Retrospective evaluation of rapid genotypic ID and phenotypic AST systems on positive blood culture turnaround time and simulated potential impacts on bloodstream infection management

Abstract

Background: Bloodstream infections are linked to heightened morbidity and mortality rates. The consequences of delayed antibiotic treatment can be detrimental. Effective management of bacteraemia hinges on rapid antimicrobial susceptibility testing.

Objectives: This retrospective study examined the influence of the VITEK® REVEAL™ Rapid AST system on positive blood culture (PBC) management in a French tertiary hospital.

Materials and methods: Between November 2021 and March 2022, 79 Gram-negative monomicrobial PBC cases underwent testing with both VITEK®REVEAL™ and VITEK®2 systems.

Results: The study found that VITEK®REVEAL™ yielded better results than the standard of care, significantly shortening the time to result (7.0 h compared to 9.6 h) as well as the turnaround time (15 h compared to 31.1 h) when applied for all isolates.

Conclusions: This study implies that the use of VITEK®REVEAL™ enables swift adaptations of antibiotic treatment strategies. By considerably minimizing the turnaround time, healthcare professionals can promptly make necessary adjustments to therapeutic regimens. Notably, these findings underscore the potential of VITEK®REVEAL™ in expediting appropriate antibiotic interventions, even in less ideal conditions. Further studies in varied laboratory contexts are required to validate these encouraging outcomes.

Figure 1.

Observed and simulated time points used to describe the SOC and simulated workflows. T₀, blood culture positivity; T₁, Gram stain time; T₂, time-to ID (VITEK MS or BCID2); T₃, AST run initiation; T₄, AST report time; T₅, validated AST report and T₆, time-to antibiotic adaptation.

Figure 2.

Average TTR obtained with the SOC and the two scenarios using VITEK^®REVEAL^™. Scenario 1: REVEAL used for PBCs with Gram stain results available before noon, or testing using SOC otherwise. Scenario 2: REVEAL used for all PBCs.

Figure 3.

(a) Turnaround time from day of PBC positivity (D0) observed with the SOC or VITEK^®REVEAL^™ for Scenario 1 when extending laboratory testing hours from 6 PM (current status) to 10 PM. (b) Turnaround time from day of PBC positivity (D0) observed with the SOC or REVEAL for Scenario 2 when extending laboratory testing hours from 6 PM (current status) to 10 PM. D0, Day 0; D1, Day 1; D2, Day 2 and D3, Day 3. This figure appears in colour in the online version of JAC and in black and white in the print version of JAC.

Figure 4.

Time-to-antibiotic adaptation from day of BC positivity (D0) observed with the SOC or REVEAL for Scenario 1 (S1) and Scenario 2 (S2). Furthermore, the clinical value of VITEK^®REVEAL^™ can be effectively used even in centres that process PBCs round the clock. This figure appears in colour in the online version of JAC and in black and white in the print version of JAC.