Laboratory automation reduces time to report of positive blood cultures and improves management of patients with bloodstream infection

Abstract

The impact on time to results (TTR) and clinical decisions was evaluated for mono-microbial positive blood cultures (BC) processed using the BD Kiestra Work Cell Automation (WCA) system. Positive BC were processed by the WCA system by full-automatic subculture on solid media and digital imaging after 8 h of incubation (8-h method) followed by identification (ID) and antimicrobial susceptibility testing (AST). To evaluate the accuracy of the 8-h method, ID and AST from 8-h and overnight incubated colonies were compared for the same organisms. To evaluate its clinical impact, results from 102 BC processed by the 8-h method (cases) were compared with those from 100 BC processed by overnight incubation method (controls) in a comparable period. Identification after 8-h and overnight incubation gave concordant results in 101/102 (99.0%) isolates. Among a total of 1379 microorganism-antimicrobial combinations, categorical agreement was 99.4% (1371/1379); no very major error, 7 major errors, and one minor error were observed. TTR in cases (32.8 h ± 8.3 h) was significantly (p < 0.001) shorter than in controls (55.4 h ± 13.3 h). A significant reduction was observed for duration of empirical therapy (cases 54.8 h ± 23.3 h vs controls 86.9 h ± 34.1 h, p < 0.001) and 30-day crude mortality rate (cases 16.7% vs controls 29.0%, p < 0.037). Automation and 8-h digital reading of plates from positive BC, followed by ID and AST, greatly reduce TTR and shorten the duration of antimicrobial empiric therapy, possibly improving outcome in patients with mono-microbial bloodstream infections.

Consolidation of Clinical Microbiology Laboratories and Introduction of Transformative Technologies

“…Equally important may be the fact that for some of the special specimens, classical technologies have to be maintained. Still, the opportunities in the automation field are considered revolutionary by many (36,73,74). For these reasons, modularity and scalability (e.g., integration of multiple incubation/imaging systems, free-standing inoculators, incubators, culture plate processing systems, and integrated workstations) become important design considerations for manufacturers, such that a laboratory of any size would have access to components of the complete system.…”

Laboratory Automation in Clinical Microbiology

“…De Socio and co-workers evaluated the effect of an automated workflow on the time to report for mono-microbial positive blood cultures [31]. In their setting the time to report was reduced by 24 h and the duration of empirical therapy (in contrast to evidence/AST-based therapy) was reduced by 32 h. The 30-day crude mortality rate was reduced by 12%.…”

Evaluation of EUCAST rapid antimicrobial susceptibility testing (RAST) for positive blood cultures in clinical practice using a total lab automation

“…ID and AST play a major role. Microbial growth in blood culture bottles usually takes 24-48 h. Identification with MALDI-TOF MS can be achieved as soon as 3-4 h after start of subculture [6][7][8]. Numerous studies have shown the performance of MALDI-TOF MS directly from positive blood culture broth with results available within few hours, but have been hampered by a poor accuracy for Gram-positive bacteria [9].…”