Comparison of Novel Approaches for Expedited Pathogen Identification and Antimicrobial Susceptibility Testing against Routine Blood Culture Diagnostics.

Blood stream infections pose a major challenge for clinicians as the immediate application of an appropriate antibiotic treatment is the vital factor to safe the patients´ lives. This preliminary study compares three different systems promising fast pathogen identification and susceptibility testing in comparison to conventional blood culture (BC): i) the rapid antimicrobial susceptibility testing protocol according to EUCAST in combination with the Sepsityper® kit (sRAST), ii) the direct inoculation method on the VITEK® 2 system (dVIT) and iii) testing with the Accelerate Pheno® system (AccPh). All methods were assessed in terms of accuracy, time to result and usability. Twenty-three BC samples obtained from patients suffering from proven sepsis were analyzed in detail. Pathogen identification was successful in 95.6%, 91.3% and 91.3% in sRAST, dVIT and AccPh, respectively. Categorical agreement in antimicrobial susceptibility testing was 89.5%, 96% and 96.6%, respectively. Time to result from sample entry to reporting ranged from an average of 4.6 h for sRAST and 6.9 h for AccPh to 10.6 h for dVIT. These results imply a significant shortening of reporting times at considerably high agreement rates for these new diagnostic approaches.