Related Experiment Video
Updated: Feb 14, 2026

Preparation of a Blood Culture Pellet for Rapid Bacterial Identification and Antibiotic Susceptibility Testing
Published on: October 15, 2014
Direct rapid antibiotic susceptibility test (dRAST) for blood culture and its potential usefulness in clinical
Jeong-Han Kim1, Taek Soo Kim2, Sang Hoon Song2
1Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
Purpose:
The direct rapid antibiotic susceptibility test (dRAST), based on analysing changes in bacterial micro-colonies under antibiotic conditions, detects antibiotic resistance within 6 h of direct smear examination results. This study aimed to assess the accuracy of dRAST and evaluate its potential usefulness for improving selection of appropriate antibiotic in real clinical practice settings.
Methodology:
We evaluated the accuracy of dRAST by comparing the antibiotic treatments that should have been administered based on dRAST results and the broth microdilution (BMD) test and its potential usefulness via simulation.
Result:
For 49/52 (94.2 %) patients with Gram-positive bacteraemia and 66/67 (98.5 %) patients with Gram-negative bacteraemia, antibiotics indicated by dRAST results were the same as those indicated by the BMD test. Among 34 patients with ineffective and suboptimal treatment, 19 (55.9 %) of patients could have received optimal treatment 1 to 2 days earlier with dRAST results. Among 33 patients given unnecessary broad-spectrum antibiotics, 1 to 2 days earlier de-escalation could have been possible for 27 (81.8 %) patients based on dRAST results.
Conclusion:
The introduction of dRAST could increase the use of optimal antibiotics and reduce unnecessary broad-spectrum antibiotic use in the early period of bacteraemia.
Related Concept Videos
Antibiotic Selection
Magnetic Susceptibility and Permeability
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
Standard Electrode Potentials
Susceptibility, Permittivity and Dielectric Constant
Development of Antibiotic Resistance
Potential Energy
Chemical bonds that form attractive forces between atoms also contain potential energy, called chemical energy. When a chemical reaction...

