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Purpose: Blood culture (BC) is the standard for diagnosing bloodstream infections. Available blood culture (BC) systems have been developed to shorten the time to detection (TTD) of positive BCs. This study aimed to evaluate the performance of the Mindray TDR automatic BC system by comparing it with the BacT/ALERT®3D system., Methods: Sixteen reference strains and 14 clinical isolates were used. Serial dilutions were prepared from all bacterial and yeast colonies with a final concentration of 100 CFU/ml and 10 CFU/ml. The prepared solutions were simultaneously inoculated into the bottles of both systems and placed in blood culture devices., Results: Three hundred and fifty-two (176 BacT/ALERT®3D and 176 Mindray TDR-X060) blood culture bottles were evaluated, 336 aerobic and 16 anaerobic. At both 10 CFU/ml and 100 CFU/ml dilution, there was no significant difference between the two systems in terms of mean detection times for all isolates ( p  = 0.965, p  = 0.245). When evaluated according to the type of organism, the detection time of gram-positive bacteria at 10 CFU/ml dilution was significantly shorter in the BacT/ALERT system ( p  = 0.019), whereas detection time for yeasts was significantly shorter with the Mindray system ( p  = 0.047). The number of anaerobic bacteria was too small to draw statistical conclusions, but we observed a trend of shorter detection times in the Mindray TDR-X060 system., Conclusion: Two systems with similar operating principles showed different concentrations-dependent performances in terms of positivity detection times depending on the type of microorganism. Mindray TDR-X060 system has been found to be safe to use at high concentrations with this at lower concentrations further comparative studies are needed on the newly introduced Mindray system.

Purpose: To evaluate the performances of the newly approved BacT/ALERT VIRTUO blood culture system for the recovery of bloodstream pathogens and compare it to the BacT/ALERT 3D system., Methods: Simulated blood cultures of eight clinically relevant microorganisms were used: Bacteroides fragilis (ATCC 25285), Escherichia coli (ATCC 25922), Haemophilus influenzae (ATCC 49247), Pseudomonas aeruginosa (ATCC 27853), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 29213), Streptococcus pneumoniae (ATCC 49619) and Candida krusei (ATCC 6258). Criteria for comparison were culture positivity and time to detection (TTD). The effects of delayed entry on recovery and TTD were also evaluated., Results: The VIRTUO exhibited around 3 h faster detection time compared to the 3D system. (p < 0.01) for aerobic and facultative microorganisms. The difference in TTD was greatest for the B. fragilis, with a median difference of 46.67 h. The anaerobic bottle of the VIRTUO (FN Plus) did not support the growth of obligate aerobes, whereas the 3D did so. Delayed entry (studied with an E. Coli isolate) had no effect on the recovery rate but proportionally reduced TTD., Conclusions: The VIRTUO performed better than the 3D in terms of TTD and hands-on-time. FN Plus vial appears to be more efficient than the SN bottle in the recovery of anaerobes.