Performance and potential clinical impact of D 2 O-labeled single-cell Raman spectroscopy for direct antimicrobial susceptibility testing of Klebsiella pneumoniae

Abstract Rapid and accurate antimicrobial susceptibility testing (AST) of bacterial infections can improve patients’ outcome. In this study, 29 Klebsiella pneumoniae strains isolated from sputum specimens from ICU patients at the Jiading Central Hospital were compared using D2O-Raman AST and traditional AST (Vitek 2). The analysis time was 4–4.5 h for a complete D2O-Raman AST result. Compared with the Vitek 2, the results of D2O-Raman spectroscopy showed good agreement for susceptibility and resistance (S/R), with a concordance of 89%. Most discrepant results were observed for intermediate and susceptible categories, as 10% of isolates labeled as intermediate and susceptible by Vitek 2 were almost all categorized as resistant by D2O-Raman spectroscopy. Moreover, discriminant factor analysis of our D2O-Raman results led to successfully discriminating the type of resistance. In addition, we evaluated the behavior of clinicians in adjusting antibiotic therapies according to routine AST results. For 9 out of 10 patients, antibiotic therapy was adjusted after the reporting of AST results. With some improvements, D2O-Raman spectroscopy provides an accurate and rapid preliminary AST result and may have at least a potential clinical benefit for patients.