Multicenter Clinical Evaluation of BacT/Alert Virtuo Blood Culture System.

BacT/Alert Virtuo is an advanced, automated blood culture system incorporating improved automation and an enhanced detection algorithm to shorten time to detection. A multicenter study of the investigational Virtuo system (bioMérieux, Inc., Durham, NC) compared to BacT/Alert 3D (BTA3D) for detection of bacteremia/fungemia in four bottle types, SA and FA Plus (aerobic) and SN and FN Plus (anaerobic), was performed in a clinical setting with patient samples in a matched system design clinical trial. Blood was added to paired aerobic or anaerobic bottles, with the volume in each bottle in each pair required to be ≤10 ml and with the volumes required to be within 30% of each other. Of 5,709 bottle sets (52.5% aerobic pairs and 47.5% anaerobic pairs), 430 (7.5%) were positive for bacterial or fungal growth, with 342 (6.0%) clinically significant and 83 (1.5%) contaminated. A total of 3,539 sets (62.0%) were volume compliant, with 203 sets (5.7%) clinically significant. The positivity rates for volume-compliant bottle pairs determined by the two systems were comparable, with 68.7% of clinically significant isolates detected by both instruments, 15.7% by Virtuo only, and 15.7% by BTA3D only. Virtuo detected microbial growth nearly 2 h sooner overall than BTA3D (mean, 15.9 h versus 17.7 h). Shorter time to detection by Virtuo was related to organism group, with the time to detection being significantly shorter for enteric Gram-negative bacilli and enterococci (means, 3.6 h and 2.3 h shorter, respectively). This large clinical study demonstrated that the Virtuo blood culture system produced results comparable to those seen with the long-established BTA3D system, with significantly shorter time to detection.

Reducing antimicrobial therapy for asymptomatic bacteriuria among noncatheterized inpatients: a proof-of-concept study.

This proof-of-concept study demonstrates that no longer routinely reporting urine culture results from noncatheterized medical and surgical inpatients can greatly reduce unnecessary antimicrobial therapy for asymptomatic bacteriuria without significant additional laboratory workload. Larger studies are needed to confirm the generalizability, safety, and sustainability of this model of care.

Evaluating the preservation and isolation of stool pathogens using the COPAN FecalSwab™ Transport System and Walk-Away Specimen Processor.

The isolation of stool pathogens is difficult due to their fastidious nature and the rapid overgrowth of fecal flora. In this study, we evaluate the preservation and isolation of enteric pathogens from stool using the automated COPAN Walk-Away Specimen Processor (WASP®) in conjunction with FecalSwab™ and selenite media. Pathogen viability and fecal commensal abundance were stable in FecalSwab™ media under both room-temperature and refrigerated incubation conditions, resulting in a significantly increased number of well-isolated pathogen colonies observed when compared to samples incubated in modified Cary-Blair media. Isolation of individual pathogen colonies was improved via WASP® planting compared to those planted using the Isoplater system. Furthermore, preincubation using the newly formulated COPAN selenite media significantly enhanced the yield of Salmonella enterica serovar Typhimurium. Together, the automated WASP® system combined with FecalSwab™ and selenite media represents a rapid and efficient approach for the processing of stool specimens compared to standard methods.