Antimicrobial resistance of Helicobacter pylori in Germany, 2015 to 2018

Similarities in the consumption trajectory of antibacterial drugs in the outpatient care sector in Germany from 1986 to 2022: identification of shared patterns, correlation analysis of prescribed defined daily dose and assessment of underlying influences

Antibacterial drugs are widely used in modern medicine, but their efficacy is increasingly threatened by antimicrobial resistance and ongoing supply shortages. This study examines the relationships among the 15 most prescribed antibacterial substances in Germany, analysing the correlations and trends of prescribed defined daily dose (DDD) of antibacterial drugs within the outpatient care sector under statutory health insurance from 1986 to 2022. Three groups of drugs with similar consumption trajectories were identified. The first group, including doxycycline, phenoxymethylpenicillin and sulfamethoxazole-trimethoprim, showed declining trends with stable trajectories, its similarities being confirmed by overlapping indications such as respiratory tract infections and declining usage due to guideline changes. The second group, comprising amoxicillin-clavulanic acid, cefpodoxime and pivmecillinam, displayed increasing trends with continuous trajectories. The third group, including ciprofloxacin, clarithromycin and cefaclor, shared declining trends with fluctuating trajectories, often related to bacterial resistance rates and substitution by other antibacterial drugs. Frequently prescribed substances often show many and strong correlations in consumption, indicating that they are more related with other substances and being susceptible to external factors, such as changes in costs, sudden events like the COVID pandemic or guideline recommendations. Less commonly used medicines, typically for niche indications, tend to have a more stable consumption trend and being less influenced by broader trends, resulting in fewer significant correlations. Distinguishing direct effects of changes in consumption from one drug to another from common but unrelated responses to external events remains a challenge, as there are many factors that can influence consumption. The findings provide a better understanding of the interdependencies in the consumption of the most commonly prescribed antibacterial drugs, improving the understanding of potential influencing factors to support strategies for rational prescribing and antimicrobial stewardship.

Evaluation of optimized Real time-PCR HRM assay and SPR-based biosensor for noninvasive isolation of H. pylori and Clarithromycin resistance 23S-SNP subtype

High Resolution Melting analysis is a highly sensitive molecular method, and the plasmonic-based sensor is a convenient test, be clinically elicited, in simultaneous H. pylori control and the prevention of Clarithromycin resistant strains related to SNPs. Comparing gold standard tests, we evaluated HRMA and the SPR-based biosensor in regard to noninvasive forms of H. pylori management, and explored resistance through a possible mechanism by 23S-SNPs.We optimized Realtime-PCR HRM analysis, and SPR-based biosensor. Referring to CTs ± 38, isolation sensitivity was evaluated at 74 %. Compared to the reference-test, results agreements were assessed with a kappa of 43 %, p = 0.001. Within melting plots (differentiation plot), the strains were detectable at Tms ranging from 81.5 to 82.3 (°C). Contributing to phenotypically determined resistant strains for 44 %, there was a wide distribution among resistant variants assessed through Tms of 82, 81.5, 82, 82.3, and 81.7 (°C). A2143C was the only mutation isolated at a specific Tm of 82.3°C; kappa = 8 %, p = 0.3. For sensing analysis, including 100 % specificity, this sensor type was associated with lower sensitivity of 49 %, kappa=19 %, p = 0. 01. For SNP, specificity, kappa value, and p-value of isolation were 100 %, 100 %, and 0.001. Lod was 0.003 ng/mL and 0.03 µg/mL for HRM assay and sensing analysis. In our evaluations, applicable priority of HRM analysis was the higher estimation of sensitivity; its differentiation plot was completely covered the results of strain variability regarding specific SNPs detection. Consistent with the biosensor for isolation of SNP, the development of biosensors is the necessity for noninvasive H. pylori detection.

Antibiotic resistance of Helicobacter pylori and related risk factors in Hunan Province: A multicenter study

BACKGROUND

Antibiotic resistance is a key factor influencing the treatment outcomes of Helicobacter pylori (H. pylori) infection. The antibiotic resistance spectrum of H. pylori varies in different regions. We investigated the current status of antibiotic resistance of H. pylori in Hunan Province and analyzed the factors related to such resistance to provide strategies for the accurate clinical treatment of H. pylori infection.

AIM

To understand the antibiotic resistance of H. pylori in Hunan Province and provide guidance for the clinical treatment of H. pylori infection.

METHODS

This study selected patients who underwent gastroscopy in five hospitals in Hunan Province from April 2022 to April 2023. The sensitivity of H. pylori to clarithromycin, levofloxacin, metronidazole, amoxicillin, furazolidone, and tetracycline was detected using the Agar dilution method.

RESULTS

H. pylori strains from a total of 566 patients were isolated and identified. The resistance rates of H. pylori strains to clarithromycin, levofloxacin, metronidazole, amoxicillin, furazolidone, and tetracycline were 49.2%, 37.8%, 76.1%, 2.3%, 1.4%, and 0.7%, respectively. The resistance rates to clarithromycin, levofloxacin, and metronidazole were high in the four regions of Hunan Province, and the overall resistance rates in central Hunan Province were higher than those in other regions. The resistance rates of H. pylori strains to clarithromycin and levofloxacin were significantly different among the different age groups (P < 0.05), with the elderly group having a higher resistance rate than the young group. The resistance rate of H. pylori strains to clarithromycin was greater in patients with atrophic gastritis, and the resistance rate to levofloxacin was the lowest in patients with peptic ulcers.

CONCLUSION

The resistance rate of H. pylori to amoxicillin, clarithromycin, and metronidazole is high in Hunan Province. Age, stomach disease, and H. pylori reinfection may affect the antibiotic resistance of H. pylori.

Analysis of the status and risk factors for Helicobacter pylori infection and drug resistance in the Lianyungang area, China

OBJECTIVE

Helicobacter pylori (H. pylori) has attracted much attention since its discovery. This bacterium has had a substantial impact on society, the economy, and public health. In recent years, with the continuous increase in drug resistance in H. pylori and the emergence of multidrug resistant strains, the existing diagnostic and treatment options are no longer able to meet clinical needs, so we need to understand the dynamically changing nature of drug resistance of H. pylori in our region. This study collected stool samples from community residents in Lianyungang to analyse the local H. pylori infection status, resistance to commonly used antibacterial agents, and risk factors to provide a reference for local clinical empirical treatment.

METHODS

Human stool samples from Lianyungang residents were collected, the DNA of H. pylori in the positive samples was extracted, the sites of mutated genes were determined by PCR and nucleic acid mass spectrometry, and genotypes of cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA) were tested. The resistance rates of local H. pylori strains to five antibacterial agents, levofloxacin, clarithromycin, furazolidone, amoxicillin, and tetracycline, were collected, and the risk factors for drug resistance were analysed statistically based on questionnaire results.

RESULTS

A total of 221 residents with qualified stool samples were enrolled. The infection rate was 25.3%. DNA was extracted from 56 H. pylori samples. Among them, only 17 H. pylori strains were sensitive to all five antibiotics, and a total of five drug resistance patterns were detected. The main drug resistance patterns were single drug resistance to clarithromycin (30.4%) and double drug resistance to levofloxacin + clarithromycin (21.4%). The levofloxacin resistance mutations were mainly located at N87K and D91Y of the gyrA sequence, and the clarithromycin resistance mutations were mainly located at A2143G in the 23S rRNA sequence. Age, gastrointestinal symptoms, and previous history of H. pylori infection were risk factors for resistant H. pylori. A previous history of H. pylori infection was an independent risk factor for the development of drug resistance in H. pylori.

CONCLUSION

The H. pylori infection rate in the Lianyungang area is lower than the national rate, but the rates of resistance to levofloxacin and clarithromycin are quite high. Drug sensitivity testing is needed to provide more accurate individualized treatment and improve the eradication rate of H. pylori. Continuous monitoring of local antibiotic resistance patterns remains the first choice for empirical treatment.

Costs are a major driver of antibacterial drug prescriptions in Germany: market analysis from 1985 to 2022

In recent years, several threatening developments regarding antibacterial drugs, such as rising bacterial resistance and delivery bottlenecks, have occurred. Since antibacterial drugs are crucial for modern medicine, understanding events and influencing factors relevant for long-term developments is essential. Therefore, we analyzed the number of prescriptions and costs, defined daily dose (DDD) and DDD costs of antibacterial drugs in Germany, based on the Arzneiverordnungsreport (AVR, Drug description report) between 1985 and 2022. Based on prescription rates in 2022, we selected the TOP15 and TOP5. For a more in-depth analysis, we analyzed data from the wissenschaftliches Institut der AOK (WidO, scientific institute of the AOK). The number of prescriptions increased between 1985 and 2013, but since 2014, there has been a declining trend with a noticeable COVID-related dip. Over the years, a shift in drug classes occurred. Once very popular drugs like penicillins and tetracyclines are no longer as important. Conversely, aminopenicillins and cephalosporins have become more relevant. Particularly, the TOP5 drugs have seen an increasing proportion. DDD costs have decreased in most substance classes over time. There is a strong association between decreasing costs and rising prescriptions. Falling costs have a stronger immediate impact on prescriptions that rising costs. When costs are very low, drugs might be prescribed excessively. Supply bottlenecks can also result. The main prescribers are mainly in primary care. Their share of prescription has changed little over the years, but is decreasing regarding total consumption. In comparison to other European countries, Germany ranks in the lower third regarding prescriptions. In most countries, the COVID pandemic has led to a reduced prescription of antibacterial drugs. In conclusion, we provided a comprehensive overview of the antibacterial drug market in Germany over the past four decades and identified costs as a major driver of antibacterial drug prescriptions. Increased costs may reduce uncritical prescription of antibacterial drugs, development of bacterial resistance, supply shortages and occurrence of adverse effects.

Treatment failure is a key factor in the development of Helicobacter pylori resistance

BACKGROUND

Helicobacter pylori eradication failure influences its antibiotic resistance.

AIMS

This study aimed to evaluate the effect of previous treatment failures on it, including the changes in the antibiotic resistance rates, minimal inhibitory concentration (MIC) distributions, and resistance patterns.

MATERIALS AND METHODS

This single-center retrospective study included 860 primary isolates and 247 secondary isolates. Antibiotic susceptibility testing was performed for amoxicillin, metronidazole, clarithromycin, levofloxacin, furazolidone, tetracycline, and rifampicin. The demographic data and detailed regimens were collected.

RESULTS

The primary resistance rates to amoxicillin, metronidazole, clarithromycin, levofloxacin, tetracycline, rifampin, and furazolidone were 5.93%, 83.84%, 28.82%, 26.28%, 0.35%, 1.16%, and 0%, while secondary were 25.10%, 92.31%, 79.76%, 63.16%, 1.06%, 3.19%, and 0%, respectively. The resistance rates to amoxicillin, metronidazole, clarithromycin, and levofloxacin increased significantly with the number of treatment failures accumulated, and showed a linear trend. The proportion of primary and secondary multidrug-resistant (MDR) isolates were 17.79% and 63.16%, respectively. The MIC values of amoxicillin, clarithromycin, and levofloxacin were elevated significantly with medication courses increased.

CONCLUSION

The prevalence of amoxicillin, clarithromycin, levofloxacin, and metronidazole resistance would increase rapidly following first-line treatment failure, as well as the MIC values of them. Clinicians should pay great attention to the first-line treatment to cure H. pylori infection successfully.

Epidemiology of Helicobacter pylori Resistance to Antibiotics (A Narrative Review)

Helicobacter pylori (H. pylori) is the most common bacterial infection worldwide and one of the main etiological factors of chronic gastritis, peptic ulcer disease, and stomach neoplasms. The mass application of antibiotics without testing, especially during the last years of the pandemic of SARS-CoV-2, could lead to a dramatic increase in antibiotic resistance and reduced effectiveness of eradication regimens for H. pylori infection. The epidemiology of H. pylori resistance to antibiotics still has unclear mechanisms. Antibiotic policy should be intensified to optimize treatment, and regular monitoring of resistance of H. pylori in different geographical regions should be conducted. Individualized treatment according to susceptibility testing is strongly advisable, and the best treatment regimens should be selected. The mutations in the genes encoding the antibiotic target protein are significant risk factors for H. pylori resistance. Iatrogenic errors in diagnosis and prescribing treatment for the failure of H. pylori eradication are other important risk factors. The low level of awareness and compliance with the correct treatment influence the rate of H. pylori resistance. Epidemiological surveillance of antibiotic resistance and the adoption of new treatment strategies are needed. The discovery of an efficient vaccine against H. pylori could reduce the pressure of the world's growing antibiotic resistance.

Antibiotic Resistance of Helicobacter pylori and Related Risk Factors in Yangzhou, China: A Cross-Sectional Study

BACKGROUND

The antibiotic resistance of Helicobacter pylori (H. pylori) is a common cause of treatment failure. Previous studies showed that H. pylori resistance may be related to some characteristics of patients. This study intended to investigate the resistance of H. pylori to five commonly used antibiotics and risk factors in Yangzhou, China.

METHODS

We recruited the subjects who joined the endoscopic screening program organized by the Affiliated Hospital of Yangzhou University between April 2018 and September 2019 and endoscopists would take biopsy samples from the antrum and the corpus of the stomach. The antrum biopsy specimens were used to culture H. pylori. Next, we extracted DNA from H. pylori strains and performed the specific DNA amplification. Finally, we use gene chip technology to test the susceptibility to clarithromycin, levofloxacin, metronidazole, amoxicillin and tetracycline. Multivariate logistic analyses were also performed to determine the risk factors for antibiotic resistance of H. pylori.

RESULTS

A total of 461 H. pylori strains were finally collected. The resistance rate of H. pylori to clarithromycin, levofloxacin, metronidazole, amoxicillin and tetracycline was 41.0%, 44.9%, 38.8%, 6.3% and 1.1%, respectively. In addition, 16 multi-resistance patterns were detected, and strains resistant to all five antibiotics were not found. Multivariate analysis showed that past medical history and clinical outcomes were significantly associated with the resistance to clarithromycin. Drinking, gastrointestinal symptoms and a family history of gastric cancer were significantly associated with the resistance of H. pylori to levofloxacin. Especially gastrointestinal symptoms were significantly associated with the resistance of H. pylori to any antibiotic.

CONCLUSION

The resistance rates of H. pylori to clarithromycin, levofloxacin and metronidazole were very high in Yangzhou, China, various factors were related to bacterial resistance, and grasping these influencing factors can guide treatment.

The influence of gastric atrophy on Helicobacter pylori antibiotics resistance in therapy-naïve patients

BACKGROUND

Antibiotic susceptibility of Helicobacter pylori to antibiotics may vary among different niches of the stomach. The progression of chronic H. pylori gastritis to atrophy changes intragastric physiology that may influence selection of resistant strains.

AIM

To study the antibiotic resistance of H. pylori taking the severity of atrophic gastritis in antrum and corpus into account.

METHODS

Helicobacter pylori-positive patients (n = 110, m = 32, mean age 52.6 ± 13.9 years) without prior H. pylori eradication undergoing upper gastrointestinal (GI) endoscopy for dyspeptic symptoms were included in a prospective study. Patients were stratified into three groups depending on the grade of atrophy: no atrophy (OLGA Stage 0), mild atrophy (OLGA Stage I-II) and moderate/severe atrophy (OLGA Stage III-IV). Two biopsies each from the antrum and the corpus and one from the angulus were taken and assessed according to the updated Sydney system. H. pylori strains were isolated from antrum and corpus biopsies and tested for antibiotic susceptibility (AST) for amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin by the agar dilution methods. A Chi-square test of independence with a 95% confidence interval was used to detect differences in the proportion of patients with susceptible and resistant H. pylori strains.

RESULTS

Among 110 patients, primary clarithromycin resistance (R) was 30.0%, both in the antrum and corpus; metronidazole resistance accounted for 36.4 and 34.5% in the antrum and corpus; and levofloxacin was 19.1 and 22.7% in the antrum and corpus, respectively. Resistance rates to amoxicillin, tetracycline, and rifampicin were below 5%. Dual antibiotic resistance rate was 21.8%, and triple resistance rate was 9.1%. There was a significant difference in the resistance rate distribution in antrum (p < 0.0001) and corpus (p < 0.0001). With increasing severity of atrophy according to OLGA stages, there was a significant increase in clarithromycin-R and metronidazole-R.

CONCLUSION

In treatment-naïve patients, antibiotic resistance and heteroresistance were related to the severity of atrophy. The high clarithromycin resistance in atrophic gastritis suggests that H. pylori antibiotic susceptibility testing should always be performed in this condition before selecting the eradication regimen.

Increased Antibiotic Resistance in Children with Helicobacter pylori Infection: A Retrospective Study

Children with recurrent abdominal pain may be suffering from a Helicobacterpylori (HP) infection. The gold standard for confirming HP gastritis is histological evaluation and microbiological tests performed on specimens collected by esophagogastroduodenoscopy (EGD). The aim of this study was to analyze HP positive cultures and antibiograms with regard to clinical and histopathological correlates. The data of 124 subjects with frequent gastrointestinal symptoms who underwent an EGD were retrospectively collected and analyzed. The mean age of the patients was 13 ± 3.6 years. The most frequent complaints were epigastric pain (84%; n = 100/119) and dyspepsia (79%; n = 94/119). HP gastritis was diagnosed in 54% (n = 67). Interestingly, 40% (n = 49) of the isolates were resistant to at least one antibiotic: amoxicillin (20%; n = 10/49), clarithromycin (45%; n = 22/49), or metronidazole (59%; n = 29/49). Isolates were resistant to two or more antibiotics in 16% (n = 20) of cases. In conclusion, we revealed remarkably high resistance rates to amoxicillin, metronidazole, and clarithromycin in our cohort. The presence of antibiotic resistance to more than one antibiotic was substantially increased in our HP-infected patients and this may negatively affect eradication treatment.

Unraveling antimicrobial resistance in Helicobacter pylori: Global resistome meets global phylogeny

BACKGROUND

Antimicrobial resistance (AMR) in Helicobacter pylori is increasing globally and can result in treatment failure and inappropriate antibiotic usage. This study used whole genome sequencing (WGS) to conduct an analysis of the H. pylori resistome and phylogeny.

MATERIALS/METHODS

A total of 1040 H. pylori isolate sequences were retrieved. Analysis was conducted via an in-house bioinformatics pipeline targeting point mutations in selected genes frequently associated with AMR (pbp1A, 23S rRNA, gyrA, rdxA, frxA, and rpoB) and phylogenomic analyses using core genome multilocus sequence typing (cgMLST).

RESULTS

Phylogenomic analysis revealed a notable geographical clustering of H. pylori genomes across world regions, but large distances of more than 1000 loci between isolates on individual branches were observed. Resistome analysis revealed the prevalence of common mutations which have previously been found to correlate with phenotypic antibiotic resistance; the most common point mutations for each gene were S589G (pbp1A, 48.8% of perfect aligned sequences), A2143G (23S rRNA, 27.4% of perfectly aligned sequences), N87 K\I\Y (gyrA, 14.7% of perfectly aligned sequences), R131K (rdxA, 65.7% of perfectly aligned sequences), and C193S (frxA, 62.6% of perfectly aligned sequences).

CONCLUSIONS

This is the largest study to date featuring the global phylogeny of H. pylori in conjunction with a global snapshot of the H. pylori resistome based on >1000 genomes. Further analyses that combine WGS and phenotypic methods will provide further understanding of the association between the mutations and resistance.

Antimicrobial resistance of Helicobacter pylori in an eastern German region

BACKGROUND

Antimicrobial therapy is recommended to eradicate Helicobacter (H.) pylori in infected individuals. As first-line treatments are empiric, knowledge of antimicrobial resistance is key to successful eradication.

AIMS

We investigated primary resistance in an eastern German region to derive recommendations for eradication treatment.

METHODS

We used molecular genetic methods to examine Helicobacter rapid urease test (RUT) positive gastric specimens of 533 patients from Berlin and the federal state of Brandenburg with allegedly no prior eradication treatment. Tissue samples were removed from RUT and screened by real-time PCR for mutations conferring resistance to clarithromycin. In addition, 182 samples out of 533 were tested for resistance to levofloxacin and tetracycline.

RESULTS

Primary resistances were 10.9% (58 out of 533) to clarithromycin; 13.7% (25/182) to levofloxacin; and 2.2% to tetracycline (4/182). Combined resistance to clarithromycin/levofloxacin was low (2.2%, 4/182). Female sex was significantly associated with clarithromycin resistance.

CONCLUSION

Clarithromycin may be a suitable first-line antibiotic for about 90% of outpatients. A simple molecular test may help physicians avoid prescription of an ineffective first-line regimen.

Review - Treatment of Helicobacter pylori infection 2020

This review summarizes important studies regarding Helicobacter pylori therapy published from April 2019 to April 2020. The main themes that emerge involve studies assessing antibiotic resistance, and there is also growing momentum behind the utility of vonoprazan as an alternative to proton pump inhibitor (PPI) therapy and also bismuth-based regimens as a first-line regimen. Antibiotic resistance is rising wherever it is being assessed, and clarithromycin resistance in particular has reached a point where it may no longer be a viable therapy without previous testing in many regions of the world. The evidence for the efficacy of a bismuth-based quadruple therapy as a first-line therapy is now very clearly established, and there is substantial evidence that it is the best performing first-line therapy. The utility of vonoprazan as an alternative to PPI therapy, especially in resistant and difficult-to-treat groups, has also been considered in great detail this year, and it may offer an opportunity in the near future to reduce the problem of antibiotic resistance.

Secondary Antibiotic Resistance, Correlation between Genotypic and Phenotypic Methods and Treatment in Helicobacter pylori Infected Patients: A Retrospective Study

The aim of this study was to evaluate the secondary resistance in Helicobacter pylori (Hp) infected patients who had failed a first-line therapy, and to compare the genotypic tests performed directly on gastric samples with phenotypic tests performed on culture media. The eradication rate of patients treated with bismuth quadruple therapy (BQT) is also evaluated. A total of 80 positive specimens were retrospectively examined. Antibiotic susceptibility testing of Hp strains was performed by E-test, whereas a molecular commercially available method was used for detecting the mutations involved in clarithromycin and levofloxacin resistance. High resistance levels to metronidazole and clarithromycin (61.6% and 35%, respectively) and worrying resistance levels to levofloxacin (15%) were found phenotypically. Multiple resistance to two or three antibiotics was observed as well. The polymorphism A2143G on clarithromycin 23S rRNA gene was found in 34/80 (42.5%) isolates including 10 mixed infections (29%), whereas 28/80 (35%) strains were resistant phenotypically. Levofloxacin resistance corresponded to 30% by PCR and 15% by E-test (statistically significant, p < 0.05). The knowledge of clarithromycin and levofloxacin resistance is crucial to establish an appropriate therapy in different geographical areas. The genetic methods were superior to phenotypic techniques in the absence of live bacteria or for identifying mixed infections that may lead to a resistance underestimation. The BQT eradication rate was effective (90%).

Update on quinolone-containing rescue therapies for Helicobacter pylori infection

Third generation of quinolones, such as levofloxacin and moxifloxacin, -containing regimens are often used in second-line or rescue treatment of Helicobacter pylori infection. However, the increasing antibiotic resistance to quinolones affects the efficacies of quinolones-containing therapies in recent years. Therefore, there is a need to enhance the effectiveness of quinolones-containing therapies. Sitafloxacin, a fourth-generation quinolone, and vonoprazan, a novel potassium-competitive acid blocker, are now available as more effective treatment options. The aim of this paper is to summarize the current evidence of quinolone-containing therapies in rescue treatments, and to discuss the importance of drug sensitivity tests or analysis of gyrA mutation before treatments.

Prevalence of Infection and Antibiotic Susceptibility of Helicobacter pylori: An Evaluation in Public and Private Health Systems of Southern Chile

Helicobacter pylori colonizes half of the human population. Age, ethnicity, and socioeconomic status are factors that influence the prevalence of the infection. This is important in southern Chile, one of the most unequal regions in the world, where a significant difference in the health access of the population occurs due to the existence of two competing health systems. Moreover, in the last few years, current protocols of H. pylori eradication have shown high rates of resistance with reduced therapeutic efficacy. This study reported the epidemiology of infection and attempted to identify divergent points among the population beneficiaries of the two health care schemes in southern Chile. Biopsies from public (n = 143) and private (n = 86) health systems were studied. At the same time, clinical and sociodemographic factors were evaluated. H. pylori strains were obtained from gastric biopsies for culture and molecular testing. Antibiotic susceptibility was determined by the agar dilution method. Differences about ethnicity, rural residence, and education (p ≤ 0.05) were observed between beneficiaries of the two health systems. The prevalence of H. pylori was 45%, with no significant differences regardless of the socioeconomic conditions. The only identified risk factor associated with H. pylori infection was Mapuche ethnicity (OR (odds ratio) = 2.30). H. pylori showed high resistance rates, particularly against clarithromycin (40%), levofloxacin (43.1%), and metronidazole (81.8%). This study highlighted the importance of Mapuche ancestry as a risk factor in southern Chile and emphasized the need to search for new eradication strategies as well as further studies evaluating therapeutic efficacy.