Identification and Antimicrobial Susceptibility Testing Performance for Short Incubation of Gram-Negative Pathogens from Bloodstream Infections at a Tertiary Care Center in Telangana

A BSTRACT Background and Objectives: Blood culture is the “gold standard” for diagnosing bacteremia. This study evaluates the performance of shortened incubation cultures in pathogen identification (ID) and antimicrobial susceptibility testing (AST) using the VITEK®2 system. Material and Methodology: A prospective study was conducted from November 2021 to October 2022, focusing Gram-negative pathogens. Flagged blood-culture bottles subjected to Gram-stain and simultaneous microbial workup by conventional 24-h protocol and faster 3–4 h and 7–8-h methods. Results: The data analysis encompassed 207 Gram-negative pathogens, Escherichia coli being the most prevalent isolate at 39.6%. Overall essential-agreement rates were 95.7% and 95.0%, and categorical-agreement rates were 96.2% and 96.0% for the respective incubation periods. Conclusions: Rapid pathogen ID and AST of positive blood cultures using shorter incubation times on solid media can significantly reduce turnaround time.