved/essential genes. The unique character and persistence of H. pylori pose obstacles to making an effective vaccine. Preferably, in developing countries, the best reasonable and logical approach is to recommend prophylactic H. pylori vaccine among children as an obligatory national program to limit primary colonization. Trying to produce a therapeutic vaccine would be postponed until later. In reality, we should not forget to prescribe narrow spectrum antibiotics. In the current review, I draw a route to define the best adopted strategy against this rogue bacterium.

In vitro antimicrobial susceptibility of Helicobacter pylori to nine antibiotics currently used in Central Italy

OBJECTIVE

Helicobacter pylori expresses an increased resistance in respect to antimicrobials currently used in therapy. The aim of this study was to evaluate the antimicrobial profiles of H. pylori isolates to nine conventional antibiotics used in a Central Region (Abruzzo) of Italy.

MATERIALS AND METHODS

Biopsies were taken from antrum and fundus of 112 adult and 3 children with Urea Breath Test positive with dyspeptic symptoms and analyzed for H. pylori culture and antibacterial activity. Antimicrobial susceptibility tests were performed for clarithromycin, metronidazole, levofloxacin, moxifloxacin, ciprofloxacin, tetracycline, amoxicillin, ampicillin, and rifabutin by a modified agar dilution susceptibility test.

RESULTS

Bacterial culture was successful in 100 out of 115 patients. Helicobacter pylori strains were isolated from 98 antrum and 83 fundus samples. The rate of recovery of H. pylori strains was 90.50% (181/200). The percentages of resistance were as follows: clarithromycin 72.44% antrum, 72.28% fundus; metronidazole 34.69% antrum, 42.16% fundus; levofloxacin 42.85% antrum, 53.01% fundus; moxifloxacin 37.35% antrum, 46.57% fundus; ciprofloxacin 39.47% antrum, 44.28% fundus; tetracycline 2.63% antrum, 2.85% fundus; amoxicillin 1.02% antrum, 1.20% fundus; ampicillin 0% antrum and fundus and rifabutin 0% antrum, 1.20% fundus. A total of 35 subjects harbored multi-resistant strains.

CONCLUSIONS

This study underlines the high rate of resistance to clarithromycin, metronidazole and quinolones, which may reflect an overuse of them. Culture and susceptibility test, should be performed to prevent the emergence of multi-resistance and to assess an efficacious regimen.

Bismuth, lansoprazole, amoxicillin and metronidazole or clarithromycin as first-line Helicobacter pylori therapy

OBJECTIVE

To evaluate the efficacy and tolerability of replacing tetracycline with amoxicillin in bismuth quadruple therapy.

DESIGN

Subjects who were infected with Helicobacter pylori and naïve to treatment were randomly (1:1) assigned to receive a 14-day modified bismuth quadruple therapy: lansoprazole 30 mg, amoxicillin 1 g, bismuth potassium citrate 220 mg (elemental bismuth), twice a day with metronidazole 400 mg four times a day (metronidazole group) or clarithromycin 500 mg twice a day (clarithromycin group). Six weeks after treatment, H. pylori eradication was assessed by 13C-urea breath test. Antimicrobial susceptibility was assessed by the twofold agar dilution method. This was a non-inferiority trial.

RESULTS

Two hundred and fifteen subjects were randomised. Metronidazole and clarithromycin containing regimens achieved high cure rates: 94 of 97 (96.9%, 95% CI 93.5% to 100%) and 93 of 98 (94.9%, 95% CI 90.5% to 99.3%) by per-protocol and 88.9% (95% CI 83.0% to 94.8%) and 88.8% (95% CI 82.8% to 94.8%) by intention-to-treat, respectively. Amoxicillin, metronidazole and clarithromycin resistance rates were 1.5%, 45.5% and 26.5%, respectively. Only clarithromycin resistance reduced treatment success (e.g., susceptible 98.6%, resistant 76.9%, p=0.001). Adverse events were more common in the metronidazole group.

CONCLUSIONS

These results suggest that amoxicillin can substitute for tetracycline in modified 14 day bismuth quadruple therapy as first-line treatment and still overcome metronidazole resistance in areas with high prevalence of metronidazole and clarithromycin resistance. Using clarithromycin instead of metronidazole was only effective in the presence of susceptible strains.

TRIAL REGISTRATION NUMBER

NCT02175901.

Prevalence of antibiotic resistance in Helicobacter pylori: A recent literature review

AIM: To review previous studies (the last 6 years) about the Helicobacter pylori (H. pylori) antibiotic resistance in order to evaluate the trend in antibiotic resistance.

METHODS: In this study, the PubMed, MEDLINE, Science Direct, Google Scholar and Scielo manuscripts were reviewed from 2009 to 2014.

RESULTS: On the whole rates of H. pylori antibiotic resistance were 47.22% (30.5%-75.02%) for metronidazole, 19.74% (5.46%-30.8%) for clarithromycin, 18.94% (14.19%-25.28%) for levofloxacin, and 14.67% (2%-40.87%) for amoxicillin, 11.70% (0%-50%) for tetracycline, 11.5% (0%-23%) for furazolidon and 6.75% (1%-12.45%) for rifabutin. The frequency of tetracycline, metronidazole and amoxicillin resistance was higher in Africa, while clarithromycin and levofloxacin resistance was higher in North America and Asian, respectively.

CONCLUSION: The most sensitive drug is rifabutin and the lowest sensitive drug is metronidazole in the world. The worldwide H. pylori antibiotic resistance to clarithromycin and levofloxacin has increased during the last 6 years. The present systematic review show alarming results and a novel plan is needed for eradication therapy of H. pylori infections.

How to Effectively Use Bismuth Quadruple Therapy: The Good, the Bad, and the Ugly

Bismuth triple therapy was the first effective Helicobacter pylori eradication therapy. The addition of a proton pump inhibitor helped overcome metronidazole resistance. Its primary indication is penicillin allergy or when clarithromycin and metronidazole resistance are both common. Resistance to the primary first-line therapy have centered on complexity and difficulties with compliance. Understanding regional differences in effectiveness remains unexplained because of the lack of studies including susceptibility testing and adherence data. We discuss regimen variations including substitutions of doxycycline, amoxicillin, and twice a day therapy and provide suggestions regarding what is needed to rationally and effectively use bismuth quadruple therapy.

Appropriate first-line regimens to combat Helicobacter pylori antibiotic resistance: an Asian perspective

Asia has the largest population of any continent and the highest incidence of gastric cancer in the world, making it very important in the context of Helicobacter pylori infection. According to current guidelines, standard triple therapy containing a proton pump inhibitor (PPI) and two antibiotics; amoxicillin (AMX) and clarithromycin (CAM) or metronidazole (MNZ), is still the preferred first-line regimen for treatment of H. pylori infection. However, the efficacy of legacy triple regimens has been seriously challenged, and they are gradually becoming ineffective. Moreover, some regions in Asia show patterns of emerging antimicrobial resistance. More effective regimens including the bismuth and non-bismuth quadruple, sequential, and dual-concomitant (hybrid) regimens are now replacing standard triple therapies as empirical first-line treatments on the basis of the understanding of the local prevalence of H. pylori antimicrobial resistance. Selection of PPI metabolized by the non-enzymatic pathway or minimal first pass metabolism and/or increasing dose of PPI are important to increase H. pylori eradication rates. Therefore, local antibiotic resistance surveillance updates, selection of appropriate first-line regimens with non-enzymatic PPI and/or increased doses of PPI, and detailed evaluation of patients' prior antibiotic usage are all essential information to combat H. pylori antibiotic resistance in Asia.

Comparison of quadruple and triple Furazolidone containing regimens on eradication of helicobacter pylori

BACKGROUND

The effectiveness of classic standard triple therapy regimen of helicobacter pylori (H. pylori) eradication has decreased to unacceptably low levels, largely related to development of resistance to metronidazole and clarithromycin. Thus successful eradication of H. pylori infections remains challenging. Therefore alternative treatments with superior effectiveness and safety should be designed and appropriately tested in all areas depending on the native resistance patterns. Furazolidone has been used successfully in eradication regimens previously and regimens containing furazolidone may be an ideal regimen.

METHODS

H. pylori infected patients with proven gastric or duodenal ulcers and /or gastric or duodenal erosions at Imam Khomeini Hospital in Sari/Northern Iran, were randomly allocated into three groups: group A (OABF) with furazolidone (F) (200 mg bid.), group B (OABM-F) metronidazole (M) (500 mg bid.) for the first five days, followed by furazolidone (F) (200 mg bid.) for the second five days and group C (OAF) with furazolidone (F) (200 mg tid.). Omeprazole (O) (20 mg bid.) and amoxicillin (A) (1000 mg bid.) were given in all groups; bismuth (B) (240 mg bid.) was prescribed in groups A & B. Duration of all eradication regimens were ten days. Eight weeks after treatment, a 14C-urea breath test was performed for evaluation of H. pylori eradication.

RESULTS

A total of 372 patients were enrolled in three groups randomly (124 patients in each group); 120 (97%) patients in group A (OABF), 120 (97%) in group B (OABM-F) and 116 (93%) in group C (OAF) completed the study. The intention-to-treat eradication rates were 83.7% (95% CI= 77.3-90.4), 79.8% (95% CI= 72.6-87), and 84.6% (95% CI= 78.2-91.1) and per-protocol eradication rates were 86.6% (95% CI= 80.5-92.8), 82.5% (95% CI= 75.6-89.4), and 90.5% (95% CI= 85.1-95.9) for groups OABF, OABM-F, and OAF, respectively. No statistical significant differences were found in case of severe drug adverse effects between the above mentioned three groups (p> 0.05). The most common side effects, namely nausea and fever, occurred in all groups, but more frequently in group C (OAF) (p< 0.05).

CONCLUSION

In developing countries such as Iran, furazolidone-based regimens can substitute clarithromycinbased regimens for H. pylori eradication because of a very low level of resistance, low cost and high effectiveness. Considering per-protocol eradication rate of ten days OAF regimen, and the acceptable limit of ninety percent, we recommend this regimen in developing countries such as Iran to be substituted of classic standard triple therapy. In order to minimize rare serious adverse effects, one week high dose OAF regimen should be taken into consideration in other studies.

Clarithromycin vs. Gemifloxacin in Quadruple Therapy Regimens for Empiric Primary Treatment of Helicobacter pylori Infection: A Randomized Clinical Trial

BACKGROUND Eradication of Helicobacter pylori infection plays a crucial role in the treatment of peptic ulcer. Clarithromycin resistance is a major cause of treatment failure. This randomized clinical trial aimed at evaluating the efficacy of a clarithromycin versus gemifloxacin containing quadruple therapy regimen in eradication of H.pylori infection. METHODS In this randomized double blind clinical trial (RCT 2012102011054N2), a total of 120 patients were randomized to two groups of 60 patients each. Patients with proven H.pylori infection were consecutively assigned into two groups to receive OBAG or OBAC in gastroenterology clinic in Rasoul-e- Akram General Hospital in Tehran, Iran. The patients in the OBAG group received omeprazole (20 mg) twice daily, bismuth subcitrate (240 mg) twice daily, amoxicillin (1 gr) twice daily, and gemifloxacin (320 mg) once daily, and those in the OBAC group received omeprazole (20 mg) twice daily, 240 mg of bismuth subcitrate twice daily, amoxicillin (1 gr) twice daily, and clarithromycin (500 mg) twice daily for 10 days. RESULTS Five patients from each group were excluded from the study because of poor compliance, so 110 patients completed the study. The intention-to-treat eradication rate was 61.6% and 66.6% for the OBAC and OBAG groups, respectively. According to the per protocol analysis, the success rates of eradication of H.pylori infection were 67.2% and 72.7% for OBAC and OBAG groups, respectively (p=0.568). CONCLUSION The results of this study suggest that gemifloxacin containing regimen is at least as effective as clarithromycin regimen; hence, this new treatment could be considered as an alternative for the patients who cannot tolerate clarithromycin.

Comparing the efficacy of four different protocols for eradicating of Helicobacter pylori infection in Ahvaz, southwest Iran

Introduction

Helicobacter pylori (H. pylori) is the common cause of many gastrointestinal diseases, especially peptic ulcer. Therefore, a successful treatment of this infection decreases the financial burden on health systems.

Aim

Different combinations of antibiotics are used for the eradication of this bacterium worldwide. The goal of this study is to compare the efficacy of four different protocols used for this purpose in Ahvaz.

Material and methods

A total number of 400 patients with H. pylori infection were randomly divided into four groups (100 in each): (1) OAC: omeprazole (20 mg/b.i.d.), amoxicillin (1000 mg/b.i.d.), clarithromycin (500 mg/b.i.d.) for 10 days. (2) OCF: omeprazole (20 mg/b.i.d.), ciprofloxacin (500 mg/b.i.d.), furazolidone (100 mg/b.i.d.) for 10 days. (3) OBAM: omeprazole (20 mg/b.i.d.), bismuth subcitrate (240 mg/b.i.d.), amoxicillin (1000 mg/b.i.d.), metronidazol (500 mg/b.i.d.) for 14 days. (4) OBTM: omeprazole (20 mg/b.i.d.), bismuth subcitrate (240 mg/b.i.d.), tetracycline (500 mg/b.i.d.), metronidazol (500 mg/b.i.d.) for 14 days. At the end the viability of the bacterium was assessed by C¹⁴ urea breath test.

Results

The rate of H. pylori eradication was 92%, 59%, 73%, and 76% in OAC, OCF, OBAM, and OBTM groups, respectively (based on intention to treat analysis). The eradication rate was 93.9%, 62.1%, 77.7%, and 84.4% in OAC, OCF, OBAM, and OBTM groups, respectively (based on per protocol analysis). There was a statistically significant increase in eradication rate in the OAC group in comparison with the others (p < 0.001).

Conclusions

Standard triple therapy (omeprazole, amoxicillin, clarithromycin) remains the most effective regimen for H. pylori eradication in Ahvaz.

Helicobacter pylori in Iran: A systematic review on the antibiotic resistance

OBJECTIVES

Helicobacter pylori (H. pylori) is a pathogenic bacterium that colonizes the stomachs of approximately 50% of the world's population. Resistance of H. pylori to antibiotics is considered as the main reason for the failure to eradicate this bacterium. The aim of this study was to determine the rate of resistant H. pylori strains to various antimicrobial agents in different areas of Iran.

MATERIALS AND METHODS

A systematic review of literatures on H. pylori antibiotic resistance in Iran was performed within the time span of 1997 to 2013. Data obtained from various studies were tabulated as following, 1) year of research and number strains tested, 2) number of H. pylori positive patients, 3) study place, 4) resistance of H. pylori to various antibiotics as percentage, and 5) methods used for evaluation of antibiotic resistance.

RESULTS

Over the period, a total of 21 studies on H. pylori antibiotic resistance have been conducted in different parts of Iran. In these studies, H. pylori resistance to various antibiotics, including metronidazole, clarithromycin, amoxicillin, tetracycline, ciprofloxacin, levofloxacin and furazolidone were 61.6%, 22.4%, 16.0%, 12.2%, 21.0%, 5.3% and 21.6%, respectively. We found no study on H. pylori resistance to rifabutin in Iran.

CONCLUSION

Compared to the global average, we noted that the prevalence of H. pylori resistance to metronidazole, clarithromycin, amoxicillin, and tetracycline has been rapidly growing in Iran. This study showed that in order to determine an appropriate drug regimen against H. pylori, information on antibiotic susceptibility of the bacterium within different geographical areas of Iran is required.

[Future trends of Helicobacter pylori eradication therapy in Korea]

The prevalence of Helicobacter pylori infection in Korea shows a decreasing trend and has changed to that of developed country, especially for those below 30 years old. However, the primary antibiotic resistance rates are higher than those of developed countries. The reason for the decrease in the efficacy of standard triple therapy is mainly due to the increase in the resistance against clarithromycin. Sequential therapy seems to be more effective than the standard triple therapy, but the intention-to-treat eradication rate of sequential therapy in Korea, which is mostly under 80.0%, is still not satisfactory. Therefore, a promising regimen is needed. Recently, the Japanese health insurance system admitted 'H. pylori-infected gastritis'as an indication of eradication. Furthermore, the Kyoto Consensus Meeting on H. pylori Gastritis held from January 30th to February 1st, 2014, proposed that 'all H. pylori positive patients should be offered to receive H. pylori eradication'. This suggests that the concept of eradication has been changed from 'treatment' to 'prevention'. Various individualized tailored therapy based on the polymorphism, age and other demographic factors and antibiotic resistance has been attempted to maximize H. pylori eradication therapy. The aim of this article is to review the current epidemiology, H. pylori resistance state, treatment guideline, and to assess the possible future strategy and treatment for H. pylori infection in Korea.

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.

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.

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.

Second and third line treatment options for Helicobacter pylori eradication

Helicobacter pylori is a highly successful bacterium with a high global prevalence and the infection carries significant disease burden. It is also becoming increasingly difficult to eradicate and the main reason for this is growing primary antibiotic resistance rates in a world where antibiotics are frequently prescribed and readily available. Despite knowing much more about the bacterium since its discovery, such as its genomic makeup and pathogenesis, we have seen declining treatment success. Therefore, clinicians today must be prepared to face one, two or even multiple treatment failures, and should be equipped with sufficient knowledge to decide on the appropriate salvage therapy when this happens. This article discusses the factors contributing to treatment failure and reviews the second and third-line treatment strategies that have been investigated. Established empiric second line treatment options include both bismuth based quadruple therapy and levofloxacin based triple therapy. Antibiotic testing is recommended prior to initiating third line treatment. In the event that antibiotic susceptibility testing is unavailable, third line treatment options include rifabutin, rifaximin and sitafloxacin based therapies.

Non-microbial approach for Helicobacter pylori as faster track to prevent gastric cancer than simple eradication

Although the International Agency for Research on Cancer declared Helicobacter pylori (H. pylori) as a definite human carcinogen in 1994, the Japanese Society for Helicobacter Research only recently (February 2013) adopted the position that H. pylori infection should be considered as an indication for either amelioration of chronic gastritis or for decreasing gastric cancer mortality. Japanese researchers have found that H. pylori eradication halts progressive mucosal damage and that successful eradication in patients with non-atrophic gastritis most likely prevents subsequent development of gastric cancer. However, those who have already developed atrophic gastritis/gastric atrophy retain potential risk factors for gastric cancer. Because chronic perpetuated progression of H. pylori-associated gastric inflammation is associated with increased morbidity culminating in gastric carcinogenesis, a non-microbial approach to treatment that provides long-term control of gastric inflammation through nutrients and other interventions may be an effective way to decrease this morbidity. This non-microbial approach might represent a new form of prerequisite "rescue" therapy that provides a quicker path to the prevention of gastric cancer as compared to simple eradication.

Meta-analysis: is sequential therapy superior to standard triple therapy for Helicobacter pylori infection in Asian adults?

BACKGROUND AND AIM

Although several meta-analyses suggested that sequential therapy (SQT) is superior to standard triple therapy (STT) for the eradication of Helicobacter pylori, these results were mainly based on the studies from Italy. The aim of this study was to assess the efficacy of 10-day SQT for H. pylori infection compared with STT in Asian adults.

METHODS

We performed an electronic search of the Cochrane Library, Medline, and Embase up to April 21, 2013, with no language restrictions. Randomized controlled trials comparing 10-day SQT with STT for H. pylori eradication in Asian adults were included in this analysis. The primary outcome measures were the risk ratios (RRs) for successful eradication of H. pylori based on intention to treat comparing SQT with STT. The secondary outcome measures were the RRs for side effects.

RESULTS

Seventeen randomized controlled trials with a total of 3419 participants (1591 for SQT and 1828 for STT) met the inclusion criteria. The eradication rate was 81.8% (95% CI: 78.9-84.6) for SQT and 74.3% (95% CI: 69.6-78.8) for SST, respectively. The pooled RR was 1.10 (95% CI: 1.04-1.16, P = 0.0005), which demonstrated significant superiority of SQT over STT, and the number needed to treat was 14 (95% CI: 9-29). There were no significant differences between SQT and STT in the risk of side effects (the pooled RR: 0.98, 95% CI: 0.87-1.10, P = 0.73).

CONCLUSION

Ten-day SQT appears to be superior to STT for H. pylori eradication in Asian adults. However, the pooled efficacy is lower than results from earlier European studies.

Poor platelet Count Response to Helicobacter Pylori Eradication in Patients with Severe Idiopathic Thrombocytopenic Purpura

INTRODUCTION

ITP is an autoimmune blood disorder in which platelet destruction is mediated by anti-platelet antibodies. The mechanisms of anti-platelet antibodies development are still a little known. The rate of some bacterial or viral agents in cause of ITP is well known. Recently, some study proposed that H pylori infection may be associated with ITP and H pylori eradication can improves platelet counts in infected ITP patients.

MATERIALS AND METHOD

A baseline platelet count <50×10(3) µL for 4 weeks prior to study entry were required. These patients were tested for H. pylori infection by urea breath. All positive H pylori patients received triple therapy for 7 or 14 days to eradicate H pylori infection. These patients followed for six months.

RESULTS

Of 92 patients with ITP, H pylori infection was found in 59.7% (55/92). After excluding patients with confounding factors, 41 patients were remained. After H pylori eradication, CR wasn't obtained in any patients. Partial response were obtained only in 3 (7.3%) of the 41 patients and no response in 38 (92.6%) patients. There is a significant difference between the platelet counts of PR and NR groups (P < 0.001).

CONCLUSION

The results of this study and our previously study showed H pylori eradication therapy has beneficial effect for patients with mild thrombocytopenia but the chance of obtaining a response by H pylori treatment is lower in patients with severe thrombocytopenia.

Treatment of Helicobacter pylori infection 2012

Helicobacter pylori resistance rates to antibiotics vary in different countries and even in different regions of the same country. Choice of treatment is strongly dependent on antibiotic resistance rates. In some countries, triple therapy with a proton-pump inhibitor, amoxicillin, and clarithromycin is still the best option, but eradication results fall short of what would be desired (90-95%) in countries with clarithromycin resistance >20%, bismuth-containing quadruple therapy, or nonbismuth sequential or concomitant therapies may then be the preferred option. Newer antibiotic regimens are awaited. Vaccination would be the best option, especially for developing countries, but little progress has been made in designing a vaccine.

Platelet Count Response to Helicobacter pylori Eradication in Iranian Patients with Idiopathic Thrombocytopenic Purpura

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune hematological disorder characterized by auto antibody-mediated platelet destruction. Although the main cause of ITP remains unclear, but its relationship with some infection was demonstrated. In recent years, many studies have demonstrated improvement of platelet counts in ITP patients after treating Helicobacter pylori infection. The aim of this study was to investigate the effects of H. pylori eradication on platelet count response in Iranian ITP patients.

A total of 26 patients diagnosed with both ITP and H. pylori infection. ITP were diagnosed whose platelet counts were less than 100×10³/μL. These patients were tested for H. pylori infection by Urea Breath Test and serum H. pylori antibody. All patients received triple therapy for 7 or 14 days to eradicate H. pylori infection. These patients followed for six months.

Prevalence of H. pylori was 67.3%. H. pylori eradication achieved in 89.5% (26/29). Of the 26 patients, 15 (57.7%) exhibited a complete response (CR) and 11 (42.3%) were unresponsive. We did not find partial responders. There was a significant difference in the baseline platelet count of responders and non-responders patients (p<0.001). All responders had platelet count ≥50×10³/μL and all non-responders had platelet count <50×10³/μL.

Results of this study revealed that eradication therapy of H. pylori infection can improve platelet counts in ITP patients especially with mild thrombocytopenia and support routine detection and treatment of H. pylori infection in ITP patients in populations with a high prevalence of this infection.

Variability in Prevalence ofHelicobacter pyloriStrains Resistant to Clarithromycin and Levofloxacin in Southern Poland

Background. An increasing resistance ofHelicobacter pyloristrains to antimicrobial agents is the serious therapeutic problem. The aim of this study was to compare the primary and secondary resistance ofH. pyloristrains isolated between 2006–2008 (data published) and 2009–2011 to clarithromycin and levofloxacin.Material and Methods. 220 dyspeptic patients (153 before treatment, 67 after), were enrolled in the study. 51H. pyloristrains were isolated. MIC values of clarithromycin and levofloxacin were determined by theE-test method. The statistical analysis was conducted with theχ2test with Yates correction at the 0.05 significance level (P≤0.05).Results. Between 2006 and 2008, 34% (39/115) ofH. pyloristrains were resistant to clarithromycin (primary 21% (19/90), secondary 80% (20/25)). 5% (6/115) of strains were resistant to levofloxacin (primary 2% (2/90), secondary 16% ((4/25); data published) Between 2009–2011, 22% (11/51) ofH. pyloristrains were resistant to clarithromycin (primary 19% (8/43), secondary 38% (3/8)). 16% (8/51) of strains were resistant to levofloxacin (primary 12% (5/43), secondary 38% (3/8)).Conclusion. The present study has shown the increasing amount of resistantH. pyloristrains isolated from patients in Southern Poland to levofloxacin and decreasing number of resistant strains to clarithromycin.