The hypothetical impact of Accelerate Pheno™ system on time to effective therapy and time to definitive therapy in an institution with an established antimicrobial stewardship programme currently utilizing rapid genotypic organism/resistance marker identification.

Background: Rapid organism identification and antimicrobial susceptibility testing (AST) can optimize antimicrobial therapy in patients with bacteraemia. The Accelerate Pheno™ system (ACC) can provide identification and AST results within 7 h of a positive culture. Objectives: To assess the hypothetical impact of ACC on time to effective therapy (TTET), time to definitive therapy (TTDT) and antimicrobial usage at the Detroit Medical Center (DMC). Methods: Patients with positive blood cultures from 29 March to 24 June 2016 were included. ACC was performed in parallel with normal laboratory procedures, but results were not made available to the clinicians. The potential benefit of having ACC results was determined if clinicians modified therapy based on actual AST results. Potential changes in TTET, TTDT and antibiotic usage were calculated. Results: One hundred and sixty-seven patients were included. The median TTET was 2.4 h (IQR 0.5, 15.1). Had ACC results been available, TTET could have been improved in four patients (2.4%), by a median decrease of 18.9 h (IQR 11.3, 20.4). The median TTDT was 41.4 h (IQR 21.7, 73.3) and ACC results could have improved TTDT among 51 patients (30.5%), by a median decrease of 25.4 h (IQR 18.7, 37.5). ACC implementation could have led to decreases in usage of cefepime (16% reduction), aminoglycosides (23%), piperacillin/tazobactam (8%) and vancomycin (4%). Conclusions: ACC results could potentially improve time to de-escalation and reduce use of antimicrobials. The impact of ACC on TTET was small, likely related to the availability of other rapid diagnostic tests at DMC.

The Hypothetical Impact of Accelerate Pheno on Time to Effective Therapy and Time to Definitive Therapy for Bloodstream Infections Due to Drug-Resistant Gram-Negative Bacilli.

Strategies are needed to improve time to optimal therapy in patients with bloodstream infections (BSI) due to resistant Gram-negative (GN) pathogens. Accelerate Pheno (ACC) can provide antimicrobial susceptibility results within 7 h of a positive culture and may more rapidly optimize therapy. The primary objective of this study was to evaluate the hypothetical impact of ACC on time to effective therapy (TTET) and time to definitive therapy (TTDT) among patients with BSI due to resistant GN pathogens. ACC was performed on resistant GN BSI isolates, and results were not available to clinicians in real time. A potential benefit of having ACC on TTET or TTDT was determined if modifications to antimicrobial regimens could have been made sooner with ACC. Comparisons on the impact of ACC in the presence or absence of testing by the Verigene Gram-negative blood culture test (Verigene GN-BC) were performed. Sixty-one patients with resistant GN BSI were evaluated. The median actual TTET and TTDT in the cohort were 25.9 h (interquartile range [IQR], 18.5, 42.1) and 47.6 h (IQR, 24.9, 79.6), respectively. Almost half of the patients had potential improvement in TTET and/or TTDT with ACC. In patients who would have had a benefit the median potential decreases in TTET and TTDT were 16.6 h (IQR, 5.5 to 30.6) and 29.8 h (IQR, 13.6 to 43), respectively. The largest potential improvements were seen in patients for whom Verigene results were not available. In conclusion, among patients with resistant GN BSI in a setting where other rapid diagnostic technologies are utilized, ACC results could have further improved TTET and TTDT.

Detection of oseltamivir resistance during treatment of 2009 H1N1 influenza virus infection in immunocompromised patients: utility of cycle threshold values of qualitative real-time reverse transcriptase PCR.

Two immunocompromised patients with 2009 H1N1 influenza pneumonia had viral shedding for over 5 weeks despite therapy with oseltamivir. Declining or persistently low cycle threshold values noted on serial qualitative real-time reverse transcriptase PCR (rRT-PCR) of respiratory specimens implied increasing viral load and probable drug resistance. Oseltamivir resistance was later confirmed by pyrosequencing.