[Does a rapid antibiotic susceptibility test optimize antibiotic therapy of patients with bacteremia ?]

We evaluated the contribution of a rapid antibiotic susceptibility test performed directly from a positive blood culture (PBC), the dRAST™, in the management of patients with bacteremia.

We retrospectively compared the time from sampling to availability of antibiotic susceptibility test (AST) results («time-to-result», TTR) between dRAST™ and classic AST (Vitek®2), in 150 patients with bacteremia. The antibiotic treatment of these 150 patients was classified into three categories (optimal, suboptimal, ineffective) according to the time of availability of AST results.

Adaptation of antibiotic treatment to optimal therapy following AST results occurred in 46/100 (46 %) of Gram-negative PBC and in 4/50 (2 %) of Gram-positive HP. TTR was significantly lower with dRAST™ compared with classic AST (29:35 (± 08:48) hours versus 50:55 (± 12:45) hours, p < 0.001).

For patients with bacteremia requiring adjustment of empirical antibiotic therapy based on AST, dRAST™ could allow a faster administration of optimal therapy.