Multicenter evaluation of the QuickMIC® rapid AST system in clinical practice: impact on turnaround time compared to routine AST systems

Abstract

Increased antibiotic resistance highlights the need for new, rapid antibiotic susceptibility tests to guide therapy, especially in critical disease such as bloodstream infections and sepsis. This study investigates a new ultra-rapid AST system in multiple clinical laboratories, with respect to accuracy, speed and turnaround time in comparison to commonly used AST systems. The QuickMIC system is compared to the commonly used automated AST systems BD Phoenix™ (BD, USA), MicroScan WalkAway plus (Beckman Coulter, USA) and VITEK ® 2 (bioMérieux, France) by concurrent testing of incoming positive blood-cultures with Gram-negative bacteria in four clinical laboratories located in the EU and USA, on the basis of agreement of results, time-to-result (TTR, analysis time) and turnaround time (TAT, time from blood culture positivity or blood culture processing to actionable result). A total of 155 patient samples were included, totaling 10 species of Gram-negative bacteria. The overall EA and CA between QuickMIC ® GN and each routine AST system was > 95%, while overall bias was within the acceptable range of ± 30%. QuickMIC time-to-result was on average 3 h and 4 min, compared to 9–19 h for the routine systems. The average QuickMIC system turnaround-time ranged from 10 to 11 h 30 min, compared to 22–45 h for the routine systems. The QuickMIC system represents a promising rapid AST technology with potential to reduce time-to-result and overall turnaround-time of clinically actionable AST results compared with the most common routinely used automated AST methods, while maintaining good accuracy and quality of results.

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