Assessment of 30/20-Microgram Disk Content versus MIC Results for Ceftazidime-Avibactam Tested against Enterobacteriaceae and Pseudomonas aeruginosa.
J Clin Microbiol
; 56(6)2018 06.
Article
in En
| MEDLINE
| ID: mdl-29563198
ABSTRACT
We evaluated the correlation between MIC and disk diffusion inhibition zones when testing ceftazidime-avibactam, using the 30/20-µg disk and the disk diffusion and MIC breakpoints established by the U.S. FDA and the Clinical and Laboratory Standards Institute (CLSI). Organisms used included 2 groups of Enterobacteriaceae isolates and 2 groups of Pseudomonas aeruginosa isolates; 1 group of each consisted of randomly selected isolates and the second group consisted of a challenge group from thousands of surveillance isolates with an increased proportion of organisms displaying ceftazidime-avibactam MIC values close to the breakpoints. Broth microdilution, disk diffusion tests, and data analysis were performed according to reference standardized methods. Ceftazidime-avibactam breakpoints of ≤8/4 (susceptible) and ≥16/4 µg/ml (resistant) for MIC and ≥21/≤20 mm for disk diffusion, as established by the U.S. FDA and the CLSI, were applied for Enterobacteriaceae and P. aeruginosa Ceftazidime-avibactam MIC and disk zone (30/20-µg disk) correlation were acceptable when testing Enterobacteriaceae (overall, very major [VM] and major [Ma] error rates of 0.4% and 0.0%, respectively) and nearly so when testing P. aeruginosa (2.3% VM and 2.9% Ma errors). In summary, disk diffusion and broth microdilution testing results demonstrated good categorical agreement for ceftazidime-avibactam against Enterobacteriaceae and P. aeruginosa, using 30/20-µg disks.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pseudomonas aeruginosa
/
Microbial Sensitivity Tests
/
Ceftazidime
/
Enterobacteriaceae
/
Disk Diffusion Antimicrobial Tests
/
Azabicyclo Compounds
/
Anti-Bacterial Agents
Type of study:
Evaluation_studies
/
Guideline
Limits:
Humans
Country/Region as subject:
America do norte
Language:
En
Journal:
J Clin Microbiol
Year:
2018
Type:
Article
Affiliation country:
United States