Antimicrobial Susceptibility of Canadian Isolates ofHelicobacter pyloriin Northeastern Ontario

BACKGROUND:Helicobacter pyloriplays a significant role in gastritis and ulcers. It is a carcinogen as defined by the WHO, and infection can result in adenocarcinomas and mucosa-associated lymphoid tissue lymphomas. In Canada, rates of antimicrobial resistance are relatively unknown, with very few studies conducted in the past 15 years.OBJECTIVE: To examine rates of resistance in Sudbury, Ontario, compare antimicrobial susceptibility methods and attempt to determine the molecular basis of antibiotic resistance.METHODS: Patients attending scheduled visits at Health Sciences North (Sudbury, Ontario) provided gastric biopsy samples on a volunteer basis. In total, 20H pyloriisolates were collected, and antimicrobial susceptibility testing (on amoxicillin, tetracycline, metronidazole, ciprofloxacin, levofloxacin and clarithromycin) was conducted using disk diffusion and E-test methods. Subsequently, genomic DNA from these isolates was sequenced to detect mutations associated with antimicrobial resistance.RESULTS: Sixty-five percent of the isolates were found to be resistant to at least one of the listed antibiotics according to E-test. Three isolates were found to be resistant to ≥3 of the above-mentioned antibiotics. Notably, 25% of the isolates were found to be resistant to both metronidazole and clarithromycin, two antibiotics that are normally prescribed as part of first-line regimens in the treatment ofH pyloriinfections in Canada and most of the world. Among the resistant strains, the sequences of 23S ribosomal RNA andgyrA, which are linked to clarithromycin and ciprofloxacin/levofloxacin resistance, respectively, revealed the presence of known point mutations associated with antimicrobial resistance.CONCLUSIONS: In general, resistance to metronidazole, ciprofloxacin/levofloxacin and clarithromycin has increased since the studies in the early 2000s. These results suggest that surveillance programs ofH pyloriantibiotic resistance may need to be revisited or improved to prevent antimicrobial therapy failure.

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Antimicrobial Susceptibility of Mycoplasma bovis and Analyses of Domain V in 23S Ribosomal RNA of Macrolide-Resistant Strains

Journal of the Japan Veterinary Medical Association ◽

10.12935/jvma.64.45 ◽

2011 ◽

Vol 64 (1) ◽

pp. 45-49 ◽

Cited By ~ 1

Author(s):

Shinpei KOIKE ◽

Yoshihide USAMI

Keyword(s):

Ribosomal Rna ◽

Antimicrobial Susceptibility ◽

Mycoplasma Bovis ◽

Resistant Strains ◽

Domain V ◽

23S Ribosomal Rna

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Helicobacter pylori Eradication According to Sequencing-Based 23S Ribosomal RNA Point Mutation Associated with Clarithromycin Resistance

Journal of Clinical Medicine ◽

10.3390/jcm9010054 ◽

2019 ◽

Vol 9 (1) ◽

pp. 54 ◽

Cited By ~ 2

Author(s):

Seung In Seo ◽

Byoung Joo Do ◽

Jin Gu Kang ◽

Hyoung Su Kim ◽

Myoung Kuk Jang ◽

...

Keyword(s):

Helicobacter Pylori ◽

Point Mutation ◽

Ribosomal Rna ◽

Eradication Rate ◽

Point Mutations ◽

Clarithromycin Resistance ◽

Clinically Significant ◽

H Pylori ◽

23S Ribosomal Rna ◽

Significant Point

Background/Aims: Clarithromycin resistance in Helicobacter pylori is associated with point mutations in the 23S ribosomal RNA (rRNA) gene. We investigated the point mutations in the 23S rRNA genes of patients with clarithromycin-resistant H. pylori and compared the H. pylori eradication rates based on the point mutations. Methods: A total of 431 adult patients with H. pylori infection were 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 seven days, while patients with clinically significant point mutations were treated with PAM (proton pump inhibitor, amoxicillin, metronidazole) for seven days. H. pylori eradication rates were compared. Results: Sequencing-based detection of point mutations identified four mutations that were considered clinically significant (A2142G, A2142C, A2143G, A2143C). 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 overall H. pylori eradication rate was 83.7%, and the seven-day PAM-treated clarithromycin-resistance group showed a significantly lower eradication rate than the seven-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 when treated with PAM for seven days. A future study comparing treatment regimens in clarithromycin-resistant H. pylori-infected patients may be necessary.

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High Primary Antibiotic Resistance of Helicobacter pylori Strains Isolated from Pediatric and Adult Patients in Poland during 2016–2018

Antibiotics ◽

10.3390/antibiotics9050228 ◽

2020 ◽

Vol 9 (5) ◽

pp. 228

Author(s):

Paweł Krzyżek ◽

Dorota Pawełka ◽

Barbara Iwańczak ◽

Radosław Kempiński ◽

Konrad Leśniakowski ◽

...

Keyword(s):

Helicobacter Pylori ◽

Antibiotic Resistance ◽

Antimicrobial Resistance ◽

Effective Treatment ◽

Adult Patients ◽

Minimum Inhibitory Concentrations ◽

Treatment Naïve ◽

Resistant Strains ◽

H Pylori ◽

High Level

Monitoring the antibiotic resistance of H. pylori is an important step in the effective treatment of this bacterium, thus the aim of the present study was to assess the prevalence of antimicrobial resistance of H. pylori strains isolated from pediatric and adult patients with primary infections in 2016–2018. Antral biopsies from 334 treatment-naïve patients (126 children and 208 adults) were obtained. A total of 71 clinical H. pylori strains (22 from children and 49 from adults) were isolated and examined for amoxicillin (AMX), clarithromycin (CLR), metronidazole (MTZ), tetracycline (TET), and levofloxacin (LEV) susceptibility. The activity of the antibiotics was measured by E-tests. Strains were considered as resistant to antibiotics with minimum inhibitory concentrations (MICs) equal to ≥0.125 μg/mL (AMX), ≥0.5 μg/mL (CLR), ≥8 μg/mL (MTZ), and ≥1 μg/mL (TET and LEV). The highest prevalence of antibiotic resistance in H. pylori strains was observed for CLR and MTZ, at frequencies of 54.5% and 31.8% vs. 30.6% and 46.9% for children and adults, respectively. A much lower frequency of isolation of resistant strains was demonstrated for LEV and TET, this being 9.1% and 4.5% vs. 18.4% and 4.1% for pediatric and adult patients, respectively. The presence of AMX-resistant strains was not observed. The H. pylori strains isolated from Polish patients with primary infections showed a high level of antibiotic resistance to CLR and MTZ (>30%).

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

10.21203/rs.2.12783/v1 ◽

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.

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Antibiotic Resistance Mechanisms ofHelicobacter pylori

Canadian Journal of Gastroenterology ◽

10.1155/1999/838072 ◽

1999 ◽

Vol 13 (3) ◽

pp. 243-249 ◽

Cited By ~ 11

Author(s):

Paul S Hoffman

Keyword(s):

Antibiotic Resistance ◽

Ribosomal Rna ◽

Resistance Mechanisms ◽

Reductive Activation ◽

Ulcer Disease ◽

Drug Products ◽

Clarithromycin Resistance ◽

H Pylori ◽

Antimicrobial Intervention ◽

23S Ribosomal Rna

Infection withHelicobacter pyloriis most frequently associated with gastritis and peptic ulcer disease. Antimicrobial intervention, together with proton pump inhibitors, has become the standard therapy for treating this disease. Resistance to clarithromycin and metronidazole, two of the most commonly used antimicrobials for treatment ofH pyloriinfections, is often associated with treatment failures and relapse of infection. Clarithromycin resistance arises through mutations leading to base changes in 23S ribosomal RNA subunits, while resistance to metronidazole is due to mutations in therdxAgene, which encodes a novel nitroreductase that is responsible for reductive activation of the drug. Products of metronidazole activation are mutagenic and can be demonstrated to increase both the mutation frequency and the frequency at which antibiotic resistance arises inH pylori.

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

Microorganisms ◽

10.3390/microorganisms9010002 ◽

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.

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Antibiotic Resistance Prevalence and Trends in Patients Infected with Helicobacter pylori in the Period 2013–2020: Results of the European Registry on H. pylori Management (Hp-EuReg)

Antibiotics ◽

10.3390/antibiotics10091058 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1058

Author(s):

Luis Bujanda ◽

Olga P. Nyssen ◽

Dino Vaira ◽

Ilaria M. Saracino ◽

Giulia Fiorini ◽

...

Keyword(s):

Helicobacter Pylori ◽

Antibiotic Resistance ◽

Antimicrobial Susceptibility ◽

Susceptibility Testing ◽

Resistance Rate ◽

Antimicrobial Susceptibility Testing ◽

Metronidazole Resistance ◽

Infected Adult ◽

H Pylori ◽

European Registry

Background: Bacterial antibiotic resistance changes over time depending on multiple factors; therefore, it is essential to monitor the susceptibility trends to reduce the resistance impact on the effectiveness of various treatments. Objective: To conduct a time-trend analysis of Helicobacter pylori resistance to antibiotics in Europe. Methods: The international prospective European Registry on Helicobacter pylori Management (Hp-EuReg) collected data on all infected adult patients diagnosed with culture and antimicrobial susceptibility testing positive results that were registered at AEG-REDCap e-CRF until December 2020. Results: Overall, 41,562 patients were included in the Hp-EuReg. Culture and antimicrobial susceptibility testing were performed on gastric biopsies of 3974 (9.5%) patients, of whom 2852 (7%) were naive cases included for analysis. The number of positive cultures decreased by 35% from the period 2013–2016 to 2017–2020. Concerning naïve patients, no antibiotic resistance was found in 48% of the cases. The most frequent resistances were reported against metronidazole (30%), clarithromycin (25%), and levofloxacin (20%), whereas resistances to tetracycline and amoxicillin were below 1%. Dual and triple resistances were found in 13% and 6% of the cases, respectively. A decrease (p < 0.001) in the metronidazole resistance rate was observed between the 2013–2016 (33%) and 2017–2020 (24%) periods. Conclusion: Culture and antimicrobial susceptibility testing for Helicobacter pylori are scarcely performed (<10%) in Europe. In naïve patients, Helicobacter pylori resistance to clarithromycin remained above 15% throughout the period 2013–2020 and resistance to levofloxacin, as well as dual or triple resistances, were high. A progressive decrease in metronidazole resistance was observed.

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Phenotypic and Genotypic Analysis of Resistant Helicobacter pylori Strains Isolated from Children with Gastrointestinal Diseases

Diagnostics ◽

10.3390/diagnostics10100759 ◽

2020 ◽

Vol 10 (10) ◽

pp. 759

Author(s):

Monika Maria Biernat ◽

Aldona Bińkowska ◽

Łukasz Łaczmański ◽

Paweł Biernat ◽

Paweł Krzyżek ◽

...

Keyword(s):

Helicobacter Pylori ◽

Antibiotic Resistance ◽

Point Mutations ◽

Gastrointestinal Diseases ◽

Drug Susceptibility Testing ◽

Test Method ◽

Ulcer Disease ◽

Genotypic Analysis ◽

Clinical Diagnoses ◽

H Pylori

Antibiotic resistance of Helicobacter pylori is currently a global issue. The aim of this study was to analyze actual antibiotic resistance rates of H. pylori strains isolated from children with primary infections and to compare the incidence of mutations that determine resistance to clarithromycin (CH) and metronidazole (MET) in children with different clinical diagnoses. A total of 91 H. pylori strains were isolated from 108 children with primary infections. Drug susceptibility testing of the strains was performed using E-test method. Classical sequencing of DNA fragments was used to detect point mutations for CH and MET resistance. Resistance to CH was detected in 31% of isolated strains (28/91), while resistance to MET and CH was detected in 35% (32/91) of strains. A2143G was the most frequently detected mutation and was dominant among strains isolated from children with peptic ulcer disease (80%). Mutations in the rdxA gene were found significantly more frequently among MET-resistant strains than MET-sensitive strains (p = 0.03, Chi2 = 4.3909). In children, a higher frequency of H. pylori multiresistant strains was observed compared with the previous study in the same area. Differences were found in the occurrence of point mutations among H. pylori strains resistant to CH isolated from children with different clinical diagnoses.

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Sequence specific detection of bacterial 23S ribosomal RNA by TLR13

eLife ◽

10.7554/elife.00102 ◽

2012 ◽

Vol 1 ◽

Cited By ~ 87

Author(s):

Xiao-Dong Li ◽

Zhijian J Chen

Keyword(s):

Ribosomal Rna ◽

Single Point ◽

Point Mutations ◽

Peptide Bond ◽

Interleukin 1Β ◽

23S Rrna ◽

Sequence Specificity ◽

Bacterial Rna ◽

Microbial Infections ◽

23S Ribosomal Rna

Toll-like receptors (TLRs) detect microbial infections and trigger innate immune responses. Among vertebrate TLRs, the role of TLR13 and its ligand are unknown. Here we show that TLR13 detects the 23S ribosomal RNA of both gram-positive and gram-negative bacteria. A sequence containing 13 nucleotides near the active site of 23S rRNA ribozyme, which catalyzes peptide bond synthesis, was both necessary and sufficient to trigger TLR13-dependent interleukin-1β production. Single point mutations within this sequence destroyed the ability of the 23S rRNA to stimulate the TLR13 pathway. Knockout of TLR13 in mice abolished the induction of interleukin-1β and other cytokines by the 23S rRNA sequence. Thus, TLR13 detects bacterial RNA with exquisite sequence specificity.

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