In:
Antimicrobial Agents and Chemotherapy, American Society for Microbiology, Vol. 65, No. 5 ( 2021-04-19)
Abstract:
Due to limited treatment options for carbapenem-resistant Acinetobacter baumannii (CR-AB) infections, antibiotic combinations are now considered potential treatments for CR-AB. This study aimed to explore the utility of fosfomycin-sulbactam combination (FOS/SUL) therapy against CR-AB isolates. Synergism of FOS/SUL against 50 clinical CR-AB isolates was screened using the checkerboard method. Thereafter, time-kill studies against two CR-AB isolates were performed. The time-kill data were described using a semimechanistic pharmacokinetic/pharmacodynamic (PK/PD) model. Monte Carlo simulations were then performed to estimate the probability of stasis, 1-log kill, and 2-log kill after 24 h of combination therapy. The FOS/SUL combination demonstrated a synergistic effect against 74% of isolates. No antagonism was observed. The MIC 50 and MIC 90 of FOS/SUL were decreased 4- to 8-fold, compared to the monotherapy MIC 50 and MIC 90 . In the time-kill studies, the combination displayed bactericidal activity against both isolates and synergistic activity against one isolate at the highest clinically achievable concentrations. Our PK/PD model was able to describe the interaction between fosfomycin and sulbactam in vitro . Bacterial kill was mainly driven by sulbactam, with fosfomycin augmentation. FOS/SUL regimens that included sulbactam at 4 g every 8 h demonstrated a probability of target attainment of 1-log 10 kill at 24 h of ∼69 to 76%, compared to ∼15 to 30% with monotherapy regimens at the highest doses. The reduction in the MIC values and the achievement of a moderate PTA of a 2-log 10 reduction in bacterial burden demonstrated that FOS/SUL may potentially be effective against some CR-AB infections.
Type of Medium:
Online Resource
ISSN:
0066-4804
,
1098-6596
DOI:
10.1128/AAC.02472-20
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2021
detail.hit.zdb_id:
1496156-8
SSG:
12
SSG:
15,3
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