Methods: Clinical isolates from patients at our institution between July 2014 and April 2015 were included. Upon blood culture positivity, gram stain results were reported to the primary medical team. Once the organism and key resistance genes were identified using the Verigene® system, the results were immediately communicated to the AST for potential intervention (24 hrs/day). Based on our institutional antibiogram, optimization of empiric antibiotic therapy was implemented within 2 hrs.
Results: Overall, 646 isolates were included, with the majority being gram-positive (67%). Only 2.5% of the gram-positive organisms and 10.5% of the gram-negative organisms were unable to be identified by the Verigene® system. Staphylococcus spp. were the most common organisms isolated with mecA detected in 50% of S. aureus and 78% of S. epidermidis. VanA was detected in 31% (20/64) of Enterococcus spp. with only 3% (1/35) detected in E. faecalis and 66% (19/29) detected in E. faecium. The most common gram-negative bacterial bloodstream organism was E. coli (39%) with CTX-M detected in 18.5% (15/81) followed by P. aeruginosa (18%), Klebsiella pneumoniae (12%), Enterobacter spp. (11%) and Acinetobacterspp. (5%) with OXA detected in 20% (2/10). The majority of the time, empiric antibiotic therapy changes were not necessary. Antibiotic escalation, however, was required in 33% of the gram-negative blood cultures.
Conclusion: Rapid identification of blood cultures with AST intervention may significantly decrease the time to effective and optimal antibiotic therapy in bloodstream infections.
D. R. Burgess,
J. Ribes, None
D. S. Burgess, None