Rapid antimicrobial susceptibility testing in patients with bacteraemia due to Enterobacterales: an implementation...

Area of Science:

• Clinical microbiology
• Infectious diseases
• Antimicrobial stewardship

Background:

• Bacteraemia due to Enterobacterales poses a significant clinical challenge.
• Optimizing antibiotic therapy through rapid diagnostics is crucial for patient outcomes.
• Automated antimicrobial susceptibility testing (AST) offers potential for faster results.

Purpose of the Study:

• To evaluate the performance and clinical impact of rapid automated AST in Enterobacterales bacteraemia.
• To analyze how rapid automated AST influences clinical decision-making regarding antibiotic therapy.
• To compare turnaround times of rapid automated AST with standard methods.

Main Methods:

• Descriptive, single-centre study of consecutive patients with Enterobacterales bacteraemia.
• Primary outcome: effect of rapid automated AST on antibiotic therapy adjustments (escalation/de-escalation).
• Comparison of rapid automated AST results with European Committee on Antimicrobial Susceptibility Testing (EUCAST) standard methods; turnaround time analysis.

Main Results:

• 116 episodes of Enterobacterales bacteraemia analyzed; 8% multidrug-resistant isolates.
• Rapid automated AST achieved 98.4% category agreement with EUCAST methods.
• Turnaround time reduced by over 20 hours; antibiotic therapy adjusted in 38.8% of cases, with 8 de-escalations.

Conclusions:

• Rapid automated AST is a valuable tool for accelerating diagnosis and potentially shortening time to suitable therapy.
• Physician reluctance to de-escalate antibiotic therapy based solely on rapid AST results currently limits its widespread clinical impact.
• Integration with antibiotic stewardship programs may enhance the utility of rapid automated AST.