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.

Dysbiosis of gut microbiota due to diet, alcohol intake, body mass index, and gastrointestinal diseases in India.

The human gut is composed of diverse microflora which is influenced by dietary intake. Body mass index (BMI) and lifestyle patterns also play a vital role in human health to alter gut microbial composition. Our study aims to determine the impact of alcohol intake, BMI, and diet on gut microbiota and its relationship with gastrointestinal disorders. Thirty-nine gastric biopsies were taken from patients with various gastrointestinal (GI) diseases, and all the patient's lifestyle behavior were recorded in a written proforma. 16S rRNA metagenome analysis for V3-V4 regions was used to examine microbial compositions. The richness and diversity of gut microbiota were analyzed by PERMANOVA using the Bray-Curtis dissimilarity index and principal component analysis. The difference in relative abundance was calculated by ANOVA (p < 0.05). Alpha diversity indexes between vegetarians and non-vegetarians showed no significant difference based on BMI, alcohol status, and GI diseases. We found that in overweight vegetarian individuals Faecalibacterium and Rumicococcus might play a role in the control of Helicobacter pylori. Similarly, the increased abundance of Akkermansia muciniphila in non-vegetarian individuals with normal BMI might play a role to decrease the level of harmful bacteria like H. pylori, and Corynebacterium sp. Also, the relative abundance of Corynebacterium sp. among the vegetarians and Streptococcus sp. in the non-vegetarians was increased in alcoholics while H. pylori was increased in non-alcoholics irrespective of diet. There is an increased abundance of Faecalibacterium prausnitzii in vegetarians among all categories; however, we did not find any correlation between disease outcomes. Our study shows that alcohol intake and dietary habits have independent effects on gut microbial composition. The relative abundance of F. prausnitzii was high among vegetarians in all categories. KEY POINTS: • The presence of H. pylori is less among alcoholics. • Good bacteria help to maintain a normal body mass index. • Gut microbiota richness is high in vegetarians and diversity in non-vegetarians.

Analysis of Functional Status of Genetically Diverse OipA Gene in Indian Patients with Distinct Gastrointestinal Disease.

Helicobacter pylori (H. pylori,) a genetically diversified bacteria which colonizes human gastric epithelium, is now established causative agent for gastric cancer worldwide. Outer membrane protein (OMP)-coding genes of H. pylori are responsible for attachment and colonization of bacteria. These genes which code proteins on outer membrane of H. pylori is a group of 33 genes which with other virulent genes are causative of giving rise to disease-causing factors in the host. OipA (Outer inflammatory protein A), a participant of Hop family of OMP, is effective in acting as a biomarker for studying progression of diseases like gastric cancer. The functionality of oipA gene is regulated by phase variation within CT repeat pattern. It is the expression, i.e., "on"/"off" of oipA gene which is related with the development of distinct gastric diseases. 40 amplified DNA sequences were studied to investigate functional status of oipA. Our results reveal 57.2% isolates with functional oipA along with significant association with cagA (P = 0.0011) and vacAs1m1/s1m2 (P = 0.0034, P = 0.0093) genotypes, respectively. In conclusion, our results indicate diversity in CT repeat pattern among Indian H. pylori strains. The prevalence of functional oipA gene was found to be ranging between 50% and 64.2% though it did not show significant correlation between functional oipA and disease outcome.

The Synergistic Role of Tip α, Nucleolin and Ras in Helicobacter pylori Infection Regulates the Cell Fate Towards Inflammation or Apoptosis.

Infection with Helicobacter pylori (H. pylori) leads to a fork in the road situation where it is critical and complex to judge the fate of the cell. We propose for the first time an in silico representation of a protein level network model that can unfold the mystery behind the cell fate decision between inflammation or cell proliferation or cell death. Upon infection TNF inducible protein α (Tip α) is internalised after binding with the cell surface receptor Nucleolin which is overexpressed on the cell surface thereby activating the Ras pathway. Tip α, Nucleolin and Ras decides the cell fate for apoptosis or abnormal cell proliferation along with ulcers in the gastric tract, hence we term it as the "death triad", which otherwise triggers the inflammatory pathway through downstream signalling of NF-κß. A series of proteins involved in the signalling cascade are portrayed through compartmentalization of the bacteria and the gut wall. The depicted network works synchronously toward an overarching goal of deciding between apoptosis or inflammation or proliferation. The model has been validated by simulating it with existing transcriptomic data along with clinical findings from patients infected with H. pylori across different regions in India. The results clearly indicate that for a short period of time there is increased binding of Tip α to Nucleolin and the receptor starts to saturate. This increases the tenacity of binding and the cell triggers an inflammatory cascade reaction which involves proinflammatory cytokines such as TNF α thereby progressing to inflammation by activating NF-κß downstream. On the other hand, Ras involved in interaction with nucleolin can be present both in its activated or inactivated state. Binding of Tip α as a monomer leads to desensitization of Nucleolin leading to cell survival and proliferation.

Rapid Electrochemical Monitoring of Bacterial Respiration for Gram-Positive and Gram-Negative Microbes: Potential Application in Antimicrobial Susceptibility Testing.

Antimicrobial resistance is a grave threat to human life. Currently used time-consuming antibiotic susceptibility test (AST) methods limit physicians in selecting proper antibiotics. Hence, we developed a rapid AST using electroanalysis with a 15 min assay time, called EAST, which is live-monitored by time-lapse microscopy video. The present work reports systematical electrochemical analysis and standardization of protocol for EAST measurement. The proposed EAST is successfully applied for Gram-positive Bacillus subtilis and Gram-negative Escherichia coli as model organisms to monitor bacterial concentration, decay kinetics in the presence of various antibiotics (ciprofloxacin, cefixime, and amoxycillin), drug efficacy, and IC50. Bacterial decay kinetics in the presence of antibiotics were validated by the colony counting method, field emission scanning electron microscopy, and atomic force microscopy image analysis. The EAST predicts the antibiotic susceptibility of bacteria within 15 min, which is a significant advantage over existing techniques that consume hours to days. The EAST was explored further by using bacteria-friendly l-lysine-functionalized cerium oxide nanoparticle coated indium tin oxide as a working electrode to observe the enhanced electron-transfer rate in the EAST. The results are very significant for future miniaturization and automation. The proposed EAST has huge potential in the development of a rapid AST device for applications in the clinical and pharmaceutical industries.

Clinical and Optical Coherence Tomography Correlation of Recurrence Patterns After Femtosecond Laser-Assisted Anterior Lamellar Keratoplasty in Reis-Bucklers Corneal Dystrophy.

PURPOSE: The aim of this study was to report the clinical profile and patterns of recurrence after femtosecond laser-assisted anterior lamellar keratoplasty (FALK) in Reis-Bucklers corneal dystrophy. METHODS: This is a case series of 5 eyes of 4 patients with Reis-Bucklers corneal dystrophy. Clinical images of recurrence were correlated with the high-resolution optical coherence tomography. Histopathologic examination of excised corneal samples was performed when possible. RESULTS: The median time to recurrence was 2 (1-5) years after FALK. Of the 5 eyes, 1 eye had primary FALK, whereas 4 eyes had secondary interventions, which included previous phototherapeutic keratectomy (once in 1 eye and twice in 2 eyes), and previous penetrating keratoplasty, followed by phototherapeutic keratectomy (1 eye). Recurrence was noted at the level of the subepithelium. In addition, 1 eye showed interface deposits along with epithelial downgrowth at the graft-host bed. CONCLUSIONS: The 2 distinct patterns of recurrence noted were at the subepithelial region and the interface. The clinical patterns of recurrence favor an epithelial origin of recurrent deposits.

Alteration of gastric microbiota in Helicobacter pylori-infected individuals suffering from GERD, DU, and gastritis.

BACKGROUND/AIM: Helicobacter pylori (H. pylori) colonization affects the gastric microbiome, causing gastrointestinal (GI) diseases. Modern sequencing technology provides insights into GI microbe interaction with H. pylori and their metabolic pathways in causing GI diseases. We aim to compare the gastric microbiota alteration due to H. pylori infection in patients suffering from GI diseases. MATERIALS AND METHODS: Genomic DNA were isolated from gastric antrum tissue from 37 H.pylori-infected patients diagnosed with GERD, duodenal ulcers, and gastritis. We conducted the genomic library preparation and sequencing of the amplified product using 16S rRNA NGS analysis. Using microbiome analyst tool diversity analysis, random forest analysis and ANOVA were conducted to find out the comparison of microbial abundance. We have also conducted functional pathway prediction analysis using PICRUSt. RESULTS: Metagenomic analysis shows high bacterial diversity in H. pylori-positive gastritis patients. Streptococcus infantis and Neisseria subflava were significantly higher in duodenal ulcer (DU) and gastritis groups. Acinetobacter lwoffii and Helicobacter pullorum were significantly high in the gastritis group only. The functional metabolic pathway analyses revealed that gastroesophageal reflux disease (GERD) samples were significantly enriched with the energy metabolism and xenobiotic biodegradation and metabolism pathways, whereas fructose-1,6-bisphosphatase III was found less in gastritis and DU groups. CONCLUSION: There is a difference in microbiota composition in different disease outcomes. We found positive association between microbial diversity and H. pylori in gastritis group only, whereas negative association was found in DU and GERD groups. The functional metabolic pathway analysis revealed significant differences in various disease outcomes.

High prevalence of cagA positive Vac A s1m1 Helicobacter pylori strains isolated from patients suffering from various gastroduodenal diseases in Guwahati, Assam, India.

AIM AND BACKGROUND: Genotyping of H. pylori strains was identified on formalin-fixed paraffin wax-embedded tissue (FFPE) sections and correlated with severity grades of gastric mucosal pathologies in biopsies from upper gastrointestinal (UGI) tract from Guwahati, Assam. MATERIALS AND METHODS: In total, 168 gastric biopsies collected from patients with UGI symptoms underwent histological evaluation as per the updated Sydney system. RESULT: H. pylori-like organisms were identified with Warthin and Starry stain, and virulent genes were amplified using polymerase chain reaction (PCR) from genomic DNA extracted from FFPE sections by using QIAamp® DNA FFPE Tissue Kit. Histological examination identified H. pylori-like organisms in 100 biopsies, of which 96 were urease + ve. The prevalence of H. pylori infection was high in age groups 71-80 (88.8%) as compared to other age groups, and it was higher in females (78.9%) when compared to males. The prevalence of virulent genes in biopsies was 88.5% cagA and vacA s1m1, 31.2% iceA1, 32.2% iceA2, and 85.2% babA2. The histological parameters mononuclear cell infiltrate (P = 0.04) and atrophy (P = 0.03), showed statistically significant association with iceA2 and intestinal metaplasia with cagA (P = 0.01) vacAs1m1 (P = 0.01) and babA (P = 0.02) genotypes. Gastric erosion due to H. pylori infection and atrophy showed a significant association. A high bacterial density score was seen with the virulent genotypes. CONCLUSION: Our work reports for the first time a high prevalence (88.5%) of H. pylori cagA vacA s1m1 genotype in Guwahati, Assam. Association of gastric atrophy and intestinal metaplasia was seen with virulent genotypes. Results show the effectiveness of the FFPE kit for DNA extraction in remote areas where transportation and storage of biopsies are otherwise difficult.

Molecular characterization and phylogenetic analysis of babA gene of Helicobacter pylori isolated from Indian patients with gastrointestinal diseases.

INTRODUCTION: Outer membrane protein (OMP) of Helicobacter pylori (H. pylori) i.e., blood group antigen binding adhesin (babA) is responsible for the attachment of H. pylori in the gastric epithelium. Its adherence is causative for gastric pathology such as gastritis, peptic ulcer disease (PUD), or digestive tract disorders like erosive reflux disease (ERD) and (NERD) non-erosive reflux disease and together called Gastroesophageal reflux disease (GERD). BabA manifests rapid and varied selection via substitution of amino acid in its Leb-carbohydrate binding domain (CBD) which enables better binding preferences for distinct human populations and ABO blood group phenotypes. The positive evolutionary selection of the pathogenic factor of this genetically diverse bacterium has enabled it to adapt to the host gastric environment. Analyzing the association of virulent genes (cagA, vacA) and babA will help us better understand bacteria's pathogenicity. METHOD: 109 H. pylori strains from patients with distinct gastrointestinal diseases were genotyped using Polymerase Chain Reaction(PCR) for cagA, vacA, and babA followed by Sanger sequencing and phylogenetic analysis. RESULT: In the babA + ve genotype, a statistically significant association with p = 0.04 and < 0.0001 is seen in gastritis and ERD respectively. A significant association of genotype vacAs1m2 (p = 0.0002) was seen in gastritis, vacAs1m1 (p = 0.02) in NERD, vacAs1m1 (p < 0.0001) and vacAs1m2 (p = 0.002) in ERD. This relationship helps to detect gastritis or ERD where BabA gene can be used as an independent marker for detecting their presence. CONCLUSION: The appearance of variants within distinct disease categories is due to local genetic variation.

Crosstalk between Helicobacter pylori and gastrointestinal microbiota in various gastroduodenal diseases-A systematic review.

Gastroduodenal diseases have prevailed for a long time and more so due to dominance of gut bacteria Helicobacter pylori in most of the cases. But habitation by other gut microbiota in gastroduodenal diseases and the relationship between Helicobacter pylori and gastrointestinal microbiota in different gastroduodenal diseases is somewhat being unravelled in the current times. For this systematic review, we did a literature search of various gastroduodenal diseases and the effect on gut microbiota pertaining to it. A search of the online bibliographic databases PUBMED and PUBMED CENTRAL was carried out to identify articles published between 1977 and May 2022. The analysis of these selected studies highlighted the inhabitation of other gut microbiota such as Fusobacteria, Bacteroidetes, Streptococcaceae, Prevotellaceae, Fusobacteriaceae, and many others. Interplay between these microbiota and H. pylori have also been noted which suggested that gastroduodenal diseases and gut microbiota are intertwined by a symbiotic association regardless of the H. pylori status. The relationship between the gut microbiota and many gastroduodenal diseases, such as gastritis, gastric cancer, lymphomas, and ulcers, demonstrates the dysbiosis of the gut microbiota in both the presence and absence of H. pylori. The evolving ways for eliminating H. pylori are provided along with inhibiting qualities of other species on H. pylori. Most significant member of our gut system is Helicobacter pylori which has been associated with numerous diseases like gastric cancer, gastritis, duodenal ulcer.

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.

Correlation of Helicobacter pylori virulence genotype & severity of mucosal inflammation in gastric biopsies from two geographically diverse regions in India.

Background: H. pylori-associated gastritis in patients from the high-altitude area of Ladakh showed severe gastritis, mucosal nodularity, atrophy, and cancer in comparison to those from North India. This study served to analyze if differences in the H. pylori virulence genotypes decide the extent of gastric mucosal inflammation. Methods: Fifty gastric biopsies each from patients with H. pylori-associated gastritis from Ladakh and a tertiary care center in North India were included. The presence of H. pylori strain was confirmed with Warthin starry stain and polymerase chain amplification of the H. pylori-specific 16S rRNA. The cagA, vacA s1, s2, and m1, m2 alleles, and dupA virulence genotypes were studied in all archival samples, followed by their histological correlations. Results: cagA (P 0.009) and vacAs1 m1 (P 0.009) genes were distinctly more in H. pylori strains colonizing the biopsies of North Indian patients. In contrast, the cagA -ve vacAs2 m2 strains were significantly more in H. pylori strain colonizing the biopsies from Ladakhi patients. dupA genotype was almost similarly present in strains from both regions. Among these, only cagA and dupA virulence genes were associated with severe mucosal neutrophilic activity and deep infiltration of H. pylori strains in North Indian patients. Conclusions: Differences in virulence genotypes of H. pylori in gastric biopsies from North Indian and Ladakhi patients were found not significant in deciding the severity of H. pylori-associated gastritis.

Prevalence of tumor necrosis factor alpha inducing protein (tipα) gene of Helicobacter pylori and its association with upper gastrointestinal diseases in India.

Helicobacter pylori (H. pylori) is known to cause several gastroduodenal diseases including chronic Gastritis, Peptic Ulcer disease and Gastric Cancer. Virulent genes of H. pylori like cagA, vacA are known to be responsible for the disease pathogenesis. However, these virulence genes are not always found to be associated with disease outcome in all populations around the world. Tumor necrosis factor alpha inducing protein tipα is a newly discovered virulence gene of H. pylori and is an inducer of certain cytokines and chemokines that are responsible for causing stomach cancer. Therefore, we conducted a study, which aims to find the prevalence of tipα gene in the Indian patients with gastroduodenal symptoms, and its association with H. pylori related gastroduodenal diseases. 267 clinical H. pylori isolates are included in our study for finding the prevalence of tipα gene and its association with cagA and vacA gene using PCR assay. The current study shows that the prevalence rate of tipα gene is 59.9%. Our study has found a significant association (p < 0.05) of tipα gene with Non Ulcer Dyspepsia (NUD) and an association of cagA and vacAs1m1 with Gastritis and Duodenal Ulcer. Our study demonstrates for the first time the presence of tipα as virulence factor of H. pylori strain in Indian population isolated from patients suffering from gastroduodenal diseases. Further, tipα is significantly associated with NUD but not with other gastroduodenal diseases in India.

Curcumin Oxidation Is Required for Inhibition of Helicobacter pylori Growth, Translocation and Phosphorylation of Cag A.

Curcumin is a potential natural remedy for preventing Helicobacter pylori-associated gastric inflammation and cancer. Here, we analyzed the effect of a phospholipid formulation of curcumin on H. pylori growth, translocation and phosphorylation of the virulence factor CagA and host protein kinase Src in vitro and in an in vivo mouse model of H. pylori infection. Growth of H. pylori was inhibited dose-dependently by curcumin in vitro. H. pylori was unable to metabolically reduce curcumin, whereas two enterobacteria, E. coli and Citrobacter rodentium, which efficiently reduced curcumin to the tetra- and hexahydro metabolites, evaded growth inhibition. Oxidative metabolism of curcumin was required for the growth inhibition of H. pylori and the translocation and phosphorylation of CagA and cSrc, since acetal- and diacetal-curcumin that do not undergo oxidative transformation were ineffective. Curcumin attenuated mRNA expression of the H. pylori virulence genes cagE and cagF in a dose-dependent manner and inhibited translocation and phosphorylation of CagA in gastric epithelial cells. H. pylori strains isolated from dietary curcumin-treated mice showed attenuated ability to induce cSrc phosphorylation and the mRNA expression of the gene encoding for IL-8, suggesting long-lasting effects of curcumin on the virulence of H. pylori. Our work provides mechanistic evidence that encourages testing of curcumin as a dietary approach to inhibit the virulence of CagA.

Geographically distinct North-East Indian Helicobacter pylori strains are highly sensitive to clarithromycin but are levofloxacin resistant.

Purpose: Helicobacter pylori causes various gastro-intestinal diseases. Antibiotic resistance to commonly used antibiotics for the treatment of H. pylori infection is the major cause for treatment failure. The aim of this study is to determine the antimicrobial susceptibility pattern for clarithromycin and levofloxacin and find the evolutionary relationship of the partial sequence of 23S rRNA and gyraseA gene of H. pylori by phylogenetic analysis. Materials and Methods: A total of 46 H. pylori strains were tested for clarithromycin and levofloxacin susceptibility pattern and phylogenetic tree were reconstructed by PhyML software. Results: In this study, we observed that only 6.5% of North-East Indian H. pylori strains were resistant for clarithromycin showing mutation at A2143G and T2182C positions of 23S rRNA gene. Resistance for levofloxacin was observed in 89.1% of the H. pylori strains showing mutations at asparagine to lysine at 87 and aspartic acid to glycine/tyrosine/asparagine at 91 positions of gyraseA gene. The phylogenetic tree of the partial sequence of 23S rRNA and gyraseA gene depicts that the North-East Indian strains falls in different cluster when compared to other countries. Conclusions: Resistance for clarithromycin was less in North-East Indian strains but high for levofloxacin indicating that first-line therapy may be best and effective for eradication of H. pylori in this region. This study is the first report that showed antibiotic susceptibility pattern for clarithromycin and levofloxacin by mutation analysis. By partial sequencing of 23s rRNA and gyraseA gene, we found that North-East Indian strains are geographically distinct.

Primary antibiotic resistance in Helicobacter pylori in the Asia-Pacific region: a systematic review and meta-analysis.

BACKGROUND: So far, a comprehensive systematic review and meta-analysis has not been done of the prevalence of primary antibiotic resistance in Helicobacter pylori in the Asia-Pacific region. We aimed to assess the trends and regional differences in primary antibiotic resistance to H pylori in the Asia-Pacific region and to examine the relation between resistance and first-line eradication. METHODS: We did a systematic review and meta-analysis of primary antibiotic resistance to H pylori and the efficacy of first-line regimens in the Asia-Pacific region. We searched PubMed, Embase, and the Cochrane Library for articles published between Jan 1, 1990, and Sept 30, 2016; we also searched abstracts from international conferences. Both observational studies and randomised controlled trials were eligible for inclusion in the analysis of primary antibiotic resistance, but only randomised controlled trials were eligible for inclusion in the analysis of efficacy of first-line therapies. Meta-analysis was by the random-effects model to account for the substantial variations in resistance across the region. We did subgroup analyses by country and study period (ie, before 2000, 2001-05, 2006-10, and 2011-15) to establish country-specific prevalences of primary antibiotic resistance and first-line eradication rates. This study is registered with PROSPERO, number CRD42017057905. FINDINGS: 176 articles from 24 countries were included in our analysis of antibiotic resistance. The overall mean prevalences of primary H pylori resistance were 17% (95% CI 15-18) for clarithromycin, 44% (95% CI 39-48) for metronidazole, 18% (95% CI 15-22) for levofloxacin, 3% (95% CI 2-5) for amoxicillin, and 4% (95% CI 2-5) for tetracycline. Prevalence of resistance to clarithromycin and levofloxacin rose significantly over time during the period investigated, whereas resistance to other antibiotics remained stable. 170 articles from 16 countries were included in analysis of efficacy of first-line therapies. We noted unsatisfactory efficacy (ie, <80%) with clarithromycin-containing regimens in countries where the clarithromycin resistance rates were higher than 20%. INTERPRETATION: The prevalence of primary antibiotic resistance varied greatly among countries in the Asia-Pacific region, and thus treatment strategy should be adapted relative to country-specific resistance patterns. Clarithromycin-containing regimens should be avoided in countries where the prevalence of clarithromycin resistance is higher than 20%. FUNDING: Ministry of Health and Welfare of Taiwan, Ministry of Science and Technology of Taiwan, and Amity University.

Low prevalence of clarithromycin-resistant Helicobacter pylori isolates with A2143G point mutation in the 23S rRNA gene in North India.

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.