Effect of MIC interpretative breakpoint revision on cephalosporin and carbapenem susceptibility among ESBL-producing enterobacteriaceae
Background: Minimum inhibitory concentration (MIC) breakpoints of selected cephalosporins and carbapenems against Enterobacteriaceae have been revised by major guidelines including CLSI and EUCAST mainly according to available pharmacokinetic/pharmacodynamic data. A decrease of breakpoint may obviat...
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Article |
| Published: |
2018
|
| Subjects: | |
| Online Access: | https://repository.li.mahidol.ac.th/handle/123456789/13599 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Institution: | Mahidol University |
| Summary: | Background: Minimum inhibitory concentration (MIC) breakpoints of selected cephalosporins and carbapenems against Enterobacteriaceae have been revised by major guidelines including CLSI and EUCAST mainly according to available pharmacokinetic/pharmacodynamic data. A decrease of breakpoint may obviate the need to detect specific resistance mechanisms such as extended-spectrum -lactamase (ESBL) and carbapenemase, which may be less correlated to treatment outcome than does the actual MIC of each agent. Objective: To analyze cephalosporin and carbapenem MIC distributions among ESBL-producing Enterobacteriaceae at a university hospital against revised interpretative breakpoints. Methods: MIC distributions of selected cephalosporins and carbapenems among 505 isolates of genotypically confirmed ESBL-producing Enterobacteriaceae were determined by E-testTM method and analyzed according to interpretative breakpoints comparing between CLSI and EUCAST guidelines. Results: ESBL-producing Enterobacteriaceae demonstrated a wide range of cephalosporin MIC (≥1 to ≤64). Up to 9.7% of isolates displayed MIC lower than a revised cephalosporin breakpoint. Most isolates remained susceptible to imipenem and meropenem while as high as 24.6% were not susceptible to ertapenem. Lowered breakpoints may result in a change in categorical interpretations. Conclusion: ESBL-producing isolates could be reported as susceptible to a cephalosporin with revised breakpoints although clinical use is uncertain. A higher proportion of isolates would be reported as nonsusceptible to cephalosporins or carbapenems with lowered breakpoints and thus increasing use of broadspectrum antimicrobial agents should be monitored. |
|---|