Genotype profiles of Helicobacter pylori from gastric biopsies and strains with antimicrobial-induced resistance

Current status of Helicobacter pylori resistance to clarithromycin and levofloxacin in Vietnam: Results from molecular analysis of gastric biopsy specimens

OBJECTIVES

The management of Helicobacter pylori in Vietnam is becoming progressively more difficult due to increasing antibiotic resistance, particularly to clarithromycin (CLR) and levofloxaxin (LVX). In Vietnam, the selection of an H. pylori eradication regimen is predominantly based on empirical evidence. However, molecular analysis aimed at identifying H. pylori antibiotic-resistant genotypes is a promising method in antibiotic susceptibility testing. In this study, we aimed to determine the rates of genotypic H. pylori resistance to CLR and LVX by using DNA strip technology in Vietnam.

METHODS

We performed DNA-strip technology-based testing on 112 patients with H. pylori-positive gastroduodenal diseases to detect 23S rRNA and gyrA mutations.

RESULTS

Helicobacter pylori genotypic resistance to CLR and LVX was evident in 81.3% and 53.6% of the patients, respectively, and dual resistance was observed in 48.2%. The 23S rRNA A2142G and A2143G mutations accounted for 1.8% and 79.5% of cases, respectively. The gyrA N87K, D91N, D91G, and D91Y mutations were present in 37.5%, 11.6%, 5.4%, and 5.4% of patients, respectively. All four gyrA mutations were observed in both the naïve and failure patients. We further found an association between the 23S rRNA A2143G mutation and a history of CLR use as well as between the gyrA N87K mutation and a history of LVX use.

CONCLUSIONS

We found a very high prevalence of H. pylori resistance to CLR and LVX and dual resistance to these antibiotics in Vietnam. The application of molecular assays is feasible and may improve the management of H. pylori infection in Vietnam.

Helicobacter pylori antibiotic resistance in different regions of China: A systematic review and meta-analysis

BACKGROUND

Increasing drug resistance of Helicobacter pylori (H. pylori) in China has become one of the major obstacles to the efficacy of empirical eradication therapy. Resistance profiles vary from region to region, which poses an additional challenge to the expansion of empirical eradication therapy.

AIM

To evaluate H. pylori antibiotic resistance in various regions of China systematically.

METHODS

A thorough computerized search of various databases, including PubMed, EMBASE, Web of Science, Sinomed, CNKI, Wanfang Data, and VIP, was conducted to identify cross-sectional studies on H. pylori resistance in various regions of China. Two researchers independently screened the literature, extracted the data, and evaluated the quality of the literature. R 4.3.1 software was used for Meta-analysis of the resistance rate to each antibiotic and their combinations.

RESULTS

A total of 46 eligible articles were included. Clarithromycin (CLA), levofloxacin (LEV), amoxicillin (AMX), tetracycline (TET), metronidazole (MNZ), and furazolidone (FZD) resistance rates in China were 27.72% (95% confidence interval [CI]: 23.80%-31.82%), 31.23% (95%CI: 26.62%-36.02%), 3.97% (95%CI: 1.96%-6.65%), 4.01% (95%CI: 1.36%-7.98%), 75.30% (95%CI: 70.31%-79.97%), and 0.64% (95%CI: 0.13%-1.53%), respectively. The rate of AMX resistance varied significantly among different regions of China, being the highest in South China (7.15%, 95%CI: 6.16%-76.10%) and the lowest in North China (1.86%, 95%CI: 0.67%-3.64%). CLA resistance in East and Central China, LEV resistance in East and Northwest China, and MNZ resistance in North and Southwest China all increased significantly over time, while AMX and TET resistance in East China notably decreased. CLA + MNZ, LEV + MNZ, and CLA + LEV dual resistance rates in China reached 14.05% (95%CI: 10.70%-17.77%), 15.12% (95%CI: 11.53%-19.10%), and 5.16% (95%CI: 2.87%-8.06%), respectively. CLA + LEV + MNZ, LEV + MNZ + AMX, and CLA + MNZ + AMX triple resistance rates were 10.36% (95%CI: 7.45%-13.69%), 0.92% (95%CI: 0.12%-2.44%), and 0.85% (95%CI: 0.20%-1.92%), respectively.

CONCLUSION

H. pylori resistance is serious in China, with MNZ resistance rate being the highest, followed by CLA and LEV resistance rates. The detection rate of some multi-resistant organisms has also reached a high level. Antibiotic resistance rates vary slightly across different regions of China, and most of them show an increasing trend over time.

Tailored therapy guided by genotypic resistance of clarithromycin and levofloxacin detected by polymerase chain reaction in the first-line treatment of Helicobacter pylori infection

OBJECTIVES

We aimed to explore the efficacy and safety of tailored therapy guided by genotypic resistance in the first-line treatment of Helicobacter pylori (H. pylori) infection in treatment-naive patients.

METHODS

Gastric mucosal specimens were taken during gastroscopy, and main mutations of clarithromycin- and levofloxacin-resistant genes were detected by polymerase chain reaction (PCR). Sensitive antibiotics were selected individually for treating H. pylori infection with tailored bismuth-containing quadruple therapy (BQT) consisting of esomeprazole 20 mg twice daily, bismuth potassium citrate 220 mg twice daily, amoxicillin 1 g twice daily, and clarithromycin 500 mg twice daily, or levofloxacin 500 mg once daily, or metronidazole 400 mg four times daily. Safety and patient compliance were assessed 1-3 days after eradication. Treatment outcome was evaluated by urea breath test 4-8 weeks after eradication.

RESULTS

One hundred and thirty-two treatment-naive patients with H. pylori infection were included. PCR results suggested resistance rates of 47.7% and 34.9% for clarithromycin and levofloxacin, respectively, and a dual resistance rate of 18.2%. Eradication rates of tailored BQT were 87.1% and 95.8% by intention-to-treat (ITT) analysis and per-protocol (PP) analysis, respectively. There was no statistically significant difference in the efficacy of 7-day clarithromycin-containing, 7-day levofloxacin-containing, and 14-day full-dose metronidazole-containing BQT (ITT analysis: P = 0.488; PP analysis: P = 0.833). The incidence of adverse events was 19.7%, and patient compliance was 97.7%.

CONCLUSION

Tailored BQT guided by genotypic resistance can achieve satisfactory efficacy, safety, and patient compliance in the first-line treatment of H. pylori infection.

Antibiotic resistance of Helicobacter pylori in Nanjing, China: a cross-section study from 2018 to 2023

Background

The increasing prevalence of antibiotic resistance in cases of Helicobacter pylori (H. pylori) infection has emerged as a significant global issue. This study offers a comprehensive examination of the alterations in drug resistance exhibited by H. pylori in the Nanjing region of China during the preceding five years. Another important objective is to investigate the influence of levofloxacin medication history on genotypic and phenotypic resistance.

Methods

This research screened 4277 individuals diagnosed with H. pylori infection between April 2018 and May 2023. The phenotype and genotypic resistance were evaluated using the Kirby-Bauer disk diffusion and PCR method.

Results

The most recent primary resistance rates for metronidazole, clarithromycin, levofloxacin, amoxicillin, furazolidone, and tetracycline were recorded at 77.23% (2385/3088), 37.24% (1150/3088), 27.72% (856/3088), 0.52% (16/3088), 0.19% (6/3088), and 0.06% (2/3088), respectively. For the recent five years, we observed a notable upsurge in the rate of metronidazole resistance and a slight elevation of clarithromycin and levofloxacin resistance. The documented resistance rates to single-drug, dual-drug, triple-drug, and quadruple-drug regimens were 35.39%, 28.32%, 25.72%, and 0.21%, respectively. The prevalence of multidrug-resistant strains escalated, rising from 37.96% in 2018 to 66.22% in 2023. The rate of phenotypic and genotypic resistance rate (57.10% and 65.57%) observed in strains obtained from patients without a levofloxacin treatment history was significantly lower than the rate in strains obtained from those with a history of levofloxacin treatment (88.73% and 94.74%). The prevailing gyrA mutations were primarily N87K (52.35%, 345/659), accompanied by D91N (13.96%, 92/659), and closely followed by D87G (10.77%, 71/659). For gyrA mutations, the 91-amino acid mutants exhibit a higher likelihood of discrepancies between phenotypic and genotypic resistance than the 87-amino acid mutants.

Conclusion

The extent of antibiotic resistance within H. pylori remains substantial within the Nanjing region. If levofloxacin proves ineffective in eradicating H. pylori during the initial treatment, its use in subsequent treatments is discouraged. The employment of levofloxacin resistance genotype testing can partially substitute conventional antibiotic sensitivity testing. Notably, predicting phenotypic resistance of levofloxacin through PCR requires more attention to the mutation type of gyrA to improve prediction accuracy.

A rapid and high-throughput multiplex genetic detection assay for detection, semi-quantification and virulence genotyping of Helicobacter pylori in non-invasive oral samples

Aim

This study established a high-throughput multiplex genetic detection assay (HMGA) for rapid identification, semi-quantification and virulence analysis of Helicobacter pylori directly from the clinical non-invasive oral samples.

Methods

The gastric mucosa and oral samples were collected from 242 patients in Shanghai from 2021 to 2022. All the samples were detected by routine clinical tests for H. pylori and Sanger sequenced for inconsistent results. A new multiplex PCR assay providing results within 4 hours was designed and optimized involving fluorescent dye-labeled specific primers targeted 16S rRNA gene, semi-quantitative gene ureC and 10 virulence genes of H. pylori. Semi-quantification was carried out by simulating the serial 10-fold dilutions of positive oral samples, and the H. pylori loads in different clinical samples were further compared. The mixed plasmids of virulence genes vacA s1, vacA m1 and vacA m2 were used to evaluate the performance on different genotypes. The consistency of 10 virulence genes in gastric mucosa, saliva, mouthwash and dental plaque of H. pylori-positive patients was compared.

Results

The non-invasive HMGA was highly specific for detection of all 12 targets of H. pylori and human internal reference gene β-globin, and the sensitivity to all target genes could reach 10 copies/μL. Compared with routine clinical tests and sequencing, non-invasive HMGA has a high level (>0.98) of sensitivity, specificity, accuracy, PPV, NPV and kappa coefficient for direct detection of H. pylori in oral samples. Moreover, by detecting peak area levels of ureC, it was confirmed that the H. pylori loads in gastric mucosa were significantly higher than those of the three kinds of oral samples (p<0.05). We also found that 45.0% (91/202) of patients had different H. pylori virulence genes in different oral samples. The concordance of positive detection rates of each virulence gene between saliva and gastric mucosa was more than 78% (p<0.05).

Conclusion

The non-invasive HMGA proved to be a reliable method for the rapid H. pylori identification, semi-quantification and detection of 10 virulence genes directly in oral samples, providing a new idea for non-invasive detection of H. pylori.

Iatrogenic factors of Helicobacter pylori eradication failure: lessons from the frontline

BACKGROUND

Iatrogenic factors play an important role in H. pylori eradication failure, whereas it can be easily missed. Therefore, we aimed to investigate and analyze these related iatrogenic factors of H. pylori eradication failure.

METHODS

A total of 508 patients who experienced H. pylori eradication failure were included in this study conducted from December 2019 to February 2022. All the patients filled out a questionnaire including demographic characteristics, duration of treatment, regimens, dosage, and time intervals in rescue treatment.

RESULTS

In the first-line treatment, 89 patients (17.5%, 89/508) used at least one antibiotic with high resistance rate in triple therapy and 57 patients (11.2%, 57/508) used two antibiotics with high resistance rates or other not recommended antibiotics in quadruple therapy. In the rescue therapy, 85 regimens were repeatedly used as salvage regimens in 58 patients (22.6%, 58/257) and 178 regimens containing antibiotics with high resistance rates were repeatedly used in 85 patients (33.1%, 85/257).

CONCLUSION

To decrease the risk of H. pylori eradication failure, iatrogenic factors need to gain more attention. Clinicians should enhance their education and training to standardize the treatment regimens, better manage the H. pylori infection, and improve the eradication rate eventually.

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.

Susceptibility-Guided Therapy vs. Bismuth-Containing Quadruple Therapy as the First-Line Treatment for Helicobacter pylori Infection: A Systematic Review and Meta-Analysis

Background

The increased antibiotic resistance of Helicobacter pylori (H. pylori) has led to the decreased efficacy of H. pylori regimens.

Aim

To evaluate the efficacy, safety, and compliance of susceptibility-guided therapy (SGT) vs. bismuth-containing quadruple therapy (BQT) as the first-line treatment for H. pylori infection.

Materials and Methods

This meta-analysis was performed in accordance with the PRISMA 2009 guidelines. A systematic search in PubMed, Embase, and Cochrane databases was conducted using the combination of “H. pylori or H. pylori or Hp,” “bismuth quadruple,” and “tailored eradication OR tailored therapy OR susceptibility-guided therapy OR personalized therapy OR antibiotic susceptibility testing.”

Results

Five studies with 2,110 H. pylori-infected patients were enrolled. The pooled eradication rates of SGT and BQT were 86 vs. 78% (p < 0.05) and 92 vs. 86% (p > 0.05) by intention-to-treat (ITT) and per-protocol (PP) analyses, respectively. SGT has a significantly superior efficacy than BQT [pooled risk ratio (RR) = 1.14, p < 0.05] in a subgroup of cultures with the susceptibility test. The pooled side effect rate was 20% in SGT and 22% in BQT, which showed no significant difference (p > 0.05). The compliances of SGT and BQT were 95 and 92%, respectively.

Conclusion

Compared with BQT, SGT showed a higher efficacy and similar safety as the first-line treatment of H. pylori infection in areas with high antibiotic resistance. The decision-making of first-line regimens for H. pylori infection should depend on the availability and cost-effectiveness of susceptibility tests and bismuth in local areas.

Characteristics of Helicobacter pylori Heteroresistance in Gastric Biopsies and Its Clinical Relevance

Background

Antimicrobial susceptibility testing (AST) plays a vital role in anti-Helicobacter pylori treatment, but the traditional AST method has difficulty detecting heteroresistance, which may cause an increased prevalence of resistant strains and eradication failure.

Aims

To investigate the characteristics of heteroresistance in H. pylori in gastric biopsies and investigate its clinical relevance.

Method

A total of 704 gastric biopsies were selected for 23S rRNA and gyrA gene sequencing, 470 H. pylori isolates from these biopsies were selected for AST, and the clinical characteristics of the patients were reviewed.

Result

For the 699 biopsies that were positive for 23S rRNA gene, 98 (14.0%) showed a heteroresistance genotype, and a wild type (WT) combined with A2143G (86.7%) genotype was found in most samples. For the 694 biopsies that were positive for gyrA gene, 99 (14.3%) showed a heteroresistance genotype, and a WT combined with 87K (26.3%) or WT combined with 91N (23.2%) genotype was predominant. According to the E-test results, the resistance rates of heteroresistance genotype samples for clarithromycin and levofloxacin were 36.2% and 68.1%, respectively. When dividing the heteroresistance samples into different groups according to the sequencing profile peaks of the mutation position, the resistance rates were higher along with mutation peaks at the mutation position. In addition, patients infected with mutated or heteroresistant strains showed lower peptic ulcer detection rates than those infected with the WT strain (p &lt; 0.05).

Conclusion

Heteroresistance genotypes for clarithromycin and levofloxacin were not rare in H. pylori. Most cases with a heteroresistance genotype showed a susceptible phenotype for clarithromycin and a resistance phenotype for levofloxacin. Patients infected with heteroresistance genotype strains showed a lower peptic ulcer detection rate than those infected with the WT strain.

Current status of Helicobacter pylori resistance to Clarithromycin and Levofloxacin in Malaysia-findings from a molecular based study

Background

Resistance to clarithromycin and levofloxacin in Helicobacter pylori which resulted in treatment failures has become a major challenge for physicians worldwide. The resistance is mainly mediated by mutations in a specific domain of the 23S rRNA, gyrA and gyrB genes for clarithromycin and levofloxacin respectively. Hence in this study, we aimed to investigate the current status of H. pylori resistance in our hospital to these two antibiotics based on the molecular approach.

Materials and Methods

Gastric biopsy samples were obtained from treatment-naïve patients. Bacterial genomic DNA was extracted using a commercial kit and continued with DNA amplification using polymerase chain reaction (PCR) with specific primers. The PCR amplicons were subjected to sequencing on 23S rRNA gene targeting nucleotide positions at 2,146, 2,147, 2,186 and amino acids at gyrA positions 87 and 91 and gyrB positions 436, 438, 481, 484 to investigate the possible mutations or polymorphisms of genes that lead to clarithromycin and levofloxacin resistance respectively.

Results

Sixty-one urease-positive gastric biopsy samples were studied. The findings revealed the primary resistance rates to clarithromycin was 14.8% and to levofloxacin was 3.3% in our current scenario based on detection of reported resistance-related mutations of A2147G and D91N in 23S rRNA and gyrA genes, respectively. Interestingly, we found a high rate of silent mutations of the gyrA codon 87Asn (32.8%, 20/61) and two polymorphisms of the gyrB D481E (16.4%, 10/61) and R484K (21.3%, 13/61). The role of these polymorphisms in gyrB remained to be elucidated whether the levels of levofloxacin resistance are related to the position/amino acid.

Conclusion

The primary resistance rate of H. pylori to clarithromycin has increased compared to the previous report in Malaysia. Therefore, molecular screening could aid and is important for the selection of antibiotics for H. pylori eradication therapies.

Correlation Analysis Among Genotype Resistance, Phenotype Resistance and Eradication Effect of Helicobacter pylori

Background

It has not been fully confirmed whether the detection of Helicobacter pylori resistance gene mutation can replace antibiotic drug sensitivity test to guide the clinical individualized treatment. Therefore, we have studied this aspect and discussed the application value of antibiotic sensitivity gene test.

Materials and Methods

The biopsy specimen of gastric mucosa from the patients examined by endoscopy and positive for rapid urease test were collected continuously for histopathological analysis, H. pylori culture, antibiotic drug sensitivity test (E-test drug sensitivity test), and antibiotic sensitivity gene test (high-throughput nucleotide sequencing). The participants received triple plus bismuth solution eradication treatment (esomeprazole 20 mg, amoxicillin 1000 mg, clarithromycin 500 mg, and bismuth potassium citrate 220 mg, twice daily for 14 days) for follow-up, and the eradication effect was determined.

Results

The 551/602 subjects, who met the inclusion criteria, were subjected to culture for H. pylori and antibiotic drug sensitivity determination; among them 506 were cultured successfully. The results showed that the resistance rates of H. pylori were 38.9% for clarithromycin and 31.0% for levofloxacin. In 489 H. pylori strains, the mutations were detected in clarithromycin and levofloxacin resistance genes, indicating the genotype resistance. The resistance genes of clarithromycin and levofloxacin were consistent with phenotype resistance with respect to sensitivity (81.2% and 69.7% for clarithromycin and levofloxacin, respectively) and specificity (88.9% and 93.7% for clarithromycin and levofloxacin, respectively). The eradication rate of H. pylori in the clarithromycin-resistant group was significantly lower than that in the sensitive group (ITT: 52.1% vs 85.0%, P < 0.001).

Conclusion

A correlation was established between the resistance genes of clarithromycin and levofloxacin and their phenotypic resistance and clinical efficacy. The detection of H. pylori resistance genes has a good clinical application prospect.