Resistell Phenotech AST to Determine the Antibiotic Susceptibility of Gram-negative Bacteria Causing Bacteremia

The aim of this study is to assess the sensitivity, specificity, and accuracy of the Resistell Phenotech device in testing antibiotic susceptibility of Gram-negative bacteria (i.e., E. coli or K. pneumoniae) to clinically relevant antibiotics. The study is designed as a prospective, non-interventional, multi-center, single-arm study.The blood culture samples from bacteremia patients that are positive for E. coli or K. pneumoniae will be tested with the Resistell Phenotech device after strain identification by MALDI-TOF. The results of the Resistell AST will be compared with the results from the disk diffusion tests (all sites use the Kirby-Bauer disk diffusion test), and site dependent tests (VITEK® 2, BD Phoenix™, MicroScan WalkAway system, and/or EUCAST RAST), which are currently the standard AST methods in the microbiology laboratories at the participating sites.

Inclusion Criteria:Patients who have signed a General Consent form approving use of their residual blood samples for research purposes (applicable at CHUV only)Patients who have signed a consent allowing the use of their residual sample (Restprobenerklärung) (applicable at MUI, only)Patients over the age of 18 years (>18)Patients with bacteremia considered to be due to E. coli or K. pneumoniaePatients whose positive blood cultures were not older than 24 hours at the time of AST startExclusion Criteria:Patients with documented refusal of the use of biological material for research purposes (applicable at CHUV, only)Patients with polymicrobial bacteremia