Rescue Therapy for Helicobacter pylori Infection 2012

MAT Gain of Activity Mutation in Helicobacter pylori Is Associated with Resistance to MTAN Transition State Analogues

Helicobacter pylori is found in the gut lining of more than half of the world's population, causes gastric ulcers, and contributes to stomach cancers. Menaquinone synthesis in H. pylori relies on the rare futalosine pathway, where H. pylori 5'-methylthioadenosine nucleosidase (MTAN) is proposed to play an essential role. Transition state analogues of MTAN, including BuT-DADMe-ImmA (BTDIA) and MeT-DADMe-ImmA (MTDIA), exhibit bacteriostatic action against numerous diverse clinical isolates of H. pylori with minimum inhibitory concentrations (MIC's) of <2 ng/mL. Three H. pylori BTDIA-resistant clones were selected under increasing BTDIA pressure. Whole genome sequencing showed no mutations in MTAN. Instead, resistant clones had mutations in metK, methionine adenosyltransferase (MAT), feoA, a regulator of the iron transport system, and flhF, a flagellar synthesis regulator. The mutation in metK causes expression of a MAT with increased catalytic activity, leading to elevated cellular S-adenosylmethionine. Metabolite analysis and the mutations associated with resistance suggest multiple inputs associated with BTDIA resistance. Human gut microbiome exposed to MTDIA revealed no growth inhibition under aerobic or anaerobic conditions. Transition state analogues of H. pylori MTAN have potential as agents for treating H. pylori infection without disruption of the human gut microbiome or inducing resistance in the MTAN target.

Efficacy and tolerability of fourteen-day sequential quadruple regimen: pantoprazole, bismuth, amoxicillin, metronidazole and or furazolidone as first-line therapy for eradication of Helicobacter pylori: a randomized, double-blind clinical trial

The optimal pharmacological regimen for eradication of Helicobacter pylori (H. pylori) has been investigated for many years. This study aimed to evaluate the efficacy and tolerability of bismuth-based quadruple therapy (B-QT) and a modified sequential therapy (ST) regimens in eradication of H. pylori. A randomized, double-blind trial was conducted on 344 patients. Patients with H. pylori infection and without a history of previous treatment were randomized to receive 14-day B-QT (bismuth subcitrate 240 mg, pantoprazole 40 mg, amoxicillin 1000 mg, and clarithromycin 500 mg twice daily) or 14-day ST (bismuth subcitrate 240 mg, pantoprazole 40 mg, amoxicillin 1000 mg, and metronidazole 500 mg twice a day for seven days followed by bismuth subcitrate 240 mg, pantoprazole 40 mg, amoxicillin 1000 mg, and furazolidone 100 mg twice a day for additional seven days). Drug adverse effects were assessed during the study. H. pylori eradication was determined eight weeks after the end of treatment using ¹⁴C-urea breath test. Based on per-protocol and intention-to-treat, the eradication rate was significantly higher (p<0.05) in the B-QT regimen 91.9 % (95 % CI; 88.1-94.0) and 90.2 % (95 % CI; 86.3-92.9), respectively compared to the ST regimen 80.8 % (95 % CI; 76.6-84.9) and 78.1 % (95 % CI; 73.7-82.4), respectively. The severity of vomiting and loss of appetite were significantly higher in ST regimen (p<0.05). The B-QT regimen was more effective and safer than the ST regimen. Conclusively, it is suggested to assess the efficacy and safety of this regimen in longer studies, larger population, and in other communities.

Current Status of the Third-Line Helicobacter pylori Eradication

Antibiotic resistance is growing worldwide, and patients who have failed consecutive 1st- and 2nd-line H. pylori eradication regimens are increasing. Therefore, the role of the bacterial culture with antibiotic susceptibility testing and molecular susceptibility testing is important for avoiding the use of ineffective antibiotics. However, antibiotic susceptibility testing-guided treatment does not necessarily guarantee successful eradication, and there have been mixed results for the effectiveness of a 3rd-line rescue therapy. Therefore, providing patients with pretreatment medication instructions and education is important. It is also crucial to determine the reason of the eradication failure, including host-related factors (poor compliance to eradication regimen, smoking, and cytochrome P450 2C19 genetic polymorphism) or treatment-related factors (inadequate dosage or duration of therapy and gastric acidity), as such factors can be modified for a tailored therapy. Although the indications for H. pylori eradication have widened, patients at a high risk of gastric cancer can gain definitive benefits with a 3rd-line or even 4th-line therapy.

Helicobacter pylori treatment: antibiotics or probiotics

Treatment of Helicobacter pylori infection is important for the management of gastrointestinal disorders such as peptic ulcer and gastric cancer. Due to the increase in the prevalence of H. pylori resistance to antibiotics, triple therapy with clarithromycin is no longer the best treatment for H. pylori, especially in some areas where the local resistance to this antibiotic is higher than 20%. Alternative treatments have been proposed for the eradication of H. pylori. Some of them including novel antibiotics or classical ones in different combinations; these treatments are being used in the regular clinical practice as novel and more effective treatments. Others therapies are using probiotics associated to antibiotics to treat this infection.The present article is a revision of H. pylori eradication treatment, focusing on emerging approaches to avoid the treatment failure, using new therapies with antimicrobials or with probiotics.

Probiotic Lactobacillus fermentum UCO-979C biofilm formation on AGS and Caco-2 cells and Helicobacter pylori inhibition

The ability of the human isolate Lactobacillus fermentum UCO-979C to form biofilm and synthesize exopolysaccharide on abiotic and biotic models is described. These properties were compared with the well-known Lactobacillus casei Shirota to better understand their anti-Helicobacter pylori probiotic activities. The two strains of lactobacilli synthesized exopolysaccharide as detected by the Dubois method and formed biofilm on abiotic and biotic surfaces visualized by crystal violet staining and scanning electron microscopy. Concomitantly, these strains inhibited H. pylori urease activity by up to 80.4% (strain UCO-979C) and 66.8% (strain Shirota) in gastric adenocarcinoma (AGS) cells, but the two species showed equal levels of inhibition (~84%) in colorectal adenocarcinoma (Caco-2) cells. The results suggest that L. fermentum UCO-979C has probiotic potential against H. pylori infections. However, further analyses are needed to explain the increased activity observed against the pathogen in AGS cells as compared to L. casei Shirota.

Evaluation of Clarithromycin Resistance Among Iranian Helicobacter pylori Isolates by E-Test and Real-Time Polymerase Chain Reaction Methods

Background

Helicobacter pylori is an important pathogen of human gastric mucosa. Antibiotic resistance, especially resistance to clarithromycin is a major factor for treatment failure of H. pylori infections. The main mechanism of clarithromycin resistance in these bacteria is related to point mutations in three different locations of 23S rRNA gene.

Objectives

The aims of this study were to evaluate the resistance rate to clarithromycin among local H. pylori isolates by the E-test method and to determine the profile of point mutation in 23S rRNA by real-time polymerase chain reaction (PCR) method.

Patients and Methods

Eighty biopsy samples were collected from dyspeptic patients by endoscopy during 2011 - 2012. All samples were homogenized immediately and cultured on supplemented brucella blood agar and incubated under microaerophilic conditions. Further biochemical tests and ureC gene PCR was done for H. pylori confirmation. The H. pylori OC1096 strain was used as the control strain, simultaneously. Frequency of clarithromycin resistance was determined by the E-test method based on the clinical and laboratory standard institute (CLSI) standards. Point mutation profile was determined by real-time PCR and further analysis of melting curve, amplicon sequencing was done continuously.

Results

From 80 biopsy samples, 20 positive H. pylori isolates were detected and confirmed by biochemical tests and PCR method. Overall, 21.7% of the H. pylori isolates, showed clarithromycin resistance phenotype by use of the E-test. Also, the minimal inhibitory concentration of clarithromycin was determined as ≥ 0.5 mg/L by the E-test method. Only point mutation in the location of A2143G with melting temperature of 54.7°C was observed in all resistant isolates.

Conclusions

This study showed that the frequency of H. pylori clarithromycin resistance in Iran is relatively high. Since clarithromycin is not commonly used in Iran for H. pylori eradication, the high rate of resistance could be related to cross-reactivity between other macrolides. Therefore, macrolide antibiotics must be prescribed with precaution in any case of treatment other than H. pylori infections. All resistant isolates showed A2143G mutation in 23S rRNA as the dominant pattern of point mutation at least in Tehran H. pylori isolates.

Effects of Clarithromycin-Containing Quadruple Therapy on Helicobacter Pylori Eradication after Nitroimidazole-Containing Quadruple Therapy Failure

BACKGROUND

Several large clinical trials and meta-analyses have shown about 20% failure to eradicate Helicobacter pylori (H.pylori), necessitating investigations for second-line treatments. The aim of this study was to evaluate the effects of clarithromycin-containing quadruple regimen after nitroimidazole-containing quadruple therapy failure.

METHODS

Thirty two patients who had failed 10-day H.pylori treatment with omeprazole, amoxicillin, bismuth subcitrate, and metronidazole (OABM) regimen and 31 patients who had failed 10-day treatment with omeprazole, amoxicillin, bismuth subcitrate, and furazolidone (OAMF) regimen entered the study. They all received omeprazole (20 mg), amoxicillin (1 gr), bismuth subcitrate (240 mg) and clarithromycin (500 mg) twice a day for 10 days. Eight weeks after treatment, H. pylori eradication was assessed by ¹⁴C-urea breath test.

RESULTS

Totally 61 patients completed the study. According to intention to treat (ITT) analysis, eradication rates by second-line OABC regimen were 84.37% (95% CI= 71.7–96.9%) in OABM group and 77.41% (95% CI= 62.71–92.11%) in OABF group (p=0.756). Per-protocol (pp) eradication rates were 87.09% (95% CI= 75.2–98.8%) and 82.75% (95% CI= 79.4–96%), respectively (p=0.638). Also the cumulative eradication rates by OABC regimen were 80.9% (95% CI= 71.2–90.6%) and 85% (95% CI= 75.9–94%) according to ITT and PP analyses, respectively. Severe side effects were reported in 3.1% of the patients.

CONCLUSION

Regarding ideal eradication rate (>80%) and very low adverse effects, it seems that clarithromycin-containing quadruple therapy can be an encouraging regimen after nitroimidazole-containing regimen failure.

Comparison of levofloxacin versus clarithromycin efficacy in the eradication of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H.pylori) infection causes multiple upper gastrointestinal diseases but optimal therapeutic regimen which can eradicate infection in all the cases has not yet been defined. This study was designed to evaluate the efficacy of triple levofloxacin-based versus clarithromycin-based therapy.

METHODS

In this open-label randomized clinical trial study 120 patients who had esophagogastroduodenoscopy (EGD) with positive rapid urease test (RUT) were enrolled and divided into 2 groups. Case group was treated with levofloxacin (500 mg daily) plus amoxicillin (1 gr twice a day) plus omeprazole (20 mg daily) for 2 weeks. Control group was treated with clarithromycin (500 mg twice a day) plus omeprazole (20 mg daily) for 2 weeks. After the main course of treatment, they received maintenance treatment with omeprazole for 4 weeks. Stool antigen test was performed on them after two weeks of not having any medicine.

RESULTS

H.pylori eradication (intention to treat analysis) was successful in 75% of case group and 51.7% of control group showing a significant difference (P=0.008). H.p infection eradication (per-protocol analysis) was successful in 80.4% in case group and 57.4%% in control group showing significant difference (P=0.009). Drugs adverse effects causing discontinuation treatment were seen in 5% of case group and 3.3% of control group which have not shown a significant difference between the two groups (P=0.648).

CONCLUSION

Triple therapy with levofloxacin-based regimen has better efficacy than clarithromycin-based regimen and as safe as it is.

The antibacterial effect of fatty acids on Helicobacter pylori infection

Eradication of Helicobacter pylori is recommended for the management of various gastric diseases, including peptic ulcers and mucosa-associated lymphoid tissue lymphoma. Because of the increasing prevalence of antibiotic resistance, the eradication rates of antibiotic-based therapies have decreased. Therefore, alternative treatments should be considered. The antibacterial properties of fatty acids (FAs) have been investigated in various organisms, including H. pylori. Some FAs, particularly polyunsaturated FAs, have been shown to have bactericidal activity against H. pylori in vitro; however, their antibacterial effects in vivo remain controversial. Poor solubility and delivery of FAs may be important reasons for this discrepancy. Recently, a series of studies demonstrated the antibacterial effects of a liposomal formulation of linolenic acid against H. pylori, both in vitro and in vivo. Further research is needed to improve the bioavailability of FAs and apply them in clinical use.

Eradication of Helicobacter pylori in Children by Triple Therapy Regimens of Amoxicillin, Omeprazole, and Clarithromycin or Azithromycin

Background and Objectives:

The present study aimed to evaluate the effect of classical and azithromycin-containing triple therapy eradication regimen against H. Pylori in children, and to determine the level of patients’ tolerance.

Patients and Methods:

This single clinical trial was performed in 2014 on 2 to 15 years old children. All children, in whom H. Pylori infection was confirmed through multiple biopsies of the stomach and required treatment, were enrolled in the study. H. Pylori-positive patients were treated alternately with two different drug regimens; Group OCA received clarithromycin 7.5 mg/kg/day every 12 hours for 10 days, amoxicillin 50 mg/kg/day every 12 hours for 10 days, and omeprazole 1 mg/kg/day every 12 hours for two weeks, and Group OAA received azithromycin 10 mg/kg/day once a day (before meal) for 6 days along with amoxicillin and omeprazole. Four to six weeks after completion of treatment, patients’ stool was tested for H. Pylori through the monoclonal method using the Helicobacter antigen quick kit.

Results:

There were no significant differences between the two groups regarding gender and age of patients. Based on ITT analysis, the therapeutic response in the OAA and OCA groups were 56.2% and 62.5%, respectively (P = 0.40). Drug adverse effects were 15.6% in the OCA and 3.1% in the OAA group (P = 0.19).

Conclusions:

The therapeutic response was seen in more than half of the patients treated with triple therapy of H. Pylori eradication regimen including azithromycin or clarithromycin, and there was no significant difference between the two treatment groups.

Efficacy of Clarithromycin Containing Bismuth-Based Regimen as a Second-Line Therapy in Helicobacter Pylori Eradication

BACKGROUND The eradication of Helicobacter pylori infection, commonly prevailing in the stomach, has been important since its introduction. Adequate preparations should be made in finding alternatives when faced with first-line treatment failures. Currently, ideal second-line treatments are indistinct and varied among countries as result of different antibiotic resistance patterns. We aimed to evaluate the safety and efficacy of a clarithromycin-containing bismuth-based quadruple regimen as a second-line treatment. METHODS Forty-eight H.pylori-positive patients with proven gastric or duodenal ulcers and/or erosions who had previously failed to respond to furazolidone-containing regimens were enrolled. They received pantoprazole (40 mg-bid), amoxicillin (1gr-bid), bismuth subcitrate (240 mg-bid), and clarithromycin (500mg-bid) for 10 days. Eight weeks after treatment, a (14)C-urea breath test was performed for the re-evaluation of H. pylori eradication. RESULTS Forty-three patients completed the study. H.pylori eradication rates were 79.2% (95% CI=65.00-89.53) and 88.4% (95% CI=74.91-96.11) according to intention-to-treat and per-protocol analyses, respectively. All patients had excellent compliance to treatment and one did not continue therapy because of adverse effects. CONCLUSION In developing countries such as Iran, a ten-day clarithromycin-containing bismuth-based quadruple regimen is encouraged as a second-line treatment because of the acceptable rate of eradication and low adverse effects.

Beyond Maastricht IV: are standard empiric triple therapies for Helicobacter pylori still useful in a South-European country?

Background

Empiric triple treatments for Helicobacter pylori (H. pylori) are increasingly unsuccessful. We evaluated factors associated with failure of these treatments in the central region of Portugal.

Methods

This single-center, prospective study included 154 patients with positive ¹³C-urea breath test (UBT). Patients with no previous H. pylori treatments (Group A, n = 103) received pantoprazole 40 mg 2×/day, amoxicillin 1000 mg 12/12 h and clarithromycin (CLARI) 500 mg 12/12 h, for 14 days. Patients with previous failed treatments (Group B, n = 51) and no history of levofloxacin (LVX) consumption were prescribed pantoprazole 40 mg 2×/day, amoxicillin 1000 mg 12/12 h and LVX 250 mg 12/12 h, for 10 days. H. pylori eradication was assessed by UBT 6–10 weeks after treatment. Compliance and adverse events were assessed by verbal and written questionnaires. Risk factors for eradication failure were determined by multivariate analysis.

Results

Intention-to-treat and per-protocol eradication rates were Group A: 68.9% (95% CI: 59.4–77.1%) and 68.8% (95% CI: 58.9–77.2%); Group B: 52.9% (95% CI: 39.5–66%) and 55.1% (95% CI: 41.3–68.2%), with 43.7% of Group A and 31.4% of Group B reporting adverse events. Main risk factors for failure were H. pylori resistance to CLARI and LVX in Groups A and B, respectively. Another independent risk factor in Group A was history of frequent infections (OR = 4.24; 95% CI 1.04–17.24). For patients with no H. pylori resistance to CLARI, a history of frequent infections (OR = 4.76; 95% CI 1.24–18.27) and active tobacco consumption (OR = 5.25; 95% CI 1.22–22.69) were also associated with eradication failure.

Conclusions

Empiric first and second-line triple treatments have unacceptable eradication rates in the central region of Portugal and cannot be used, according to Maastricht recommendations. Even for cases with no H. pylori resistance to the used antibiotics, results were unacceptable and, at least for CLARI, are influenced by history of frequent infections and tobacco consumption.

Seven-day quintuple regimen as a rescue therapy for Helicobacter pylori eradication

AIM: To determine the efficacy of two quintuple regimens for eradication of Helicobacter pylori (H. pylori) in patients who failed previous therapies.

METHODS: This prospective, open-label, randomized controlled trial was a phase II study conducted from April 2011 to March 2012 at the Gastrointestinal and Liver Diseases Research Center in Rasht, Iran. A total of 208 patients with dyspepsia who failed previous H. pylori eradication with a ten-day quadruple therapy were enrolled. A random block method was used to assign patients to one of two treatment groups. Patients in the first group were treated with 240 mg bismuth subcitrate, 20 mg omeprazole, 1000 mg amoxicillin, 500 mg clarithromycin and 500 mg tinidazole (BOACT group). Patients in the second group received a regimen containing 240 mg bismuth subcitrate, 20 mg omeprazole, 500 mg tetracycline, 500 mg metronidazole and 200 mg ofloxacin (BOTMO group). Both regimens were given twice daily for a duration of seven days. The eradication was confirmed by a ¹⁴C urea breath test 12 wk after completion of therapy. Patient compliance and drug side effects were evaluated at the end of the treatment period. The success rates were calculated by intention-to-treat and per-protocol analyses.

RESULTS: A total of 205 patients completed the course of treatment, with three patients excluded due to drug intolerance. The mean age of patients did not differ between the BOACT and BOTMO groups (41.6 ± 12.2 years vs 39.6 ± 11.8 years), and no significant differences were found between the two groups in terms of age, sex, smoking habits or the initial eradication regimen. The intention-to-treat and per-protocol eradication rates were significantly higher in the BOTMO group (86.5%, 95%CI: 0.85-0.87 and 86.7%, 95%CI: 0.80-0.89, respectively) compared with the BOACT group (75.5%, 95%CI: 0.73-0.76 and 76%, 95%CI: 0.69-0.80, respectively) (P < 0.05). Univariate analyses for both groups did not show any association of sex, smoking and initial therapeutic regimen with eradiation rate (P > 0.05 for all). Significantly more patients experienced side effects in the BOACT group compared to the BOTMO group (77.4% vs 36.6%, P < 0.01). This difference was exemplified by increases in headache and taste disturbance (P < 0.05).

CONCLUSION: Quintuple therapy with a BOTMO regimen is an alternative second-line rescue therapy for Iranian patients with failed first-line eradication treatment of H. pylori.

Treatment of Helicobacter pylori infection: Past, present and future

Helicobacter pylori (H. pylori) is a major human pathogen associated with significant morbidity and mortality. However, after decades of efforts, treatment of H. pylori remains a challenge for physicians, as there is no universally effective regimen. Due to the rising prevalence of antimicrobial resistance, mainly to clarithromycin, efficacy of standard triple therapies has declined to unacceptably low levels in most parts of the world. Novel regimens, specifically experimented to improve the therapeutic outcome against antibiotic-resistant H. pylori strains, are now recommended as first-line empirical treatment options providing high efficacy (reportedly > 90% in intention to treat analysis) even in high clarithromycin resistance settings. These include the bismuth quadruple, concomitant, sequential and hybrid therapies. Due to the rapid development of quinolone resistance, levofloxacin-based regimens should be reserved as second-line/rescue options. Adjunct use of probiotics has been proposed in order to boost eradication rates and decrease occurrence of treatment-related side effects. Molecular testing methods are currently available for the characterization of H. pylori therapeutic susceptibility, including genotypic detection of macrolide resistance and evaluation of the cytochrome P450 2C19 status known to affect the metabolism of proton pump inhibitors. In the future, use of these techniques may allow for culture-free, non-invasive tailoring of therapy for H. pylori infection.

The clinical and bacteriological factors for optimal levofloxacin-containing triple therapy in second-line Helicobacter pylori eradication

Quinolone has the disadvantage of easily acquired drug resistance. It is important to prescribe it wisely for a high eradication rate. The current study aimed to determine the clinical and bacteriological factors for optimal levofloxacin-containing triple therapies in second-line H. pylori eradication. We enrolled a total of 158 H. pylori-infected patients who failed H. pylori eradication using the 7-day standard triple therapy (proton-pump inhibitor [PPI] twice daily, 500 mg clarithromycin twice daily, and 1 g amoxicillin twice daily). They were prescribed with either a 10-day (group A) or 14-day (group B) levofloxacin-containing triple therapy group (levofloxacin 500 mg once daily, amoxicillin 1 g twice daily, and esomeprazole 40 mg twice daily for 10 days) by their clinicians. Follow-up studies to assess treatment responses were carried out 8 weeks later. The eradication rates attained by groups A and B were 73.6% (95% confidence interval [CI] = 63.9–85.3%) and 90.5% (95% CI = 84.5–98.1%), respectively in the per protocol analysis (P = 0.008 in the per protocol analysis) and 67.1% (95% CI = 56.6–78.5%) and 84.8% (95% CI = 76.8–93.4%), respectively, in the intention-to-treat analysis (P = 0.009). The subgroup analysis revealed that H. pylori eradication rates for group A patients with levofloxacin-susceptible strains were 92.9% (13/14) but it dropped to 12.5% (1/8) when levofloxacin-resistant strains existed. H. pylori was eradicated among all the group B patients with levofloxacin-susceptible strains, but only half of patients with levofloxacin-resistant strains were successfully eradicated. In conclusion, this study confirms the effectiveness of 14-day treatment. Importantly, the results imply that 10-day treatment duration should be optimal if a culture can be performed to confirm the existence of susceptible strains. The duration of H. pylori eradication and levofloxacin resistance were the influencing factors for successful treatment. This study suggests that tailored levofloxacin-containing therapy should be administered only for patients with susceptible strains because it can achieve >90% success rates.

Treatment of Helicobacter pylori infection: meeting the challenge of antimicrobial resistance

Treatment of Helicobacter pylori (H. pylori) infection is paramount for the management of prevalent gastrointestinal disorders including peptic ulcer disease and gastric cancer. Due to the wide increase in prevalence of H. pylori resistance to antibiotics, clarithromycin-based triple therapies are not any more suitable for unconditional empiric use, and should not be recommended, unless local resistance to this antibiotic is low (< 20%). Alternative strategies have been proposed to overcome the issue of increasing clarithromycin resistance, and some of them are already implemented in clinical practice. These comprise: (1) adoption of novel, more effective, empirical treatments: bismuth quadruple, sequential, non-bismuth quadruple (concomitant), dual-concomitant (hybrid), and levofloxacin-based regimens, the latter mainly designated as second-line/rescue options; (2) perspectives for a susceptibility-guided (tailored) therapeutic approach based on culture-free molecular testing methods; and (3) adjunct use of probiotics to improve eradication rates. The present article is aimed to provide a comprehensive overview of current and emerging strategies in the treatment of H. pylori infection, focusing on the challenge of antimicrobial resistance.

Fluoroquinolone-based protocols for eradication of Helicobacter pylori

Helicobacter pylori (H. pylori) is a widespread pathogen infecting about 40% of people living in urban areas and over 90% of people living in the developing regions of the world. H. pylori is well-documented as the main factor in the pathogenesis of peptic ulcer disease, chronic gastritis, and gastric malignancies such as cancer and mucosa-associated lymphoid tissue-lymphoma; hence, its eradication is strongly recommended. The Maastricht IV consensus, which focused on the management of H. pylori infection, set important new strategies in terms of treatment approaches, particularly with regards to first- and second-line treatment protocols and led to improved knowledge and understanding of H. pylori resistance to antibiotics. In recent years, various fluoroquinolone-based protocols, mainly including levofloxacin, have been proposed and effectively tested at all therapeutic lines for H. pylori eradication. The aim of the present paper is to review the scientific literature focused on the use of fluoroquinolones in eradicating H. pylori.

Helicobacter pylori infection in older people

Since the discovery of Helicobacter pylori (H. pylori) infection as the major cause of gastroduodenal disorders three decades ago, H. pylori has been the focus of active research and debate in the scientific community. Its linkage to several diseases, such as peptic ulcer disease, gastritis and gastric malignancy is incontestable. In particular, it has been noticed that, as the aged population is increasing worldwide, older people are at increased risk of developing several gastroduodenal diseases and related complications. At the same time, gastric cancer is definitely more frequent in elderly than in adult and young people. In addition, it has been showed that peptic ulcer and related complications occur much more commonly in aged individuals than in young people, resulting in a significantly higher mortality. Although this infection plays a crucial role in gastrointestinal disorders affecting all age groups and in particular older people, only a few studies have been published regarding the latter. This article presents an overview of the epidemiology, diagnosis, clinical manifestations and therapy of H. pylori infection in elderly people.

Triple therapy with high-dose proton-pump inhibitor, amoxicillin, and doxycycline is useless for Helicobacter pylori eradication: a proof-of-concept study

INTRODUCTION

Helicobacter pylori resistance to antibiotics is steadily increasing and multidrug-resistant strains are common and difficult to eliminate, mainly in countries where bismuth, tetracycline, furazolidone, and rifabutin are unavailable.

AIM

To evaluate the efficacy and safety of a triple therapy with proton-pump inhibitor (PPI), amoxicillin, and doxycycline in patients with multidrug-resistant H. pylori.

PATIENTS AND METHODS

This prospective study involved 16 patients (13 females; mean age - 50 ± 11.3 years) infected by H. pylori with known resistance to clarithromycin, metronidazole, and levofloxacin, but susceptibility to amoxicillin and tetracycline. All patients were previously submitted to upper endoscopy with gastric biopsies for H. pylori culture and susceptibility testing by Etest. Mutations in 23S rRNA and gyrA genes were determined by real-time PCR. A 10-day eradication regimen with PPI (double-standard dose b.i.d.), amoxicillin (1000 mg b.i.d.), and doxycycline (100 mg b.i.d.) was prescribed after pretreatment with PPI during 3 days. Eradication success was assessed by (13) C-urea breath test 6-10 weeks after treatment. Compliance and adverse events were determined through phone contact immediately after treatment and specific written questionnaires.

RESULTS

Only one patient did not complete treatment due to adverse events. Another four patients experienced mild side effects not affecting compliance. The control (13) C-urea breath test was positive in all patients. Per-protocol and intention-to-treat eradication rates were 0%.

CONCLUSIONS

Although safe, a triple-therapy protocol with high-dose PPI, amoxicillin, and doxycycline is useless for multidrug-resistant H. pylori eradication.

Third-line rescue therapy with bismuth-containing quadruple regimen after failure of two treatments (with clarithromycin and levofloxacin) for H. pylori infection

BACKGROUND

Helicobacter pylori eradication therapy with a proton pump inhibitor (PPI), clarithromycin, and amoxicillin fails in >20 % of cases. A rescue therapy with PPI-amoxicillin-levofloxacin still fails in >20 % of patients.

AIM

To evaluate the efficacy and tolerability of a bismuth-containing quadruple regimen in patients with two consecutive eradication failures.

METHODS

Prospective multicenter study of patients in whom 1st treatment with PPI-clarithromycin-amoxicillin and 2nd with PPI-amoxicillin-levofloxacin had failed. A 3rd eradication regimen with a 7- to 14-day PPI (standard dose b.i.d.), bismuth subcitrate (120 mg q.i.d. or 240 mg b.i.d.), tetracycline (from 250 mg t.i.d. to 500 mg q.i.d.) and metronidazole (from 250 mg t.i.d. to 500 mg q.i.d.). Eradication was confirmed by (13)C-urea-breath-test 4-8 weeks after therapy. Compliance was determined through questioning and recovery of empty medication envelopes. Adverse effects were evaluated by means of a questionnaire.

RESULTS

Two hundred patients (mean age 50 years, 55 % females, 20 % peptic ulcer/80 % uninvestigated-functional dyspepsia) were initially included, and two were lost to follow-up. In all, 97 % of patients complied with the protocol. Per-protocol and intention-to-treat eradication rates were 67 % (95 % CI 60-74 %) and 65 % (58-72 %). Adverse effects were reported in 22 % of patients, the most common being nausea (12 %), abdominal pain (11 %), metallic taste (8.5 %), and diarrhea (8 %), none of them severe.

CONCLUSION

A bismuth-containing quadruple regimen is an acceptable third-line strategy and a safe alternative after two previous H. pylori eradication failures with standard clarithromycin- and levofloxacin-containing triple therapies.

Helicobacter pylori: Future perspectives in therapy reflecting three decades of experience

The rising prevalence of antibiotic resistance has created a need to reassess the established Helicobacter pylori (H. pylori) eradication protocols, and to develop new ones. Various bacterial and host factors are evaluated, and their contribution to eradication failure is estimated. For a long time being considered the cornerstone eradication scheme, the standard triple therapy has been replaced with novel, more efficient regimens, namely sequential and concomitant, along with the emergence of a new design of bismuth quadruple therapy. A rescue levofloxacin based regimen has overcome the fear of therapy failure due to higher prevalence of dual resistant (clarithromycin and metronidazole) H. pylori. Culture-free and efficient susceptibility test are reestablishing the concept of tailored therapy, making eradication success close to originally desirable rates. Alleviating therapy side effects and improving patient compliance are as important as choosing appropriate eradication schemes, so various probiotic compound supplements are taken into consideration. Finally, we summarize the emerging efforts and obstacles in creating efficient H. pylori vaccine.

Epidemiology and pattern of antibiotic resistance in Helicobacter pylori: scenario from Saudi Arabia

Helicobacter pylori is recognized as a major cause of gastritis, peptic ulcer, gastric cancer, and mucosa-associated lymphoma. Infection with this gram-negative microaerophile has been treated using combination of antibiotics and proton pump inhibitors for different gastrointestinal diseases. The most commonly used treatment is triple therapy which consists of administration of a proton pump inhibitor, clarithromycin, and amoxicillin. Many factors contribute to treatment failure, but one of the main reasons is development of bacterial antibiotic resistance. The percent prevalence of antibiotic resistance varies among different countries; it appears to be partly determined by the geographic factors and its ability to undergo frequent homologous recombination. The aim of this paper is to review the prevalence of H. pylori infection, association of clinical outcomes with H. pylori genotypes, and current status of antibiotic resistance in H. pylori in Saudi Arabia. It also discusses the different alternative approaches for the treatment of H. pylori using antibiotics. In addition, association of antibiotic resistance with H. pylori virulent genotypes in Saudi population and its underlying resistance mechanism will also be discussed.

[Ideal treatment for Helicobacter pylori: a systematic review]

BACKGROUND

The success rates of therapies for treating Helicobacter pylori vary greatly worldwide and the ideal treatment has yet to be clearly established.

AIMS

A systematic review was carried out to evaluate the effectiveness of current first and second-line therapies in treating H.pylori infection.

METHODS

Two researchers independently carried out Internet search engine reviews (PUBMED, EMBASE, MEDLINE) of clinical trials on adults published between 1990 and 2012 in both English and Spanish.

RESULTS

Forty-three (n=8,123) clinical trials were evaluated that included first and second-line triple, quadruple, and sequential therapies. The eradication rates of the standard triple therapy are unacceptable (≤80%) in countries where H.pylori is highly resistant to clarithromycin and metronidazole. Administration of the standard triple therapy for more than 7 days does not improve its effectiveness. No statistically significant differences were observed between the eradication rates of the quadruple therapy with bismuth and the standard triple therapy. Even though the sequential and concomitant therapies are equally successful regimens, the triple therapy with levofloxacin offers the best results as first and second-line treatment, but quinolone resistance can diminish its effectiveness. The triple therapy with levofloxacin and the sequential and concomitant treatments were superior to the standard triple regimen as first-line therapy.

CONCLUSIONS

Currently there is no ideal first or second-line treatment for achieving 100% eradication. The therapeutic order should be carried out according to the initial treatment and local antimicrobial resistance studies.

Current options for the treatment of Helicobacter pylori

INTRODUCTION

Treatment of Helicobacter pylori (H. pylori) infection is crucial for prevalent disease's management, including gastritis, peptic ulcer and gastric cancer, whereas novel extradigestive causal associations are increasingly being recognized. Despite long-standing efforts, there is not as yet an optimal empirical therapy to eradicate H. pylori.

AREAS COVERED

In the present article the authors review current options for H. pylori eradication. Advantages and disadvantages of each of the recommended regimens, and the perspectives for their rational use in clinical practice, are critically discussed.

EXPERT OPINION

The continuous rising of antimicrobial resistance has accounted for the declined efficiency of standard triple therapies, yielding < 70% eradication in most countries. Alternative first-line strategies have been proposed and largely validated and are now replacing standard-of-care therapies in areas with a high incidence of clarithromycin-resistance (> 20%). Such treatments include the bismuth-containing quadruple therapy, concomitant, sequential and levofloxacin-based regimens, the later mainly designated, together with rifabutin-based therapies as second-line/rescue options. Clinicians should be aware of the local resistance pattern and maintain first-line eradication to levels > 90% (per-protocol efficacy). This will prevent both exposing the patient to repeated treatments and spreading of secondary antimicrobial resistance. In the future, perspectives of tailored therapy and a prophylactic vaccine will obviate any treatment concern.

Second-line rescue triple therapy with levofloxacin after failure of non-bismuth quadruple "sequential" or "concomitant" treatment to eradicate H. pylori infection

BACKGROUND

Non-bismuth quadruple "sequential" and "concomitant" regimens, including a proton pump inhibitor (PPI), amoxicillin, clarithromycin and a nitroimidazole, are increasingly used as first-line treatments for Helicobacter pylori infection. Eradication with rescue regimens may be challenging after failure of key antibiotics such as clarithromycin and nitroimidazoles.

AIM

To evaluate the efficacy and tolerability of a second-line levofloxacin-containing triple regimen (PPI-amoxicillin-levofloxacin) in the eradication of H. pylori after non-bismuth quadruple-containing treatment failure.

DESIGN

prospective multicenter study.

PATIENTS

in whom a non-bismuth quadruple regimen, administered either sequentially (PPI + amoxicillin for 5 days followed by PPI + clarithromycin + metronidazole for 5 more days) or concomitantly (PPI + amoxicillin + clarithromycin + metronidazole for 10 days) had previously failed.

INTERVENTION

levofloxacin (500 mg b.i.d.), amoxicillin (1 g b.i.d.) and PPI (standard dose b.i.d.) for 10 days.

OUTCOME

eradication was confirmed with (13)C-urea breath test 4-8 weeks after therapy. Compliance and tolerance: compliance was determined through questioning and recovery of empty medication envelopes. Incidence of adverse effects was evaluated by means of a questionnaire.

RESULTS

100 consecutive patients were included (mean age 50 years, 62% females, 12% peptic ulcer and 88% dyspepsia): 37 after "sequential", and 63 after "concomitant" treatment failure. All patients took all medications correctly. Overall, per-protocol and intention-to-treat H. pylori eradication rates were 75.5% (95% CI 66-85%) and 74% (65-83%). Respective intention-to-treat cure rates for "sequential" and "concomitant" failure regimens were 74.4% and 71.4%, respectively. Adverse effects were reported in six (6%) patients; all of them were mild.

CONCLUSION

Ten-day levofloxacin-containing triple therapy constitutes an encouraging second-line strategy in patients with previous non-bismuth quadruple "sequential" or "concomitant" treatment failure.

Standard triple versus levofloxacin based regimen for eradication of Helicobacter pylori

AIM

To compare the eradication rates for Helicobacter pylori (H. pylori) and ulcer recurrence of standard triple therapy (STT) and levofloxacin based therapy (LBT).

METHODS

Seventy-four patients with perforated duodenal ulcer treated with simple closure and found to be H. pylori infected on 3 mo follow up were randomized to receive either the STT group comprising of amoxicillin 1 g bid, clarithromycin 500 mg bid and omeprazole 20 mg bid or the LBT group comprising of amoxicillin 1 g bid, levofloxacin 500 mg bid and omeprazole 20 mg bid for 10 d each. The H. pylori eradication rates, side effects, compliance and the recurrence of ulcer were assessed in the two groups at 3 mo follow up.

RESULTS

Thirty-four patients in the STT group and 32 patients in the levofloxacin group presented at 3 mo follow up. H. pylori eradication rates were similar with STT and the LBT groups on intention-to-treat (ITT) analysis (69% vs 80%, P = 0.425) and (79% vs 87%, P = 0.513) by per-protocol (PP) analysis respectively. Ulcer recurrence in the STT and LBT groups on ITT analysis was (20% vs 14%, P = 0.551) and (9% vs 6%, P = 1.00) by PP analysis. Compliance and side effects were also comparable between the groups. A complete course of STT costs Indian Rupees (INR) 1060.00, while LBT costs only INR 360.00.

CONCLUSION

H. pylori eradication rates and the rate of ulcer recurrence were similar between the STT and LBT. The LBT is a more economical option compared to STT.

Standard triple versus levofloxacin based regimen for eradication of Helicobacter pylori

AIM

To compare the eradication rates for Helicobacter pylori (H. pylori) and ulcer recurrence of standard triple therapy (STT) and levofloxacin based therapy (LBT).

METHODS

Seventy-four patients with perforated duodenal ulcer treated with simple closure and found to be H. pylori infected on 3 mo follow up were randomized to receive either the STT group comprising of amoxicillin 1 g bid, clarithromycin 500 mg bid and omeprazole 20 mg bid or the LBT group comprising of amoxicillin 1 g bid, levofloxacin 500 mg bid and omeprazole 20 mg bid for 10 d each. The H. pylori eradication rates, side effects, compliance and the recurrence of ulcer were assessed in the two groups at 3 mo follow up.

RESULTS

Thirty-four patients in the STT group and 32 patients in the levofloxacin group presented at 3 mo follow up. H. pylori eradication rates were similar with STT and the LBT groups on intention-to-treat (ITT) analysis (69% vs 80%, P = 0.425) and (79% vs 87%, P = 0.513) by per-protocol (PP) analysis respectively. Ulcer recurrence in the STT and LBT groups on ITT analysis was (20% vs 14%, P = 0.551) and (9% vs 6%, P = 1.00) by PP analysis. Compliance and side effects were also comparable between the groups. A complete course of STT costs Indian Rupees (INR) 1060.00, while LBT costs only INR 360.00.

CONCLUSION

H. pylori eradication rates and the rate of ulcer recurrence were similar between the STT and LBT. The LBT is a more economical option compared to STT.

Standard triple versus levofloxacin based regimen for eradication of Helicobacter pylori

AIM: To compare the eradication rates for Helicobacter pylori (H. pylori) and ulcer recurrence of standard triple therapy (STT) and levofloxacin based therapy (LBT).

METHODS: Seventy-four patients with perforated duodenal ulcer treated with simple closure and found to be H. pylori infected on 3 mo follow up were randomized to receive either the STT group comprising of amoxicillin 1 g bid, clarithromycin 500 mg bid and omeprazole 20 mg bid or the LBT group comprising of amoxicillin 1 g bid, levofloxacin 500 mg bid and omeprazole 20 mg bid for 10 d each. The H. pylori eradication rates, side effects, compliance and the recurrence of ulcer were assessed in the two groups at 3 mo follow up.

RESULTS: Thirty-four patients in the STT group and 32 patients in the levofloxacin group presented at 3 mo follow up. H. pylori eradication rates were similar with STT and the LBT groups on intention-to-treat (ITT) analysis (69% vs 80%, P = 0.425) and (79% vs 87%, P = 0.513) by per-protocol (PP) analysis respectively. Ulcer recurrence in the STT and LBT groups on ITT analysis was (20% vs 14%, P = 0.551) and (9% vs 6%, P = 1.00) by PP analysis. Compliance and side effects were also comparable between the groups. A complete course of STT costs Indian Rupees (INR) 1060.00, while LBT costs only INR 360.00.

CONCLUSION: H. pylori eradication rates and the rate of ulcer recurrence were similar between the STT and LBT. The LBT is a more economical option compared to STT.

Anti-Helicobacter pylori and urease inhibition activities of some traditional medicinal plants

Different parts of Acacia nilotica (L.) Delile, Calotropis procera (Aiton) W.T. Aiton, Adhatoda vasica Nees, Fagoniaar abica L. and Casuarina equisetifolia L. are traditionally used in folk medicine for the treatment of a variety of common ailments like nausea, cold, cough, asthma, fevers, diarrhea, sore throat, swelling, etc. The present study was aimed to evaluate the anti-Helicobacter pylori and urease inhibition activities of extracts produced from the above selected medicinal plants native to Soon Valley (home to an old civilization) in the Punjab province of Pakistan. Methanol, acetone and water extracts of the plants were evaluated for anti-bacterial activity against thirty four clinical isolates and two reference strains of H. pylori. Minimum inhibitory concentrations (MICs) of the extracts were determined using the agar dilution method and compared with some standard antibiotics like amoxicillin (AMX), clarithromycin (CLA), tetracycline (TET) and metronidazole (MNZ), used in the triple therapy for H. pylori eradication. H. pylori urease inhibition activity of the extracts was assessed by the phenol red method, wherein, Lineweaver-Burk plots were used to determine Michaelis-Menten constants for elucidating the mechanism of inhibition. Methanol and acetone extracts from Acacia nilotica and Calotropis procera exhibited stronger anti-H. pylori activity than MNZ, almost comparable activity with TET, but were found to be less potent than AMX and CLT. The rest of the extracts exhibited lower activity than the standard antibiotics used in this study. In the H. pylori urease inhibitory assay, methanol and acetone extracts of Acacia nilotica and Calotropis procera showed significant inhibition. Lineweaver-Burk plots indicated a competitive mechanism for extract of Acacia nilotica, whereas extract of Calotropis procera exhibited a mixed type of inhibition.

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

Background

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

Methods

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

Results

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

Conclusions

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

Real-Time PCR detection and quantitation of Helicobacter pylori clarithromycin-resistant strains in archival material and correlation with Sydney classification

BACKGROUND

Helicobacter pylori (H. pylori), infects gastric mucosa causing gastritis. Treatment failure is mainly due to certain genetic changes in the peptidyltransferase loop of 23S rRNA of the microorganism. The aim of the study was to evaluate genetic changes in gastric biopsies of H. pylori (+) patients that lead to clarithromycin resistance and to correlate them with histology data.

METHODS

A total of 150 H. pylori (+) gastric biopsies were studied, taken before and after eradication therapy from 75 dyspeptic patients divided in 2 groups: group A consisted of 25 H. pylori (+) triple-therapy resistant patients and group B consisted of 50 H. pylori (+) successfully treated patients. Histological classification of the H. pylori (+) gastritis was done according to the Sydney criteria. Genetic material was analyzed with the ClariRes™ RT-PCR bi-probe based assay for the determination of point mutations in the 23S rRNA gene and with a Quantitative-RT-PCR (Q-RT-PCR) method for the quantitation of H. pylori.

RESULTS

We showed that in 18/ 25 group A patients certain point mutations of 23S rRNA at sites A2142C, A2142G and A2143G had occurred. Nine of these 18 mutated cases (50%) were characterized as mixed infections. Mixed infections in 2/50 patients of group B were also observed. Using Q-RT-PCR, we found that gastric mucosal density of H. pylori correlates well with bacterial colonization. There was a statistically significant association (P<0.005) between the presence of the detected H. pylori genetic alterations and inflammation, activity and H. pylori density as histologically determined.

CONCLUSION

Certain point mutations in H. pylori genome that affect susceptibility to clarithromycin correlate with histological features of gastritis.