Estimating the precision of disc diffusion antibiotic susceptibility data published by the European committee on antimicrobial susceptibility testing

Apmis ◽  
2014 ◽  
pp. n/a-n/a ◽  
Author(s):  
Peter Smith ◽  
Göran Kronvall
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Disc Diffusion ◽  
Susceptibility Data ◽  
European Committee

Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing Position Statements on Polymyxin B and Colistin Clinical Breakpoints

2020 ◽  
Author(s):  
Michael J Satlin ◽  
James S Lewis ◽  
Melvin P Weinstein ◽  
Jean Patel ◽  
Romney M Humphries ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Polymyxin B ◽  
Antimicrobial Susceptibility Testing ◽  
In Vitro Susceptibility ◽  
Susceptibility Data ◽  
European Committee ◽  
Clinical Breakpoints ◽  
State Concentration

Abstract Recent data on polymyxin pharmacokinetics, pharmacodynamics, toxicity, and clinical outcomes suggest these agents have limited clinical utility. Pharmacokinetics-pharmacodynamics data show a steady-state concentration of 2 μg/mL is required for killing bacteria with colistin minimum inhibitory concentrations of 2 μg/mL. Less than 50% of patients with normal renal function achieve this exposure, and it is associated with high risk of nephrotoxicity. This exposure does not achieve bacterial stasis in pneumonia models. Randomized and observational studies consistently demonstrate increased mortality for polymyxins compared with alternative agents. The Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) are 2 global organizations that establish interpretive criteria for in vitro susceptibility data. CLSI has recently taken the step to eliminate the “susceptible” interpretive category for the polymyxins, whereas EUCAST maintains this interpretive category. This viewpoint describes the opinions of these organizations and the data that were used to inform their perspectives.

scholarly journals Evaluation of the European Committee on Antimicrobial Susceptibility Testing Guidelines for Rapid Antimicrobial Susceptibility Testing of Bacillus anthracis-, Yersinia pestis- and Francisella tularensis-Positive Blood Cultures

2021 ◽  
Vol 9 (5) ◽  
pp. 1055
Author(s):  
Ohad Shifman ◽  
Tamar Aminov ◽  
Moshe Aftalion ◽  
David Gur ◽  
Hila Cohen ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Yersinia Pestis ◽  
Antibiotic Treatment ◽  
Francisella Tularensis ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Blood Cultures ◽  
Antimicrobial Susceptibility Testing ◽  
Disc Diffusion ◽  
European Committee

Rapid determination of bacterial antibiotic susceptibility is important for proper treatment of infections. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) has recently published guidelines for rapid antimicrobial susceptibility testing (RAST) performed directly from positive blood culture vials. These guidelines, however, were only published for a limited number of common pathogenic bacteria. In this study, we evaluated the applicability of these guidelines to three Tier 1 bioterror agents (Bacillus anthracis, Yersinia pestis and Francisella tularensis) that require prompt antibiotic treatment to mitigate morbidity and mortality. We used spiked-in human blood incubated in a BACTEC™ FX40 system to determine the proper conditions for RAST using disc-diffusion and Etest assays. We found that reliable disc-diffusion inhibition diameters and Etest MIC values could be obtained in remarkably short times. Compared to the EUCAST-recommended disc-diffusion assays that will require adjusted clinical breakpoint tables, Etest-based RAST was advantageous, as the obtained MIC values were similar to the standard MIC values, enabling the use of established category breakpoint tables. Our results demonstrate the promising applicability of the EUCAST RAST for B. anthracis-, Y. pestis- or F. tularensis-positive blood cultures, which can lead to shorter diagnostics and prompt antibiotic treatment of these dangerous pathogens.

Effect on Physician Prescribing Practices of Changing from a Qualitative to a Quantitative Antimicrobial Susceptibility Test Reporting System

1983 ◽  
Vol 17 (7-8) ◽  
pp. 552-555 ◽  
Author(s):  
Thomas T. Ward ◽  
Michael J. Regner ◽  
Karen L. Collell ◽  
Ronald R. Brown ◽  
David L. Sewell
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Susceptibility Test ◽  
Disc Diffusion ◽  
Prescribing Practices ◽  
Susceptibility Data ◽  
Before And After ◽  
Physician Prescribing

The use of disc diffusion susceptibility testing has been criticized because it often fails to take into consideration achievable levels of antimicrobial agents at the actual sites of infection. An increasing number of hospitals are converting from disc diffusion antimicrobial susceptibility testing to more quantitative susceptibility testing techniques. Advocates of these latter techniques have suggested that providing information beyond sensitive, intermediate, and resistant reporting will emphasize, more effectively, the importance of considering achievable antibiotic concentrations at the site of infection, when choosing an antimicrobial agent. This study examined whether providing more quantitative susceptibility test reports would affect physicians' antimicrobial prescribing practices. Results obtained on the preeducation and posteducation questionnaires indicate success in improving the collective knowledge of physicians. In retrospective audits of the appropriateness of antimicrobial use, both before and after the educational program, physician usage of antimicrobial agents was categorized as inappropriate in more than ⅔ of the cases. The major reason for the negative outcome in this study is probably due to physicians' indifference to the results of urine culture and susceptibility test data. A change was made in antimicrobial therapy after return of the susceptibility report less than 20 percent of the time. As more laboratories convert to quantitative antimicrobial susceptibility testing, there will be a need for a closer liaison among physicians, clinical pharmacists, microbiologists, and infectious disease specialists, to ensure optimum utilization of the additional susceptibility data provided.

scholarly journals In Vitro Activities of Various Antifungal Drugs against Aspergillus terreus: Global Assessment Using the Methodology of the European Committee on Antimicrobial Susceptibility Testing

2008 ◽  
Vol 53 (2) ◽  
pp. 794-795 ◽  
Author(s):  
Cornelia Lass-Flörl ◽  
Ana Alastruey-Izquierdo ◽  
Manuel Cuenca-Estrella ◽  
Susanne Perkhofer ◽  
Juan Luis Rodriguez-Tudela
Keyword(s):  
Antimicrobial Susceptibility ◽  
Aspergillus Terreus ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Antifungal Drugs ◽  
In Vitro Susceptibility ◽  
Susceptibility Data ◽  
European Committee ◽  
Susceptibility Patterns

ABSTRACT This study presents in vitro susceptibility data for clinical (n = 48) and environmental (n = 31) isolates of Aspergillus terreus against nine antifungal agents. The methodology of the European Committee on Antimicrobial Susceptibility Testing was applied. Posaconazole and anidulafungin had the lowest and amphotericin B the highest MICs. No differences in susceptibility patterns were observed between environmental and clinical isolates.

Evaluation of standardized automated rapid antimicrobial susceptibility testing of Enterobacterales-containing blood cultures: a proof-of-principle study

2020 ◽  
Vol 75 (11) ◽  
pp. 3218-3229
Author(s):  
Stefano Mancini ◽  
Elias Bodendoerfer ◽  
Natalia Kolensnik-Goldmann ◽  
Sebastian Herren ◽  
Kim Röthlin ◽  
...  
Keyword(s):  
Standard Method ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Bloodstream Infections ◽  
Inhibition Zone ◽  
Blood Cultures ◽  
Antimicrobial Susceptibility Testing ◽  
Disc Diffusion ◽  
Inhibition Zones ◽  
Reading System

Abstract Background Rapid antimicrobial susceptibility testing (RAST) of bacteria causing bloodstream infections is critical for implementation of appropriate antibiotic regimens. Objectives We have established a procedure to prepare standardized bacterial inocula for Enterobacterales-containing clinical blood cultures and assessed antimicrobial susceptibility testing (AST) data generated with the WASPLabTM automated reading system. Methods A total of 258 blood cultures containing Enterobacterales were examined. Bacteria were enumerated by flow cytometry using the UF-4000 system and adjusted to an inoculum of 106 cfu/mL. Disc diffusion plates were automatically streaked, incubated for 6, 8 and 18 h and imaged using the fully automated WASPLabTM system. Growth inhibition zones were compared with those obtained with inocula prepared from primary subcultures following the EUCAST standard method. Due to time-dependent variations of the inhibition zone diameters, early AST readings were interpreted using time-adjusted tentative breakpoints and areas of technical uncertainty. Results and conclusions Inhibition zones obtained after 18 h incubation using an inoculum of 106 cfu/mL prepared directly from blood cultures were highly concordant with those of the EUCAST standard method based on primary subcultures, with categorical agreement (CA) of 95.8%. After 6 and 8 h incubation, 89.5% and 93.0% of the isolates produced interpretable results, respectively, with CA of >98.5% and very low numbers of clinical categorization errors for both the 6 h and 8 h readings. Overall, with the standardized and automated RAST method, consistent AST data from blood cultures containing Enterobacterales can be generated after 6–8 h of incubation and subsequently confirmed by standard reading of the same plate after 18 h.

scholarly journals CIM City: the Game Continues for a Better Carbapenemase Test

2019 ◽  
Vol 57 (7) ◽  
Author(s):  
Romney M. Humphries
Keyword(s):  
Antimicrobial Susceptibility ◽  
Clinical Microbiology ◽  
Susceptibility Testing ◽  
Clinical Care ◽  
Antimicrobial Susceptibility Testing ◽  
European Committee ◽  
Link Type ◽  
Clinical Laboratories ◽  
The Right

ABSTRACT The Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing agree that carbapenemase testing is not necessary for clinical care, provided that the laboratory is up to date with current breakpoints. Nonetheless, publication on the development and modification of carbapenemase tests continues, as is the case in this issue of the Journal of Clinical Microbiology (R. W. Beresford and M. Maley, J Clin Microbiol 57:e01852-18, 2019, https://doi.org/10.1128/JCM.01852-18). This commentary explores modifications to the carbapenem inactivation method—but is this the right focus for clinical laboratories?

scholarly journals Point-Counterpoint: Differences between the European Committee on Antimicrobial Susceptibility Testing and Clinical and Laboratory Standards Institute Recommendations for Reporting Antimicrobial Susceptibility Results

2019 ◽  
Vol 57 (9) ◽  
Author(s):  
Gunnar Kahlmeter ◽  
Christian G. Giske ◽  
Thomas J. Kirn ◽  
Susan E. Sharp
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Test Results ◽  
Diffusion Test ◽  
Disk Diffusion Test ◽  
Technical Variability ◽  
European Committee ◽  
Clinical Laboratories ◽  
Antibiotic Susceptibility Test

INTRODUCTION Antibiotic susceptibility test results are among the most important results issued by clinical microbiology laboratories because they routinely guide critical treatment decisions. Interpretations of MIC or disk diffusion test results, such as “susceptible” or “resistant,” are easily understood. Clinical laboratories also need to determine whether and how their reports will reflect more complex situations. Such situations include, first, whether there is need to administer higher or more frequent doses of antibiotic than usual for clinical efficacy; second, whether an antimicrobial is likely to be effective at a body site where it concentrates; and third, whether there is some uncertainty in the test results due to technical variability that cannot be eliminated. Two leading organizations that set standards for antimicrobial susceptibility testing, the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI), have taken different strategies to deal with these challenges. In this Point-Counterpoint, Gunnar Kahlmeter and Christian Giske discuss how EUCAST is addressing these issues, and Thomas Kirn and Susan Sharp discuss the CLSI approach.

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