Efflux Pump Inhibition May Reverse the Clarithromycin Resistance of H. pylori with 23S rRNA Mutation

2009 ◽  
Vol 104 ◽  
pp. S51-S52
Author(s):  
Kenro Hirata ◽  
Hidekazu Suzuki ◽  
Toshihiro Nishizawa ◽  
Hitoshi Tsugawa ◽  
Hiroe Muraoka ◽  
...  
Keyword(s):  
Efflux Pump ◽  
23S Rrna ◽  
Clarithromycin Resistance ◽  
Efflux Pump Inhibition ◽  
H Pylori ◽  
Rrna Mutation

scholarly journals Pathophysiology of Antibiotic Resistance: Clarithromycin

2000 ◽  
Vol 14 (10) ◽  
pp. 891-894 ◽  
Author(s):  
Diane E Taylor
Keyword(s):  
Inhibitory Concentration ◽  
Natural Transformation ◽  
Rrna Genes ◽  
23S Rrna ◽  
Cross Resistance ◽  
In Vitro Mutagenesis ◽  
Clarithromycin Resistance ◽  
23S Rrna Genes ◽  
H Pylori

Resistance ofHelicobacter pylorito antibiotics ranges from 3% to 10% and may exceed these levels in some countries. The pathophysiology of clarithromycin resistance is reviewed, including the mode of action by which the antibiotic inhibits protein synthesis and the mechanism of resistance, which involves a mutation at position 2142 or 2143 in the V loop domain of the 23S rRNA genes. Mutations of A2142G confer a higher minimum inhibitory concentration than mutations of A2143G. The former demonstrate cross-resistance to macrolide, lincosamide and streptogramin antibiotics, whereas the latter are susceptible to streptogramin B. In vitro mutagenesis combined with natural transformation were used to create several types of clarithromycin-resistant mutants.H pyloristrains with A2142G and A2143G mutations had a higher growth rate than those with A2142C, A2143 or A2142T mutations. Data from this study indicate why clarithromycin-resistant clinical isolates ofH pyloriare more likely to have A2142G or A2143G mutations and only occasionally A2142C mutations.

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.

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 Helicobacter pylori eradication according to sequencing-based 23S ribosomal RNA point mutation associated with clarithromycin resistance

2019 ◽  
Author(s):  
Seung In Seo ◽  
Byoung Joo ◽  
Jin Gu Kang ◽  
Hyoung Su Kim ◽  
Myoung Kuk Jang ◽  
...  
Keyword(s):  
Point Mutation ◽  
Ribosomal Rna ◽  
Point Mutations ◽  
23S Rrna ◽  
Rrna Gene ◽  
Clarithromycin Resistance ◽  
Clinically Significant ◽  
H Pylori ◽  
23S Ribosomal Rna ◽  
Significant Point

Abstract Background Clarithromycin resistance in Helicobacter pylori (H. pylori) is associated with point mutations in the 23S ribosomal RNA (rRNA) gene. A sequencing-based method can detect more point mutations than a polymerase chain reaction (PCR)-based method. We investigated the point mutations in the 23S rRNA genes of patients infected with clarithromycin-resistant H. pylori and compared the H. pylori eradication rates based on the identified clinically significant point mutations. Methods A total of 431 adult patients with H. pylori infection were retrospectively recruited in Kangdong Sacred Heart Hospital in 2017 and 2018. Patients who did not have point mutations related to clarithromycin resistance and/or had clinically insignificant point mutations were treated with PAC (proton pump inhibitor, amoxicillin, clarithromycin) for 7 days, while patients with clinically significant point mutations were treated with PAM (proton pump inhibitor, amoxicillin, metronidazole) for 7 days. H. pylori eradication rates were compared between the two groups. Results Sequencing-based detection of point mutations identified four mutations that were considered clinically significant (A2142G, A2142C, A2143G, A2143C), while all the other mutations were considered clinically insignificant. The clarithromycin resistance rate was 21.3% in the overall group of patients. A2143G was the most clinically significant point mutation (84/431, 19.5%), while T2182C was the most clinically insignificant point mutation (283/431, 65.7%). The H. pylori eradication rate in the overall group of patients was 83.7%, and the 7-day PAM-treated clarithromycin-resistance group showed a significantly lower eradication rate than the 7-day PAC-treated nonresistance group [ITT; 55.4% (51/92) vs. 74.3% (252/339), P=0.001, PP; 66.2% (51/77) vs. 88.4% (252/285), P=0.0001]. Conclusions There were significantly lower eradication rates in the patients with clarithromycin-resistant H. pylori as identified by the sequencing of point mutations in the 23S rRNA gene when treated with PAM for 7 days. A future study comparing treatment regimens in clarithromycin-resistant H. pylori-infected patients may be necessary.

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.

Helicobacter pylori 23S rRNA gene A2142G, A2143G, T2182C, and C2195T mutations associated with clarithromycin resistance detected in Sudanese patients

2020 ◽  
Author(s):  
Aalaa Mahgoub Albasha ◽  
Maram M. Alnosh ◽  
Esraa Hassan Osman ◽  
Duha M Zeinalabdin ◽  
Amira A M Fadl ◽  
...  
Keyword(s):  
Dna Sequencing ◽  
Point Mutations ◽  
23S Rrna ◽  
Rrna Gene ◽  
Specific Pcr ◽  
Clarithromycin Resistance ◽  
23S Rrna Gene ◽  
Allele Specific ◽  
H Pylori ◽  
Allele Specific Pcr

Abstract Background: Clarithromycin resistant Helicobacter pylori (H. pylori) strains represent a worldwide health problem. These stains are usually carrying mutations within the 23S rRNA gene associated with clarithromycin resistance. This study aimed to detect H. pylori and clarithromycin resistant associated mutations from Sudanese patients with gastritis symptoms.Materials and Methods: Two hundred and eighty-eight gastric biopsies were collected using gastrointestinal endoscopy from patients with gastritis symptoms in different hospitals in Khartoum state. H. pylori was detected by PCR using primers targeting 16S rRNA and 23S rRNA. Then allele-specific PCR and DNA sequencing were used to screen for the presence of A2142G and A2143G point mutations.Results: Out of 288 samples, H. pylori was detected in 97 (33.7%) sample. Allele-specific PCR detected the variant A2142G in 9/97 (9.3%) sample, while A2143G mutation was not found in any sample. The DNA sequencing revealed the presence of mutations associated with clarithromycin-resistance in 48% (12/25) of samples; the A2142G was present in one sample, A2143G in 5 samples, T2182C in 4 samples, and C2195T in 3 samples. There was no association of 23S rRNA gene point mutations with gender, age group and geographical distribution of patients.Conclusion: This study revealed a high frequency (48%) of mutations associated with clarithromycin resistance using DNA sequencing of the 23S rRNA gene's V domain. This information should be taken into consideration before choosing optimal therapy for H. pylori eradication.

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

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