Comparative analysis of the detection capabilities of BacT/ALERT and BACTEC blood culture systems for simulated and clinical bacteremia specimens.

We aimed to compare the performance of BacT/ALERT and BACTEC blood culture systems in detecting bacteremia in simulated and clinical samples. Antibiotic neutralization tests using specific microorganism–antibiotic combinations were conducted to simulate bacteremia. Blood cultures from 228 hospitalized patients in the emergency and intensive care units were collected bilaterally and in duplicate. In the simulated scenarios, Candida albicans was detected at a 100% rate solely in the BacT/ALERT FA Plus aerobic bottles. For Bacteroides fragilis treated with meropenem, BacT/ALERT FN Plus anaerobic bottles achieved full detection, whereas BACTEC Lytic/10 anaerobic/F bottles failed. Among the 228 patients, the bacteremia positivity rate was 17.97% for BacT/ALERT bottles compared to 11.52% for BACTEC bottles. Moreover, the positive detection rates for the BacT/ALERT FN Plus anaerobic and BACTEC Lytic/10 anaerobic/F bottles were 15.20% and 5.99%, respectively. Notably, 100 clinical strains were identified, with BacT/ALERT identifying 15 types (65 strains) and BACTEC identifying 10 types (35 strains). Only BacT/ALERT FN Plus anaerobic bottles effectively adsorbed meropenem. BACTEC Lytic/10/F anaerobic bottles may miss bacteremia cases associated with carbapenem use. Compared to BACTEC, BacT/ALERT exhibited higher positivity rates and superior detection capabilities.