Early Empirical Antibiotic Therapy Modification in Sepsis Using Beta-Lacta Test Directly on Blood Cultures

Abstract

Background: Sepsis caused by multi-drug-resistant Gram-negative bacilli lead physicians to prescribe broad-spectrum antibiotic therapy, such as carbapenems. Rapid susceptibility testing can help with the rational use of antibiotics. The aim of this study was to measure the clinical impact associated with rapid reporting of Beta-Lacta test (BLT) directly on blood cultures positive with Gram-negative bacilli. Methods: In an observational, multicentric, prospective study, we included patients with sepsis caused by Enterobacterales observed on Gram staining of the positive blood cultures. BLT and antimicrobial susceptibility testing (AST) were performed directly on the blood cultures. Clinical impact was measured on the proportion of patients for whom the probabilistic antibiotic therapy was modified according to BLT, including patients receiving carbapenem. Results: 170 patients were included, of whom 44 (25.9%) were receiving inadequate empirical antibiotic therapy. Among them, 27 (15.9%) benefited from an early modification, according to the BLT results. Among 126 (74.1%) patients receiving appropriate probabilistic antibiotic therapy, we modified the antibiotic therapy for 28 (16.5%) of them, including 4/14 (28.5%) de-escalation from carbapenem to a third-generation cephalosporin. Conclusions: Implementation of BLT performed directly on blood cultures allowed us to rapidly modify the empirical antibiotic therapy for about one-third of patients with sepsis caused by Enterobacterales.