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

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.

Refractoriness to anti-Helicobacter pylori treatment attributed to phenotypic resistance patterns in patients with gastroduodenopathy in Guayaquil-Ecuador

BACKGROUND

Treatment of Helicobacter pylori gastric infection is complex and associated with increased rates of therapeutic failure. This research aimed to characterize the H. pylori infection status, strain resistance to antimicrobial agents, and the predominant lesion pattern in the gastroduodenal mucosa of patients with clinical suspicion of refractoriness to first- and second-line treatment who were diagnosed and treated in a health center in Guayaquil, Ecuador.

METHODS

A total of 374 patients with upper gastrointestinal symptoms and H. pylori infection were preselected and prescribed one of three triple therapy regimens for primary infection, as judged by the treating physician. Subsequently, 121 patients who returned to the follow-up visit with persistent symptoms after treatment were studied.

RESULTS

All patients had H. pylori infection. Histopathological examination diagnosed chronic active gastritis in 91.7% of cases; premalignant lesions were observed in 15.8%. The three triple therapy schemes applied showed suboptimal efficacy (between 47.6% and 77.2%), with the best performance corresponding to the scheme consisting of a proton pump inhibitor + amoxicillin + levofloxacin. Bacterial strains showed very high phenotypic resistance to all five antimicrobials tested: clarithromycin, 82.9%; metronidazole, 69.7%; amoxicillin and levofloxacin, almost 50%; tetracycline, 38.2%. Concurrent resistance to clarithromycin-amoxicillin was 43.4%, to tetracycline-metronidazole 30.3%, to amoxicillin-levofloxacin 27.6%, and to clarithromycin-metronidazole 59.2%.

CONCLUSIONS

In vitro testing revealed resistance to all five antibiotics, indicating that H. pylori exhibited resistance phenotypes to these antibiotics. Consequently, the effectiveness of triple treatments may be compromised, and further studies are needed to assess refractoriness in quadruple and concomitant therapies.

Historical and Molecular Perspectives on the Presence of Helicobacter pylori in Latin America: A Niche to Improve Gastric Cancer Risk Assessment

Helicobacter pylori (H. pylori) is responsible for causing chronic gastritis, which can cause peptic ulcer and premalignant lesions such as atrophic gastritis, intestinal metaplasia, and dysplasia, with the risk of developing gastric cancer. Recent data describe that H. pylori colonizes the gastric mucosa of more than 50% of the world's population; however, this bacterium has been described as infecting the human population since its prehistory. This review focuses on the populations and subpopulations of H. pylori, differentiated by the polymorphisms present in their constitutive and virulence genes. These genes have spread and associated with different human populations, showing variability depending on their geographical distribution, and have evolved together with the human being. The predominant genotypes worldwide, Latin America and Chile, are described to understand the genetic diversity and pathogenicity of H. pylori in different populations and geographic regions. The high similarity in the sequence of virulence genes between H. pylori strains present in Peruvian and Spanish natives in Latin America suggests a European influence. The presence of cagA-positive strains and vacA s1 m1 allelic variants is observed with greater prevalence in Chilean patients with more severe gastrointestinal diseases and is associated with its geographical distribution. These findings highlight the importance of understanding the genetic diversity of H. pylori in different regions of the world for a more accurate assessment of the risk of associated diseases and their potential impact on health.

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

Background

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

Method

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

Results

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

Conclusion

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

MALDI-TOF MS and 16S RNA Identification of Culturable Gastric Microbiota: Variability Associated with the Presence of Helicobacter pylori

Helicobacter pylori is the main bacteria associated with gastroduodenal diseases. Recent studies have reported that gastric microbiota might be modified by the H. pylori colonization, favoring gastric lesions′ development. In Chile, the region of La Araucanía concentrates a high risk of gastric cancer associated with Helicobacter pylori colonization, rurality, poverty, and Mapuche ethnicity. Hence, we aimed to identify the culturable gastric microbiota and characterize its variability at different stages of epithelial injury, based on its H. pylori colonization in dyspeptic patients from this Chilean region. Microaerophilic bacteria strains were isolated from antrum biopsies of 155 dyspeptic patients′ biopsies and identified using MALDI-TOF MS or 16sRNA gene sequencing for non-pylori species identification, and UreC gene amplification for H. pylori confirmation. We found 48 species from 18 families, mainly belonging to Neisseriaceae (21.3%), Streptococcaceae (20.0%), Actynomicetaceae (9.0%), Enterobacteriaceae, and Lactobacillaceae (4.5%); however, Streptococcaceae and Actinomycetaceae families showed a significant reduction in samples infected with H. pylori, along with a considerably lower diversity of species. Our results revealed a microbiota modification due to H. pylori colonization associated with the gastric epithelial state, suggesting a potential microbiota role for developing and progressing gastric diseases.

Evaluation of Helicobacter pylori Infection, Neutrophil–Lymphocyte Ratio and Platelet–Lymphocyte Ratio in Dyspeptic Patients

Recent studies have shown a correlation between Helicobacter pylori (H. Pylori) infection and the neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR). The aim of this study was to investigate the relationship between H. Pylori infection and hematimetric indices in patients with dyspepsia symptoms. Overall, 448 patients who underwent gastroscopy were analyzed retrospectively. Histopathological evaluation of biopsies according to H. pylori presence was classified as H. Pylori positive and negative groups, which are analyzed in relation with hematimetric indices. NLR and PLR measurements did not show a statistically significant difference between H. pylori negative and positive groups (p > 0.05). NLR revealed a negative correlation between hemoglobin (HGB), iron, and ferritin measurements in the correlation analysis of the H. Pylori positive group (r = −0.133, p = 0.031; r = −0.270, p = 0.002; r = −0.162, p = 0.032). Again, with PLR, there was a negative correlation between HGB, mean corpuscular volume (MCV), iron, and ferritin measurements (r = −0.310, p = 0.001, r = −0.187, p = 0.002, r = −0.335, p = 0.001; r = −0.290; p = 0.001). The results of our study do not reveal an association between H. pylori presence and inflammatory response, which is evaluated by NLR and PLR measurements in patients with dyspepsia. However, low serum iron and ferritin values of H. pylori-positive patients suggest the effect of H. pylori on iron metabolism.

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.

Gastric Cancer Mortality Trends in the Southern Cone: Disentangling age, period and cohort patterns in Argentina and Chile

Although Argentina and Chile are neighboring countries, gastric cancer (GC) is the first cancer death cause in the Chilean male population, while it is ranked in fifth place for Argentinean males. This study is the first to identify the differential time-patterns associated with the age-period-cohort effects for the last few decades (1990-2015) in these Southern Cone countries. Trends of age-standardized truncated mortality rates (ASMR) for GC were analyzed using log-linear Poisson age-period-cohort models, including cubic splines for each component. The ASMR trends for GC decreased in both sexes but more considerably in Chile and more favorably for males (annual percentage changes 2002-2015 = -3.5, 95%CI: -3.9 to -3.1). Moreover, GC age-specific mortality rates were noticeably higher in Chile. A favorable decreasing mortality risk throughout the periods (from 2000) and by cohort was observed for both countries; however, the risk reduction has stabilized in younger female cohorts since 1950-cohort. In conclusion, overall favorable decreasing trends for GC mortality were found; however, when age-period-cohort effects were disentangled, Chile and younger female cohorts showed a more unfavorable scenario. Obesity, lifestyles, and environmental conditions (like altitude) may explain country differences. This analytical approach may be a valuable tool to be replicated in other countries with no population-based cancer registries and acceptable mortality data quality.

High prevalence of clarithromycin resistance and effect on Helicobacter pylori eradication in a population from Santiago, Chile: cohort study and meta-analysis

Helicobacter pylori (H. pylori) eradication using standard triple therapy (STT) with proton pump inhibitors (PPI), amoxicillin and clarithromycin (CLA) has been the standard in Latin America. However, CLA resistance is a rising problem affecting eradication rates. Genetic polymorphisms of CYP2C19, a PPI metabolizer may also affect eradication. The primary aims of this study were to evaluate the effect of clarithromycin resistance on H. pylori eradication in a population from Santiago, and to establish the pooled clarithromycin resistance in Santiago, Chile. Symptomatic adult patients attending a tertiary hospital in Santiago were recruited for this study. CLA resistance and the polymorphisms of CYP2C19 were determined on DNA extracted from gastric biopsies, using PCR. The STT was indicated for 14 days and eradication was determined by a urea breath test 4–6 weeks after therapy. A meta-analysis of CLA resistance studies among adult residents in Santiago was performed. Seventy-three out of 121 consecutive patients had positive rapid urease test (RUT) and received STT. Sixty-nine patients (95%) completed the study. The H. pylori eradication rate was 63% and the prevalence of CLA resistance was 26%. According to the CYP2C19 polymorphisms, 79.5% of the RUT-positive patients were extensive metabolizers. Multivariable analyses showed that only CLA resistance was significantly and inversely associated with failure of eradication (OR: 0.13; 95% confidence interval [95% CI], 0.04–0.49). A meta-analysis of two previous studies and our sample set (combined n = 194) yielded to a pooled prevalence of CLA resistance of 31.3% (95% CI 23.9–38.7). Our study shows that CLA resistance is associated with failure of H. pylori eradication. Given the high pooled prevalence of CLA resistance, consideration of CLA free therapies in Santiago is warranted. We could recommend bismuth quadruple therapy or high-dose dual therapy, according to bismuth availability. Further studies need to evaluate the best therapy.