scholarly journals Susceptibility-guided bismuth quadruple therapies for resistant Helicobacter pylori infections

2020 ◽  
Vol 3 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Tiankuo Yang ◽  
Renwei Hu ◽  
Xiaoqiong Tang ◽  
Yalin Shen ◽  
Alfred Tay ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Point Mutations ◽  
Previous Treatment ◽  
Cost Effective ◽  
Subsequent Treatment ◽  
Chinese Patients ◽  
23S Rrna ◽  
Molecular Testing ◽  
Sequencing Analysis ◽  
H Pylori

Abstract Increasing Helicobacter pylori resistance to antibiotics has ledthat molecular testing is appropriate as a sub to adoption of seven different bismuth quadruple therapies (BQT) in China without differentiation of first-line or second-line regimens. The objective of this study was to evaluate the efficacy of susceptibility-guided BQT for patients who had experienced previous treatment failures. A total of 133 patients was included and H. pylori was successfully cultured from 101 patients (75.9%) for subsequent antimicrobial susceptibility testing (AST). Based on the AST results, 88 patients completed one of five AST-guided 14-day BQT regimens: esomeprazole and bismuth colloidal pectin, along with either, amoxicillin and clarithromycin (EBAC), amoxicillin and levofloxacin (EBAL), amoxicillin and furazolidone (EBAF), amoxicillin and tetracycline (EBAT), or tetracycline and furazolidone (EBTF). H. pylori eradication rates were 100% for EBAC (5/5), EBAL (13/13), EBAF (14/14), and EBTF (43/43), but 76.9% for EBAT (10/13). The three patients that failed the EBAT regimen were all cured after subsequent treatment with the EBTF regimen. Our study demonstrates the excellent efficacy of the AST-guided BQT for referred H. pylori patients, and that the current EBAT regimen, used in clinics, needs to be optimized. In addition, 57 of the isolates were subjected to whole-genome sequencing. Analysis of the sequences revealed that point mutations in 23S rRNA correlated well with the phenotypic clarithromycin resistance with a concordance of 91.2%, while the concordance between phenotypic levofloxacin resistance and gyrA point mutations was 82.3%. This suggests that molecular testing is appropriate as a substitute for AST as a more rapid and cost-effective method for determining clarithromycin and levofloxacin resistance in Chinese patients.

scholarly journals Genomic Analysis of Antimicrobial Resistance Genotype-to-Phenotype Agreement in Helicobacter pylori

2020 ◽  
Vol 9 (1) ◽  
pp. 2
Author(s):  
Tal Domanovich-Asor ◽  
Yair Motro ◽  
Boris Khalfin ◽  
Hillary A. Craddock ◽  
Avi Peretz ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antimicrobial Resistance ◽  
Point Mutations ◽  
Genomic Analysis ◽  
23S Rrna ◽  
Phenotype Correlation ◽  
Bioinformatics Pipeline ◽  
Phenotypic Resistance ◽  
Commercial Kits ◽  
H Pylori

Antimicrobial resistance (AMR) in Helicobacter pylori is increasing and can result in treatment failure and inappropriate antibiotic usage. This study used whole genome sequencing (WGS) to comprehensively analyze the H. pylori resistome and phylogeny in order to characterize Israeli H. pylori. Israeli H. pylori isolates (n = 48) underwent antimicrobial susceptibility testing (AST) against five antimicrobials and WGS analysis. Literature review identified 111 mutations reported to correlate with phenotypic resistance to these antimicrobials. Analysis was conducted via our in-house bioinformatics pipeline targeting point mutations in the relevant genes (pbp1A, 23S rRNA, gyrA, rdxA, frxA, and rpoB) in order to assess genotype-to-phenotype correlation. Resistance rates of study isolates were as follows: clarithromycin 54%, metronidazole 31%, amoxicillin 10%, rifampicin 4%, and levofloxacin 2%. Genotype-to-phenotype correlation was inconsistent; for every analyzed gene at least one phenotypically susceptible isolate was found to have a mutation previously associated with resistance. This was also observed regarding mutations commonly used in commercial kits to diagnose AMR in H. pylori cases. Furthermore, 11 novel point mutations associated with a resistant phenotype were detected. Analysis of a unique set of H. pylori isolates demonstrates that inferring resistance phenotypes from WGS in H. pylori remains challenging and should be optimized further.

scholarly journals Macrolide resistance in Helicobacter pylori: rapid detection of point mutations and assays of macrolide binding to ribosomes.

1997 ◽  
Vol 41 (12) ◽  
pp. 2724-2728 ◽  
Author(s):  
A Occhialini ◽  
M Urdaci ◽  
F Doucet-Populaire ◽  
C M Bébéar ◽  
H Lamouliatte ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Point Mutations ◽  
Restriction Enzymes ◽  
The United States ◽  
Drug Binding ◽  
Macrolide Resistance ◽  
Rrna Genes ◽  
23S Rrna ◽  
Dependent Manner ◽  
H Pylori

Resistance of Helicobacter pylori to macrolides is a major cause of failure of eradication therapies. Single base substitutions in the H. pylori 23S rRNA genes have been associated with macrolide resistance in the United States. Our goal was to extend this work to European strains, to determine the consequence of this mutation on erythromycin binding to H. pylori ribosomes, and to find a quick method to detect the mutation. Seven pairs of H. pylori strains were used, the parent strain being naturally susceptible to macrolides and the second strain having acquired an in vivo resistance during a treatment regimen that included clarithromycin. The identity of the strains was confirmed by random amplified polymorphic DNA testing with two different primers, indicating that resistance was the result of the selection of variants of the infecting strain. All resistant strains were found to have point mutations at position 2143 (three cases) or 2144 (four cases) but never on the opposite DNA fragment of domain V of the 23S rRNA gene. The mutation was A-->G in all cases except one (A-->C) at position 2143. Using BsaI and BbsI restriction enzymes on the amplified products, we confirmed the mutations of A-->G at positions 2144 and 2143, respectively. Macrolide binding was tested on purified ribosomes isolated from four pairs of strains with [14C]erythromycin. Erythromycin binding increased in a dose-dependent manner for the susceptible strain but not for the resistant one. In conclusion we suggest that the limited disruption of the peptidyltransferase loop conformation, caused by a point mutation, reduces drug binding and consequently confers resistance to macrolides. Finally, the macrolide resistance could be detected without sequencing by performing restriction fragment length polymorphism with appropriate restriction enzymes.

scholarly journals Rapid screening of clarithromycin resistance in Helicobacter pylori by pyrosequencing

2007 ◽  
Vol 56 (10) ◽  
pp. 1370-1376 ◽  
Author(s):  
Karen-Anja Moder ◽  
Franziska Layer ◽  
Wolfgang König ◽  
Brigitte König
Keyword(s):  
Helicobacter Pylori ◽  
Point Mutations ◽  
Rapid Screening ◽  
23S Rrna ◽  
Resistance Testing ◽  
Resistance Mutations ◽  
Additional Time ◽  
Clarithromycin Resistance ◽  
H Pylori ◽  
Domain V

Helicobacter pylori infections can be effectively treated with clarithromycin, a macrolide, in combination with other antibiotics, such as amoxicillin, tetracycline or metronidazole. The failure of H. pylori eradication is mainly associated with macrolide-resistant strains. Three point mutations (A2142G/C, A2143G, T2182C) in the peptidyltransferase region of domain V of the 23S rRNA have been described as being associated with clarithromycin resistance. Therefore, the determination of clarithromycin resistance by pyrosequencing was evaluated. H. pylori from 81 gastric biopsies was cultured and clarithromycin resistance was determined by Etest, as well as by pyrosequencing technology (PSQ 96 system; Biotage). The respective mutations were set in relation to the MIC measured in μg ml−1 by Etest. In this study, point mutations in positions 2142 and 2143 were associated with clarithromycin resistance. Mutations in position 2182 did not contribute to clarithromycin resistance. In addition, from 22 out of the 81 biopsies, clarithromycin resistance was determined directly without culturing H. pylori to save additional time. Identical results were obtained as compared to resistance testing with pure H. pylori strains. All results obtained by pyrosequencing were evaluated by Sanger sequencing. The data show that pyrosequencing to detect point mutation is a fast and reliable method for determining clarithromycin resistance in H. pylori, and provides the same results as the Etest.

scholarly journals Rapid Detection, by PCR and Reverse Hybridization, of Mutations in the Helicobacter pylori 23S rRNA Gene, Associated with Macrolide Resistance

1999 ◽  
Vol 43 (7) ◽  
pp. 1779-1782 ◽  
Author(s):  
Leen-Jan van Doorn ◽  
Yvette J. Debets-Ossenkopp ◽  
Armelle Marais ◽  
Ricardo Sanna ◽  
Francis Mégraud ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Fragment Length Polymorphism ◽  
Simultaneous Detection ◽  
Point Mutations ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Reverse Hybridization ◽  
23S Rrna Gene ◽  
H Pylori

ABSTRACT A PCR-based reverse hybridization system (research prototype kit INNO-LiPA for H. pylori resistance) was developed and evaluated for simultaneous detection of 23S ribosomal DNA point mutations, associated with macrolide resistance in Helicobacter pylori. Fifty-seven H. pylori strains (51 natural, 6 laboratory-derived artificial, 52 resistant, and 5 susceptible strains) were tested by PCR-LiPA (detecting mutations A2115→G, G2141→A, A2142→G, A2142→C, A2143→G, A2143→C, and A2143→T), DNA sequencing, restriction fragment length polymorphism, and/or hybridization to oligonucleotide probes. Results were highly concordant, but PCR-LiPA appears to be more sensitive for the simultaneous detection of multiple mutants.

scholarly journals Molecular Assessment of Resistance to Clarithromycin in Helicobacter pylori Strains Isolated from Patients with Dyspepsia by Fluorescent In Situ Hybridization in the Center of Iran

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Jina Vazirzadeh ◽  
Jamal Falahi ◽  
Sharareh Moghim ◽  
Tahmineh Narimani ◽  
Rahmatollah Rafiei ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
In Situ Hybridization ◽  
Point Mutations ◽  
23S Rrna ◽  
Rrna Gene ◽  
Clarithromycin Resistance ◽  
Genotypic Analysis ◽  
23S Rrna Gene ◽  
H Pylori

Background and Aims. Helicobacter pylori is a common infectious bacterium mostly found in gastroduodenal diseases. The increased prevalence of clarithromycin-resistant H. pylori strains is a major challenge in the successful treatment of infections caused by this organism. The present study is aimed at detecting the clarithromycin resistance pattern of H. pylori strains isolated from gastric biopsies and evaluating point mutations of the 23S rRNA gene. Patients and methods. In the present descriptive cross-sectional study, 165 patients with gastrointestinal disorders, who were referred to the Endoscopy Center of Dr. Shariati Hospital of Isfahan, Iran, were enrolled from April to July 2018. H. pylori infection was diagnosed by culture, and susceptibility of the isolates to clarithromycin was assessed by the E-test. Minimum inhibitory concentration (MIC) values were obtained based on EUCAST recommendations. Also, fluorescence in situ hybridization (FISH) was used to determine point mutations associated with clarithromycin resistance. Results. By using culturing, H. pylori was isolated from 50.3% (83/165) gastric biopsy specimens. The overall frequency of resistance to clarithromycin was 25.3% (21/83) by the E-test. In the resistance genotypic analysis, 19 isolates had mutations. The prevalence of A2143G and A2144G mutations was 68.4% (13/19) and 31.5% (6/19), respectively. A2143C mutation was not tracked in any isolate. Two isolates with MIC>0.5 μg/mL had no mutations that could be related to other mechanisms of resistance. Conclusion. As presented in the study, the high prevalence of clarithromycin-resistant H. pylori due to point mutations of the 23S rRNA gene indicates the necessity of revising the standard treatment regimen based on antibiotic susceptibility pattern of each region.

scholarly journals PCR-RFLP detection of point mutations A2143G and A2142G in 23S rRNA gene conferring resistance to clarithromycin in Helicobacter pylori strains.

2014 ◽  
Vol 61 (2) ◽  
Author(s):  
Karolina Klesiewicz ◽  
Paweł Nowak ◽  
Elżbieta Karczewska ◽  
Iwona Skiba ◽  
Izabela Wojtas-Bonior ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Point Mutations ◽  
Rflp Analysis ◽  
23S Rrna ◽  
Rrna Gene ◽  
Efficient Management ◽  
Clarithromycin Resistance ◽  
Pcr Rflp ◽  
23S Rrna Gene ◽  
H Pylori

The occurrence of clarithromycin resistance among Helicobacter pylori strains is a major cause of the treatment failure. Resistance to this drug is conferred by point mutations in 23S rRNA gene and the most prevalent mutations are A2143G and A2142G. The aim of the study was to evaluate the occurrence of A2143G and A2142G mutations in a group of H. pylori strains resistant to clarithromycin. The study included 21 clarithromycin-resistant H. pylori strains collected between 2006 and 2009 in southern Poland. Resistance to clarithromycin was quantitatively tested with the E-test to determine the minimal inhibitory concentration (MIC value). The point mutations of H. pylori isolates were detected by PCR followed by RFLP analysis. The MIC values for clarithromycin for the analyzed strains ranged from 1.5 mg/L to 64 mg/L. Nine H. pylori strains exhibited A2143G mutation and A2142G mutation was found in 9 isolates as well. The results of RFLP analysis of 3 clarithromycin-resistant strains were negative for both mutations. The average MIC values for A2143G and A2142G mutants were 6 and 30 mg/L, respectively. Frequencies of A2143G and A2142G mutations were the same in all isolates tested. Strains with A2143G mutation exhibited lower MIC values than A2142G mutants. Application of PCR-RFLP method for detection of clarithromycin resistance allows for better and more efficient management of H. pylori infections.

PCR-RFLP DETECTION OF POINT MUTATIONS CONFERRING RESISTANCE TO CLARITHROMYCIN OF HELICOBACTER PYLORI IN QUANG NGAI

2015 ◽  
pp. 54-61
Author(s):  
Ngoc Doanh Pham ◽  
Van Huy Tran ◽  
Thi Minh Thi Ha
Keyword(s):  
Helicobacter Pylori ◽  
General Hospital ◽  
Chronic Gastritis ◽  
Point Mutations ◽  
23S Rrna ◽  
Rrna Gene ◽  
Clarithromycin Resistance ◽  
Urease Test ◽  
Pcr Rflp ◽  
H Pylori

Background: Clarithromycin resistance of H-pylori is the main cause leading to treatment failure. Aim: The purpose of this study was to determine the rate of clarithromycin resistance mutation on gene 23S ribosomal popular robonucleotide acid (rRNA) of H-pylori in patients with chronic gastritis in Quang Ngai General Hospital PCR-RFLP. Method: This is a cross-sectional study in 64 patients infected with H-pylori was determined by 3 methods and chronic gastritis proven by histology. Sample collection conducted in Quang Ngai general hospital and molecular biology tests were conducted in the medical genetics department Hue of Medical and Pharmaceutical University. Urease test, histopathological examination and perform HE staining PCR 23S rRNA gene fragment of H-pylori to determine H-pylori infection. Analysis of genetic mutations in the 23S rRNA point is performed by PCR-RFLP technique. Results: Of the 64 biopsies qualify included in the study, 41 samples with clarithromycin resistance point mutations (64%), of which 40 (62.5%) had mutations A2143A, one sample with A2142A (2%). No samples had mutations A2142C and no more than one mutation.Conclusion: This is the first time we report mutations related to clarithromycin of H-pylori in Quang Ngai province. Mutations rate is high (64%), among the common mutations, the most common mutantation is A2143G. Key words: Helicobacter pylori, clarithromycin resistance, PCR-RFLP, point mutations

scholarly journals Helicobacter pylori Primary and Secondary Genotypic Resistance to Clarithromycin and Levofloxacin Detection in Stools: A 4-Year Scenario in Southern Italy

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 723
Author(s):  
Giuseppe Losurdo ◽  
Floriana Giorgio ◽  
Maria Pricci ◽  
Bruna Girardi ◽  
Francesco Russo ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Point Mutations ◽  
Amino Acid Position ◽  
Geographic Area ◽  
23S Rrna ◽  
Genotypic Resistance ◽  
Secondary Resistance ◽  
Resistant Strains ◽  
Polymerase Chain ◽  
H Pylori

Antibiotic resistance has become an emerging problem for treating Helicobacter pylori (H. pylori) infection. Clarithromycin and levofloxacin are two key antibiotics used for its eradication. Therefore, we reviewed our experience with genotypic resistance analysis in stools to both clarithromycin and levofloxacin in the last four years to evaluate time trends, both in naive and failure patients. Patients collected a fecal sample using the THD fecal test device. Real-time polymerase chain reaction was performed to detect point mutations conferring resistance to clarithromycin (A2142C, A2142G, and A2143G in 23S rRNA) and levofloxacin (substitutions at amino acid position 87 and 91 of gyrA). One hundred and thirty-five naive patients were recruited between 2017–2020. Clarithromycin resistance was detected in 37 (27.4%). The time trend did not show any significant variation from 2017 to 2020 (p = 0.33). Primary levofloxacin resistance was found in 26 subjects (19.2%), and we observed a dramatic increase in rates from 2017 (10%) to 2018 (3.3%), 2019 (20%), and 2020 (37.8%). Ninety-one patients with at least one eradication failure were recruited. Secondary resistance to clarithromycin and levofloxacin was found in 59 (64.8%) and 45 patients (59.3%), respectively. In conclusion, our geographic area has a high risk of resistance to clarithromycin. There is also a progressive spreading of levofloxacin-resistant strains.

scholarly journals The Bifunctional Enzyme SpoT Is Involved in the Clarithromycin Tolerance of Helicobacter pylori by Upregulating the Transporters HP0939, HP1017, HP0497, and HP0471

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Xiwen Geng ◽  
Wen Li ◽  
Zhenghong Chen ◽  
Sizhe Gao ◽  
Wei Hong ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Point Mutations ◽  
23S Rrna ◽  
Bifunctional Enzyme ◽  
Key Factors ◽  
Content Type ◽  
Bacterial Drug Resistance ◽  
Resistant Strains ◽  
H Pylori

ABSTRACT Clarithromycin (CLA) is a commonly recommended drug for Helicobacter pylori eradication. However, the prevalence of CLA-resistant H. pylori is increasing. Although point mutations in the 23S rRNA are key factors for CLA resistance, other factors, including efflux pumps and regulation genes, are also involved in the resistance of H. pylori to CLA. Guanosine 3′-diphosphate 5′-triphosphate and guanosine 3′,5′-bispyrophosphate [(p)ppGpp)], which are synthesized by the bifunctional enzyme SpoT in H. pylori, play an important role for some bacteria to adapt to antibiotic pressure. Nevertheless, no related research involving H. pylori has been reported. In addition, transporters have been found to be related to bacterial drug resistance. Therefore, this study investigated the function of SpoT in H. pylori resistance to CLA by examining the shifts in the expression of transporters and explored the role of transporters in the CLA resistance of H. pylori. A ΔspoT strain was constructed in this study, and it was shown that SpoT is involved in H. pylori tolerance of CLA by upregulating the transporters HP0939, HP1017, HP0497, and HP0471. This was assessed using a series of molecular and biochemical experiments and a cDNA microarray. Additionally, the knockout of genes hp0939, hp0471, and hp0497 in the resistant strains caused a reduction or loss (the latter in the Δhp0497 strain) of resistance to CLA. Furthermore, the average expression levels of these four transporters in clinical CLA-resistant strains were considerably higher than those in clinical CLA-sensitive strains. Taken together, our results revealed a novel molecular mechanism of H. pylori adaption to CLA stress.

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

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Lili Yang ◽  
Ao Zou ◽  
Huihua Wu ◽  
Hai Guo ◽  
Fangting Zhang ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibiotic Resistance ◽  
Confidence Interval ◽  
Acid Secretion ◽  
Antimicrobial Agents ◽  
Point Mutations ◽  
Eradication Therapy ◽  
23S Rrna ◽  
Tailored Therapy ◽  
H 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.

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