Comparison of Clinical Performance Between BacT/Alert Virtuo and BacT/Alert 3D Blood Culture Systems

Abstract

Background BacT/Alert Virtuo (BioMérieux, Durham, NC, USA) is a recently developed blood culture system that includes functions of automatic registration, loading, and unloading of the blood culture bottles, as well as measurement of blood volume. We compared the performances between the BacT/Alert Virtuo and 3D (BioMérieux) blood culture systems. Methods A total of 952 patients (1,904 sets) visiting an university-affiliated hospital in Korea for blood cultures were enrolled. Five milliliters of blood was added into each of the two aerobic (FA Plus) and two anaerobic (FN Plus) bottles of the Virtuo and 3D systems for a single set. Positive rate and time to detection (TTD) were compared between the two systems. Results The positive rates were 8.3% and 8.4% in FA Plus bottles and 7.8% and 8.3% in FN Plus bottles, in the Virtuo and 3D systems, respectively ( P >0.05). Median TTDs were shorter in the Virtuo than in the 3D system for all isolates (11.5 hours [N=305] vs 11.8 hours [N=318], P <0.001), Staphylococcus aureus (N=38; 14.3 hours vs 16.0 hours, P =0.021), and Escherichia coli (N=117; 10.4 hours vs 11.0 hours, P <0.001). Conclusions The Virtuo has the potential to detect pathogens early in all bottle types. This might improve the prognosis of sepsis by allowing for implementation of expeditious management.

Evaluation of Optimal Blood Culture Incubation Time To Maximize Clinically Relevant Results from a Contemporary Blood Culture Instrument and Media System

“…The AccuMed ESP-384 system with a 3-day incubation was considered sufficient, with 94.2% of positives detected ( 23 ). There are reports of the Virtuo system having an even faster time to positivity compared to other blood culture systems—BD Bactec FX ( 6 , 24 , 25 ) and the BacT/Alert 3D system ( 8 – 10 , 24 , 26 – 28 )—although the vast majority of these investigations used seeded studies. It should be noted that the epidemiological prevalence of species throughout these studies was similar to that in the present study.…”

“…Our institution implemented the BacT/Alert Virtuo (Virtuo) blood culture detection system with FA Plus (aerobic) and FN Plus (anaerobic) resin culture bottles (bioMérieux) in mid-2018. This system has been shown to have a faster time to positivity compared to other systems using seeded cultures ( 5 – 7 ) and paired clinical cultures ( 8 – 10 ). These findings, along with anecdotal observations from the laboratory noting mostly growth of clinically insignificant microbes after 4 days of incubation, prompted a review of blood cultures from the Virtuo system.…”

Detection of Microorganisms in Body Fluids via MTT-PMS Assay

“…Current bacterial detection systems detect pathogens through CO 2 emission, based on the colorimetric detection of pH changes caused by the CO 2 output of pathogenic microorganisms and have been successfully used in clinical settings since 1990 [ 41 ]. The reported threshold concentration for detection using these systems is approximately 10 4 CFU/mL [ 11 ], and the processing time is approximately 10–15 h. More importantly, to execute these techniques, a central laboratory and trained technicians are required [ 41 , 42 ]. For the broader application of the MTT-PMS assay, we developed a colorimetric MTT-PMS assay using ImageJ, an open-source image processing program, using a smartphone (iPhone XS, Apple).…”

Effect of delayed entry on performance of the BACT/ALERT FAN PLUS bottles in the BACT/ALERT VIRTUO blood culture system

“…The VIRTUO is a nextgeneration BTA instrument that detects microbial growth and CO 2 production by optically monitoring the reflectance of a colorimetric sensor in each bottle over time. The VIRTUO is equipped with new algorithms designed to enhance the sensitivity and specificity and deliver significantly faster TTDs for most microorganisms tested compared with the BTA 3D and BACTEC™ FX (BD Diagnostics, Franklin Lakes, NJ, USA) automated blood culture detection systems [7][8][9]. Two types of aerobic bottles, BTA FA PLUS and BTA PF PLUS, and anaerobic BTA FN PLUS bottles, were inoculated with a panel of clinically relevant microorganisms and loaded into the VIRTUO.…”