Surveillance of Levofloxacin Resistance in Helicobacter pylori Isolates in Bogotá-Colombia (2009-2014)

Efficacy and Safety of Standard Triple Therapy for Helicobacter pylori Eradication in Latin America: A Systematic Review and Meta-Analysis

GOALS

To evaluate the efficacy and safety of standard triple therapy (STT) in Latin America.

BACKGROUND

Helicobacter pylori infection affects more than 50% of the Latin Americans and leads to gastric mucosa damage. Scarce data on effective therapeutic approaches in the region underscores the need for comprehensive information.

STUDY

The analysis included Randomized Controlled Trials published up to the year 2020, comparing STT with other treatments. Cumulative relative risks (RR) were estimated, with 95% CI, according to intention-to-treat (ITT) and per protocol (PP) analysis.

RESULTS

Eleven studies (clinical trials conducted between 1995 and 2013), revealed cumulative eradication rates of 78.31-90.63% (ITT) and 76.71-93.55% (PP). The eradication with the STT was superior to sequential therapy (ITT-RR: 10.6, 95% CI: 1.01 to 1.12) (PP-RR: 10.6, 95% CI: 1.02-1.11) and dual therapy (ITT-RR: 1.61, 95% CI: 1.13-2.30) (PP-RR: 1.72, 95% CI: 1.25-2.37), but is less effective than other triple therapies (PP-RR: 0.85, 95% CI: 0.78-092). Regarding adverse effects, diarrhea, metallic taste, nausea, vomiting, and headache were the most common symptoms across treatments. Abdominal pain was associated with STT (ITT-RR: 1.75, 95% CI: 1.07-2.86).

CONCLUSION

STT was a safe regimen but with acceptable efficacy (most eradication rates <90%). Due to rising clarithromycin resistance, the study suggests avoiding STT as a first-line treatment. These results must be considered with caution due to the low representativeness of several Latin American countries and the lack of recent high-quality randomized studies.

Antimicrobial susceptibility of clinical Helicobacter pylori isolates and its eradication by standard triple therapy: a study in west central region of Colombia

The aim of the present study was first to isolate Helicobacter pylori from gastric biopsy specimens and to test their antibiotic susceptibility. Second, it was to evaluate the efficacy of the standard triple therapy from patients of the west central region of Colombia. H. pylori positive patients received standard triple therapy with proton pump inhibitor (PPI) (40 mg b.i.d.), clarithromycin (500 mg b.i.d.), and amoxicillin (1 g b.i.d.) for 14 days. Thereafter, antibiotic susceptibility of the isolates was assessed by E-Test. From 94 patients enrolled, 67 were positive for H. pylori by histology or culture. Overall resistance to metronidazole, levofloxacin, rifampicin, clarithromycin, and amoxicillin was 81%, 26.2%, 23.9%, 19%, and 9.5%, respectively. No resistance was found for tetracycline. A total of 54 patients received standard triple therapy, 48 attended follow-ups testing, and of them, 30 had resistance test reports. Overall eradication rate was 81.2%. Second-line treatment was given to eight patients, four of whom were followed up with a 13C urea breath test (UBT) and remained positive for H. pylori. Eradication was significantly higher in patients with clarithromycin susceptible than in resistant strains (95.6% vs 42.8% P = 0.001). The updated percentages of resistance to clarithromycin in this geographical area had increased, so this value must be considered when choosing the treatment regimen.IMPORTANCEAntibiotic resistance in Helicobacter pylori has increased worldwide, as has resistance to multiple antimicrobials (MDRs), which seriously hampers the successful eradication of the infection. The ideal success rate in eradicating H. pylori infection (≥90%) was not achieved in this study (81.2%). This is the first time that MDR is reported (14.3%) in the region; the resistance to clarithromycin increased over time (3.8%-19%), and levofloxacin (26.2%) and rifampicin (23%) resistant isolates were detected for the first time. With these results, strain susceptibility testing is increasingly important, and the selection of treatment regimen should be based on local antibiotic resistance patterns.

Helicobacter pylori Secondary Antibiotic Resistance after One or More Eradication Failure: A Genotypic Stool Analysis Study

Helicobacter pylori (H. pylori) antibiotic resistance is the leading cause for unsuccessful eradication therapy. After one or more failures, the chance of encountering secondary antibiotic resistance increases. The aim of this study was to characterize genotypic secondary resistance in a cohort of southern Italian H. pylori patients with at least one previous failure. Such patients collected stool samples using a dedicated kit (THD fecal testTM), and bacterial DNA was extracted and amplified using RT-PCR. Resistance to clarithromycin, amoxicillin, metronidazole, levofloxacin, and tetracycline was assessed using a high-resolution melting curve. We enrolled 50 patients. A total of 72% of patients failed one previous antibiotic course, 16% failed two, 10% failed three, and 2% failed four. The rate of secondary antibiotic resistance was 16% for clarithromycin, 18% for metronidazole, 14% for amoxicillin, 14% for levofloxacin, and 2% for tetracycline. Among the eight clarithromycin-resistant patients, five (62.5%) previously received a clarithromycin-based regimen. The same rate was 33.3% (3/9) for metronidazole. The only tetracycline-resistant patient had received Pylera. In conclusion, our data seem to show that, even though secondary resistance is not very high, resistance to clarithromycin could be very likely related to previous exposure to this antibiotic.

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.

The dark side of drug repurposing. From clinical trial challenges to antimicrobial resistance: analysis based on three major fields

Drug repurposing is a strategic endeavor that entails the identification of novel therapeutic applications for pharmaceuticals that are already available in the market. Despite the advantageous nature of implementing this particular strategy owing to its cost-effectiveness and efficiency in reducing the time required for the drug discovery process, it is essential to bear in mind that there are various factors that must be meticulously considered and taken into account. Up to this point, there has been a noticeable absence of comprehensive analyses that shed light on the limitations of repurposing drugs. The primary aim of this review is to conduct a thorough illustration of the various challenges that arise when contemplating drug repurposing from a clinical perspective in three major fields-cardiovascular, cancer, and diabetes-and to further underscore the potential risks associated with the emergence of antimicrobial resistance (AMR) when employing repurposed antibiotics for the treatment of noninfectious and infectious diseases. The process of developing repurposed medications necessitates the application of creativity and innovation in designing the development program, as the body of evidence may differ for each specific case. In order to effectively repurpose drugs, it is crucial to consider the clinical implications and potential drawbacks that may arise during this process. By comprehensively analyzing these challenges, we can attain a deeper comprehension of the intricacies involved in drug repurposing, which will ultimately lead to the development of more efficacious and safe therapeutic approaches.

Levofloxacin induces erythrocyte contraction leading to red cell death

Background

Levofloxacin, a fluoroquinolone, is an extensively used antibiotic effective against both positively and negatively staining bacteria. It works by inhibiting bacterial topoisomerase type II and topoisomerase type IV, resulting in impaired DNA synthesis and bacterial cell death. Eryptosis is another term for apoptotic cell death of erythrocyte marked by cell shrinkage, phosphatidylserine (PS) flipping, and membrane blebbing.

Methods

The intent of the present research was to look at the eryptotic effect of levofloxacin by exposing erythrocytes to therapeutical doses (7, 14 µM) of levofloxacin for 48 hours. Cell size evaluation, PS subjection to outside, and calcium channel inhibition were carried out to investigate eryptosis. Oxidative stress generated by levofloxacin was measured as a putative mechanism of eryptosis using glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase activities. Similarly, hemolysis measurements demonstrated levofloxacin's cytotoxic effect.

Results

Our findings showed that therapeutic doses of levofloxacin can cause a considerable decline in antioxidant enzymes activities, as well as induce cell shrinkage, PS externalization, and hemolysis in erythrocytes. The role of calcium in triggering erythrocyte shrinkage was also confirmed.

Conclusion

In conclusion, our findings showed that the indicated levofloxacin doses caused oxidative stress, which leads to erythrocyte death via eryptosis and hemolysis. These findings emphasize the importance of using levofloxacin with caution and the need for additional research to mitigate these side effects.

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.

The Helicobacter pylori single nucleotide polymorphisms SNPs associated with multiple therapy resistance in Colombia

The eradication of Helicobacter pylori (H. pylori) using multiple therapies is used as a prevention strategy. However, its efficacy has been compromised by the emergence of single nucleotide polymorphisms in genes associated with H. pylori's resistance to multiple antibiotics. To estimate antibiotic resistance rates associated with mutations in H. pylori genes in the high-cancer-risk population in Colombia, we included 166 H. pylori whole genome sequences from a cohort of individuals with a high risk of gastric cancer. By using the reference strain ATCC 26695, we identified mutations in specific genes to evaluate resistance rates for different antibiotics: 23S rRNA for clarithromycin, 16S rRNA for tetracycline, pbp1A for amoxicillin, gyrA for levofloxacin, and rdxA for metronidazole. The phylogenomic analysis was conducted using the core genome consisting of 1,594 genes of H. pylori-ATCC 26695. Our findings revealed that the resistance rate of H. pylori to clarithromycin was 3.62%, primarily associated with mutations A2143G and A2142G in the 23S rRNA gene. For tetracycline, the resistance rate was 7.23%, with mutations A926G, A926T, and A928C observed in the 16S rRNA gene. Amoxicillin resistance was found in 25.9% of cases, with observed mutations in the pbp1A gene, including T556S, T593, R649K, R656P, and R656H. In the gyrA gene, mutations N87K, N87I, D91G, D91N, and D91Y were identified, resulting in a resistance rate of 12.04% to levofloxacin. The most common mutations in the rdxA gene associated with metronidazole resistance were a stop codon, and mutations at D59N and D59S, resulting in a resistance rate of 99.3%. The high resistance rate of H. pylori to metronidazole indicated that this drug should be excluded from the eradication therapy. However, the resistance rates for tetracycline and clarithromycin did not exceed the established resistance threshold in Colombia. The increased resistance rate of H. pylori to levofloxacin and amoxicillin may partially explain the observed therapeutic failures in Colombia. The phylogenomic tree showed that the H. pylori isolate belongs to its own lineage (hspColombia). These findings offer valuable insights to enhance the characterization of treatment protocols for the specific H. pylori lineage (hspColombia) at the local level.

Efficacy and Safety of Antofloxacin-Based Triple Therapy for Helicobacter pylori Eradication Failure in China

AIMS

Quinolone-containing triple therapy has been considered as the second-line therapy for eradication of Helicobacter pylori (H. pylori). At present, there are no data to show the efficacy and safety of antofloxacin-based rescue therapy for the eradication of H. pylori, and this pilot clinical trial was designed.

METHODS

A total of 196 patients who failed H. pylori eradication using the clarithromycin-based or metronidazole-based triple or bismuth quadruple therapy were randomly allocated to one of the following rescue eradication therapy groups: AEA group (antofloxacin 200 mg once daily, esomeprazole 20 mg + amoxicillin 1000 mg twice daily) for 14 days, or LEA group (levofloxacin 500 mg once daily, esomeprazole 20 mg + amoxicillin 1000 mg twice daily) for 14 days. The minimal inhibitory concentrations were tested by the E-test method. The gyrA mutation was analyzed by sequencing. Follow-up ^13/14C-urea breath test was examined at 1 month after discontinuation.

RESULTS

A total of 178 eligible patients were included in this study. The eradication rate was significantly higher in AEA group than in LEA group according to both ITT (87.6% vs. 68.5%; P = 0.002) and PP analyses (90.7% vs. 70.1%; P = 0.001). ITT analyses indicated that the eradication rate was significantly higher in AEA group than in LEA group with Asn87 mutation (78.9% vs. 31.3%; P = 0.005) and levofloxacin-resistant strains (76.9% vs. 44.2%; P = 0.003). Two groups exhibited similar adverse event rates (AEA 14.6% vs. LEA 20.2%, P = 0.323).

CONCLUSIONS

The findings showed that antofloxacin may be a promising candidate in rescue therapy for H. pylori eradication failure in China.

Mutations associated with Helicobacter pylori antimicrobial resistance in the Ecuadorian population

AIMS

We described the presence of Helicobacter pylori (HP) and estimated the prevalence of primary and secondary resistance using molecular detection in gastric biopsies of Ecuadorian patients.

METHODS AND RESULTS

66.7% (238/357) of the patients demonstrated the presence of HP using CerTest qPCR. Of these, 69.79% (104/149) were without previous HP eradication treatment and 64.42% (134/208) with prior HP eradication treatment. The mutation-associated resistance rate for clarithromycin was 33.64% (primary resistance) and 32.82% (secondary resistance), whereas that in levofloxacin the primary and secondary resistance was 37.38% and 42%, respectively. For tetracycline and rifabutin, primary and secondary resistance was 0%. Primary and secondary resistance for metronidazole and amoxicillin could not be evaluated by genotypic methods (PCR and sequencing).

CONCLUSIONS

The analysis of mutations in gyrA, 23S rRNA and 16S rRNA is useful to detect bacterial resistance as a guide for eradication therapy following failure of the first-line regimen.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study carried out in an Ecuadorian population indicates that the resistance of HP to first-line antibiotics is high, which may contribute to the high rates of treatment failure, and other treatment alternatives should be considered.

Levofloxacin-based therapy as an efficient alternative for eradicating Helicobacter pylori infection in Iran: a systematic review and meta-analysis

OBJECTIVES

Despite excessive resistance of Helicobacter pylori to clarithromycin among Iranian population, unfortunately, clarithromycin-based therapy is still prescribed in Iran. Recent studies have shown high rates of H. pylori eradication in patients treated with levofloxacin. The main purpose of this study was to compare the effect of levofloxacin with clarithromycin on the eradication of H. pylori infection in Iranian population.

METHODS

A comprehensive meta-analysis was done for the relevant cohort studies and clinical trials to compare the therapeutic effects of levofloxacin with clarithromycin in Iranian population. We pooled the data using odds ratio corresponding to 95% confidence intervals to find the clinical efficacy of levofloxacin versus clarithromycin to treat H. pylori infection. The heterogeneity and publication bias were also measured for the included studies.

RESULTS

A total of 13 studies were included in the quantitative synthesis. Eradication rate in patients receiving levofloxacin and clarithromycin were 75% and 66.3%, respectively (OR: 1.76; 95% CI: 1.40-2.20). In addition, in the subgroup analysis, it was confirmed that cure rate is relatively higher in levofloxacin-treated cases. However, there is significant heterogeneity as well as publication bias, thus, the results need to be interpreted with caution.

CONCLUSIONS

We found that the success of levofloxacin treatment was significantly higher than that of clarithromycin. Therefore, it is suggested that clarithromycin-based triple therapy be replaced by levofloxacin-based triple therapy in countries with high resistance rate to clarithromycin such as Iran. Nevertheless, findings of the present study need to be approved with larger investigation on Iranian population.

A retrospective study of the antibiotic-resistant phenotypes and genotypes of Helicobacter pylori strains in China

Helicobacter pylori antibiotic resistance is a serious concern in China, where it severely influences treatment for H. pylori infection. To overcome this, it is essential to apply personalized therapies based on local or individual data on antibiotic-resistant phenotypes or genotypes. We conducted a large-scale multi-center study with a retrospective cross-sectional observational design to investigate the antibiotic-resistant phenotypes and genotypes of H. pylori in China. Strains were isolated from the gastric biopsy samples of H. pylori-infected patients from five different regions in China. The strains were tested for antibiotic-resistant phenotypes and genotypes, and the agreement between the two was assessed. In total, 4242 H. pylori strains were isolated and cultured, with an 84.43% success rate. The primary and secondary antibiotic resistance rates of H. pylori were 37.00% and 76.93% for clarithromycin, 34.21% and 61.58% for levofloxacin, 2.20% and 6.12% for amoxicillin, 1.61% and 3.11% for furazolidone, 1.18% and 3.31% for tetracycline, and 87.87% and 93.48% for metronidazole, respectively. The dual-resistance patterns for metronidazole/clarithromycin, metronidazole/levofloxacin, and clarithromycin/levofloxacin were 43.6%, 38.4%, and 26.1%, respectively. Clarithromycin- and levofloxacin-resistant H. pylori phenotypes and genotypes showed satisfactory agreement. Based on these findings, clarithromycin- and levofloxacin-resistant genotype testing could partially replace traditional antibiotic susceptibility testing in China. Continuous monitoring and personalized treatments based on individual and local H. pylori antibiotic-resistance data remain necessary.

Therapeutic Potential of Sitafloxacin as a New Drug Candidate for Helicobacter Eradication in Korea: An In Vitro Culture-Based Study

Background: Increased prevalence of antibiotic resistance to Helicobacter pylori (H. pylori) infection worldwide has driven the search for a new therapeutic candidate. Recently, sitafloxacin, a novel 4-quinolone agent, has emerged as a new therapeutic option for H. pylori eradication, in Japan. However, data on its efficacy for H. pylori eradication in Korea are limited. Therefore, we aimed to investigate the therapeutic potential of sitafloxacin as a first-line treatment for patients with Helicobacter infection through gastric tissue culture-based studies. Materials and Methods: We prospectively enrolled treatment-naïve patients with H. pylori infection who visited the Gil Medical Center between March 2015 and March 2018. After obtaining written informed consent from patients, a total of 121 H. pylori strains were collected. We tested the susceptibility of these strains to sitafloxacin, and other antibiotics for Helicobacter eradication, including clarithromycin (CLR), metronidazole (MTZ), amoxicillin (AMX), tetracycline (TET), levofloxacin (LEV), and ciprofloxacin (CIP) using the agar dilution technique. The minimum inhibitory concentration (MIC) of these antibiotics against H. pylori strains were determined. Results: None of the H. pylori strains obtained were resistant to sitafloxacin (MIC > 1, n = 0), while other conventional eradication drugs including CLR, MTZ, AMX, and TET showed 24.8% (n = 30), 30.6% (n = 37), 5.0% (n = 6), and 0.8% (n = 1) resistance, respectively. Compared to the resistance rates of other quinolones (LEV [36.4%, n = 44] and CIP [37.2%, n = 45]), sitafloxacin showed the best antibiotic performance against Helicobacter strains (0%, n = 0). Furthermore, sitafloxacin also inhibited the growth of 14 H. pylori strains (12.4%), which were resistant to both of clarithromycin, and metronidazole, and 27 strains (22.3%) with multidrug resistance. Conclusions: Sitafloxacin might be a new promising candidate for Helicobacter eradication where antibiotic resistance for Helicobacter is an emerging medical burden, such as in Korea.

Whole-Genome Sequencing and Comparative Genomics of Three Helicobacter pylori Strains Isolated from the Stomach of a Patient with Adenocarcinoma

Helicobacter pylori is a common pathogen associated with several severe digestive diseases. Although multiple virulence factors have been described, it is still unclear the role of virulence factors on H. pylori pathogenesis and disease progression. Whole genome sequencing could help to find genetic markers of virulence strains. In this work, we analyzed three complete genomes from isolates obtained at the same point in time from a stomach of a patient with adenocarcinoma, using multiple available bioinformatics tools. The genome analysis of the strains B508A-S1, B508A-T2A and B508A-T4 revealed that they were cagA, babA and sabB/hopO negative. The differences among the three genomes were mainly related to outer membrane proteins, methylases, restriction modification systems and flagellar biosynthesis proteins. The strain B508A-T2A was the only one presenting the genotype vacA s1, and had the most distinct genome as it exhibited fewer shared genes, higher number of unique genes, and more polymorphisms were found in this genome. With all the accumulated information, no significant differences were found among the isolates regarding virulence and origin of the isolates. Nevertheless, some B508A-T2A genome characteristics could be linked to the pathogenicity of H. pylori.

A comparative whole genome analysis of Helicobacter pylori from a human dense South Asian setting

Helicobacter pylori, a Gram-negative bacterium, is associated with a wide range of gastric diseases such as gastritis, duodenal ulcer, and gastric cancer. The prevalence of H pylori and risk of disease vary in different parts of the world based on the prevailing bacterial lineage. Here, we present a contextual and comparative genomics analysis of 20 clinical isolates of H pylori from patients in Bangladesh. Despite a uniform host ethnicity (Bengali), isolates were classified as being part of the HpAsia2 (50%) or HpEurope (50%) population. Out of twenty isolates, eighteen isolates were cagA positive, with two HpEurope isolates being cagA negative, three EPIYA motif patterns (AB, AB-C, and ABC-C) were observed among the cagA-positive isolates. Three vacA genotypes were observed with the s1m1i1dic1 genotype observed in 75% of isolates; the s1m2i1d1c2 and s2m2i2d2c2 genotypes were found to be 15% and 10% of isolates, respectively. The non-virulent genotypes s2m2i2d2c2 was only observed in HpEurope population isolates. Genotypic analysis of oipA gene, present in all isolates, revealed five different patterns of the CT repeat; all HpAsia2 isolates were in "ON" while 20% of HpEurope isolates were genotypically "OFF." The three blood group antigen binding adhesins encoded genes (bab genes) examined and we observed that the most common genotype was (babA/babB/-) found in eight isolates, notably six were HpAsia2 isolates. The babA gene was found in all HpAsia2 isolates but present in only half of the HpEurope isolates. In silico antibiotic susceptibility analysis revealed that 40% of the strains were multi-drug resistant. Mutations associated with resistance to metronidazole, fluoroquinolone, and clarithromycin were detected 90%, 45%, and 5%, respectively, in H pylori strain. In conclusion, it is evident that two populations of H pylori with similar antibiotic profiles are predominant in Bangladesh, and it appears that genotypically the HpAisa2 isolates are potentially more virulent than the HpEurope isolates.

Antimicrobial Resistance of Helicobacter pylori in Gastric Biopsy Samples from Lima/Peru

Background: Helicobacter pylori prevalence and gastric cancer rates are remarkably high in Peru. Effective antimicrobial regimens are essential for successful H. pylori eradication. We aimed at assessing antimicrobial resistance rates to first- and second-line therapeutic agents in H. pylori strains detected in gastric biopsy samples. Materials and Methods: Gastric biopsy samples (antrum and corpus) were collected from therapy-naive patients (n = 154). H. pylori presence in the samples was confirmed by histopathology. Genotypic resistance to clarithromycin and quinolones was determined by real-time PCR. Results: Histology results were 100% concordant with PCR results (97/154; 63% H. pylori-positive in both). In 6% (6/97) of the patients, we found discordant results of H. pylori infection in antrum and corpus samples from the same patient. Resistance rates to clarithromycin and quinolone were 34% (33/97) and 68% (56/82), respectively. Antimicrobial resistance to both antimicrobials was 30% (25/82). Conclusion: Antimicrobial resistance rates of H. pylori to clarithromycin and quinolones are very high in Lima, Peru. Many first- and second-line, empiric eradication regimens may not be recommended for Peruvian patients.

Controversias en cirugía: Erradicación del Helicobacter pylori ¿Terapia a todos o según indicaciones usuales?

La infección por Helicobacter pylori (H. pylori), es la infección bacteriana crónica más frecuente de la raza humana, afecta al 50 % de la población mundial y, por lo menos, al 80 % de la población colombiana. Esta bacteria es reconocida desde hace más de 15 años como un carcinógeno tipo I. De acuerdo con las indicaciones del Consenso de “Maastricht V” esta infección debe ser buscada y tratada en los pacientes con úlcera péptica activa, Linfoma MALT (por sus siglas en inglés, mucosa associated lymphoid tissue), cáncer gástrico temprano, púrpura que presenten síntomas dispépticos crónicos y usuarios crónicos de AINES. Debido al papel que tiene en la fisiopatología del cáncer gástrico, nace la iniciativa de realizar una búsqueda activa del H. pylori y erradicarlo en todas las personas, incluyendo aquellas asintomáticas en países con alta incidencia de esta neoplasia. Existen diversas publicaciones alrededor del mundo que así lo sugieren, mostrando resultados con impacto positivo en el curso y progresión de la enfermedad, sobre todo en las etapas más tempranas de la infección. Sin embargo, otros autores resaltan la creciente problemática de la resistencia bacteriana, y demuestran que el peso estadístico y los diferentes análisis de los estudios disponibles en la actualidad tienen poca validez para dar una recomendación extendida al paciente asintomático. Se cuestiona que tal vez, estamos utilizando las estrategias inadecuadas para manejar una situación de salud pública, ya que estamos enfocados en impactar a cada individuo con terapias antibióticas complejas, en vez de a la población en general con políticas de salud pública.

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.

Reevaluation of the Efficacy of First Line Regimen for Helicobacter pylori

Background

Helicobacter pylori is a common cause of gastritis, peptic ulcer disease, and non-ulcer dyspepsia, and is also associated with gastric adenocarcinoma and mucosa associated lymphoid tissue lymphoma. Despite being known about for more than 30 years, finding an effective therapeutic strategy against it remains a challenge.

Aim

There are no US studies evaluating the efficacy of a Levofloxacin based therapy for H. pylori infection. We here intend to study the efficacy of Levofloxacin based triple antibiotic regimen as compared to Clarithromycin based triple therapy and Bismuth based quadruple therapy in our patient population.

Methods

This is a retrospective single center observational study. Patients with Helicobacter pylori infection who underwent treatment for H. pylori with one of the three therapies, i.e. Clarithromycin triple, Bismuth Quadruple or Levofloxacin triple, were included in the study and the eradication rates were compared. The confirmation of the H. pylori was done 4 weeks after the completion of anti-microbial therapy.

Results

A total of 177 individuals underwent the H. pylori treatment in our retrospective review. Of these, 54% (n=97) of patients were treated with Clarithromycin based triple therapy (Group 1), 35% (n=63) were treated with Levofloxacin based regimen (Group 2), and the remaining 11% (n=17) were treated with Bismuth based quadruple therapy (Group 3). The eradication rates were significantly higher in patients treated with Clarithromycin based triple therapy as compared to Levofloxacin based triple therapy and Bismuth quadruple therapy (78.3% vs 49.2% vs 41.1% P=0.001).

Conclusion

In conclusion, our study shows significantly lower eradication rates with Levofloxacin triple therapy among a selected US population. Thus, it may not be a good first-line therapy among this US population and the Clarithromycin based regimen may still be used successfully.

High Prevalence of Antibiotic Resistance in Iranian Helicobacter pylori Isolates: Importance of Functional and Mutational Analysis of Resistance Genes and Virulence Genotyping

The high prevalence of antibiotic resistance in Helicobacter pylori has become a great challenge in Iran. The genetic mutations that contribute to the resistance have yet to be precisely identified. This study aimed to investigate the prevalence of antibiotic resistance and virulence markers in Iranian H. pylori isolates and to analyze if there is any association between resistance and genotype. Antibiotic susceptibility patterns of 68 H. pylori isolates were investigated against metronidazole, clarithromycin, amoxicillin, rifampicin, ciprofloxacin, levofloxacin, and tetracycline by the agar dilution method. The frxA, rdxA, gyrA, gyrB, and 23S rRNA genes of the isolates were sequenced. The virulence genotypes were also determined using PCR. Metronidazole resistance was present in 82.4% of the isolates, followed by clarithromycin (33.8%), ciprofloxacin (33.8%), rifampicin (32.4%), amoxicillin (30.9%), levofloxacin (27.9%), and tetracycline (4.4%). Overall, 75% of the isolates were resistant to at least two antibiotics tested and considered as a multidrug resistance (MDR) phenotype. Most of the metronidazole-resistant isolates carried frameshift mutations in both frxA and rdxA genes, and premature termination occurred in positions Q5Stop and Q50Stop, respectively. Amino acid substitutions M191I, G208E, and V199A were predominantly found in gyrA gene of fluoroquinolone-resistant isolates. A2143G and C2195T mutations of 23S rRNA were found in four clarithromycin-resistant isolates. Interestingly, significant associations were found between resistance to metronidazole (MNZ) and cagA-, sabA-, and dupA-positive genotypes, with p = 0.0002, p = 0.0001, and p = 0.0001, respectively. Furthermore, a significant association was found between oipA “on” status and resistance to amoxicillin (AMX) (p = 0.02). The prevalence of H. pylori antibiotic resistance is high in our region, particularly that of metronidazole, clarithromycin, ciprofloxacin, and MDR. Simultaneous screening of virulence and resistance genotypes can help clinicians to choose the appropriate therapeutic regime against H. pylori infection.

Mutations in the Helicobacter pylori 23S rRNA gene associated with clarithromycin resistance in patients at an endoscopy unit in Medellín, Colombia

Introduction: Clarithromycin is the first-line antibiotic for the treatment of Helicobacter pylori infection. Bacterial resistance is mainly due to the presence of specific mutations in the 23S ribosomal RNA (rRNA) gene. Objective: To determine the frequency of A2143G and A2142G specific mutations in the 23S rRNA gene associated with clarithromycin resistance of H. pylori in samples from patients with dyspeptic manifestations in Medellín, northwestern Colombia. Materials and methods: DNA was extracted from gastric biopsy samples of patients with dyspeptic manifestations seen at an endoscopy unit in Medellín between 2016 and 2017. PCR was performed to amplify the bacterial s and m vacA regions, and a region in the 23S rRNA gene. The presence of the A2142G and A2143G mutations was determined using the restriction fragment length polymorphism (RFLP) technique with the BbsI and BsaI enzymes, respectively. Results: The prevalence of infection was 44.2% (175/396), according to the histopathology report. The positive samples were analyzed and the three regions of the bacterial genome were amplified in 143 of the 175 samples. The A2143G and A2142G mutations were identified in 27 samples (18.8%, 27/143). The most frequent mutation was A2143G (81.5%, 22/27). Conclusions: We found a high prevalence of H. pylori mutations associated with clarithromycin resistance in the study population. Further studies are required to determine the bacterial resistance in the Colombian population in order to define first line and rescue treatments.

The antibiotic resistance of Helicobacter pylori to five antibiotics and influencing factors in an area of China with a high risk of gastric cancer

Background

H. pylori exhibits antibiotic resistance with regional differences. In this paper, we explored antibiotic resistance of H. pylori to five antibiotics in an area with a high risk of gastric cancer.

Results

H. pylori resistance rates to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were 78.0, 56.0, 31.0, 9.0, and 15.0%, respectively. Double, triple, quadruple, and quintuple resistance rates were 23, 20, 6, and 4%, respectively. The clarithromycin and multidrug resistance rates were significantly higher in males than females (clarithromycin: 44.4% vs 15.2%, respectively, P = 0.002; multidrug: 75.5% vs 37.2%, respectively; P < 0.001). During the three periods of 1998–1999, 2002–2004 and 2016–2017, the resistance rates to levofloxacin and amoxicillin were increasing (OR: 2.089, 95%CI: 1.142–3.821, P = 0.017; and OR: 5.035, 95%CI: 1.327–19.105, P = 0.018, respectively). The antibiotic resistance rates were unassociated with the host disease state. Metronidazole resistance was lower in the vacAs1m1/m2 group than the vacAs1m1m2 group (65% vs 85.7%, respectively; P = 0.026). As for levofloxacin resistance, it was higher with cagA⁺ than cagA⁻ (60.9% vs 23.1%, respectively; P = 0.020) but lower with slyD⁺ than slyD⁻ (41.4% vs 68.5%, respectively; P = 0.009). Clarithromycin had a lower resistance rate with iceA⁺⁺ than iceA⁻⁺ (19.7% vs 52.4%, respectively; P = 0.017). For amoxicillin, the iceA⁺⁺ group had a lower resistance rate than the iceA⁻⁻ group (1.6% vs 27.8%, respectively; P = 0.009).

Conclusions

The total resistance rates of H. pylori to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were high in Zhuanghe. The resistanc rates to levofloxacin and amoxicillin increased over time. Clarithromycin resistance was associated with male and iceA. The resistance of metronidazole was related to vacA. Levofloxacin resistance was concerned with cagA and slyD and amoxicillin resistance was concerned with iceA. While, the antibiotic resistance of H. pylori had nothing to do with the status of gastric disease.

Helicobacter pylori: Multiple resistance in patients from Bogotá, Colombia

Introduction: The main cause for Helicobacter pylori infection treatment failure is antibiotic resistance, where clarithromycin and metronidazole play the main role. In Colombia, primary resistance as a consequence of the use of these two antibiotics and excessive levofloxacin use is above the accepted limit (13.6%, 83%, and 16%, respectively). Despite this fact, empirical therapies that include the combination of these antibiotics are used in patients with previous therapeutic failure. Objective: To determine antibiotic resistance in patients previously treated for H. pylori in Bogotá, Colombia. Materials and methods: We conducted a descriptive study that included ten isolates obtained from five patients with three or four previous failed treatments for H. pylori. Antibiotic resistance to amoxicillin, clarithromycin, levofloxacin, and metronidazole was investigated by agar dilution and confirmed by DNA sequencing (Magrogen, Korea). Results: Eight isolates were resistant to two or more antibiotics. All isolates were resistant to levofloxacin. Susceptibility patterns in isolates from the gastric antrum and the body of the stomach were different in three patients. Conclusion: As far as we know, this is the first evidence of multiple H. pylori resistance in Colombia in previously treated patients. Results demonstrated the consequences of using an ineffective antibiotic scheme and the need to assess antibiotic susceptibility in different anatomical sites of the stomach. The consequences of multiple resistance decrease possible antibiotic effectiveness to eradicate H. pylori in the future.

Point Mutations at gyrA and gyrB Genes of Levofloxacin-Resistant Helicobacter pylori Isolates in the Esophageal Mucosa from a Venezuelan Population

The treatment of Helicobacter pylori infection is complicated by antibiotic resistance. A high levofloxacin (LVX) resistance rate was previously demonstrated in H. pylori isolates from gastric mucosa (40%) and esophagus (19%) in individual hosts of a Venezuelan population. We aimed to assess the molecular mechanisms of LVX resistance and susceptibility in isolates from the gastroesophageal mucosa, by studying point mutations in the quinolone resistance-determining region of gyrA and gyrB genes. Sequencing of gyrA and gyrB genes (N = 120) helped to identify point mutations in 60 isolates (30 from antrum and 30 from esophagus) of five dyspeptic patients. Double (Asn87Thr and Asp91Asn) and single (Asn87Ile or Asn87Thr) mutations in the gyrA gene were identified in the esophageal mucosa. These mutations have been commonly found in the stomach. Occurrence of a single (Asn87Ile) mutation was associated with high resistance (minimum inhibitory concentration ≥ 32 μg/mL) to LVX. Only a single (Ser479Gly) mutation was found in the gyrB gene in both mucosae. One patient presented isolates with no mutations in the two genes studied. Isolates with the same mutation pattern in individual hosts revealed identical genetic profiles for these genes, confirming that isolates identified in the esophageal mucosa come from isolates colonizing the stomach. Helicobacter pylori resistance to LVX in the esophagus is related to double- and single-point mutations in gyrA and gyrB genes, such as those found in the stomach. Levofloxacin should be applied with caution, because its antibiotic effect on H. pylori is decreasing in Latin America, perhaps owing to high prescription rates.

Antibiotic resistance in Helicobacter pylori

PURPOSE OF REVIEW

Treatment of Helicobacter pylori is difficult nowadays because of its high resistance. The prevalence and mechanism of resistance, the different methods to detect it and the clinical implication of resistance were addressed in several research papers last year.

RECENT FINDINGS

Clarithromycin-resistant H. pylori has been recognized by the WHO as 'high priority', for which new antibiotics are needed. Moreover, the Maastricht consensus recommended, in areas with high resistance, that susceptibility tests should be performed, at least after a treatment failure.

SUMMARY

Metronidazole and clarithromycin resistance rates are alarming although they vary among populations. Tetracycline and amoxicillin-resistance are very low in most countries. H. pylori resistance can be detected by phenotypic or by molecular methods. Different break points may be used when performing an antimicrobial susceptibility test, so comparing resistance among different populations is challenging. Genomic techniques open new possibilities in the diagnosis of H. pylori, and the detection of H. pylori and its antimicrobial resistance in faeces is an interesting approach. Eradication rates are dependent on the susceptibility of the strain to metronidazole and clarithromycin, being lower in patients infected with a resistant strain.

Resistance mechanisms of Helicobacter pylori and its dual target precise therapy

Helicobacter pylori drug resistance presents a significant challenge to the successful eradication of this pathogen. To find strategies to improve the eradication efficacy of H. pylori, it is necessary to clarify the resistance mechanisms involved. The mechanisms of H. pylori drug resistance can be investigated from two angles: the pathogen and the host. A comprehensive understanding of the molecular mechanisms of H. pylori resistance based on both pathogen and host would aid the implementation of precise therapy, or ideally "dual target precise therapy" (bacteria and host-specific target therapy). In recent years, with increased understanding of the mechanisms of H. pylori resistance, the focus of eradication has shifted from disease-specific to patient-specific treatment. The implementation of "precision medicine" has also provided a new perspective on the treatment of infectious diseases. In this article, we systematically review current research on H. pylori drug resistance from the perspective of both the pathogen and the host. We also review therapeutic strategies targeted to pathogen and host factors that are aimed at achieving precise treatment of H. pylori.

Treatment of Helicobacter pylori infection 2017

This review summarizes important studies regarding Helicobacter pylori therapy published from April 2016 to April 2017. The main themes that emerge involve studies assessing the efficacy of bismuth and nonbismuth quadruple regimens. While in recent years, much of the emphasis on the use of bismuth has focussed on its utility in a second-line setting, an increasing number of studies this year have shown excellent efficacy in first-line therapy. The efficacy of bismuth as a second-line after sequential and concomitant therapy was particularly noteworthy. Antibiotic resistance was more intensely studied this year than for a long time, and definite trends are presented regarding an increase in resistance, including the fact that clarithromycin resistance in particular is now at a level where the continued use of clarithromycin triple therapy first-line as a mainstream treatment is not recommended. Another exciting trend to emerge this year is the utility of vonoprazan as an alternative to PPI therapy, especially in resistant and difficult-to-treat groups.

Peptic ulcer disease

The rapidly declining prevalence of Helicobacter pylori infection and widespread use of potent anti-secretory drugs means peptic ulcer disease has become substantially less prevalent than it was two decades ago. Management has, however, become more challenging than ever because of the threat of increasing antimicrobial resistance worldwide and widespread use of complex anti-thrombotic therapy in the ageing population. Peptic ulcers not associated with H pylori infection or the use of non-steroidal anti-inflammatory drugs are now also imposing substantial diagnostic and therapeutic challenges. This Seminar aims to provide a balanced overview of the latest advances in the pathogenetic mechanisms of peptic ulcers, guidelines on therapies targeting H pylori infection, approaches to treatment of peptic ulcer complications associated with anti-inflammatory analgesics and anti-thrombotic agents, and the unmet needs in terms of our knowledge and management of this increasingly challenging condition.

Prospective multicentre clinical study on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori

OBJECTIVES

We report on a large prospective, multicentre clinical investigation on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori.

METHODS

Therapy-naive patients (n = 2004) who had undergone routine diagnostic gastroscopy were prospectively included from all geographic regions of Austria. Gastric biopsy samples were collected separately from antrum and corpus. Samples were analysed by histopathology and real-time PCR for genotypic resistance to clarithromycin and quinolones. Clinical and demographic information was analysed in relation to resistance patterns.

RESULTS

H. pylori infection was detected in 514 (26%) of 2004 patients by histopathology and confirmed in 465 (90%) of 514 patients by real-time PCR. PCR results were discordant for antrum and corpus in 27 (5%) of 514 patients, indicating inhomogeneous infections. Clarithromycin resistance rates were 17% (77/448) and 19% (84/455), and quinolone resistance rates were 12% (37/310) and 10% (32/334) in antrum and corpus samples, respectively. Combination of test results per patient yielded resistance rates of 21% (98/465) and 13% (50/383) for clarithromycin and quinolones, respectively. Overall, infection with both sensitive and resistant H. pylori was detected in 65 (14%) of 465 patients.

CONCLUSIONS

Anatomically inhomogeneous infection with different, multiple H. pylori strains is common. Prospective clinical study design, collection of samples from multiple sites and microbiologic methods that allow the detection of coinfections are mandatory for collection of reliable data on antimicrobial resistance patterns in representative patient populations. (ClinicalTrials.gov identifier: NCT02925091).