In:
Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 65, No. 6 ( 2021-05-18)
Abstract:
The Clinical and Laboratory Standards Institute (CLSI) revised the fluoroquinolone MIC breakpoints for Enterobacterales in 2019, based on pharmacokinetic/pharmacodynamic analyses. However, clinical evidence supporting these breakpoint revisions is limited. A retrospective study was conducted at 3 hospitals in Taiwan between January 2017 and March 2019. Patients treated with levofloxacin for bacteremia caused by members of the Enterobacterales with high MICs (1 or 2 μg/ml; levofloxacin susceptible by pre-2019 CLSI breakpoints) were compared with those with low-MIC bacteremia (≤0.5 μg/ml; levofloxacin susceptible by 2019 CLSI breakpoints) to assess therapeutic effectiveness by multivariable logistic regression. The primary outcome was 30-day mortality, and the secondary outcome was the emergence of levofloxacin-resistant isolates within 90 days after levofloxacin initiation. A total of 308 patients were eligible for the study. Kaplan-Meier analysis showed that patients infected with high-MIC isolates ( n = 63) had a significantly lower survival rate than those infected with low-MIC isolates ( n = 245) ( P = 0.001). Multivariable logistic regression revealed that high levofloxacin MIC was a predictor of 30-day mortality (odds ratio [OR], 6.05; 95% confidence interval [CI] , 1.51 to 24.18; P = 0.011). We consistently found similar results in a propensity score-matched cohort (OR, 5.38; 95% CI, 1.06 to 27.39; P = 0.043). The emergence of levofloxacin-resistant isolates was more common in the high-MIC group than the low-MIC group (25.0% versus 7.5%; P = 0.065). An estimated area under the concentration-time curve/MIC ratio of ≥87 was significantly associated with better survival ( P = 0.002). In conclusion, patients infected with isolates with levofloxacin MICs within the pre-2019 CLSI susceptible range of 1 or 2 μg/ml exhibited higher mortality than those infected with isolates with MICs of ≤0.5 μg/ml.
Type of Medium:
Online Resource
ISSN:
0066-4804
,
1098-6596
DOI:
10.1128/AAC.00074-21
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2021
detail.hit.zdb_id:
1496156-8
SSG:
12
SSG:
15,3
