Abstract:Objective To compare the detection performance of BACT/ALERT VIRTUO and BACTECTM FX blood culture systems for simulated bacteremia specimens. Methods This study adopted simulated blood culture, three kinds of Gram-negative bacilli, two kinds of Gram-positive cocci, one kind of obligate anaerobe and two kinds of candida that are frequent in blood stream infection, as well as nine tested antimicrobial agents. The BACT/ALERT VIRTUO blood culture system with FA Plus aerobic vials (FA+) and FN Plus anaerobic vials (FN+), as well as the BACTECTM FX blood culture system with resin aerobic culture vials (AF) and hemolysin anaerobic culture vials (ANF) were compared. Detection rate and positive detection time of each microorganism were determined. The absorption rates of FA+, FN+, AF and ANF to vancomycin, meropenem and fluconazole were detected by chromatography. Results In simulated blood culture with the presence of antimicrobial agents, the positive detection rates of culture vials of VIRTUO system were FN+(42/50, 84.00%)>VIRTUO FA+(30/50, 60.00%) >FX AF (20/50, 40.00%). Due to the lack of antimicrobial adsorption ability, the positive detection rates of FX ANF hemolysin anaerobic vials was 0. The median positive detection times for FA+, FN+, AF, and ANF were 13.96, 16.22, 20.30 hours, and >120 hours, respectively. Antimicrobial concentration test results showed that the adsorption effect of meropenem by VIRTUO FN+anaerobic vials was obvious, and about 90% of meropenem could be adsorbed in 2 minutes. Conclusion There are differences in the detection rate and positive detection time between the two systems in the presence of antimicrobial agents. The BACT/ALERT VIRTUO blood culture system is superior to the BACTECTM FX blood culture system in detecting microorganisms.