Evaluation of rapid phenotypic identification and antimicrobial susceptibility testing in a pediatric oncology center

- Susceptibility testing of blood-born infections is rate-limiting for clinical care.
- Newly developed automated systems can provide rapid susceptibility results.
- Accelerate Phenosystem gave accurate results in this pediatric healthcare setting.
- The Accelerate Phenosystem panel has limited coverage in some populations.
- Findings suggest future studies may show significant impact on clinical care.

Identification (ID) and antimicrobial susceptibility testing (AST) remain rate limiting steps in producing actionable data for clinical care of bloodstream infections. Rapid, automated phenotypic ID and AST by fluorescent in situ hybridization and automated microscopy were used to characterize blood stream infections in a predominantly pediatric oncology patient population. Results were compared to standard of care (SOC) phenotypic methods. The Accelerate Pheno System (AXDX) had a sensitivity of 91.2% and an accuracy of 100% to the genus level for identification, and an overall categorical agreement 91.2-91.8% for susceptibility, depending on the breakpoints used. The AXDX required a mean time of 1.4 hours for identification and 6.6 hours for susceptibility testing compared to SOC, requiring 32.5 and 46.7 hours, respectively. Identification and susceptibility by rapid phenotypic methods shows a high degree of accuracy; the marked reduction in time to results may have significant implications for patient care.