MINIMAL INHIBITORY CONCENTRATION (MIC) VALUES AND DIFFERENT POINT MUTATIONS IN THE 23S rRNA GENE FOR CLARITHROMYCIN RESISTANCE IN 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.

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

Acta Biochimica Polonica ◽

10.18388/abp.2014_1901 ◽

2014 ◽

Vol 61 (2) ◽

Cited By ~ 22

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.

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

10.21203/rs.3.rs-87256/v1 ◽

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.

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

BMC Microbiology ◽

10.1186/s12866-021-02096-3 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Aalaa Mahgoub Albasha ◽

Maram M. Elnosh ◽

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 primer targeting 16S 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 88 (~ 30.6%) samples by 16 s RNA. Allele-specific PCR detected the variant A2142G in 9/53 (~ 17%) sample, while A2143G mutation was not found in any sample. The DNA sequencing revealed the presence of mutations associated with clarithromycin-resistance in 36% (9/25) of samples; the A2142G was present in one sample, A2143G in 5 samples and T2182C in 4 samples. Additionally, another point mutation (C2195T) was detected in 3 samples. There was no association of 23S rRNA gene point mutations with gender, age group, and patients’ geographical distribution. Conclusion This study revealed a high frequency (36%) of mutations associated with clarithromycin resistance using DNA sequencing of the 23S rRNA gene’s V domain. This information should be taken into consideration to avoid eradication therapy failing.

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STUDY ON POINT MUTATIONS AT POSITIONS 2132 AND 2143 IN 23S RRNA GENE OF HELICOBACTER PYLORI AMONG PATIENTS WITH CHRONIC GASTRITIS

Journal of Medicine and Pharmacy ◽

10.34071/jmp.2015.6.2 ◽

2016 ◽

pp. 12-20

Author(s):

Thi Minh Thi Ha ◽

Van Huy Tran ◽

Viet Nhan Nguyen ◽

Thanh Hoa Nguyen ◽

Phan Tuong Quynh Le

Keyword(s):

Helicobacter Pylori ◽

Chronic Gastritis ◽

Point Mutations ◽

23S Rrna ◽

Rrna Gene ◽

Clarithromycin Resistance ◽

Pcr Rflp ◽

23S Rrna Gene ◽

History Of ◽

H Pylori

Background: Clarithromycin resistance in Helicobacter pylori has been found to be associated with point mutations at positions 2142 and 2143 in 23SrRNA gene. The aims of this study were: (1) to determine the rates of point mutations A2143G, A2142G and A2142C in 23SrRNA gene of H. pylori among patients with chronic gastritis by PCR-RFLP technique; and (2) to assessthe association between these mutations and some clinical, endoscopic and histopathological characteristics of chronic gastritis. Patients and methods: two hundreds and twenty six patients with H. pylori-positive chronic gastritis were determined A2143G, A2142G and A2142C mutations by PCR-RFLP technique with DNA extracted from endoscopic biopsy specimens of gastric mucosa. Results: The rate of point mutations at positions 2142 and 2143 in 23S rRNA gene of H. pylori was 35.4% in total, the A2143G and A2142G mutationsaccounted for 92.5% and 7.5% of all point mutations, respectively. No A2142C mutation was found. These mutations were not associated with age, gender,distribution of gastritis, and the presence of atrophic gastritis. The rate of A2143G mutation in groups with and without a history of clarithromycin treatment were 44.9% and 24.8%, respectively (p = 0,0065). The A2142G mutation was associated with intestinal metaplasia and/or dysplasia. Conclusion: The point mutations at positions 2142 and 2143 in 23S rRNA gene were found at a high rate in H. pylori strains amongpatients with chronic gastritis, with the absolute predominance of A2143G mutation. The A2143G mutation was associated with a history of clarithromycin treatment. Key words: 23S rRNA gene, Helicobacter pylori, A2143G, A2142G, A2142C mutation, clarithromycin resistance, chronic gastritis.

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Phenotypic and Molecular Antimicrobial Susceptibility of Helicobacter pylori

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02530-16 ◽

2017 ◽

Vol 61 (4) ◽

Cited By ~ 11

Author(s):

Derrick Chen ◽

Scott A. Cunningham ◽

Nicolynn C. Cole ◽

Peggy C. Kohner ◽

Jayawant N. Mandrekar ◽

...

Keyword(s):

Antimicrobial Susceptibility ◽

Susceptibility Testing ◽

Point Mutations ◽

The United States ◽

23S Rrna ◽

Rrna Gene ◽

Content Type ◽

Clarithromycin Resistance ◽

23S Rrna Gene ◽

H Pylori

ABSTRACT Failure to eradicate Helicobacter pylori infection is often a result of antimicrobial resistance, which for clarithromycin is typically mediated by specific point mutations in the 23S rRNA gene. The purpose of this study was to define current patterns of antimicrobial susceptibility in H. pylori isolates derived primarily from the United States and to survey them for the presence of point mutations in the 23S rRNA gene and assess the ability of these mutations to predict phenotypic clarithromycin susceptibility. Antimicrobial susceptibility testing was performed using agar dilution on 413 H. pylori isolates submitted to Mayo Medical Laboratories for susceptibility testing. For a subset of these isolates, a 150-bp segment of the 23S rRNA gene was sequenced. A total of 1,970 MICs were reported over the 4-year study period. The rate of clarithromycin resistance was high (70.4%), and elevated MICs were frequently observed for metronidazole (82.4% of isolates had an MIC of >8 μg/ml) and ciprofloxacin (53.5% of isolates had an MIC of >1 μg/ml). A total of 111 archived H. pylori isolates underwent 23S rRNA gene sequencing; we found 95% concordance between genotypes and phenotypes (P = 0.9802). Resistance to clarithromycin was most commonly due to an A2143G mutation (82%), followed by A2142G (14%) and A2142C (4%) mutations. Clinical H. pylori isolates derived primarily from the United States demonstrated a high rate of clarithromycin resistance and elevated metronidazole and ciprofloxacin MICs. The relative distribution of point mutations at positions 2143 and 2142 in the 23S rRNA gene in clarithromycin-resistant H. pylori was similar to that reported from other parts of the world; these mutations predict phenotypic resistance to clarithromycin.

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Site-Specific Mutations in the 23S rRNA Gene ofHelicobacter pylori Confer Two Types of Resistance to Macrolide-Lincosamide-Streptogramin B Antibiotics

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.42.8.1952 ◽

1998 ◽

Vol 42 (8) ◽

pp. 1952-1958 ◽

Cited By ~ 67

Author(s):

Ge Wang ◽

Diane E. Taylor

Keyword(s):

Point Mutations ◽

Clinical Isolates ◽

23S Rrna ◽

Cross Resistance ◽

Rrna Gene ◽

Type I ◽

Type Ii ◽

Clarithromycin Resistance ◽

23S Rrna Gene ◽

H Pylori

ABSTRACT Clarithromycin resistance in Helicobacter pylori is mainly due to A-to-G mutations within the peptidyltransferase region of the 23S rRNA. In the present study, cross-resistance to macrolide, lincosamide, and streptogramin B (MLS) antibiotics (MLS phenotypes) has been investigated for several clinical isolates of H. pylori. Two major types of MLS resistance were identified and correlated with specific point mutations in the 23S rRNA gene. The A2142G mutation was linked with high-level cross-resistance to all MLS antibiotics (type I), and the A2143G mutation gave rise to an intermediate level of resistance to clarithromycin and clindamycin but no resistance to streptogramin B (type II). In addition, streptogramin A and streptogramin B were demonstrated to have a synergistic effect on both MLS-sensitive and MLS-resistant H. pyloristrains. To further understand the mechanism of MLS resistance inH. pylori, we performed in vitro site-directed mutagenesis (substitution of G, C, or T for A at either position 2142 or 2143 of the 23S rRNA gene). The site-directed point mutations were introduced into a clarithromycin-susceptible strain, H. pylori UA802, by natural transformation followed by characterization of their effects on MLS resistance in an isogenic background. Strains with A-to-G and A-to-C mutations at the same position within the 23S rRNA gene had similar levels of clarithromycin resistance, and this level of resistance was higher than that for strains with the A-to-T mutation. Mutations at position 2142 conferred a higher level of clarithromycin resistance than mutations at position 2143. All mutations at position 2142 conferred cross-resistance to all MLS antibiotics, which corresponds to the type I MLS phenotype, whereas mutations at position 2143 were associated with a type II MLS phenotype with no resistance to streptogramin B. To explain that A-to-G transitions were predominantly observed in clarithromycin-resistant clinical isolates, we propose a possible mechanism by which A-to-G mutations are preferentially produced in H. pylori.

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