scholarly journals Mutations in 23S rRNA are associated with clarithromycin resistance in Helicobacter pylori.

1996 ◽  
Vol 40 (2) ◽  
pp. 477-480 ◽  
Author(s):  
J Versalovic ◽  
D Shortridge ◽  
K Kibler ◽  
M V Griffy ◽  
J Beyer ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
23S Rrna ◽  
Treatment Regimens ◽  
Clarithromycin Resistance ◽  
Transition Mutation ◽  
H Pylori ◽  
Domain V ◽  
Ulcer Treatment

Twelve clarithromycin-resistant Helicobacter pylori isolates (100% of resistant isolates examined) from seven different patients each contained an A-->G transition mutation within a conserved loop of 23S rRNA. A-->G transition mutations at positions cognate with Escherichia coli 23S rRNA positions 2058 and 2059 were identified. Clarithromycin-susceptible H. pylori isolates from 14 different patients displayed no polymorphisms in a conserved loop within domain V of 23S rRNA. The study is the first to report mutations in H. pylori associated with resistance to an antimicrobial agent used in established peptic ulcer treatment regimens.

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 New Site of Modification of 23S rRNA Associated with Clarithromycin Resistance of Helicobacter pylori Clinical Isolates

2002 ◽  
Vol 46 (12) ◽  
pp. 3765-3769 ◽  
Author(s):  
Carla Fontana ◽  
Marco Favaro ◽  
Silvia Minelli ◽  
Anna Angela Criscuolo ◽  
Antonio Pietroiusti ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
23S Rrna ◽  
Dilution Method ◽  
Rrna Gene ◽  
Functional Sites ◽  
Biopsy Specimens ◽  
Clarithromycin Resistance ◽  
Pcr Product ◽  
23S Rrna Gene ◽  
H Pylori

ABSTRACT Resistance of Helicobacter pylori to clarithromycin occurs with a prevalence ranging from 0 to 15%. This has an important clinical impact on dual and triple therapies, in which clarithromycin seems to be the better choice to achieve H. pylori eradication. In order to evaluate the possibility of new mechanisms of clarithromycin resistance, a PCR assay that amplified a portion of 23S rRNA from H. pylori isolates was used. Gastric tissue biopsy specimens from 230 consecutive patients were cultured for H. pylori isolation. Eighty-six gastric biopsy specimens yielded H. pylori-positive results, and among these 12 isolates were clarithromycin resistant. The latter were studied to detect mutations in the 23S rRNA gene. Sequence analysis of the 1,143-bp PCR product (portion of the 23S rRNA gene) did not reveal mutation such as that described at position 2142 to 2143. On the contrary, our findings show, for seven isolates, a T-to-C transition at position 2717. This mutation conferred a low level of resistance, equivalent to the MIC for the isolates, selected using the E-test as well as using the agar dilution method: 1 μg/ml. Moreover, T2717C transition is located in a highly conserved region of the 23S RNA associated with functional sites: domain VI. This fact has a strong effect on the secondary structure of the 23S RNA and on its interaction with macrolide. Mutation at position 2717 also generated an HhaI restriction site; therefore, restriction analysis of the PCR product also permits a rapid detection of resistant isolates.

Clavulanic Acid in the Scope of Helicobacter pylori Treatment: A Literature Review and Beyond

2020 ◽  
Vol 15 ◽  
Author(s):  
Nasr Alrabadi ◽  
Iyad S. Albustami ◽  
Husam A. Abuhayyeh ◽  
Khaled M. El-Muwalla ◽  
Rama J. Alawneh ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Peptic Ulcer Disease ◽  
Clavulanic Acid ◽  
Clinical Studies ◽  
Filamentous Form ◽  
Ulcer Disease ◽  
Treatment Regimens ◽  
Randomized Controlled Studies ◽  
H Pylori

Background: Helicobacter pylori (H.pylori) infection is the most common cause of peptic ulcer disease and it can be associated with many complications including malignancies. In clinical practice, some clinicians may use clavulanic acid (CA) in combination with amoxicillin or other beta-lactams as an addition to the standard treatment regimens. This practice may be made by habitual mistake, non-evidence based hypothetical assumptions, or by prescribing it as an alternative treatment. This review aims to expose the effect of CA against H.pylori infection and to review the possible mechanisms that may contribute to that effect. Methods: A PubMed and Google Scholar literature search was obtained on both pre-clinical and clinical studies related to CA and H.pylori infection. Results: Available clinical studies showed improvement in the eradication of H. pylori by about 10-20% when CA was added to the treatment regimens. This effect for CA could be related to several mechanisms including inhibition of H. pylori growth by binding to penicillin-binding proteins (PBPs), the transformation of H. pylori from the active filamentous form into coccoidal form, induction of the release of dopamine, modulation of immunological response towards H. pylori infection and its relationship with other microbiota. Randomized-controlled studies on patients with resistance H. pylori are needed. Moreover, In_vitro studies to evaluate the mechanisms by which CA may influence H. pylori are warranted. Conclusion: The presented literature suggests potential avenues for the use of CA in the management of peptic ulcer disease and H.pylori infection.

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 T2182C Mutation in 23S rRNA Is Associated with Clarithromycin Resistance in Helicobacter pylori Isolates Obtained in Bangladesh

2004 ◽  
Vol 48 (9) ◽  
pp. 3567-3569 ◽  
Author(s):  
Rasel Khan ◽  
Shamsun Nahar ◽  
Jinath Sultana ◽  
Mian Mashhud Ahmad ◽  
Motiur Rahman
Keyword(s):  
Helicobacter Pylori ◽  
Gene Sequence ◽  
Point Mutations ◽  
23S Rrna ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Clarithromycin Resistance ◽  
Gene Sequence Analysis ◽  
23S Rrna Gene ◽  
Transition Mutation

ABSTRACT Twelve clarithromycin-resistant (MIC, ≥1 μg/ml) Helicobacter pylori isolates were analyzed for point mutations in the 23S rRNA gene. Sequence analysis of all of the resistant isolates revealed a T-to-C transition mutation at position 2182. Transformation experiments confirmed that a single T-to-C transition mutation at position 2182 is associated with clarithromycin resistance.

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

Novel high resolution melt curve assay for the analysis of predominance of Helicobacter pylori clarithromycin resistance

2019 ◽  
Vol 77 (4) ◽  
Author(s):  
Doron Boltin ◽  
Olga Ashorov ◽  
Lucie Benejat ◽  
Dalal Hamouda ◽  
Rachel Gingold Belfer ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
High Resolution ◽  
23S Rrna ◽  
Rrna Gene ◽  
High Resolution Melt ◽  
Clarithromycin Resistance ◽  
Stool Antigen ◽  
Stool Samples ◽  
Antigen Tests ◽  
H Pylori

ABSTRACT Clarithromycin resistance is the most common cause of Helicobacter pylori treatment failure and it is attributed to three point mutations, A2142G, A2142C and A2143G, within the 23S rRNA gene. We aimed to determine the prevalence of H. pylori clarithromycin resistance using a novel high resolution melt assay. A total of 151 stool samples were collected from treatment-naïve patients with general gastric discomfort who also performed 13CO2 breath tests. Stool antigen tests were also performed on 126 of the 151 stool samples collected. Bacterial DNA was extracted from the stool and analyzed by comparing it with four reference plasmids incorporating the three mutations and the wild type (WT) sequences. The melt assay detected 106 H. pylori positive samples, of which 54 had a WT sequence, and 52 had a point mutation associated with clarithromycin resistance, including A2142G in 10, A2142C in 13, A2143G in 18 and heterozygosity (multiple peaks) in 11. Compared with the gold standards (13CO2 breath and stool antigen tests), the melt assay had a sensitivity of 100% and 99% and a specificity of 82% and 78%, respectively. Therefore, our stool-based molecular assay is able to identify H. pylori infection and clarithromycin resistance. It could be used for screening prior to administration of clarithromycin eradication therapy.

scholarly journals Effectiveness ofCitrusFruits onHelicobacter pylori

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Giuseppina Mandalari ◽  
Carlo Bisignano ◽  
Santa Cirmi ◽  
Michele Navarra
Keyword(s):  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Side Effects ◽  
Gastric Carcinoma ◽  
Current Knowledge ◽  
Therapeutic Strategies ◽  
Treatment Regimens ◽  
H Pylori ◽  
Novel Therapeutic Strategies ◽  
Novel Therapeutic

It is known thatHelicobacter pyloriinfection is associated with chronic gastritis, peptic ulcer, and gastric carcinoma. Due to the increased side effects of the treatment regimens and the development of antimicrobial resistance, a number of natural compounds have been tested as potential alternatives. In this review, we will examine the current knowledge on the effect ofCitrusfruits and their derivatives againstH. pylori, highlighting the remaining outstanding questions on the development of novel therapeutic strategies.

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