Commentary: Can Automated Blood Culture Systems Be Both New and Improved?

Automated continuous monitoring blood culture (CMBC) systems are a cornerstone of the clinical microbiology laboratory. Despite the critical role of these systems in diagnosing life-threatening bloodstream infections, their core technologies and performance characteristics have remained largely unchanged since their introduction in the 1990s. This stability and uniformity have enabled the development of quality benchmarks, such as percent positivity and contamination rate; downstream diagnostics, such as direct identification and susceptibility testing of microorganisms in positive cultures; and clinical guidelines based on time to positivity or duration of bacteriemia. In this issue of the , Chavez et al. (J Clin Microbiol 60:e02261-21. 2021, https://doi.org/10.1128/JCM.02261-21) built on a prior study to examine clinical impacts following the introduction of a new blood culture system which boasts enhanced organism recovery and more rapid time to detection of positive blood cultures. While one might assume that these "improvements" would result in clinical benefits, the authors uncovered some unexpected consequences associated with altering long-accepted performance characteristics. Their central finding was that implementation of the new CMBC system did result in alterations to the management of patients with S. aureus bacteremia; however, this did not have any overall consequences for patient outcomes.