Direct inoculation procedure for the rapid classification of bacteria from blood culture

A procedure was developed for 4-h identification of bacteria from blood culture. From a turbid blood culture bottle a 10- to 15-ml aliquot was drawn off and centrifuged. The pellet was utilized to inoculate a series of enzymatic and physiologic reactions. Three hundred eight positive blood cultures were tested including 222 strains of Enterobacteriaceae, 40 strains of facultative grampositive cocci, 26 strains of anaerobes, and 20 assorted strains. There was over 96.5% agreement between 4-h and conventional methods with the Enterobacteriaceae, 98% with facultative gram-positive cocci, 100% with anaerobes, and 99% with the assorted strains.