Extremely High Prevalence of Metronidazole-Resistant Helicobacter pylori Strains in Mountain People (Karen and Hmong) in Thailand

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.

A Survey of Helicobacter pylori Antibiotic-Resistant Genotypes and Strain Lineages by Whole-Genome Sequencing in China

Antibiotic resistance is the most important factor leading to failed Helicobacter pylori eradication therapy, and personalized treatment based on antibiotic susceptibility is becoming increasingly important. To strengthen the understanding of antibiotic genotypic resistance of H. pylori and identify new antibiotic resistance loci, in this study, we identified phenotypic resistance information for 60 clinical isolates and compared the concordance of phenotypic and genotypic resistance using whole-genome sequencing (WGS). Clarithromycin and levofloxacin genotypic resistance was in almost perfect concordance with phenotypic resistance, with kappa coefficients of 0.867 and 0.833, respectively. All strains with the R16H/C mutation and truncation in rdxA were metronidazole resistant, with 100% specificity. For other genes of concern, at least one phenotypically sensitive strain had a previous mutation related to antibiotic resistance. Moreover, we found that the A1378G mutation of HP0399 and the A149G mutation of FabH might contribute to tetracycline resistance and multidrug resistance, respectively. Overall, the inference of resistance to clarithromycin and levofloxacin from genotypic resistance is reliable, and WGS has been very helpful in discovering novel H. pylori resistance loci. In addition, WGS has also enhanced our study of strain lineages, providing new ways to understand resistance information and mechanisms.

The Emergence of Multidrug-Resistant Helicobacter pylori in Southeast Asia: A Systematic Review on the Trends and Intervention Strategies Using Antimicrobial Peptides

The emergence of multidrug-resistant H. pylori poses a public healthcare threat, particularly in low- and middle-income countries. Recently, the World Health Organization has classified clarithromycin-resistant H. pylori as high priority in the research and discovery of novel antibiotics. This study was aimed to systematically review the prevalence of primary antibiotic resistance in H. pylori in Southeast Asian countries (SEAC) and to review current studies of antimicrobial peptides against H. pylori. We systematically searched through electronic databases of studies conducted on antimicrobial resistance of H. pylori in SEA countries. Furthermore, we searched articles that conducted studies on antimicrobial peptides, naturally occurring host’s defense molecules, against H. pylori. After a series of screening processes, 15 studies were included in our systematic review. Our analysis revealed that primary resistance of H. pylori to metronidazole, clarithromycin, and levofloxacin were high in SEAC, although the primary resistance to amoxicillin and tetracycline remains low. Multidrug-resistant H. pylori are emerging in SE Asian countries. The antimicrobial peptides show promising antibacterial and antibiofilm activity against drug-resistant H. pylori. The research and discovery of antimicrobial peptides against H. pylori in SEAC will help in limiting the spread of antimicrobial resistance of H. pylori.

FBPAII and rpoBC, the Two Novel Secreted Proteins Identified by the Proteomic Approach from a Comparative Study between Antibiotic-Sensitive and Antibiotic-Resistant Helicobacter pylori-Associated Gastritis Strains

Helicobacter pylori infection is the leading cause of chronic gastritis, which can develop into gastric cancer. Eliminating H. pylori infection with antibiotics achieves the prevention of gastric cancer. Currently, the prevalence of H. pylori resistance to clarithromycin and metronidazole, and the dual resistance to metronidazole and clarithromycin (C_R, M_R, and C/M_R, respectively), remains at a high level worldwide. As a means of exploring new candidate proteins for the management of H. pylori infection, secreted proteins from antibiotic-susceptible and antibiotic-resistant H. pylori-associated gastritis strains were obtained by in-solution tryptic digestion coupled with nano-liquid chromatography tandem mass spectrometry (nano-LC-MS/MS). A total of 583, 582, 590, and 578 differential expressed proteins were identified from C_R, M_R, C/M_R, and antibiotic-sensitive strain (S_S) samples, respectively. Of these, 23 overlapping proteins were found by Venn diagram analysis. Based on heat map analyses, the most and least differing protein expressions were observed from C/M_R strains and S_S strains, respectively. Of the proteins secreted by the S_S strain, only nine were found. After predicting the protein interaction with metronidazole and clarithromycin via the STITCH database, the two most interesting proteins were found to be rpoBC and FBPAII. After quantitative real-time reverse transcription PCR (qRT-PCR) analysis, a downregulation of rpoB from M_R strains was observed, suggesting a relationship of rpoB to metronidazole sensitivity. Inversely, an upregulation of fba from C_R, M_R, and C/M_R strains was noticed, suggesting the paradoxical expression of FBPAII and the fba gene. This report is the first to demonstrate the association of these two novel secreted proteins, namely, rpoBC and FBPAII, with antibiotic-sensitive H. pylori -associated gastritis strains.

Adapted first-line treatment of Helicobacter pylori infection in Algerian children

BACKGROUND

Helicobacter pylori (H. pylori) infection is acquired in early life and continues to have a high prevalence, especially in developing countries. Growing antibiotic-resistant strains necessitate adapted treatments. This study aimed to compare the efficacy, side effects, and influence of resistance of H. pylori strains between two different treatments.

METHODS

This prospective, randomized blind study enrolled 112 symptomatic children infected with H. pylori (66 girls, mean age 11.1 years). Treatments, allocated randomly irrespective of the susceptibility of the strains, were either the standard omeprazole-amoxicillin-clarithromycin combination for 7 days (OAC7; group A) or omeprazole-amoxicillin with a higher dose of metronidazole (40 instead of 20 mg/kg/d) for 10 days (OAM10; group B).

RESULTS

Before treatment, the resistance rates of H. pylori strains to metronidazole or clarithromycin were 37% and 13%, respectively, with 7% resistant to both antibiotics and neither to amoxicillin. Eradication rates obtained with OAM10 (80% by intention-to-treat [ITT] and 88% by per protocol [PP] analysis) were higher than with OAC7 (68% in ITT and 71% PP) and the differences (12% in ITT and 17% PP) were statistically significant (P=0.03). Successful treatments with OAM10 were obtained in metronidazole resistant strains and were more effective in children aged >10 years (P=0.02 by ITT and P=0.04 by PP). Only light or moderate side effects, mainly digestive, were observed.

CONCLUSION

Because of its therapeutic efficacy, good tolerance and lower cost the OAM10 can be considered as an appropriate first-line therapeutic scheme in Algeria.

Prevalence of Antibiotic Resistance in Helicobacter pylori: A Systematic Review and Meta-analysis in World Health Organization Regions

BACKGROUND & AIMS

In 2017, the World Health Organization (WHO) designated clarithromycin-resistant Helicobacter pylori a high priority for antibiotic research and development. However, there are no clear data on the global distribution of resistance or its clinical effects. We performed a systematic review and meta-analysis to assess the distribution of H pylori resistance to commonly used antibiotics and to measure the association between antibiotic resistance and treatment failure.

METHODS

We searched publication databases for studies that assessed rates of H pylori resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, or tetracycline. Pooled estimates of primary and secondary resistance and 95% confidence intervals (CIs) were grouped by WHO region. The association between antibiotic resistance and treatment failure was measured by extracting data on treatment efficacy in patients with resistant and susceptible isolates and pooling odds ratios with 95% CIs.

RESULTS

We identified 178 studies, comprising 66,142 isolates from 65 countries. Primary and secondary resistance rates to clarithromycin, metronidazole, and levofloxacin were ≥15% in all WHO regions, except primary clarithromycin resistance in the Americas (10%; 95% CI, 4%-16%) and South-East Asia region (10%; 95% CI, 5%-16%) and primary levofloxacin resistance in the European region (11%; 95% CI, 9%-13%). There was considerable heterogeneity (I2 > 75%) among all analyses-this might have resulted from the grouping of resistance rates by country. Increasing antibiotic resistance was observed in most WHO regions. Resistance to clarithromycin was significantly associated with failure of clarithromycin-containing regimens (odds ratio, 6.97; 95% CI, 5.23-9.28; P < .001).

CONCLUSIONS

Resistance of H pylori to antibiotics has reached alarming levels worldwide, which has a great effect on efficacy of treatment. Local surveillance networks are required to select appropriate eradication regimens for each region.

Anti-proliferation effect of blue light-emitting diodes against antibiotic-resistant Helicobacter pylori

BACKGROUND AND AIM

Infection by Helicobacter pylori is implicated in a wide range of upper gastrointestinal diseases. Owing to the rapid emergence of antibiotic-resistant strains of H. pylori, the development of novel treatment modalities for antibiotic-resistant H. pylori infection is a key priority. Blue light-emitting diodes (LED) may represent a unique option owing to their antimicrobial effect. In this study, we aimed to evaluate the anti-proliferative effect of blue LED against antibiotic-resistant H. pylori.

METHODS

Ten antibiotic-resistant strains and one sensitive H. pylori strain were used in this study. After irradiation by blue LED along time course, the viability of H. pylori was evaluated by enumerating colony forming units. Morphological changes in H. pylori were observed using a scanning electron microscope. Reductase activity was measured as an indicator of bacterial cellular activity. Total reactive oxygen species was monitored using fluorescence intensity and fluorescence microscope imaging.

RESULTS

After irradiation by blue LED, the numbers of H. pylori in all the strains were significantly reduced compared with control group. The H. pylori exhibited a short rod-shaped morphology after irradiation; no such change was observed in H. pylori not exposed to blue LED. Re-irradiation of surviving strain after the initial irradiation also exhibited the same anti-proliferation effect. After blue LED irradiation, bacterial cellular activity was lower, and total reactive oxygen species production was significantly higher in blue LED group, compared with that in control.

CONCLUSIONS

Blue LED could be a new treatment to eradicate infection with antibiotic-resistant H. pylori.

Helicobacter pylori infection in children

Helicobacter pylori infection in children differs from that in adults, from the point of view of epidemiology, host response, clinical features, related diseases, and diagnosis, as well as treatment strategies. The prevalence of H. pylori infection, in both children and adults, is decreasing in the Western World as well as in some developing countries, which contrasts with the increase in childhood asthma and allergic diseases. Recurrent abdominal pain is not specific during H. pylori infection in children. The role of H. pylori infection and failure to thrive, children's growth, type I diabetes mellitus (T1DM) and celiac disease remains controversial. The main initial diagnosis is based on upper digestive endoscopy with biopsy-based methods. Nodular gastritis may be a pathognomonic endoscopic finding of childhood H. pylori infection. The infection eradication control is based on validated noninvasive tests. The main cause of treatment failure of H. pylori infection is its clarithromycin resistance. We recommend standard antibiotic susceptibility testing of H. pylori in pediatric patients prior to the initiation of eradication therapy. H. pylori treatment in children should be based on an evaluation of the rate of eradication in the local population, a systematic use of a treatment adapted to the susceptibility profile and a treatment compliance greater than 90%. The last meta-analysis in children did not show an advantage for sequential therapy when compared to a 14-day triple therapy. Finally, the high rate of antibiotic resistance responsible for therapy failure in recent years justifies the necessity of a novel vaccine to prevent H. pylori infection in children.

Low Re-infection Rate of Helicobacter pylori after Successful Eradication in Thailand: A 2 Years Study

Background:

H. pylori is an important cause of chronic gastritis, peptic ulcers and gastric cancer. Re-infection rates after successful eradication vary in different regions of the world but only limited studies have been performed in ASEAN Countries to clarify this important issue. The present study was designed to evaluate the H. pylori re-infection rate and predictors of re-infection in Thailand.

Methods:

We recruited patients with chronic gastritis after 1 and 2 years successful H. pylori eradication from Thammasat University Hospital, Pathumthani (Central urban area) and Maesod district, Tak (Northern rural area), Thailand. 13C-UBT was performed to evaluate re-infection status after cessation of PPI, H2 blocker and antibiotics for at least 4 weeks. Statistical analysis was performed using SPSS for Windows Version 22.0 (IBM Corp., Armonk, NY).

Results:

A total of 105 subjects were enrolled (40 M and 65F with a mean age of 53.1 years). The overall re-infection rate was 6/105 (5.7%). The 1-year and 2-year H. pylori re-infection rates after successful eradication were only 5.1% (2/39) and 6.1% (4/66). 1-year and 2-year reinfection rates in urban areas were 2/39 (5.1%) and 1/26 (3.8%), while the 2-year reinfection rate in rural areas was 3/40 (7.5%). Location (urban vs rural area) and sex did not show any association with either 1-year or 2-year H. pylori re-infection. With 2-year reinfection, the mean age of H. pylori re-infected patients was significantly higher than those who remained cured (63.0 years vs. 51.6 years, p-value = 0.01). The annual H. pylori infection rate was 2.9%.

Conclusions:

1-year and 2-year H. pylori re-infection rates after successful eradication in Thailand appear low in both rural and urban areas. H. pylori eradication for prevention of significant upper GI disease should be recommended and confirmation of successful eradication should be the aim. Patients at higher risk such as the elderly should be monitored for possible risk of H. pylori re-infection.

High Fluoroquinolone Resistant Strains of Helicobacter pylori in the Golden triangle

Background and aims:

Helicobacter pylori (H. pylori) infections, associated with fatal GI diseases such as gastric cancer and MALT lymphoma, remain a major health problem in ASEAN countries. The Golden triangle has long been known as one of Asia’s main opium-producing areas. There have been no prior studies of H. pylori infection in this area. The major objectives of this project were therefore to establish prevalence, antibiotic resistance patterns and associated predictive in the Golden triangle.

Methods:

We recruited dyspeptic patients in Chiang khong and Chiang saen districts, Chiangrai province of Thailand. All subjects underwent gastroscopy, and 3 antral gastric biopsies were collected for rapid urease tests and H. pylori culture. E-tests were used to evaluate the MICs for metronidazole (MNZ), levofloxacin (LVX), ciprofloxacin (CIP), amoxicillin(AMX), tetracycline (TET) and clarithromycin (CLR).

Results:

Total of 148 patients was included. H. pylori infection was present in 36.3%(37/102) of Chiang khong and 34.8 % (16/46) of Chiang saen subjects and the overall H. pylori infection rate was 35.8% (53/148). Antibiotic resistance was demonstrated in 44%, including 2% for CLR and 26% for MNZ, whereas fluoroquinolone resistance was demonstrated to be as high as 25% in Chiang khong. Multi-drug resistant H. pylori was detected in 4%. There was no AMX and TET resistance in this study. The prevalence of CLR resistance on a background of gastritis was significantly higher than peptic ulcer disease in the golden triangle area (100%vs 0%: P= 0.04).

Conclusions:

H. pylori remains a common infection in the Golden triangle. MNZ resistance appears to be high, whereas fluoroquinolone resistance is prevalent and is becoming a significant problem in this area. Diagnosis of gastritis might be a predictor of CLR resistance in the Golden triangle. H. pylori eradication with an appropriate regimen by using the local antibiotic resistant pattern is a key important tool to reduce H. pylori associated GI diseases in this particular part of the world.