1. Introduction
Acinetobacter baumannii is an aerobic Gram-negative bacterium which causes facultative hospital infections and, in settings such as Greece, exhibits high resistance rates against most antimicrobial agents []. Cefiderocol is a siderophore cephalosporin intended to treat infections due to multi-drug resistant (MDR) Gram-negative aerobic bacteria []. The aim of our study was to assess the in vitro activity of cefiderocol and comparators against multidrug-resistant Acinetobacter baumannii isolates.
2. Methods
A total of 29 MDR Acinetobacter baumannii strains recovered from clinical samples (23 blood, 2 central line catheters, 2 bronchial aspirates, 1 pus and 1 urine) from January to April 2022 were included in the study. Species identification and antimicrobial susceptibility testing for most comparators were performed with the Vitek® 2 automated system (bioMérieux, Lyon, France) except for colistin tested by the broth microdilution method using the ComASP™ Colistin 0.25–16 μg/mL panel (Liofilchem®, Roseto degli Abruzzi, Italy) and tigecyclin tested by Liofilchem® MIC Test Strips. Cefiderocol MICs were determined via the Liofilchem® MIC Test Strips on Mueller Hinton II Agar (BD™, Heidelberg, Germany). MIC50 and MIC90 were calculated for all antimicrobials and EUCAST 2022 clinical breakpoints [] were applied wherever applicable. Susceptibility to tigecyclin was interpreted according to the FDA breakpoints, and to cefiderocol according to the EUCAST PK/PD breakpoints. Pseudomonas aeruginosa ATCC25853 and Klebsiella pneumoniae ATCC700603 were used as quality control.
3. Results
Cefiderocol MICs ranged from 0.064 to >256 mg/L, with the majority of the isolates being susceptible. The comparators had very-low-to-zero susceptibility rates against the tested isolates. MIC50, MIC90, MIC range and susceptibility rates are displayed analytically on Table 1.
Table 1.
Antimicrobial activity of cefiderocol and comparators.
4. Discussion
Cefiderocol exhibited potent in vitro activity against MDR Acinetobacter baumannii isolates. It seems to be a valuable option where limited or no therapeutic alternatives are available.
Supplementary Materials
The following are available online at https://www.mdpi.com/article/10.3390/eca2022-12741/s1.
Author Contributions
Conceptualization, E.P.; methodology, A.T.; software, G.M.; validation, P.M.; investigation, I.G.; resources, E.P., P.M. and L.S.; data curation, G.M.; writind-original draft preparation, A.T.; writing-review and editing, E.P. and L.S.; visualization, A.T.; supervision, E.P. and L.S.; project administration, E.P.; funding acquisition, E.P. and L.S. All authors have read and agreed to the published version of the manuscript.
Funding
This research received no external funding.
Institutional Review Board Statement
The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of the AHEPA University Hospital of Thessaloniki (Ref. No. 36129/05-07-2022).
Informed Consent Statement
Patient consent was waved due to the fact that all samples were obtained and tests were performed for diagnostics in terms of standard patient care.
Data Availability Statement
Not applicable.
Conflicts of Interest
The authors declare no conflict of interest.
References
- ECDC Surveillance Atlas—Antimicrobial Resistance. Available online: https://www.ecdc.europa.eu/en/antimicrobial-resistance/surveillance-and-disease-data/data-ecdc (accessed on 15 April 2022).
- Zhanel, G.G.; Golden, A.R.; Zelenitsky, S.; Wiebe, K.; Lawrence, C.K.; Adam, H.J.; Idowu, T.; Domalaon, R.; Schweizer, F.; Zhanel, M.A.; et al. Cefiderocol: A Siderophore Cephalosporin with Activity against Carbapenem-Resistant and Multidrug-Resistant Gram-Negative Bacilli. Drugs 2019, 79, 271–289. [Google Scholar] [CrossRef]
- EUCAST Breakpoint Tables and Dosages v 12.0. 2022. Available online: https://www.eucast.org/eucast_news/news_singleview/?tx_ttnews%5Btt_news%5D=464&cHash=ea8540c0fbdaa71b3bbcb3bf765239de (accessed on 22 April 2022).
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