Clinical impacts of the rapid diagnostic method on positive blood cultures.

OBJECTIVE: This study aimed to evaluate the impact of short-term incubation (STI) protocol on clinical outcomes of bloodstream infection (BSI) patients. METHODS: A total of 1363 positive blood culture records from January 2019 to December 2021 were included. The main clinical outcomes included pathogen identification turnaround time (TAT), antimicrobial susceptibility testing (AST) TAT, and length of total hospital stay. RESULTS: The TAT of pathogen identification and AST significantly decreased after implementing the STI protocol (2.2 vs 1.4 days and 3.4 vs 2.5 days, respectively, with P < .001 for both). Moreover, for patients with Gram-negative bacteria (GNB)-infected BSIs, the length of total hospital stay decreased from 31.9 days to 27.1 days, indicating that these patients could be discharged 5 days earlier after implementing the STI protocol (P < .01). CONCLUSION: The protocol led to a significant reduction in TAT and improved clinical outcomes, particularly for GNB organisms. The findings suggest that the STI protocol can improve patient outcomes and hospital resource utilization in the management of BSIs.

Shortening the Time of the Identification and Antimicrobial Susceptibility Testing on Positive Blood Cultures with MALDI-TOF MS.

The current processes used in clinical microbiology laboratories take ~24 h for incubation to identify the bacteria after the blood culture has been confirmed as positive and fa further ~24 h to report the results of antimicrobial susceptibility tests (ASTs). Patients with suspected bloodstream infection are treated with empiric broad-spectrum antibiotics but delayed targeted antimicrobial therapy. This study aimed to develop a method with a significantly shortened turnaround time for clinical application by identifying the optimal incubation period of a subculture. A total of 188 positive blood culture samples obtained from Nov. 2019 to Aug. 2020 were included. Compared to the conventional 24-h incubation for bacterial identification, our approach achieved 96.1% and 97.4% identification accuracy after shortening the incubation time to 4.5 and 3.5 h for gram-positive (GP) and gram-negative (GN) bacterial samples, respectively. Samples from short-term incubation without any intermediate step or process were directly subjected to analysis with the Phoenix M50 AST. Compared to the conventional disk diffusion AST, the category agreements for GP (excluding Streptococcus spp.), Streptococcus spp., and GN bacterial samples were 91.8%, 97.5%, and 92.7%, respectively. Our approach significantly reduced the average turnaround time from 48 h to 28 h for reporting bacterial identity and decreased average AST from 72 h to 50.3 h compared to the conventional methods. Accordingly, this approach allows a physician to prescribe the appropriate antibiotic(s) ~21.7 h earlier, thereby improving patient outcomes.

Desiccation and ethanol resistances of multidrug resistant Acinetobacter baumannii embedded in biofilm: The favorable antiseptic efficacy of combination chlorhexidine gluconate and ethanol.

BACKGROUND/PURPOSE: Globally, multidrug-resistant Acinetobacter baumannii (MDRAB) has emerged as an important pathogen in nosocomial outbreaks. This study aimed to investigate the correlation between the biofilm formation and survival of MDRABs, and to investigate the antiseptic efficacy of hand sanitizers for the MDRABs, embedded with biofilm (MDRAB-Bs). METHODS: The MDRABs were selected randomly after pulsed-field gel electrophoresis (PFGE), and their biofilm formation was analyzed. Desiccation and ethanol tolerances were assayed to test the bacterial survival. The antiseptic efficacy of combined chlorhexidine gluconate (CHG) and 70% ethanol agents against MDRAB-Bs were compared with the 70% ethanol cleanser. RESULTS: Eleven MDRABs, which varied in biofilm formation (MRDAB-B) and planktonic type (MDRAB-P), were tested. In desiccation survival, the mean survival time for the MDRAB-Bs was 49.0 days which was significantly higher than that of their planktonic type (17.3 days) (P < 0.005). The MDRAB-Ps could be eliminated after a 10 min contact with a 30% ethanol agent, however, it took 10 min of 70% ethanol to eliminate the MDRAB-Bs. On the other hand, a 2% CHG in 70% ethanol solution completely eliminated all MDRAB-Bs after 1 min contacted time. The 2% CHG in 70% ethanol agent provided a significantly superior efficacy than the 70% ethanol solution at eliminating the MDRAB-Bs (P < 0.005). CONCLUSION: MDRAB with biofilm-formation presented significantly higher desiccation and ethanol resistances than their planktonic type. Moreover, the 2% CHG in 70% ethanol agent provided a superior antiseptic efficacy for MDRAB-Bs than that of the 70% ethanol agent.