E-Test or Agar Dilution for Metronidazole Susceptibility Testing of Helicobacter Pylori: Importance of the Prevalence of Metronidazole Resistance

2021 ◽  
Author(s):  
Jinnan Chen ◽  
Yu Huang ◽  
Zhaohui Ding ◽  
Xiao Liang ◽  
Hong Lu
Keyword(s):  
Helicobacter Pylori ◽  
Susceptibility Testing ◽  
Resistance Rate ◽  
Test Method ◽  
Major Error ◽  
Metronidazole Resistance ◽  
Agar Dilution ◽  
H Pylori ◽  
High Level ◽  
Level Resistance

Abstract Background: A number of studies have shown that E-test overestimated the presence of Helicobacter pylori (H. pylori) resistance compared to agar dilution.Objective: The purpose of this study was to explore whether E-test could be an alternative for agar dilution to detect the metronidazole susceptibility of H. pylori.Method: E-test and agar dilution were used to assess susceptibility of H. pylori to metronidazole, clarithromycin and levofloxacin in 281 clinical isolates obtained from China where resistance was high. Cohen kappa analysis, McNemar test, essential and categorical agreement analysis were performed for these two methods. Results: Overall, the result of E-test showed similar prevalence of resistance rate to all antibiotics compared with agar dilution. The essential agreement (EA) of E-test method and agar dilution in the evaluation susceptibility of H. pylori to clarithromycin and levofloxacin were moderate, with 89.0% and 79.7% respectively, but only 45.9% for metronidazole. Results showed categorical agreement (CA) between E-test and agar dilution were 100% for both clarithromycin and levofloxacin. As for metronidazole, the CA was 98.7%, no major error was identified, and rate of very major error was 1.8%.Conclusion: E-test can be an alternative method to detect the metronidazole susceptibility of H. pylori in regions where high-level resistance is common.

scholarly journals 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 ◽  
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.

scholarly journals Evaluation of clinical and socio-demographic risk factors for antibacterial resistance of Helicobacter pylori in Bulgaria

2009 ◽  
Vol 58 (1) ◽  
pp. 94-100 ◽  
Author(s):  
Lyudmila Boyanova ◽  
Juliana Ilieva ◽  
Galina Gergova ◽  
Zoya Spassova ◽  
Rossen Nikolov ◽  
...  
Keyword(s):  
Risk Factors ◽  
Helicobacter Pylori ◽  
Resistance Rate ◽  
Symptom Duration ◽  
Antibacterial Resistance ◽  
Clarithromycin Resistance ◽  
Metronidazole Resistance ◽  
H Pylori ◽  
Demographic Risk ◽  
Demographic Risk Factors

The aim of this study was to assess the clinical and socio-demographic risk factors for primary Helicobacter pylori antibacterial resistance. In total, 266 consecutive H. pylori strains, from untreated symptomatic adult patients who answered a questionnaire, were evaluated. Strain susceptibility to amoxicillin, metronidazole, clarithromycin and tetracycline was tested by a breakpoint susceptibility test. Metronidazole resistance was found in fewer (17.0 %) peptic ulcer patients than in non-ulcer subjects (28.3 %, P=0.037), as well as in fewer patients born in villages (12.7 %) than in those born in towns (27.6 %, P=0.016). Clarithromycin resistance varied from 8.8 to 23.4 % (P=0.009) within the hospital centres. The highest clarithromycin resistance rate was found in hospital centre A (23.4 %) compared to other centres (12.9 %, P=0.041). The factors sex, age, symptom duration, non-steroidal anti-inflammatory drug use, diabetes, type of profession and educational level were not associated with H. pylori resistance. Logistic regression revealed that the risk factors for metronidazole resistance were non-ulcer disease [odds ratio (OR) 1.95, 95 % confidence interval (95 % CI) 1.04–3.65] and a birthplace of a town (OR 2.64, 95 % CI 1.18–5.93). The hospital centre may be a risk factor (OR 2.07, 95 % CI 1.02–4.21) for clarithromycin resistance but further studies are required to verify this suggestion. In conclusion, the knowledge of the risk factors for H. pylori resistance to antibacterials could facilitate the treatment choice for H. pylori eradication.

scholarly journals Proton motive force-dependent efflux of tetracycline in clinical isolates of Helicobacter pylori

2009 ◽  
Vol 58 (10) ◽  
pp. 1309-1313 ◽  
Author(s):  
Mona Anoushiravani ◽  
Tahereh Falsafi ◽  
Vahid Niknam
Keyword(s):  
Helicobacter Pylori ◽  
Proton Motive Force ◽  
Motive Force ◽  
Clinical Isolates ◽  
Carbonyl Cyanide ◽  
Agar Dilution ◽  
Resistant Mutants ◽  
H Pylori ◽  
High Level

The aim of this study was to evaluate the role of proton motive force (PMF)-dependent efflux in resistance of Helicobacter pylori to tetracycline (Tet). Tet MIC was determined by agar dilution in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP), an inhibitor of PMF. Antibiotic accumulation was conducted in the presence or absence of CCCP and the fluorescence of the accumulated antibiotic was measured by spectrofluorometry. In the presence of CCCP, antibiotic accumulation was increased by 2–17-fold in 17/20 Tetr isolates and by 3–10-fold in four of five high-level-resistant mutants. Correlation was observed between this increase and diminution of MIC with CCCP. PMF-dependent efflux mechanisms therefore appear to play an important role in the resistance of clinical isolates of H. pylori to Tet.

scholarly journals Trend of changes in antibiotic resistance in Helicobacter pylori from 2013 to 2019: a multicentre report from Taiwan

2020 ◽  
Vol 13 ◽  
pp. 175628482097699
Author(s):  
Chih-Ming Liang ◽  
Wei-Chen Tai ◽  
Pin-I Hsu ◽  
Deng-Chyang Wu ◽  
Chao-Hung Kuo ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibiotic Resistance ◽  
Linear Trend ◽  
Eradication Therapy ◽  
Resistance Rate ◽  
Test Method ◽  
Success Rates ◽  
Primary Resistance ◽  
Secondary Resistance ◽  
H Pylori

Background: Antibiotic resistance plays a crucial role in the treatment failure of Helicobacter pylori (H. pylori) infection. This study aimed to determine the trend of changes in the primary, secondary and tertiary antibiotic resistance of H. pylori in Taiwan over the last 7 years. Methods: We retrospectively analysed H. pylori-infected isolates from patients with primary resistance ( n = 1369), secondary resistance ( n = 196) and tertiary resistance ( n = 184) from January 2013 to December 2019. The H. pylori strains were tested for susceptibility to amoxicillin, clarithromycin, levofloxacin, metronidazole and tetracycline using the Epsilometer test method. Results: A progressively higher primary resistance rate was observed for clarithromycin (11.8–20.4%, p = 0.039 in χ2 test for linear trend), levofloxacin (17.3–38.8%, p < 0.001) and metronidazole (25.6–42.3%, p < 0.001) among naïve patients who received first-line eradication therapy. The dual primary resistance to clarithromycin and metronidazole also progressively increased in a linear trend (2.4–10.4%, p = 0.009). For secondary resistance, an increase was observed for levofloxacin (30.5–64.7%, p = 0.006) and metronidazole (40.5–77.4%, p < 0.001). For tertiary resistance, the observed increase was even more significant for levofloxacin (65.9–100.0%, p = 0.106) and metronidazole (44.4–88.2%, p < 0.001). The resistance to amoxicillin and tetracycline remained very low in Taiwan regardless of primary, secondary and tertiary resistance. Conclusion: Primary, secondary and tertiary antibiotic resistance to clarithromycin, levofloxacin and metronidazole for H. pylori has been increasing in Taiwan since 2013. Treatment should be targeted for eradication success rates of more than 90%. Third-line treatment should be based on antibiotic susceptibility.

scholarly journals High-Level β-Lactam Resistance Associated with Acquired Multidrug Resistance in Helicobacter pylori

2003 ◽  
Vol 47 (7) ◽  
pp. 2169-2178 ◽  
Author(s):  
Dong H. Kwon ◽  
M. P. Dore ◽  
J. J. Kim ◽  
M. Kato ◽  
M. Lee ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Multidrug Resistance ◽  
Natural Transformation ◽  
Multidrug Resistant ◽  
Resistant Isolate ◽  
Terminal Portion ◽  
Nucleotide Substitutions ◽  
H Pylori ◽  
High Level ◽  
Level Resistance

ABSTRACT Four clinical Helicobacter pylori isolates with high-level resistance to β-lactams exhibited low- to moderate-level resistance to the structurally and functionally unrelated antibiotics ciprofloxacin, chloramphenicol, metronidazole, rifampin, and tetracycline. This pattern of multidrug resistance was transferable to susceptible H. pylori by natural transformation using naked genomic DNA from a clinical multidrug-resistant isolate. Acquisition of the multidrug resistance was also associated with a change in the genotype of the transformed multidrug-resistant H. pylori. DNA sequence analyses of the gene encoding penicillin binding protein 1A (PBP 1A) showed 36 nucleotide substitutions resulting in 10 amino acid changes in the C-terminal portion (the putative penicillin binding domain). Acquisition of β-lactam resistance was consistently associated with transfer of a mosaic block containing the C-terminal portion of PBP 1A. No changes of genes gyrA, rpoB, rrn16S, rdxA, and frxA, and nine other genes (ftsI, hcpA, llm, lytB, mreB, mreC, pbp2, pbp4, and rodA1) encoding putative PBPs or involved in cell wall synthesis were found among the transformed resistant H. pylori. Antibiotic accumulations of chloramphenicol, penicillin, and tetracycline were all significantly decreased in the natural and transformed resistant H. pylori compared to what was seen with susceptible H. pylori. Natural transformation also resulted in the outer membrane protein profiles of the transformed resistant H. pylori becoming similar to that of the clinical resistant H. pylori isolates. Overall, these results demonstrate that high-level β-lactam resistance associated with acquired multidrug resistance in clinical H. pylori is mediated by combination strategies including alterations of PBP 1A and decreased membrane permeability.

scholarly journals Impact of Helicobacter pylori resistance in unsuccessfully pluritreated patients in a Department of Infectious Diseases in Rome

2010 ◽  
Vol 1 (1) ◽  
pp. 3
Author(s):  
Maria Teresa Mascellino ◽  
Barbara Porowska ◽  
Rosa Nicosia ◽  
Alessandra Oliva ◽  
Priscilla Boccia ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Resistance Rate ◽  
Test Method ◽  
Resistance Testing ◽  
Antibiotic Resistant ◽  
Diffusion Technique ◽  
Resistant Strains ◽  
Unrelated Strain ◽  
H Pylori ◽  
Rapid Emergence

Twenty-five pluritreated patients were examined. Fifty-six percent yielded Helicobacter pylori (H. Pilory); of these, 9 patients showed a concomitant colonization of the three gastric regions. The highest resistance rate was found for metronidazole (71.8%) followed by chlaritromycin (53.1%). Amoxycillin showed the best susceptibility (only 6% of resistance), tetracycline showed 12% of resistant strains and levofloxacin appeared to be a promising antibacterial agent (18% of resistance). The E-test method was shown to be more suitable than disk diffusion technique for resistance testing. Combined resistance to both chlaritromycin and metronidazole appeared in 50% of the strains. The isolates showing this dual resistance are known to be difficult to eradicate. Resistotypes were shown to be genotypically different even if the strains with the resistance to both chlaritromycin and metronidazole are more likely to belong to genotype cagA+ and vacA s1m1. Heteroresistance (different susceptibility of the isolated strains in a single stomach) resulted in 36% of patients with pangastritis. Indeed, the concomitant presence of H. pylori strains in the same subject, either susceptible or resistant or vice versa, may interfere with the eradication outcomes. In our study, antibiotic resistant H. pylori typically develops from pre-existing susceptible strains rather than from co-infection with a different and unrelated strain. In fact, each pair of isolates detected in our 4 patients with heteroresistance belonged to the same genotype (cagA+ s1m2 in patient 1 and cagA+ s1m1 in patients 2, 3 and 4). In conclusion, H. pylori antibiotic resistance does present several issues in pluritreated patients owing to the rapid emergence of multi-resistant strains.

scholarly journals Trends in Secondary Antibiotic Resistance of Helicobacter pylori from 2007 to 2014: Has the Tide Turned?

2014 ◽  
Vol 53 (2) ◽  
pp. 522-527 ◽  
Author(s):  
Doron Boltin ◽  
Haim Ben-Zvi ◽  
Tsachi Tsadok Perets ◽  
Zvi Kamenetsky ◽  
Zmira Samra ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Antibiotic Resistance ◽  
Susceptibility Testing ◽  
Demographic Data ◽  
Epidemiological Data ◽  
Secondary Resistance ◽  
Content Type ◽  
Metronidazole Resistance ◽  
H Pylori ◽  
Rational Use Of Antibiotics

The current guidelines recommend culture and antibiotic susceptibility testing ofHelicobacter pylorifollowing two failed eradication attempts. Where testing is unavailable, epidemiological data for secondaryH. pyloriresistance are essential to allow for the rational use of antibiotics. The aim of this study was to describe the temporal changes in antibiotic resistance among adults previously treated forH. pyloriinfections and to identify predictors of resistance. Between 2007 and 2014, consecutive patients undergoing gastroscopy withH. pyloriculture and susceptibility testing at our institution following at least two treatment failures were retrospectively identified. Antibiotic susceptibilities were recorded and linked to the demographic data. A total of 1,042 patients were identified, including 739 (70.9%) males, aged 39.3 ± 18.9 years. Resistance to clarithromycin, metronidazole, and levofloxacin was found in 57.2%, 64.4%, and 5.1% of isolates, respectively. Dual resistance to clarithromycin and metronidazole was seen in 39.9%. Over the study period, clarithromycin resistance increased annually in a linear manner (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.03 to 1.14;P< 0.01), levofloxacin resistance decreased annually (OR, 0.78; 95% CI, 0.61 to 0.92;P< 0.01), and metronidazole resistance was nonlinear. Age was an independent predictor of resistance to all antibiotics. Time elapsed predicted resistance for clarithromycin and levofloxacin and dual resistance for clarithromycin-metronidazole. Secondary resistance ofH. pylorito clarithromycin and metronidazole remains high. The low secondary resistance to levofloxacin makes it an attractive treatment option in our region for patients following two failed eradication attempts.

scholarly journals Antibiotic Susceptibilities ofHelicobacter pyloriStrains Isolated in the Province of Alberta

1998 ◽  
Vol 12 (4) ◽  
pp. 295-298 ◽  
Author(s):  
Diane E Taylor ◽  
Qin Jiang ◽  
Richard N Fedorak
Keyword(s):  
Helicobacter Pylori ◽  
Antibiotic Resistance ◽  
Gastric Biopsy ◽  
Minimal Inhibitory Concentrations ◽  
Antibiotic Susceptibilities ◽  
Biopsy Specimens ◽  
Metronidazole Resistance ◽  
Agar Dilution ◽  
Resistant Strains ◽  
H Pylori

The incidence of antibiotic resistance to amoxicillin, clarithromycin, erythromycin, metronidazole and tetracycline inHelicobacter pyloristrains isolated from gastric biopsy specimens obtained in Alberta was investigated. Results for all antibiotics were obtained using agar dilution, and in addition to metronidazole, the E test was used. Resistance to amoxicillin and tetracycline was not detected. Metronidazole resistance determined using agar dilution was approximately 12% (95% CI 4% to 26%) when minimal inhibitory concentrations (MICs) were at least 8 µg/mL, but fell to 2% (95% CI 0.1% to 13%) when MICs were set at 32 µg/mL or greater. The E test for metronidazole resistance (MIC 8 µg/mL or greater) yielded a slightly higher percentage of resistant strains compared with agar dilution tests (14%, 95% CI 5% to 29%). One of the 31 strains was resistant to clarithromycin (MIC 8 µg/mL) and erythromycin (MIC 16 µg/mL). Thus, the incidence of resistance to clarithromycin, part of the currently used triple therapy for eradication ofH pylori, was 3% (95% CI 0.1% to 17%).

scholarly journals Antimicrobial Susceptibility of Helicobacter pylori Determined by the E Test Using Tetrazolium Egg Yolk Agar

1998 ◽  
Vol 36 (9) ◽  
pp. 2784-2785 ◽  
Author(s):  
Yanet Valdez ◽  
Billie Velapatiño ◽  
Robert H. Gilman ◽  
Vilma Gutierrez ◽  
Carlos León
Keyword(s):  
Helicobacter Pylori ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Agar Medium ◽  
Egg Yolk ◽  
Blood Agar ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Agar Dilution ◽  
H Pylori

Metronidazole and tetracycline E tests were compared to an agar dilution method for the antimicrobial susceptibility testing ofHelicobacter pylori. Sixteen strains were tested by using tetrazolium egg yolk (TEY) agar. The characteristic E test inhibition ellipse was clearer on TEY agar than on standard blood agar and gave results comparable to those of the agar dilution test. The use of TEY medium is preferable to that of blood agar medium in E test MIC determinations for H. pylori.

scholarly journals Antimicrobial susceptibility testing of 230 Helicobacter pylori strains: importance of medium, inoculum, and incubation time.

1997 ◽  
Vol 41 (12) ◽  
pp. 2634-2639 ◽  
Author(s):  
S H Hartzen ◽  
L P Andersen ◽  
A Bremmelgaard ◽  
H Colding ◽  
M Arpi ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Incubation Time ◽  
Susceptibility Testing ◽  
Development Of Resistance ◽  
Mueller Hinton ◽  
Mueller Hinton Agar ◽  
Agar Dilution ◽  
Horse Blood ◽  
Preliminary Study ◽  
H Pylori

No standardized method of susceptibility testing for Helicobacter pylori is currently available, so before a large agar dilution study comprising 230 H. pylori strains belonging to more than 80 genetically different groups was initiated, we performed a relatively small preliminary study to determine the influences of medium, inoculum density, and incubation time. Seven media were investigated and were primarily evaluated on the basis of their abilities to support growth both semiquantitatively and qualitatively; Iso-Sensitest agar supplemented with 10% horse blood was found to be well suited for the purpose; this was closely followed by Mueller-Hinton agar with 10% horse blood, Mueller-Hinton with 10% sheep blood, and finally, 7% lysed horse blood agar. Investigations of two inoculum densities and two incubation times resulted in recommendations for the use of 10(9) CFU/ml (10[6] CFU/spot) as the inoculum and 72 h as the incubation time. A modest inoculum effect was noted for amoxicillin and metronidazole. By the methodology derived from our preliminary study, the susceptibilities of 230 H. pylori strains to six antibiotics were subsequently determined. The results were generally in accord with those of others, and apart from metronidazole, the MIC of which for approximately 25% of the strains tested was >8 microg/ml, resistance was low in Denmark. The situation might, however, quickly change when and if the number of indications for antibiotic therapy for H. pylori infections increase. Consequently, susceptibility testing of all H. pylori strains is recommended in order to survey the development of resistance, and in our hands the described methodology was relatively easy to perform and the results were easy to read.

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