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

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 1.4hours for identification and 6.6hours for susceptibility testing compared to SOC, requiring 32.5 and 46.7hours, 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.