Performance of disk diffusion method for aztreonam in combination with avibactam against Enterobacteriales

  • J Antimicrob Chemother. 2024 Apr 2:dkae097. doi: 10.1093/jac/dkae097.
Dandan Yin  1 ,  Peipei Song  1  2 ,  Lan Jiang  1  3 ,  Jian Xu  2 ,  Fupin Hu  1
Affiliations
  • 1. Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.
  • 2. Department of Laboratory, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China.
  • 3. Department of Laboratory, Urumqi Maternal and Child Health Care Hospital, Urumqi, China.
PMID: 38564262 DOI: 10.1093/jac/dkae097
Abstract

Objectives: To evaluate the performance of an in-house developed disk diffusion method for aztreonam in combination with avibactam against Enterobacteriales.

Methods: The in vitro Antibacterial activity of aztreonam with avibactam against 204 carbapenemase-producing Enterobacteriales was determined by a disk diffusion method, with a broth microdilution method as a reference.

Results: The optimal S/R breakpoints for disk diffusion tests of 30/20 and 10/4 µg disks, calculated by the dBETs software using the model-based approaches, were ≥22/≤21 and ≥12/≤11 mm, respectively. On the basis of the estimated breakpoints, the CAs for disk diffusion tests of 30/20 and 10/4 µg aztreonam/avibactam disks were both 98.0%, with 0.5% major error and 37.5% very major error.

Conclusions: The home-made disk diffusion method is an economical and practical method for clinical microbiology laboratories to determine the Antibacterial susceptibility of aztreonam with avibactam against Enterobacteriales.

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