Most Helicobacter pylori strains of Kolkata in India are resistant to metronidazole but susceptible to other drugs commonly used for eradication and ulcer therapy

Antibiotic susceptibility pattern of Helicobacter pylori against eight antibiotics: A study from North India

BACKGROUND

The purpose of this analysis is to evaluate the antimicrobial susceptibility of eight drugs effective against Helicobacter pylori (H. pylori) strains and the genetic diversity of H. pylori virulence genes to foresee clinical outcomes in North India.

MATERIALS AND METHODS

Fifty-eight H. pylori strains isolated from patients suffering from various gastrointestinal (GI) diseases were included in the study. MICs of various antibiotics were determined by the agar dilution method. The chi-squared test and Fisher exact test were used to determine the p-value, which was considered significant at p-value ≤ 0.05. RStudio 4.0 was used to for the data visualization.

RESULTS

The prevalence of drug resistance was found to be: cefixime (CFM) (41.3%), furazolidone (FZD) (34.4%), amoxicillin (AMX) (20.7%), levofloxacin (LVFX) (70.7%), metronidazole (MTZ) (39.6%), tetracycline (TET) (20.7%), clarithromycin (CLA) (17.2%), and rifabutin (RIF) (17.2%). Out of 58 H. pylori strains, 3 were pan susceptible. There were H. pylori strains with single-drug resistance (21.8%, 12/55), dual resistance (30.9%, 17/55), triple resistance (20%, 11/55), and multidrug resistance (27.3%, 15/55). The resistance rate in MTZ, CLA and RIF were found to be significantly higher in females as compared to males (p = 0.005, p = 0.002, and p = 0.02), respectively. The resistance to TET exhibited significantly higher levels in gastritis compared to GERD, DU, and other disease groups (p = 0.04) respectively.

CONCLUSION

TET, AMX, CLA, and RIF were found to be more effective antibiotics against H. pylori infections, whereas more studies are required to provide evidence on increasing resistance rate of LVFX.

Primary antibiotic resistance of Helicobacter pylori in India over the past two decades: A systematic review

BACKGROUND

Helicobacter pylori antibiotic resistance has undergone vast changes in the last two decades. No systematic review has been done on the prevalence of antibiotic resistant H. pylori in India in the last two decades. We evaluated the pattern of resistance rates across various regions of India.

MATERIALS AND METHODS

A systematic review of the geographical variations in antibiotic resistance pattern of H. pylori was conducted using PubMed, Google Scholar, Web of Science, Science Direct, etc. for articles published between January 1, 2000 and May 30, 2023. Random effects-model-based Cochran's Q test, I2 statistics, and chi-squared tests were used to measure heterogeneity.

RESULTS

The overall resistance was highest against metronidazole (77.65%) followed by amoxicillin (37.78%), levofloxacin (32.8%), clarithromycin (35.64%), furazolidone (12.03%), and tetracycline (11.63%). 14.7% of the H. pylori isolates were multi-drug resistant. Under meta-analysis of each antibiotic, high heterogeneity levels were observed having I2 ranges from 86.53% to 97.70% at p < 0.0001. In sub-group analysis, Metronidazole has a stable rate of resistance as compared to other antibiotics. Other antibiotics have had a downtrend in the last 5 years except for levofloxacin, which has had an uptrend in the resistance rate for the past 5 years. Hence, one should avoid using metronidazole for any kind of first-line treatment.

CONCLUSIONS

Metronidazole resistance is high in most regions of India except Assam and Mumbai while clarithromycin is found to be ineffective in South India, Gujarat, and Kashmir. As compared to other antibiotics, resistance to amoxicillin is generally low except in certain regions (Hyderabad, Chennai, and the Gangetic belt of North India). Tetracycline and Furazolidone have the least resistance rates and should be part of anti- H. pylori regimens. The resurgence of high single and multidrug resistance to the commonly used drugs suggests the need for newer antibiotics and regular resistance surveillance studies.

Drug Resistance Patterns of Commonly Used Antibiotics for the Treatment of Helicobacter pylori Infection among South Asian Countries: A Systematic Review and Meta-Analysis

Background: In South Asia, resistance to commonly used antibiotics for the treatment of Helicobacter pylori infection is increasing. Despite this, accurate estimates of overall antibiotic resistance are missing. Thus, this review aims to analyze the resistance rates of commonly used antibiotics for the treatment of H. pylori in South Asia. Methods: The systematic review and meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. We searched five medical databases for relevant studies from inception to September 2022. A random effect model with a 95% confidence interval (CI) was used to calculate the pooled prevalence of antibiotic resistance. Results: This systematic review and meta-analysis included 23 articles, 6357 patients, 3294 Helicobacter pylori isolates, and 2192 samples for antibiotic resistance. The prevalences of antibiotic resistance to common antibiotics were clarithromycin: 27% (95%CI: 0.17–0.38), metronidazole: 69% (95%CI: 0.62–0.76), tetracycline: 16% (95%CI: 0.06–0.25), amoxicillin: 23% (95%CI: 0.15–0.30), ciprofloxacin: 12% (95%CI: 0.04–0.23), levofloxacin: 34% (95%CI: 0.22–0.47), and furazolidone: 14% (95%CI: 0.06–0.22). Subgroup analysis showed antibiotic resistances were more prevalent in Pakistan, India, and Bangladesh. Furthermore, a ten-year trend analysis showed the increasing resistance prevalence for clarithromycin (21% to 30%), ciprofloxacin (3% to 16%), and tetracycline (5% to 20%) from 2003 to 2022. Conclusion: This meta-analysis showed a high prevalence of resistance among the commonly used antibiotics for H. pylori in South Asian countries. Furthermore, antibiotic resistance has been increasing over the time of 20 years. In order to tackle this situation, a robust surveillance system, and strict adherence to antibiotic stewardship are required.

Development and evaluation of a simple PCR assay and nested PCR for rapid detection of clarithromycin-resistant Helicobacter pylori from culture and directly from the biopsy samples in India

BACKGROUND

Eradication of Helicobacter pylori provides the most effective treatment for gastroduodenal diseases caused by H. pylori infection. Clarithromycin, a member of the macrolide family, still remains the most important antibiotic used in H. pylori eradication treatment. But the increasing prevalence of clarithromycin resistant H. pylori strains due to point mutations in the V region of the 23S rRNA, poses a great threat in treating the ailing patients. So, we aimed for PCR-mediated rapid detection of the point mutation at 2143 position of 23S rRNA gene in H. pylori that is relevant to clarithromycin resistance from culture and simultaneously from biopsy specimens to avoid the empirical treatment.

RESULTS

Newly developed PCR assay using DNA of pure culture detected point mutation in 23S rRNA gene in 21 (8.04%) of 261 clinical strains tested. The agar dilution method showed that all these 21 strains were resistant to clarithromycin indicating the perfect match of the PCR based results. Additionally, the sequencing study also identified the A to G mutation at 2143 position in 23S rRNA gene of the resistant strains only. Consequently, the newly developed Nested-ASP-PCR dealing directly with 50 biopsy specimens demonstrated 100% sensitivity and specificity with the findings of agar dilution method taken as Gold standard. Bioinformatics based analysis such as accessibility analysis and dot plot clearly stated that the base pairing probability has increased due to mutation. Computational studies revealed that the point mutation confers more stability in secondary structure due to conversion of loop to stem. Furthermore, interaction studies showed binding affinity of the CLR to the mutant type is weaker than that to the wild type.

CONCLUSION

This assay outlines a rapid, sensitive and simple approach to identify point mutation that confers clarithromycin resistance as well as clarithromycin sensitive strains, providing rapid initiation of effective antibiotic treatment. Additionally, it is simple to adopt for hospital based diagnostic laboratories to evaluate the degree of regional clarithromycin resistance from biopsy specimens itself. Furthermore, in silico studies provide evidence or a signal that the prevalence of clarithromycin resistance may rise in the near future as a result of this point mutation.

Region-specific genomic signatures of multidrug-resistant Helicobacter pylori isolated from East and South India

Helicobacter pylori is a ubiquitous bacterium and contributes significantly to the burden of chronic gastritis, peptic ulcers, and gastric cancer across the world. Adaptive phenotypes and virulence factors in H. pylori are heterogeneous and dynamic. However, limited information is available about the molecular nature of antimicrobial resistance phenotypes and virulence factors of H. pylori strains circulating in India. In the present study, we analyzed the whole genome sequences of 143 H. pylori strains, of which 32 are isolated from two different regions (eastern and southern) of India. Genomic repertoires of individual strains show distinct region-specific signatures. We observed lower resistance phenotypes and genotypes in the East Indian (Kolkata) H. pylori isolates against amoxicillin and furazolidone antibiotics, whereas higher resistance phenotypes to metronidazole and clarithromycin. Also, at molecular level, a greater number of AMR genes were observed in the east Indian H. pylori isolates as compared to the southern Indian isolates. From our findings, we suggest that metronidazole and clarithromycin antibiotics should be used judicially in the eastern India. However, no horizontally acquired antimicrobial resistance gene was observed in the current H. pylori strains. The comparative genome analysis shows that the number of genes involved in virulence, disease and resistance of H. pylori isolated from two different regions of India is significantly different. Single-nucleotide polymorphisms (SNPs) based phylogenetic analysis distinguished H. pylori strains into different clades according to their geographical locations. Conditionally beneficial functions including antibiotic resistance phenotypes that are linked with faster evolution rates in the Indian isolates.

Ten-day concomitant and sequential therapy for Helicobacter pylori effective in region with high antibiotic resistance rates

BACKGROUND

Increasing antibiotic-resistant Helicobacter pylori (H. pylori) strains complicate efforts to eradicate infection. In regions with high dual resistance to both clarithromycin and metronidazole, bismuth quadruple therapy is recommended. But, with lack of easy availability of bismuth, the (non-bismuth) concomitant and sequential regimens are used commonly as first-line therapy. Recent reports indicate suboptimal results with sequential therapy in such regions. We aimed to compare the efficacy of concomitant therapy vs. sequential therapy in the eradication of H. pylori in a region with high antibiotic resistance rates, and to compare adherence rates and adverse events with the regimens.

METHODS

One hundred and twenty-four consecutive H. pylori-infected patients (diagnosed using rapid urease test or urea breath test) were randomized to receive sequential or concomitant therapy for 10 days each. Four weeks after treatment completion, urea breath test was done to confirm eradication of the infection. Cure rates were compared between the two regimens and note was made of adherence rates and adverse events.

RESULTS

Concomitant therapy showed a statistically non-significant higher cure rate compared to sequential therapy in intention-to-treat (87.1% vs. 81.4%%, p = 0.46) and per-protocol (94.7% vs. 83.9%, p = 0.07) analyses. Both the regimens were well tolerated and showed similar adherence rates (p = 1.00) and incidence of adverse events (p = 0.44).

CONCLUSION

In a region with high dual resistance, both concomitant and sequential therapy for H. pylori infection achieved eradication rates >80%, but concomitant therapy showed a statistically non-significant higher cure rate, with similar adherence and adverse event profiles.

“Helicobacter pylori treatment guideline: An Indian perspective”: Letter to the editor

Treatment guidelines in many countries for Helicobacter pylori (H. pylori) may differ. Owing to the various characteristics of bacteria, clinical manifestations, resistance to antibiotics and recurrence rate, treatment regimens may change. In this letter, we would like to give an Indian perspective on H. pylori treatment guidelines.

Molecular Docking of Anti Helicobacter pylori Antibiotics and Proton Pump Inhibitor: A Single Center Survey

Helicobacter pylorus (H. pylori) is a deadly bacterium responsible for significant worldwide Gastric Cancer (GC) related mortality. The present study aimed to screen all the anti-microbial drugs used to eradicate H .pylori infection and to identify the most efficient drug by using computational methods through molecular docking analysis. The 3-D structure of protein chorismate synthase of H. pylori was downloaded from the Protein data bank (PDB) online browser. The x-ray crystallography structures of 13 common drugs used against H.pylori infection were also downloaded from the drug bank. We screened all 13 common drugs through molecular docking to know the most efficient binding interaction between the diverse ligand-protein complexes. The results were further compared with clinical survey data from the patients with diverse gastrointestinal H. pylori infected cases. Among the screened compounds, by in-silico approach we found that fluoroquinolone (FLRQ) and tetracycline (TET) manifested more significant interactions with chorismate synthase (CS) protein along with binding energies of -9.2 and -8.1 kcal/mole respectively. Further, the drugs were also corroborated with the survey data from patients with varied gastrointestinal disorders in our study. With this computational study, we could find FLRQ and TET may be the most efficient drug for H. pylori treatment, which can be tried in case of anti H. Pylori treatment failure due to resistance. Hence, effective inter-analysis between the experimental and computational approaches is crucial to build up a strong inhibitor.

Management of Helicobacter pylori infection: The Bhubaneswar Consensus Report of the Indian Society of Gastroenterology

The Indian Society of Gastroenterology (ISG) felt the need to organize a consensus on Helicobacter pylori (H. pylori) infection and to update the current management of H. pylori infection; hence, ISG constituted the ISG's Task Force on Helicobacter pylori. The Task Force on H. pylori undertook an exercise to produce consensus statements on H. pylori infection. Twenty-five experts from different parts of India, including gastroenterologists, pathologists, surgeons, epidemiologists, pediatricians, and microbiologists participated in the meeting. The participants were allocated to one of following sections for the meeting: Epidemiology of H. pylori infection in India and H. pylori associated conditions; diagnosis; treatment and retreatment; H. pylori and gastric cancer, and H. pylori prevention/public health. Each group reviewed all published literature on H. pylori infection with special reference to the Indian scenario and prepared appropriate statements on different aspects for voting and consensus development. This consensus, which was produced through a modified Delphi process including two rounds of face-to-face meetings, reflects our current understanding and recommendations for the diagnosis and management of H. pylori infection. These consensus should serve as a reference for not only guiding treatment of H. pylori infection but also to guide future research on the subject.

A Mouse Model of Helicobacter pylori Infection

Infection with Helicobacter pylori (H. pylori) is of great distress because of its vital role in the pathogenesis of chronic gastritis, peptic ulcers, and in the multi-step carcinogenic process of gastric cancer. The increasing antibiotic resistance pattern of H. pylori worldwide has prompted the World Health Organization to put this organism in the priority pathogens list. To study the disease biology, evaluation of drugs, treatment outcome and to come up with probable vaccination strategies, competent animal models that reproduce the signature of human infection are essential. Initial reports about animal colonization with H. pylori have shown significant heterogeneity, to such an extent that Barry Marshall, Nobel laureate for the discovery of H. pylori , infected himself with the bacterium to show its involvement in acute gastric illness. A paradigm-shift discovery of the H. pylori mouse-adapted strain SS1 has opened the avenues of research regarding the organism and its pathogenicity. Although the mouse model of H. pylori infection is being utilized all over the world, there are certain issues that need awareness and specific information to achieve successful, consistent colonization with symptoms resembling human. This chapter details an established and reliable protocol for the development of a competent mouse model for H. pylori infection leading to various gastro-intestinal diseases.

Oral rinses in growth inhibition and treatment of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H. pylori) is well-known for its role in chronic gastritis and gastric cancer. Eradication of these carcinogenic bacteria from the gut is one of the challenges for clinicians. The complexity of treatment mainly owes to antibiotic resistance and relapse due to an additional reservoir in the oral cavity. Our study emphases the isolation of H. pylori from distinct habitats of the gut microenvironment (gastric biopsy and gastric juice) and its subsequent characterization. We have also evaluated the effect of various oral rinses on isolated H. pylori from different anatomical locations of included subjects.

RESULTS

The possible strains isolated from two different habitats of the same subject shows a striking difference in their growth pattern. Promisingly, some of the included oral rinses are efficient in growth inhibition as per recommended 30 s treatment. The subsequent evaluation shows that oral rinse B (among A-E) is most effective and down-regulates the expression of one of the potent H. pylori gene, CagA, in the infected gastric adenocarcinoma (AGS) cells.

CONCLUSION

Our study, for the first time, revealed that H. pylori, isolated from the different habitat of the same subject, show a different growth pattern. The expression of H. pylori pathogenic gene (CagA) was down-regulated by the use of oral rinses. Hence, oral rinses will reduce the H. pylori in the oral cavity and help to control its migration from oral to the gastric compartment and may be used as an adjuvant treatment option for its re-infection.

Antimicrobial activity of ellagic acid against Helicobacter pylori isolates from India and during infections in mice

Objectives

Because of the rise in antimicrobial resistance, an inexpensive, diet-based treatment against Helicobacter pylori infection would be of great interest. The present study was performed to assess the in vitro effects of ellagic acid against clinical H. pylori strains that were resistant to antibiotics used for therapy and also to observe the morphological structure following treatment with ellagic acid. The effectiveness of ellagic acid in eradicating H. pylori infection in a murine (C57BL/6) infection model, one of the standard inbred mouse lines often used for experimental infection, was also assessed.

Methods

A total of 55 strains were screened. The agar dilution method was used to determine the susceptibility of isolates to test compounds. Transmission electron microscopy was used to observe the morphology following treatment with ellagic acid. The antibacterial activity of ellagic acid in an H. pylori SS1-infected mouse model and its effect on gastric mucosal injury were determined by histology and PCR.

Results

Ellagic acid inhibited the growth of all 55 of the H. pylori strains tested. The MIC of ellagic acid ranged from 5 to 30 mg/L, showing its bactericidal properties in vitro. Ellagic acid also demonstrated anti-H. pylori efficacy in eradication of this organism in an in vivo model, as well as restitution and repair of H. pylori-induced gastric mucosal damage.

Conclusions

The present study paves the way for the preventive and therapeutic use of ellagic acid against H. pylori infection and, thus, ellagic acid can be considered a promising antibacterial agent against H. pylori-associated gastroduodenal diseases in humans.

High primary resistance to metronidazole and levofloxacin, and a moderate resistance to clarithromycin in Helicobacter pylori isolated from Karnataka patients

Background

Due to increased prevalence of H. pylori antimicrobial resistance worldwide and more importantly the resistance patterns vary between different geographical regions, it is important to survey local H. pylori antibiotic resistance profile to provide physicians with more informed drug choices to better treat H. pylori infection. To our knowledge, this is the first study to examine the prevalence of antimicrobial resistance of H. pylori in Karnataka state of South India.

Results

A total of 113 H. pylori strains were isolated from gastric biopsies and tested: 81.4% were resistant to metronidazole, 54.9% were resistant to levofloxacin, 20.4% were resistant to clarithromycin, 5.3% were resistant to tetracycline and 7.1% were resistant to amoxicillin. Multidrug resistance was detected in 59.3% of total isolated strains, among which 86.6% were resistant to at least both metronidazole and levofloxacin. In this study, 38 out of 113 H. pylori strains had been whole-genome sequenced. Based on the draft genomes, RdxA and/or FrxA inactivation mutations were found to present in 75% of metronidazole-resistant strains. Clarithromycin-resistant strains had mainly A2143G and G2224A mutations in the 23 rRNA gene. While 87.1% levofloxacin-resistant strains had amino acid substitution mutations occurring predominantly at N87 and D91 in GyrA, novel mutations in the same protein including an insertion of five amino acid residues (QDNSV), immediately after the start codon, and a substitution mutation at R295 were identified.

Conclusion

High primary resistance to metronidazole and levofloxacin, and a modest occurrence of clarithromycin resistance were revealed in H. pylori strains isolated from Karnataka patients. Therefore metronidazole-, levofloxacin- and clarithromycin-based triple therapies are not suitable as first-line treatment in Karnataka. Both amoxicillin and tetracycline can still be used to eradicate H. pylori infection in this region. We also revealed novel mutations in GyrA protein that possibly contribute to H. pylori resistance in levofloxacin, which merit further investigations.

Low prevalence of clarithromycin-resistant Helicobacter pylori isolates with A2143G point mutation in the 23S rRNA gene in North India. J Glob Antimicrob Resist. 2016;6:39-43. [PMID: 27530837 DOI: 10.1016/j.jgar.2016.02.007]

Resistance of Helicobacter pylori to clarithromycin is associated with a single base substitution in the 23S rRNA gene. In this study, clarithromycin-resistant H. pylori isolates were analysed for the presence of 23S rRNA gene mutations. H. pylori were isolated from 68 patients suffering from various gastroduodenal diseases in North India. Minimum inhibitory concentrations (MICs) were determined by the agar dilution method, and point mutations in clarithromycin-resistant strains were identified by PCR-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing. Clarithromycin resistance was observed in 11.8% (8/68) of the H. pylori isolates in North India. The A2143G point mutation in the 23S rRNA gene was found in 87.5% (7/8) of the clarithromycin-resistant strains, and the A2142G mutation in association with the T2182C mutation was found in 12.5% (1/8). In conclusion, the continued high prevalence of clarithromycin-sensitive H. pylori strains (88.2%) observed in this study allows the use of the triple-therapy regimen for the treatment of H. pylori infection in this region. Surveillance studies need to be conducted at regular intervals for clarithromycin resistance in the population. To our knowledge, this is the first study in India to report that point mutations at position A2143G and at A2142G in association with T2182C are associated with clarithromycin resistance, confirming reports from other parts of the world.

Antimicrobial susceptibility profiles of Helicobacter pylori isolated from patients in North India

Helicobacter pylori-related gastroduodenal diseases are very common in India. Antibiotic resistance to commonly used antibiotics against H. pylori is increasing very rapidly. The aim of this study was to determine the antimicrobial susceptibility patterns of H. pylori strains from India against commonly used antibiotics in H. pylori treatment. Helicobacter pylori were cultured from 68 patients suffering from various gastroduodenal diseases in North India. Minimum inhibitory concentrations (MICs) to different antibiotics were determined by agar dilution. The clinical diagnosis of the 68 patients who were H. pylori culture-positive were gastro-oesophageal reflux disease (GERD) (n=23), non-erosive reflux disease (NERD) (n=22), non-ulcer dyspepsia (NUD) (n=13), antral gastritis (n=3), duodenal ulcer (n=2) and others (n=5). Of the 68 H. pylori isolates, 20 (29.4%) showed no resistance. The prevalence of drug resistance was 70.6%, including resistance to metronidazole (48.5%), furazolidone (22.1%), amoxicillin (17.6%), tetracycline (16.2%) and clarithromycin (11.8%). Dual and multiple drug resistance were found in 26.5% and 8.8% of cases, respectively. In conclusion, more than two-thirds of the isolated H. pylori strains showed resistance to at least one of the antibiotics for H. pylori treatment. Metronidazole resistance was most prevalent amongst the isolates tested. Emergence of dual and multidrug resistance is of great concern and there is an urgent need for regular antibiotic resistance surveillance studies. Amoxicillin- and clarithromycin-based anti-H. pylori regimens commonly prescribed for triple therapy in India show least resistance and hence are appropriate for anti-H. pylori management in India.

Emerging antimicrobial resistance pattern of Helicobacter pylori in central Gujarat

BACKGROUND

Antimicrobial resistance is a growing problem in H. pylori treatment. The study was intended to evaluate the prevalence of resistance amongst 80 H.pylori isolates cultured from biopsy taken during routine endoscopies in 2008-2011.

MATERIALS AND METHODS

855 gastro duodenal biopsies were collected and cultured on H.pylori selective medium (containing Brucella agar and Columbia agar (Hi media), with Skirrow's supplement (antibiotic supplement) and 7% human blood cells). H.pylori was isolated from 80 specimens. The antimicrobial susceptibility of H.pylori isolates was carried out by the Kirby Bauer technique against metronidazole (5 µg), clarithromycin (15 µg), ciprofloxacin (5 µg), amoxicillin (10 µg), tetracycline (30 µg), erythromycin (15 µg), levofloxacin (5 µg), and furazolidone (50 µg) (Sigma- Aldrich, MO).

RESULTS

83.8% isolates were resistant to metronidazole, 58.8% were resistant to Clarithromycin 72.5% were resistant to Amoxicillin, 50% to Ciprofloxacin and 53.8% to tetracycline. furazolidone, erythromycin and Levofloxacin showed only 13.8% resistance to H.pylori. Multi drug resistance with metronidazole+clarithromycin+tetracycline was 85%. For all the drugs Antimicrobial resistance rate was found higher in males compare to females. Metronidazole and amoxicillin resistance was found noteworthy in patients with duodenal ulcer (p=0.018), gastritis (P=0.00), and in reflux esophagitis (P=0.00). clarithromycin and tetracycline resistance was suggestively linked with duodenitis (P=0.018), while furazolidone, erythromycin and levofloxacin showed excellent sensitivity in patients with duodenitis (P value--0.018), gastritis (P=0.00) and reflux esophagitis (P=0.00). Resistance with metronidazole (P=0.481), clarithromycin (P=0.261), amoxicillin (P=0.276), tetracycline (P=0.356), ciprofloxacin (P=0.164) was not correlated well with Age-group and Gender of the patients.

CONCLUSION

A very high percentage of patients were infected with metronidazole and clarithromycin resistant strains. The use of antibiotics for other indications seems to be the major risk factor for the development of primary resistance. High incidence should alarm the gastroenterologist while prescribing the eradication regimen.

[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.

Clarithromycin-based triple therapy for treatment of peptic ulcer in Helicobacter pylori-positive children

AIM: To observe the clinical efficacy of triple therapy with clarithromycin, metronidazole and omeprazole in the treatment of Helicobacter pylori (H. pylori) infection-related peptic ulcer in children.

METHODS: A retrospective analysis of 96 children with peptic ulcer associated with H. pylori infection treated at our hospital from July 2011 to July 2013 was performed. Depending on the treatment, the patients were divided into either a treatment group or a control group (n = 48 for each). The treatment group received triple therapy with clarithromycin, metronidazole and omeprazole, while the control group was treated with amoxicillin, metronidazole and omeprazole. After treatment, children in both groups underwent gastroscopy and H. pylori examination to compare clinical efficacy, rate of H. pylori eradication and adverse reactions.

RESULTS: The clinical efficacy was better in the treatment group than in the control group. The overall effective rate was significantly higher in the treatment group than in the control group (95.83% vs 70.83%, P < 0.05). Five weeks after treatment, the rate of H. pylori eradication was significantly higher in the treatment group than in the control group (87.50% vs 62.5%, P < 0.05). There was no significant difference in the incidence of adverse reactions between the two groups.

CONCLUSION: Triple therapy with clarithromycin, metronidazole and omeprazole is associated with a higher rate of H. pylori eradication and a lower rate of adverse reactions in the treatment of H. pylori infection-associated peptic ulcer in children.

Sequential therapy versus standard triple-drug therapy for Helicobacter pylori eradication: a randomized study

BACKGROUND

Antimicrobial resistance has decreased eradication rates for Helicobacter pylori infection worldwide. A sequential treatment schedule has been reported to be effective, but studies published to date were performed in Italy. We undertook this study to determine whether these results could be replicated in India.

METHODS

A randomized, open-labeled, prospective controlled trial comparing sequential vs. standard triple-drug therapy was carried out at Lokmanya Tilak Municipal General Hospital, Mumbai. Two hundred and thirty-one patients with dyspepsia were randomized to a 10-day sequential regimen (40 mg of pantoprazole, 1 g of amoxicillin, each administered twice daily for the first 5 days, followed by 40 mg of pantoprazole, 500 mg of clarithromycin, and 500 mg of tinidazole, each administered twice daily for the remaining 5 days) or to standard 14-day therapy (40 mg of pantoprazole, 500 mg of clarithromycin, and 1 g of amoxicillin, each administered twice daily).

RESULTS

The eradication rate achieved with the sequential regimen was significantly greater than that obtained with the triple therapy. Per-protocol eradication rate of sequential therapy was 92.4% (95% CI 85.8-96.1%) vs. 81.8% (95% CI 73.9-87.8%) (p = 0.027) for standard drug therapy. Intention-to-treat eradication rates were 88.2% (95% CI 80.9-93.0%) vs. 79.1% (95% CI 71.1-85.4%), p = 0.029, respectively. The incidence of major and minor side effects between therapy groups was not significantly different (14.6% in the triple therapy group vs. 23.5% in sequential group, p = 0.12). Follow up was incomplete in 3.3% and 4.7% patients in standard and sequential therapy groups, respectively. Sequential therapy includes one additional antibiotic (tinidazole) that is not contained in standard therapy.

CONCLUSIONS

Sequential therapy was significantly better than standard therapy for eradicating H. pylori infection.

Guidelines for treatment of Helicobacter pylori in the East and West

Infection with Helicobacter pylori remains a major healthcare burden, with persistently high prevalence rates, especially in less-developed countries. H. pylori infection is causally related to non-malignant and malignant gastroduodenal diseases, such as peptic ulcer diseases, gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. Current international guidelines recommend a standard triple therapy as first-line therapy, including a proton pump inhibitor and a combination of amoxicillin and clarithromycin. Standard triple therapy has shown a decreasing efficacy over the years. The main reason is the increasing antibiotic resistance, particular to clarithromycin of H. pylori strains. Several new treatment options or modifications of already established regimens have been introduced to overcome treatment failure. In this article, we intend to report the reasons for treatment failure, and furthermore we give an overview of new treatment options as alternatives to the current treatment regimens. Finally, the strategy for the future is considered.

Furazolidone-based quadruple therapy as first-line treatment for Helicobacter pylori infection

AIM: To observe the rates of symptom remission, adverse reactions, and Helicobacter pylori (H. pylori) eradication of furazolidone-based quadruple therapy as first-line treatment for patients with H. pylori infection.

METHODS: One hundred and fifty-two patients who were diagnosed with H. pylori-positive chronic gastritis or duodenal ulcer were randomly divided into three groups: control group (esomeprazole + bismuth potassium critrate + amoxicillin + clarithromycin), 7-day furazolidone-based quadruple therapy group (esomeprazole + bismuth potassium critrate + amoxicillin + furazolidone), and 10-day furazolidone-based quadruple therapy group (esomeprazole + bismuth potassium critrate + amoxicillin + furazolidone). Patients were followed to observe symptom remission and adverse reactions. After at least 4 wk of treatment and 2 wk of non-use of PPIs, H. pylori status was assessed using the urea breath test. H. pylori eradication rate was assessed by PP and ITT analysis. Cost-effectiveness ratio and incremental cost-effectiveness ratio were used to evaluate the three treatments.

RESULTS: On PP analysis, the rates of H. pylori eradication in the three groups were 87.50%, 88.89% and 93.62%. On ITT analysis, the rates of H. pylori eradication in the three groups were 79.25%, 83.33% and 86.27%. There were no significant differences in the rates of H. pylori eradication among the three groups either on PP analysis or on ITT analysis. The rates of symptom remission and adverse reactions in the three groups also showed no significant difference (all P > 0.05). The cost-effectiveness ratios of the three groups were 3.69, 2.48 and 3.37. The incremental cost-effectiveness ratios of the 7-day and 10-day furazolidone-based quadruple therapy groups relative to the control group were -73.22 and -1.17.

CONCLUSION: Furazolidone-based quadruple therapy is associated with a high rate of H. pylori eradication and few slight side effects and can reduce the costs of quadruple treatment.

Efficacy and safety of sequential therapy versus standard triple therapy in Helicobacter pylori eradication in Kashmir India: a randomized comparative trial

BACKGROUND

Increasing resistance against Helicobacter pylori has resulted in reduced eradication rates.

OBJECTIVE

This study aims to determine whether eradication rates for H. pylori infection with sequential therapy is better than standard triple therapy.

PATIENTS

Patients with endoscopy documented peptic ulcer and H. pylori infection confirmed by histology and rapid urease test.

INTERVENTION

Patients were randomized into two groups; 134 received standard triple therapy (pantoprazole 40 mg, clarithromycin 500 mg and amoxicillin 1 g each administered twice daily) for 10 days and 138 received sequential regimen (pantoprazole 40 mg plus amoxicillin 1 g twice daily for 5 days followed by 40 mg pantoprazole, 500 mg clarithromycin, and 500 mg tinidazole each administered twice daily for 5 days). Eradication was confirmed by histology and rapid urease test. Compliance and adverse effects were determined by the recovery of empty medicine strips and questioning.

RESULTS

The eradication rates with sequential therapy were significantly greater than with standard therapy on both intention-to-treat analysis (76.0 % vs. 61.9 %, p = 0.005; difference, 14.1 % [95 % CI, 6.5-19 %] and per protocol analysis (84.6 % vs. 67.4 %, p = 0.002; difference, 17.2 % [95 % CI, 8.5-23.5 %]). The incidence of side effects did not differ between the two therapy groups. One patient in standard therapy discontinued treatment due to side effects.

LIMITATION

Cultures were not performed. Loss to follow up was 5.2 % in standard therapy and 6.5 % in sequential therapy.

CONCLUSION

Sequential therapy was significantly more effective than standard therapy for eradicating H. pylori infection in peptic ulcer disease in Asian patients. Side effects were similar.

Anti-Helicobacter pylori potential of artemisinin and its derivatives. Antimicrob Agents Chemother. 2012;56:4594-4607. [PMID: 22687518 DOI: 10.1128/aac.00407-12]

The antimalarial drug artemisinin from Artemisia annua demonstrated remarkably strong activity against Helicobacter pylori, the pathogen responsible for peptic ulcer diseases. In an effort to develop a novel antimicrobial chemotherapeutic agent containing such a sesquiterpene lactone endoperoxide, a series of analogues (2 natural and 15 semisynthetic molecules), including eight newly synthesized compounds, were investigated against clinical and standard strains of H. pylori. The antimicrobial spectrum against 10 H. pylori strains and a few other bacterial and fungal strains indicated specificity against the ulcer causing organism. Of five promising molecules, a newly synthesized ether derivative β-artecyclopropylmether was found to be the most potent compound, which exhibited MIC range, MIC(90), and minimum bactericidal concentration range values of 0.25 to 1.0 μg/ml, 1.0 μg/ml, and 1 to 16 μg/ml, respectively, against both resistant and sensitive strains of H. pylori. The molecule demonstrated strong bactericidal kinetics with extensive morphological degeneration, retained functional efficacy at stomach acidic pH unlike clarithromycin, did not elicit drug resistance unlike metronidazole, and imparted sensitivity to resistant strains. It is not cytotoxic and exhibits in vivo potentiality to reduce the H. pylori burden in a chronic infection model. Thus, β-artecyclopropylmether could be a lead candidate for anti-H. pylori therapeutics. Since the recurrence of gastroduodenal ulcers is believed to be mainly due to antibiotic resistance of the commensal organism H. pylori, development of a candidate drug from this finding is warranted.

Antimicrobial susceptibility of Helicobacter pylori strains isolated from patients in Shiraz, Southern Iran

AIM: To improve our understanding of Iranian regional variation in Helicobacter pylori (H. pylori) antibiotic resistance rates to find the best antibiotic therapy for eradication of H. pylori infections.

METHODS: A total of 266 patients undergoing endoscopy in Shiraz, Southern Iran, were included in this study. H. pylori strains were isolated from antral biopsies by culture and confirmed by the rapid urease-test and gram staining. Antibiotic susceptibility of H. pylori isolates was determined by E-test.

RESULTS: A total of 121 H. pylori strains were isolated, 50 from male and 71 from female patients. Data showed that 44% (n = 53), 20% (n = 24), 5% (n = 6), and 3% (n = 4) of all strains were resistant to the antibiotics metronidazole, amoxicillin, clarithromycin, and tetracycline, respectively. When the antibiotics were considered together we found 11 sensitivity patterns for the strains. Resistance to metronidazole was significantly higher in female than in male patients (P < 0.05). In about 71% of the metronidazole-resistant isolates, the minimum inhibitory concentrations (MICs) exceeded 256 μg/mL.

CONCLUSION: We found a moderate rate of primary resistance to metronidazole. However, a high MIC (> 256 mg/L) which was found in 71% of the isolates is considerable. In the case of amoxicillin, an increased resistance rate of 20% is worrying. Resistance to clarithromycin and tetracycline is also emerging among the H. pylori strains in our region.

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

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

Antimicrobial susceptibility and mutations involved in clarithromycin resistance in Helicobacter pylori isolates from patients in the western central region of Colombia

Resistance to metronidazole, clarithromycin, and amoxicillin (amoxicilline) was found in 82, 3.8, and 1.9% of 106 Helicobacter pylori isolates, respectively. No tetracycline-resistant isolates were found. In all of the clarithromycin-resistant isolates, only one point mutation was present, either A2143G or A2142G. Our results indicate that metronidazole should not be included in the empirical treatment of H. pylori infection in this region.

Antimicrobial activity of curcumin against Helicobacter pylori isolates from India and during infections in mice. Antimicrob Agents Chemother. 2009;53:1592-1597. [PMID: 19204190 DOI: 10.1128/aac.01242-08]

Treatment failure is a major cause of concern for the Helicobacter pylori-related gastroduodenal diseases like gastritis, peptic ulcer, and gastric cancer. Curcumin, diferuloylmethane from turmeric, has recently been shown to arrest H. pylori growth. The antibacterial activity of curcumin against 65 clinical isolates of H. pylori in vitro and during protection against H. pylori infection in vivo was examined. The MIC of curcumin ranges from 5 microg/ml to 50 microg/ml, showing its effectiveness in inhibiting H. pylori growth in vitro irrespective of the genetic makeup of the strains. The nucleotide sequences of the aroE genes, encoding shikimate dehydrogenase, against which curcumin seems to act as a noncompetitive inhibitor, from H. pylori strains presenting differential curcumin MICs showed that curcumin-mediated growth inhibition of Indian H. pylori strains may not be always dependent on the shikimate pathway. The antimicrobial effect of curcumin in H. pylori-infected C57BL/6 mice and its efficacy in reducing the gastric damage due to infection were examined histologically. Curcumin showed immense therapeutic potential against H. pylori infection as it was highly effective in eradication of H. pylori from infected mice as well as in restoration of H. pylori-induced gastric damage. This study provides novel insights into the therapeutic effect of curcumin against H. pylori infection, suggesting its potential as an alternative therapy, and opens the way for further studies on identification of novel antimicrobial targets of curcumin.

Antibiotic resistance of Helicobacter pylori

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

Nitrofuran-based regimens for the eradication of Helicobacter pylori infection

Several aspects of Helicobacter pylori eradication have been meta-analyzed; however, nitrofuran-based therapies constitute an exception. The aim of this study was the systematic review and meta-analysis of the effect of furazolidone- and nitrofurantoin-based regimens in the eradication of infection. Studies evaluating the effects of nitrofurans on H. pylori were identified from Medline, EMBASE, the Cochrane Controlled Trials Register and congress abstracts. The studies were classified into groups based on first-, second- and third-line regimens. The pooled eradication rates and combined odd ratios of the individual studies were calculated and compared with the published meta-analysis. The factors influencing the efficiency of the regimens were also analyzed. Side-effects of nitrofuran-based regimens were also analyzed. The pooled eradication rate of primary proton pump inhibitor-based regimens containing furazolidone was 76.3% (CI 67.8-84.2). The odds ratio for furazolidone-based regimens versus standard triple therapies was 2.34 (CI 0.76-3.92). Ranitidine bismuth citrate + furazolidone-based triple regimens were equally efficient (83.5%, CI 74.0-93.0, P = 0.06 versus triple therapies). Schedules including a H(2) antagonist + furazolidone + one other antibiotic achieved pooled eradication rates of 79.9% (CI 67.8-89.9, P = 0.04). Bismuth-based triple therapies achieved 84.5% (CI 72.6-93.0, P = 0.002). Primary quadruple regimens containing furazolidone were superior to triple therapies (83.4%, CI 69.7-92.3, P = 0.01). Second-line schedules containing furazolidone obtained eradication rates of 76.1% (CI 66.4-85.0, P = 0.28 versus primary regimens). Third-line 'rescue' therapies were efficient in 65.5% of the cases (CI 56.3-75.5, P = 0.0001). Side-effects of the regimens containing furazolidone were more frequent than in standard therapies (P = 0.02). The combined odds ratio of side-effects for furazolidone-based versus standard therapies was 0.74 (CI 0.32-1.98). The duration of treatment, but not the furazolidone dose, influenced the treatment outcome. Primary triple regimens containing furazolidone are slightly less efficient than the standard primary combinations; primary quadruple regimens were more efficient than triple therapies. Furazolidone is also efficient as a component of second-line or rescue therapies.

High prevalence and level of resistance to metronidazole, but lack of resistance to other antimicrobials in Helicobacter pylori, isolated from a multiracial population in Kuwait

BACKGROUND

The primary treatment regimen for Helicobacter pylori infection for Kuwaitis does not contain metronidazole, but that for expatriates does. There is also increasing failure of antimicrobial therapy.

AIM

To determine the susceptibility of H. pylori from upper gastrointestinal biopsies of Kuwaitis and non-Kuwaitis to find out if differences existed in the susceptibilities of the isolates from the two different populations.

METHODS

The susceptibilities of 96 H. pylori isolates were tested against metronidazole, amoxicillin, clarithromycin and tetracycline by the E test. The rdxA gene was analysed from selected metronidazole-susceptible and metronidazole-resistant strains to find out polymorphism and the basis of metronidazole resistance.

RESULTS

Approximately, 70% of isolates from both populations were metronidazole resistant with 65% isolates showing high minimum inhibitory concentration values of >256 mug/mL. No resistance to the other three antimicrobials was found. There were novel nonsense and missense mutations with no deletion in the rdxA gene by insertion of mini-IS605.

CONCLUSIONS

The prevalence and level of metronidazole resistance in H. pylori in the two populations was high with no difference, in spite of different treatment regimens. Metronidazole resistance in this transitional country appeared to be independent of prior metronidazole use for treatment of H. pylori infection.

Antibiotic Susceptibility of Helicobacter pylori Clinical Isolates: Comparative Evaluation of Disk-Diffusion and E-Test Methods

Antimicrobial susceptibility of 25 Helicobacter pylori strains isolated from patients with acid peptic diseases were tested for in vitro sensitivity to commonly used antibiotics using disk-diffusion and E-test, methods. All strains tested were susceptible to tetracycline by E-test, with the minimum inhibitory concentration (MIC) values being <0.125 microg/ml for all strains except for 6 (<0.023 microg/ml). However 1 strain was resistant by disk-diffusion method. One strain was resistant to clarithromycin both by disk diffusion and E-test (MIC <48 microg/ml), and 1 strain was resistant only by disk diffusion. Only one strain was resistant to amoxicillin by disk diffusion and E-test (MIC >256 microg/ml). For ciprofloxacin, three strains were resistant by disk diffusion and two by E-test (MIC <32 microg/ml). Sixteen strains were resistant to metronidazole by disk diffusion and E-test (MIC >or= 8 microg/ml), and 1 was resistant only by E-test (MIC <48 microg/ml). Overall, 64% of the strains were resistant to metronidazole. The MIC for metronidazole was also tested by agar-dilution method, and metronidazole resistant strains had an, MIC >8 microg/ml. The disk-diffusion method showed excellent correlation with E-test results; there was 100% agreement for amoxicillin a other antibiotics showed 90% to 95% accuracy. Disk diffusion is cheaper than E-test (approximately 2.6 cents vs. 2.60 US dollars), is easy to perform, and is a reliable method for testing H. pylori susceptibility to antimicrobial agents in the clinical microbiology laboratory.

Incidence of Helicobacter felis and the effect of coinfection with Helicobacter pylori on the gastric mucosa in the African population

Helicobacter pylori and Helicobacter felis are two of the Helicobacter spp. that infect humans. H. pylori has been linked to significant gastric pathology. Coinfection with Helicobacter spp. may influence infectious burden, pathogenesis, and antibiotic resistance; however, this has not been studied. The aims of this study were to identify the incidence of H. felis and to analyze the effects of coinfection with both organisms on gastric pathology in a well-characterized South African population. Biopsy samples from the gastric corpora and antra of volunteers (n = 90) were subjected to histological examination and PCR for the identification of H. pylori and H. felis. We further investigated the effect of global strain type on the occurrence of precursor lesions by assigning nucleotide sequences derived from PCR amplification of three genes to global groupings (ancestral Africa1, ancestral Africa2, ancestral Europe, ancestral Asia, and mixed). H. pylori was detected in 75 (83.3%), H. felis in 23 (25.6%), and coinfection in 21 (23.3%) of the volunteers by PCR. H. felis was randomly distributed among adults and children but clustered within families, suggesting intrafamilial transmission. Analysis of histopathology scores revealed no differences in atrophy, activity, and helicobacter density between H. felis-positive and H. felis-negative volunteers. H. pylori substrains common to southern Africa showed no differences in inflammation or atrophy scores. The incidences of H. felis and coinfection with H. pylori in the African population are high. H. felis infection, however, does not influence specific gastric pathology in this population.