Application of gene chip technology in the diagnostic and drug resistance detection of Helicobacter pylori in children

Advances in Helicobacter pylori Antimicrobial Resistance Detection: From Culture-Based to Multi-Omics-Based Technologies

Helicobacter pylori (H. pylori), a proven carcinogenic microbe, necessitates antimicrobial treatment once infected. However, H. pylori worldwide currently faces serious antibiotic resistance (AMR), requiring infected patients to undergo antibiotic susceptibility testing (AST) to guide therapy. Currently, the recommended ASTs for H. pylori are culture-based methods, which are time-consuming, complicated, and expensive, impeding their widespread application. With in-depth researches on the AMR mechanisms of H. pylori, specific gene mutations and novel proteins have been confirmed as the cause of AMR and can serve as targets of ASTs. Accordingly, molecular biology detection has been developed and tremendously shortened the time and reduced difficulty of AST. However, these assays still struggle to meet the enormous testing demand and need for even faster, simpler, and more accurate methods. In recent years, researchers have developed various new platforms based on biosensors, transcriptomics, proteomics, and single-cell analysis. This review introduces the AMR mechanisms of H. pylori and summarizes the current ASTs from the working principles to application characteristics. Additionally, we draw attention to the potentially applicable techniques for AST of H. pylori from DNA, RNA, protein, and cell perspectives. By systematically recapitulating the past, present, and future of AST for H. pylori, this review provides valuable insights for developing novel assays.

Efficacy and safety of ephedra-containing oral medications: a systematic review, meta-analysis, and exploratory dose-response analysis for weight reduction

Introduction

Despite the widespread use of ephedra in various forms, including food supplements and herbal prescriptions, comprehensive studies reviewing its efficacy and safety across different countries are lacking.

Methods

We systematically searched 5 electronic databases and conducted a meta-analysis of 16 randomized controlled trials (RCTs) on ephedra-containing oral medications (EOMs), performing a dose-response analysis for weight loss.

Results

The meta-analysis results revealed a statistically significant reduction in the body mass index (BMI) (MD: 1.5 kg/m2; 95% CI: -2.46 to -0.54) and secondary outcomes like body weight (BW) and waist circumference (WC). The dose-response analysis indicated a correlation between ephedra and weight reduction. The safety analysis showed no significant difference in adverse effects between the treatment and control groups (RR = 0.99, 95% CI = 0.80 ∼ 1.21, and p = 0.90).

Discussion

In conclusion, EOMs demonstrated effectiveness in promoting weight loss, and the dose-response analysis indicated a correlation between ephedra and weight reduction. However, additional research is necessary due to the limited number of studies and inconsistent results among the assessment criteria. Moreover, if prescribed by traditional medicine physicians within the permissible daily ephedrine dosage range of 150 mg set by the Food and Drug Administration (FDA) and monitored by healthcare professionals, the risk of severe adverse events is likely to be minimal.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=387895, identifier CRD42023387895.

[Viable Bacteria Assay of Helicobacter pylori by RT-qPCR Measurement of cgt Gene Expression Levels: Establishment and Application of a New Method]

Objective

To establish a viable bacteria assay for Helicobacter pylori (H. pylori) by assessing the cgt gene expression, and to develop accordingly a rapid and novel testing method for clinical precision treatment.

Methods

Viable bacteria count was determined in bacterial cultures. The transcriptional expression level of cgt (hp0421), the conserved gene that encodes cholesterol-α-glucosyltransferase (CGT) in H. pylori, was measured by RT-PCR. The correlation between the number of colonies and cgt gene transcription expression was analyzed and the regression model was constructed. The linear range, sensitivity, and specificity of the new method were examined accordingly. The bactericidal action of clarithromycin was assessed using this method to verify the performance of the method in determining clinical bacterial drug resistance.

Results

The Ct values of cgt for H. pylori colony counts of 102, 104, 106, and 108 CFU/mL were 29.67±0.14, 23.37±0.36, 17.65±0.37, and 11.38±0.39, respectively. In the range of 101-108 CFU/mL, the regression equation for cgt gene expression and viable bacterial counts determined by RT-qPCR was y=-0.3501x+12.49, with the correlation coefficient being R 2=0.9992 and the sensitivity being 101 CFU/mL, showing no cross-reaction with 13 other bacteria. The lg values of live H. pylori bacteria treated with clarithromycin at 0, 5, 10, 20, and 40 μg/mL for 12 h were 2.57±0.02, 2.45±0.01, 2.19±0.02, 1.91±0.07, and 1.33±0.05, respectively. The corresponding cgt gene Ct values were 27.76±0.09, 28.37±0.24, 29.51±0.14, 30.11±0.12, and 31.66±0.11. By applying the cgt gene expression in the equation, the estimated counts of viable bacteria were found to be 2.73±0.03, 2.52±0.08, 2.11±0.05, 1.89±0.02, and 1.33±0.04, showing no significant difference in statistical analysis (P>0.05).

Conclusion

The method for assessing viable bacteria account by evaluating cgt gene expression in H. pylori was successfully established, significantly reducing the time required to determine viable bacteria count and providing a new method for clinical viable bacteria testing.

Updated joint ESPGHAN/NASPGHAN guidelines for management of Helicobacter pylori infection in children and adolescents (2023)

BACKGROUND

Evolving epidemiological data and increasing antibiotic resistance mandate an update of the European and North American Societies of Pediatric Gastroenterology, Hepatology and Nutrition guidelines.

METHODS

Certainty of evidence and strength of recommendations were rated by experts according to the Grading of Recommendation Assessment, Development, and Evaluation approach. PICO (patient population, intervention, comparator, and outcome) questions were developed and voted on by the group. Recommendations were formulated using the Evidence to Decision framework.

RESULTS

The current literature supports many of the previous recommendations and several new recommendations. Invasive testing with strain antimicrobial susceptibility analysis is recommended for the diagnosis and selection of eradication therapy for H. pylori infection. Molecular methods are acceptable for detection of infection and of antibiotic resistance in gastric biopsy specimens. Reliable, noninvasive tests can be used as a screening method for children with history of gastric cancer in a first-degree relative. When investigating causes of chronic immune thrombocytopenic purpura, testing for H. pylori is no longer recommended. When investigating other diseases such as inflammatory bowel disease, celiac disease, or eosinophilic esophagitis, specific diagnostic biopsies for H. pylori infection are not indicated. However, if H. pylori is an incidental finding, treatment may be considered after discussing the risks and benefits. Treatment should be based on antibiotic antimicrobial susceptibility testing and, if unavailable, regimens containing clarithromycin should be avoided.

CONCLUSIONS

Due to decreasing prevalence of infection, increasing challenges with antibiotic resistance, and emerging evidence regarding complications of infection, clinicians must be aware of these recommended changes to appropriately manage H. pylori infection and its clinical sequelae in children.

Advances on diagnosis of Helicobacter pylori infections

The association of Helicobacter pylori to several gastric diseases, such as chronic gastritis, peptic ulcer disease, and gastric cancer, and its high prevalence worldwide, raised the necessity to use methods for a proper and fast diagnosis and monitoring the pathogen eradication. Available diagnostic methods can be classified as invasive or non-invasive, and the selection of the best relies on the clinical condition of the patient, as well as on the sensitivity, specificity, and accessibility of the diagnostic test. This review summarises all diagnostic methods currently available, including the invasive methods: endoscopy, histology, culture, and molecular methods, and the rapid urease test (RUT), as well as the non-invasive methods urea breath test (UBT), serological assays, biosensors, and microfluidic devices and the stool antigen test (SAT). Moreover, it lists the diagnostic advantages and limitations, as well as the main advances for each methodology. In the end, research on the development of new diagnostic methods, such as bacteriophage-based H. pylori diagnostic tools, is also discussed.

Phenotype and genotype analysis for Helicobacter pylori antibiotic resistance in outpatients: a retrospective study

To investigate the antibiotic resistance of Helicobacter pylori (H. pylori) in outpatients and to explore the consistency between genotype and phenotype of H. pylori antibiotic resistance. A retrospective study on outpatients screened with urea breath test for H. pylori infection in Nanjing First Hospital from April 2018 to January 2022. Patients who tested positive underwent a consented upper endoscopy, and the H. pylori infection was confirmed by rapid urease test (RUT) and H. pylori culture. For antibiotic resistance phenotype analysis, the H. pylori strains isolated from gastric biopsy were tested for antibiotic resistance phenotype by the Kirby-Bauer disk diffusion test. In addition, the antibiotic resistance genotype of isolated H. pylori was tested with a real-time polymerase chain reaction. A total of 4,399 patients underwent H. pylori infection screening, and 3,306 H. pylori strains were isolated. The antibiotic resistance phenotype test revealed that the resistance rates of metronidazole (MTZ), clarithromycin (CLR), levofloxacin (LEV), amoxicillin (AMX), furazolidone (FR), and tetracycline (TE) were 74.58%, 48.61%, 34.83%, 0.76%, 0.27%, and 0.09%, respectively. Additionally, the antibiotic resistance genotype test revealed that rdxA gene mutation A610G (92.96%), A91G (92.95%), C92A (93.00%), and G392A (95.07%) were predominant in H. pylori with MTZ resistance; 23S rRNA gene mutation A2143G (86.47%) occurred in most H. pylori with CLR resistance; and gyrA gene mutation 87Ile/Lys/Tyr/Arg (97.32%) and 91Asn/Gly/Tyr (90.61%) were the most popular mutations in strains with LEV resistance. The phenotypic resistance and genotypic resistance to CLR (kappa value = 0.824) and LEV (kappa value = 0.895) were in good agreement. The history of eradication with MTZ, CLR, LEV, and AMX was correlated with H. pylori resistance. In short, this study demonstrated that drug resistance of H. pylori was mainly to MTZ, CLR, and LEV in local outpatients. Three drugs can be selected for increased MICs (Minimum Inhibitory Concentration) via single chromosomal mutations. In addition, the genotype could be used to predict the phenotypic H. pylori resistance to CLR and LEV. IMPORTANCE Helicobacter pylori is a key bacterium that causes stomach diseases. There was a high prevalence of H. pylori in the Chinese population. We analyzed the resistance phenotype and genotype characteristics of H. pylori in 4,399 outpatients at the First Hospital of Nanjing, China. We found a higher resistance rate to metronidazole (MTZ) , clarithromycin (CLR), and levofloxacin (LEV), and the genotype could be used to predict the phenotypic H. pylori resistance to CLR and LEV. This study provides information on H. pylori infection and also provides guidance for clinical doctors' drug treatment.

Helicobacter pylori Infections in Children

In the context of epidemiology, host response, disease presentation, diagnosis, and treatment management, the manifestation of Helicobacter pylori (H. pylori) infection diverges between children and adults. H. pylori infection stands out as one of the most prevalent bacterial infections globally, and its prevalence in both children and adults is decreasing in many developing countries but some still struggle with a high prevalence of pediatric H. pylori infection and its consequences. The majority of infected children are asymptomatic and pediatric studies do not support the involvement of H. pylori in functional disorders such as recurrent abdominal pain. The pathophysiology of H. pylori infection relies on complex bacterial virulence mechanisms and their interaction with the host immune system and environmental factors. This interaction gives rise to diverse gastritis phenotypes, which subsequently influence the potential development of various gastroduodenal pathologies. In clinical settings, the diagnosis of this infection in childhood requires an upper gastrointestinal endoscopic exam with mucosal biopsy samples for histology and culture, or Polymerase Chain Reaction (PCR) at the very least. When warranted, eradication treatment should be given when good compliance is expected, and there should be systematic use of a treatment adapted to the antimicrobial susceptibility profile. To combat the burgeoning threat of multidrug resistance, vigilant surveillance of resistance patterns and strategic antibiotic management are paramount.

Fusarium diversity associated with diseased cereals in China, with an updated phylogenomic assessment of the genus

Fusarium species are important cereal pathogens that cause severe production losses to major cereal crops such as maize, rice, and wheat. However, the causal agents of Fusarium diseases on cereals have not been well documented because of the difficulty in species identification and the debates surrounding generic and species concepts. In this study, we used a citizen science initiative to investigate diseased cereal crops (maize, rice, wheat) from 250 locations, covering the major cereal-growing regions in China. A total of 2 020 Fusarium strains were isolated from 315 diseased samples. Employing multi-locus phylogeny and morphological features, the above strains were identified to 43 species, including eight novel species that are described in this paper. A world checklist of cereal-associated Fusarium species is provided, with 39 and 52 new records updated for the world and China, respectively. Notably, 56 % of samples collected in this study were observed to have co-infections of more than one Fusarium species, and the detailed associations are discussed. Following Koch's postulates, 18 species were first confirmed as pathogens of maize stalk rot in this study. Furthermore, a high-confidence species tree was constructed in this study based on 1 001 homologous loci of 228 assembled genomes (40 genomes were sequenced and provided in this study), which supported the "narrow" generic concept of Fusarium (= Gibberella). This study represents one of the most comprehensive surveys of cereal Fusarium diseases to date. It significantly improves our understanding of the global diversity and distribution of cereal-associated Fusarium species, as well as largely clarifies the phylogenetic relationships within the genus. Taxonomic novelties: New species: Fusarium erosum S.L. Han, M.M. Wang & L. Cai, Fusarium fecundum S.L. Han, M.M. Wang & L. Cai, Fusarium jinanense S.L. Han, M.M. Wang & L. Cai, Fusarium mianyangense S.L. Han, M.M. Wang & L. Cai, Fusarium nothincarnatum S.L. Han, M.M. Wang & L. Cai, Fusarium planum S.L. Han, M.M. Wang & L. Cai, Fusarium sanyaense S.L. Han, M.M. Wang & L. Cai, Fusarium weifangense S.L. Han, M.M. Wang & L. Cai. Citation: Han SL, Wang MM, Ma ZY, Raza M, Zhao P, Liang JM, Gao M, Li YJ, Wang JW, Hu DM, Cai L (2023). Fusarium diversity associated with diseased cereals in China, with an updated phylogenomic assessment of the genus. Studies in Mycology 104: 87-148. doi: 10.3114/sim.2022.104.02.

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.

Methods and Advances in the Design, Testing and Development of In Vitro Diagnostic Instruments

With the continuous improvement of medical testing and instrumentation engineering technologies, the design, testing and development methods of in vitro diagnostic instruments are developing rapidly. In vitro diagnostic instruments are also gradually developing into a class of typical high-end medical equipment. The design of in vitro diagnostic instruments involves a variety of medical diagnostic methods and biochemical, physical and other related technologies, and its development process involves complex system engineering. This paper systematically organizes and summarizes the design, testing and development methods of in vitro diagnostic instruments and their development in recent years, focusing on summarizing the related technologies and core aspects of the R&D process, and analyzes the development trend of the in vitro diagnostic instrument market.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Alarming antibiotics resistance of Helicobacter pylori from children in Southeast China over 6 years

The increasing rates of antibiotic resistance in Helicobacter pylori (H. pylori) are a major concern of the decreasing eradication rate. Large-scale and long-period studies on antimicrobial susceptibility of H. pylori in children are limited. This study aimed to describe the temporal changes of antibiotic resistance among children in southeast China. Gastric biopsies obtained from children were cultured for H. pylori from 2015 to 2020. Susceptibility to clarithromycin (CLA), amoxicillin (AML), metronidazole (MTZ), furazolidone (FZD), tetracycline (TET) and levofloxacin (LEV) was tested. Data from 2012 to 2014 reported previously were obtained for comparing the change in temporal trends of antibiotic resistance. A total of 1638 (52.7%) H. pylori strains were isolated from 3111 children recruited. The resistance rates to CLA, MTZ and LEV were 32.8%, 81.7% and 22.8%, respectively. There were 52.9% strains resistant to single resistance, 28.7% to double resistance, and 9.0% to triple resistance. The total resistance rate and resistance rates to CLA, MTZ, LEV, CLA + LEV and CLA + MTZ + LEV increased annually in a linear manner. All resistant patterns except single resistance increased obviously from 2015 to 2017 and 2018 to 2020 compared to that from 2012 to 2014. Double resistance to CLA + MTZ increased significantly with age. The resistance rate to CLA and triple resistance to CLA, MTZ and LEV increased in children with prior H. pylori treatment than that from children without prior treatment. The antibiotic resistance rates of H. pylori were high in a large pediatric population in southeast China from 2015 to 2020. Individual treatment based on susceptibility test is imperative and optimal regimens should be chosen in H. pylori eradication therapy.

Study on the value of antibiotic-resistant gene detection in Helicobacter pylori in China

The aim of the present study was to explore the value of detecting antibiotic-resistant genes in Helicobacter pylori (H. pylori) and the association between genotype and antibiotic resistance. Two gastric mucosa samples from each H. pylori-positive patient were collected. Each patient's H. pylori sample was cultured in vitro, and the agar plate dilution method was conducted. In addition, all patient samples were analyzed for the detection of antibiotic resistance-related mutant genes and VacA gene genotypes. The association between VacA genotypes and antibiotic resistance was also determined and the value of mutant gene detection in predicting H. pylori resistance to antibiotics was evaluated. In total, 133 H. pylori-positive patients were enrolled. A total of 22 strains of H. pylori failed to grow in in vitro culture and 25 strains were negative in a H. pylori gene test. Among 108 strains detected by PCR, a total of 39 VacA s1m1 strains, 69 VacA s1m2 strains and no VacA s2 strain were identified. There was no significant association between VacA genotypes and antibiotic resistance. The mutation rates of G616A in the rdxA gene, T87A, G91A, A91G and G91T in the gyrA gene and A2143G and A2142G in the 23S rRNA gene were 32.1, 32.3, 22.6, 12.9, 6.5, 81.8 and 0.0%, respectively. Among these mutant sites, the mutation coincidence rates were as follows, according to the agar plate dilution method: rdxA G616A (81.8%), gyrA G91T (66.7%), gyrA G91A (54.5%), 23 S rRNA A2143G (49.1%), gyrA T87A (45.5%), gyrA A91G (33.3%), penicillin-binding protein 1 (PBP1) C556G (0.0%), PBP1 A562T (0.0%), PBP1 A562G (0.0%) and 16 S rRNA 926-927 (AT-GT) (0.0%). VacA m subtypes were not associated with H. pylori antibiotic resistance. In conclusion, the present findings suggested that the detection of related mutant genes had a clinical application value in predicting the antibiotic resistance of H. pylori, particularly resistance to clarithromycin and levofloxacin.

Hydrogel Droplet Microarray for Genotyping Antimicrobial Resistance Determinants in Neisseria gonorrhoeae Isolates

A multiplex assay based on a low-density hydrogel microarray was developed to identify genomic substitutions in N. gonorrhoeae that determine resistance to the currently recommended treatment agents ceftriaxone and azithromycin and the previously used drugs penicillin, tetracycline, and ciprofloxacin. The microarray identifies 74 drug resistance determinants in the N. gonorrhoeae penA, ponA, porB, gyrA, parC, rpsJ, mtrR, bla_TEM, tetM, and 23S rRNA genes. The hydrogel elements were formed by automated dispensing of nanoliter-volume droplets followed by UV-induced copolymerization of NH₂-containing oligonucleotides with gel-forming monomers. Polybutylene terephthalate plates without special modifications were used as microarray substrates. Sequences and concentrations of immobilized oligonucleotides, gel composition, and hybridization conditions were carefully selected, and the median discrimination ratio ranged from 2.8 to 29.4, allowing unambiguous identification of single-nucleotide substitutions. The mutation identification results in a control sample of 180 N. gonorrhoeae isolates were completely consistent with the Sanger sequencing results. In total, 648 clinical N. gonorrhoeae isolates obtained in Russia during the last 5 years were analyzed and genotyped using these microarrays. The results allowed us to draw conclusions about the present situation with antimicrobial susceptibility of N. gonorrhoeae in Russia and demonstrated the possibility of using hydrogel microarrays to control the spread of antibiotic resistance.

Genotyping Helicobacter pylori antibiotic resistance - and virulence-associated genes in patients with gastric cancer in Wenzhou, China

BACKGROUND AND STUDY AIMS

Helicobacter pylori infection affects approximately 50% of the global population and has become a serious health concern related to gastric cancer, gastritis, and peptic ulcers. This organism acquires drug resistance through gene mutations, and its increasing resistance to antibiotics has severely influenced the effectiveness of eradication efforts. Therefore, we designed this study to determine the prevalence of H. pylori virulence- (cagA and vacA) and antibiotic resistance - associated genotypes in patients with gastric cancer infected with H. pylori in Whenzhou, China.

PATIENTS AND METHODS

We used polymerase chain reaction (PCR) to confirm H. pylori in cancerous and paracancerous tissue specimens from 225 patients. Then we tested the prevalence of virulence- and antibiotic resistance - associated genotypes in H. pylori using a PCR-based DNA-sequencing assay.

RESULTS

We observed H. pylori DNA in 222 of the 225 patients and found the most prevalent virulence-associated genotypes in cagA⁺ (97.75%) and vacAs1m1 (93.25%). Metronidazole resistance - associated gene mutation was G616A in rdxA; levofloxacin resistance - associated gene mutations were N87K, N87I, and D91G in gyrA; clarithromycin resistance - associated gene mutations were A2143G and A2142G in 23SrRNA; and amoxicillin resistance - associated gene mutation was T556S in pbp1. The most prevalent mutation related to antibiotic resistance was present in rdxA (97.30%), followed by gyrA (41.44%) and 23SrRNA (16.67%); the least prevalent was in pbp1 (2.25%). We observed single-gene mutations in 102 patients (45.95%) and found mutations in multiple genes (≥2 genes) in 116 patients (52.25%).

CONCLUSION

Patients with gastric cancer in Wenzhou, China, have high incidence infection caused by H. pylori with high-toxicity virulence genotypes. The frequency of gene mutations associated with metronidazole, levofloxacin, and clarithromycin resistances was high and that associated with amoxicillin resistance was relatively low. The mutation patterns were diverse, and the rates of multiple gene mutations were high.

Application of Visual Gene Clip-Based Tailored Therapy for the Eradication of Helicobacter pylori

Background

Helicobacter pylori eradication with therapies employing a proton pump inhibitor (PPI) and antimicrobial agents is mainly achieved via bacterial susceptibility to antimicrobial agents and the magnitude of acid secretion inhibition. However, annual eradication rates have greatly declined in Mainland China, and therefore, tailored H. pylori eradication regimens that inhibit acid secretion and employ optimal antimicrobial agents determined based on gene clip testing may improve eradication rates. This study was aimed at evaluating the efficacy of tailored H. pylori eradication therapy guided by visual gene clip testing for antibiotic resistance and PPI metabolism genotypes.

Methods

This prospective study included 244 patients (141 men and 103 women aged 20-79 years) receiving initial treatment for H. pylori infection. Visual gene clip testing using gastric mucosal specimens was performed to detect antibiotic resistance to clarithromycin conferred by the A2142G and A2143G point mutations of the H. pylori 23S rRNA gene and to levofloxacin conferred by the Asn87 and Asp91 point mutations of the H. pylori gyrA gene. Patients received a 14-day bismuth quadruple therapy regimen guided by testing for antibiotic resistance and CYP2C19 polymorphisms, and primary H. pylori eradication was assessed at least 4 weeks after therapy.

Results

H. pylori strains were successfully isolated from the gastric mucosa tissues of 244 patients. Antibiotic resistant isolates were identified in 63 patients, with clarithromycin resistance observed in 50 patients, levofloxacin resistance in 7 patients, and dual resistance in 6 patients. The PPI metabolic genotype of CYP2C19 was detected in 242 of 244 cases, and 97 cases were categorized as extensive metabolizers, 141 as intermediate metabolizers, and 4 as poor metabolizers. Among the 242 patients who received tailored therapy, the H. pylori eradication rate was 90.9% (95% confidence interval 87.3%~94.6%) in the intention-to-treat analysis and 96.9% (95% confidence interval 94.7%~99.2%) in the per protocol analysis.

Conclusions

Tailored therapy for H. pylori infection guided by determination of antibiotic resistance and CYP2C19 polymorphism using visual gene chip technology may provide high clinical effectiveness as initial H. pylori eradication therapy.

Molecular testing for H. pylori clarithromycin and quinolone resistance: a prospective Chinese study

In China, there is a high prevalence of antibiotic-resistant Helicobacter pylori infections in the population. The aim of the study was to assess a new ARMS-PCR test for detection of H. pylori clarithromycin resistance (CR) and quinolone resistance (QR) mutations and evaluate the spectrum of antibiotic resistance in patients from three Chinese provinces. Sanger sequencing and multiplex ARMS-PCR were used to detect H. pylori CR and QR bacteria in gastric biopsy samples. Among the 1,182 patients enrolled with gastritis, 643 (54.4%) were positive for H. pylori. Of these, 371 (57.7%) had antibiotic-resistant strains, comprising 236 (63.6%) with a single drug antibiotic-resistant strain and 135 (36.4%) with multiple drug-resistant strains. Following Sanger sequencing analysis of 23S rRNA and gyrA gene for mutations (antibiotic resistance markers), rates of CR, QR, and multidrug resistance (CR and QR) were 19.9, 12.0, and 25.8%, respectively. The 23S rRNA CR mutation A2143G (286, 96.9%) and the gyrA QR mutations C261A (85, 31.5%) and G271A (71, 26.3%) were common. Benchmarking against Sanger sequencing results, multiplex ARMS-PCR test had a high diagnostic sensitivity and specificity for detection of CR (96 and 93%), QR (95 and 92%) and multidrug resistance (95 and 95%). Based on our findings, the high incidence of single and multiple antibiotic resistance requires the routine checking of antibiotic resistance in all patients with suspected H. pylori infections. Multiplex ARMS-PCR is a simple and rapid test that can be now used for more efficient treatment of H. pylori infections and reduces the misuse of antibiotics.