Comparison of 'time to detection' values between BacT/ALERT VIRTUO and BacT/ALERT 3D instruments for clinical blood culture samples.

OBJECTIVES:The early detection of bacteraemia and fungemia is of paramount importance to guide antimicrobial therapy in septic patients. In this study the 'time to detection' (TTD) value for the new blood culture system BacT/ALERT VIRTUO (VIRTUO) was evaluated in 1462 positive clinical bottles and compared with the TTD for 1601 positive clinical bottles incubated in the BacT/ALERT 3D system (BTA-3D). METHODS:The most representative microorganisms isolated from bottles incubated in both blood culture systems were divided into eight categories (in order of frequency): coagulase-negative staphylococci (CoNS), Escherichia coli, Enterobacteriaceae (other than E. coli), Staphylococcus aureus, Enterococcus spp, viridans group streptococci, Pseudomonas aeruginosa, and Candida spp. RESULTS:The comparison of TTD values for the two blood culture systems strongly indicated that growth of the first five groups listed above was detected earlier with VIRTUO than with BTA-3D (p < 0.05). CONCLUSIONS:The new VIRTUO blood culture system can reduce the TTD for more than 75% of isolated microorganisms.