Silent Colistin Resistance by VITEK 2 Compact Versus Broth Microdilution in Bloodstream Klebsiella pneumoniae and Escherichia coli: A Prospective Single-Centre Study

Background/Objectives: Colistin remains a last-resort therapy for carbapenem-resistant Klebsiella pneumoniae bloodstream infections, yet its accurate reporting depends on the reference broth microdilution (BMD) method that few clinical laboratories routinely deploy. We aimed to determine the prevalence of colistin resistance in bloodstream isolates and to quantify the diagnostic performance of the widely used VITEK 2 Compact automated system in a Turkish tertiary-care hospital.